Vital functions, such as blood pressure, are regulated within a framework of neurovisceral integration in which various factors are involved under normal conditions maintaining a delicate balance. Imbalance of any of these factors can lead to various pathologies. Blood pressure control is the result of the balanced action of central and peripheral factors that increase or decrease. Special attention for blood pressure control was put on the neurovisceral interaction between Angiotensin II and the enzymes that regulate its activity as well as on nitric oxide and dopamine. Several studies have shown that such interaction is asymmetrically organized. These studies suggest that the neuronal activity related to the production of nitric oxide in plasma is also lateralized and, consequently, changes in plasma nitric oxide influence neuronal function. This observation provides a new aspect revealing the complexity of the blood pressure regulation and, undoubtedly, makes such study more motivating as it may affect the approach for treatment. In fact, most of the anti-hypertensive treatment's protocols include drugs that inhibit or block the RAAS The function of brain angiotensin-hydrolyzing aminopeptidases in hypertension has been studied by various authors. Wright et al. Therefore, a key role in the central and peripheral function of the RAAS is linked to aminopeptidase A (EC 3.4.11.7) and aminopeptidase M (EC 3.4.11.2) respectively responsible for inactivating angiotensin II and promoting the formation of angiotensin III, and for inactivating angiotensin III 3.The neuronal bodies, from which all the cerebral dopamine originates, are located in the brainstem, mainly in the pars compact of the substantia nigra and in the ventrotegmental area. Its brain distribution is unilateral without bilateral crossing The relationship between dopamine and the control of blood pressure has been known for quite a while: whereas its central administration decreased blood pressure, the intravenous injection increased it 4.Nitric oxide is a gas, highly diffusible through cell membranes, which produces vasodilatation and therefore is of hypotensive nature. It also acts as a neurotransmitter with important functions such as synaptic plasticity or memory processes. It is therefore an important central and peripheral regulator of the blood pressure Although nNOS has been studied primarily in brain, it is also found peripherally in perivascular nerves, heart or skeletal muscle. Therefore, although the importance of eNOS in cardiovascular regulation is clearly established, the participation of nNOS in the physiological regulation of systemic vascular resistance and blood pressure in healthy humans by modulating sympathetic activity, renal release of renin, hydro-electrolytic balance as well as cardiac function is also proposed Ischemic or hemorrhagic stroke is a serious acute cerebrovascular process in which nitric oxide could play an important role due to its essential role in the maintenance of vascular tone. It has been suggested that nitric oxide derived from the action of iNOS and nNOS have neurotoxic character while nitric oxide derived from the action of eNOS have a neuroprotective role in acute ischemic stroke. In relation to cerebral hemorrhage, there is no clear differentiation in the role that nitric oxide derived from the different NOS isoenzymes can exert, suggesting that an increase in nitric oxide levels after cerebral hemorrhage would improve the prognosis of these patients 5.Neurovisceral Integration” in the control of blood pressure is more than 100 years old The concept of “We have contributed to studies that suggest a bidirectional connection between the brain and various peripheral tissues, such as heart and kidney, for the control of blood pressure and hydro-electrolytic balance: these involve several enzymes of the RAAS cascade. Such neuro-visceral interaction is modified by changes in blood pressure induced by the use of vasoactive hypertensive or hypotensive drugs and suggests to be mediated by the autonomic nervous system On the other hand, changes in blood pressure induce variations in the bilateral brain distribution of aminopeptidase activities as well as in the intra-hemispheric and inter-hemispheric interactions established between several of these enzymes Finally, other data suggest that this neurovisceral interaction between aminopeptidases that hydrolyze angiotensin peptides in the control of blood pressure is asymmetrically organized. An asymmetry has been observed in the correlation established between the frontal cortex and the plasma in hypertensive animals: while in hypertensive animals a correlation between plasma and the right frontal cortex is observed, such correlation is established with the left frontal cortex after the treatment with captopril and the related reduction of blood pressure All these previously reviewed factors, renin-angiotensin aldosterone system, dopamine, nitric oxide and asymmetry in neurovisceral integration for the control of blood pressure could be inter-connected.6.The asymmetric behavior of the relationship between nitric oxide, dopamine and RAAS in blood pressure control was not apparent until the work of Banegas et al. The asymmetric character of Parkinson's disease produced by a lateralized distribution of brain dopamine is not only manifested by lateralized consequences of motor behavior but also by the rise of cognitive and autonomic changes including cardiovascular alterations Banegas et al. The asymmetric behavior after the left or right unilateral lesions of the nigrostriatal system is not only reflected in changes in blood pressure but also extends to differential changes in the levels of plasma factors which are depending on whether the lesion occurred on the left side or in the right one. Among others, nitric oxide and aminopeptidase A are modified in plasma. While in normotensive animals (WKY) the left lesion increases plasma nitric oxide and reduces aminopeptidase A, the right lesion does not modify either of the two factors. In contrast, in hypertensive animals (SHR) while the left lesion does not modify nitric oxide and decreases aminopepidase A, the right lesion decreases nitric oxide and increases aminopeptidase A. This is just the inverse behavior to what happened in normotensive animals with left lesion . If we tThe correlation study between nitric oxide and plasma aminopeptidase A in the various groups studied showed significant negative correlations  between aminopeptidase A and nitric oxide in the WKY group with right lesion and in the group of SHR with left lesion.Banegas et al. If we consider the relationship “high enzymatic activity/low concentration of the substrate” and vice versa, we would obtain angiotensin III levels that would correspond to the inverse behavior of the previously described one for aminopeptidase M i.e. in the left lesion WKY animals, the left hemisphere would have elevated levels of angiotensin III and the right one decreased values compared with control animals. In comparison with the WKY, the left lesion in the SHR would result in an opposite response: low levels of Angiotensin III in the left side and high levels in the right one. Also, the right lesion in SHR increases Ang III in the left side but decreases it in the right one . This is7.Physiology is an integrating discipline, in which it is clearly shown that there are no independent compartments in the functioning of the organism but it works as an integrated whole. The control of cardiovascular function is an example of this integration. In this review we have discussed how factors with very diverse functions and from several locations can interact with each other for the control of blood pressure. From our results, it is also deduced that the neurovisceral integration for the control of blood pressure is organized asymmetrically and the response is not the same if the alteration occur on the left or right side of the brain. In relation to cardiovascular function, we could hypothesize from these results a greater severity in the processes that affect the left hemisphere than in those involving the right one. This situation would have to be taken into account in processes such as for example Parkinson's disease or schizophrenia in which an asymmetric development and evolution of the disease is clearly demonstrated. The vascular and/or autonomic consequences will vary depending on the alteration of the nitric oxide if the process involves one side or the other of the brain. Indeed, in brain strokes involving the left or right hemisphere, we have been able to confirm that the response in the plasma levels of nitric oxide varies depending on the injured side. A possible beneficial treatment aimed to restore nitric oxide levels will therefore depend on the affected brain side. The understanding of the bilateral behavior of the interaction of multiple factors with functions apparently opposite in some cases constitutes a complex challenge. Thus further studies are necessary to structure the bilateral behavior of the nervous system and the peripheral response in the control of blood pressure.


Background and objectives: In kidney transplant recipients (KTR), hyperuricemia (HU) is a commonly-observed phenomenon, due to calcineurin inhibitors and reduced kidney graft function. Factors predicting HU, and its association with graft function, remains equivocal. Materials and Methods: We conducted a retrospective longitudinal study to assess factors associated with HU in KTR, and to determine risk factors associated with graft function, measured as glomerular filtration rate (GFR). Moreover, GFR > 60 mL/min/1.73 m2 was considered normal. HU was defined as a serum uric acid level of > 416 μmol/L (4.70 mg/dL) in men and >357 μmol/L (4.04 mg/dL) in women, or xanthine-oxidase inhibitor use. We built multiple logistic regression models to assess predictors of HU in KTR, as well as the association of demographic, clinical, and biochemical parameters of patients with normal GFR after a three-year follow-up. We investigated the effect modification of this association with HU. Results: There were 144 patients (mean age 46.6 ± 13.9), with 42.4% of them having HU. Predictors of HU in KTR were the presence of cystic diseases ), the use of diuretics ), and the male gender ). Being a younger age, of female gender, with a normal BMI, and the absence of diuretic medications increased the possibility of normal GFR. HU was the effect modifier of the association between demographic, clinical, and biochemical factors and a normal GFR. Conclusions: Factors associated with HU in KTR: Presence of cystic diseases, diuretic use, and male gender. HU was the effect modifier of the association of demographic, clinical, and biochemical factors to GFR. Traditionally, hyperuricemia (HU) is associated with clinical consequences when saturating concentrations result in symptomatic urate or uric acid crystal deposition—gout, acute or chronic uric acid nephropathy, and urolithiasis , which mRecent experimental studies demonstrate many deleterious effects of UA on vascular cells, resulting in smooth muscle cell proliferation and inflammation: this occurs through increased production of growth factors , vasoconstrictive substances (cyclooxygenase-2 induced thromboxane and angiotensin II) and proinflammatory molecules (C-reactive protein and monocyte chemoattractant protein) ,8,9. HU HU has a particularly high prevalence in the KTR population, or 30% to 84% . In addiHowever, studies investigating the association of HU with kidney transplant function and the effect of UA-lowering therapy on kidney transplant function are scarce. Very few studies investigated factors related to HU itself. In this study, there were two specific aims: (1) To investigate demographic, clinical, and biochemical factors that could be associated with HU, and (2) to assess the role of HU as an effect measure modifier in the association between these factors and as a function of kidney transplant.2 for normal weight, and ≥30 kg/m2 as overweight), clinical parameters , biochemical parameters , and use of medications that could affect HU after kidney transplantation  inhibitors/angiotensin receptor blocker, xanthine oxidase inhibitors, and/or diuretics). Hypertension was defined as systolic blood pressure > 140 mmHg and diastolic blood pressure > 90 mmHg, or regular use of blood pressure lowering medications. Presence of diabetes mellitus was defined as the presence of diagnosis in patient records, or a glucose level of ≥126 mg/dl, or use of antidiabetic medications. HU was defined as the level of uric acid in blood >416 μmol/l (4.70 mg/dL) for men or 357 μmol/L (4.04 mg/dL) for women, or the use of xanthine oxidase inhibitors. Dyslipidemia was defined as the level of total serum cholesterol >200 mg/dl or the regular use of antilipidemic medications. All patients received triple immunosuppressive therapy—calcineurin inhibitors (cyclosporine A or tacrolimus), antiproliferative agents (mycofenolate mofetil or azathioprine), and prednisone. Data were collected about the use of ACE inhibitors/angiotensin receptor blockers, diuretics, and xanthine oxidase inhibitors  as well.We performed a longitudinal retrospective study, using patient records with kidney transplantation from 01.01.2009 until 31.12.2011 in the Latvian Transplantation Centre. Only patients with data available for more than 12 months were included in the analysis, patients with a gout diagnosis were excluded. This study was approved by the Ethical Committee for Scientific Research of the University of Latvia . We also assessed demographic parameters of patients , according to the Cockroft-Gault equation:For the subsequent analysis, we calculated the function of the kidney transplant after the third year follow-up, with GFR . A p-value of less than 0.05 was considered statistically significant. Differences between patients both with and without HU in their demographic, clinical, and biochemical parameters, and with the use of medications were assessed using Chi-square/Exact Fisher tests for group variables or the t-test for continuous variables, as all continuous variables in this study were normally distributed. Statistical analysis was performed using the Statistical Program for the Social Sciences (SPSS) software, 23We performed two-stage multivariate analysis: Stage 1. Multiple logistic regression model was built to assess demographic, clinical, and biochemical factors associated with HU. Stage 2: The multiple logistic regression model investigated the association of demographic, clinical, and biochemical factors with GFR after a three-year follow-up. The adjustment set for the main model was based on variables univariately associated with GFR, with a significance level at 0.1, and other clinically meaningful variables. The full adjustment set consisted of age, gender, BMI (<30 or ≥30), hypertension, dyslipidemia, diabetes mellitus, use of ACE inhibitors/angiotensin receptor blockers, and diuretics. Effect modification: We investigated the possible effect measure modification by HU for the association between predictors and GFR. Sensitivity analysis: We performed a sensitivity analysis to evaluate the possible role of HU as a predictor of GFR, using the model built for Stage 2. As such, we also adjusted the main model for HU. 2) BMI (79.9%). We found the same proportion of men and women in the study sample . Groups with and without HU differed on dyslipidemia and the presence of cystic diseases, use of ACE inhibitors/angiotensin receptor blockers, and use of diuretics  were younger than 60 years, with a normal ) followed by use of diuretics (and a four-fold higher risk of HU in those who used diuretics), or those of the male gender  were a younger age ), the female gender ), BMI less than 30 kg/m2 ), and the absence of diuretic medications ) ) . The proEffect modification: We observed an effect modification from HU for the association observed in the main model. For patients without HU, factors associated with normal GFR were female gender ) and normal BMI ), although for patients with HU, the only factor significantly associated with normal GFR was younger age ) ) . For patSensitivity analysis: We did not observe HU to be predictive of normal GFR ) ) .In this study, we observed that three major factors associated with HU in KTR included: presence of cystic diseases, use of diuretics and male gender. HU was the effect modifier of the association of demographic, clinical, and biochemical factors with GFR, as a better explanation of variation in GFR for those with HU. According to our research, the presence of cystic diseases was a significant predictor of HU after kidney transplantation. To our knowledge, there are no studies that analysed cystic kidney disease as a risk factor for HU in KTR. Future studies must be performed to confirm this finding. According to many epidemiological studies, the main diseases considered to be associated with a risk of HU are diabetes, metabolic syndrome, hypertension, and cardiovascular diseases ,15,16,17+, K+, and 2Cl- cotransporter; this results from decreased levels of uromodulin in the UMOD genetic form, or renin deficiency that leads to aldosterone deficiency in the REN genetic form, which subsequently decreases sodium and chloride reabsorption, in turn leading to a volume depletion which may promote proximal reabsorption of UA [The physiological mechanisms of HU in these two diseases are completely different. ADTKD is a group of genetic kidney diseases that cause progressive loss of kidney function, thereby resulting in end stage renal disease (ESRD) in the third through seventh decade of life . HU and on of UA ,22. Also, ADPKD is the most common inherited kidney disorder, known to affect all ethnic groups at a prevalence of 1:400–1:1000 live births . This isAccording to the results of our study, we would like to emphasize that regular testing of HU in patients with an underlying diagnosis of cystic kidney disease is especially important after kidney transplantation in order to prevent symptomatic HU. It should be noted that with haemodialysis, patients often have normal or even lower uric acid levels , but aftOur study also found that the use of diuretics was independently associated with higher risk for HU. In the general population, diuretics are one of the most important causes of secondary HU. Loop diuretics and thiazide diuretics interact with renal organic anion transporters (OAT), entering the proximal tubular cell from the blood side via OAT1 and OAT3 transporters may be considered as competitive substrates of uric acid . MoreoveIn the current study, we observed that the male gender to be a significant predictor of HU. Gender is a common nonmodifiable risk factor for HU and gout, which is the most severe complication of HU in the general adult population. Men have a greater risk of developing gout than women in all age groups, although the sex ratio tends to equalize with advancing age . In a maOur study confirmed that the male gender is an independent risk factor for post-transplant HU. Thus, this could be the group of patients who need more intensive monitoring of UA concentration and as such, initiation of UA-lowering treatment is necessary to protect the kidney graft function.The results of our study did not indicate HU as an independent risk factor for graft function. We demonstrated that in certain clinical situations HU may affect renal transplant function along with some other risk factors. Controversial to our results, some studies revealed possible association between increased serum uric acid concentration and transplant failure. For example, in FAVORIT study with 3512 patients followed up for 3.9 years  uric aciThis study had several limitations. First, a small number of patients can reduce the power of a study, so more studies are needed to assess possible predictors of HU, as well as its role in KTR. In addition, a possibility of human mistakes whilst using electronic data bases should be taken into account. A second and major limitation of this study was the absence of electronic registers in Latvia, which makes more human mistakes possible. As one of the limitations of this study should be mentioned a lack of possibility to assess the number of patients with HU, that did not undergo KTR. In that case, we cannot be fully sure that some of observed associations will remain correct for patients without KTR. For example, lack of association with cyclosporine that was observed in this study may be not proved by studies that include participants with and without KTR. Finally, 24 patients who had been lost to follow-up could be those with an abnormal GFR, and this loss would be meaningful for such a small sample size.To our knowledge, this is the first study that investigates sociodemographic factors that predict HU, as well as the role of HU in KTR. Without a doubt, this study adds to the global evidence about KTR patients and provides understanding about the necessity for therapy in cases of asymptomatic HU. The novelty of the study is the fact that hyperuricemia after kidney transplantation is an effect modifying factor. Up to date, there is a broad discussion in literature in the effect of hyperuricemia on graft function. We demonstrated that in certain clinical situations , hyperuricemia may affect graft function. We also identified cystic kidney disease as a significant risk factor for hyperuricemia after kidney transplantation. Our study is in line with studies that exist in the field. The fact that we can reproduce results of studies performed in completely different conditions and in completely different populations provides additional validation of results of studies by other authors affirming previously observed results.In this study, factors associated with HU in KTR were presence of cystic diseases, use of diuretics, and male gender. HU might be seen as the effect modifier of the association of demographic, clinical, and biochemical factors with GFR. According to this study, it can be proposed for patients with abnormal GFR to have special care even in the case of asymptomatic HU.


There was no correlation between avgGCC, supGCC, infGCC, FLV, GLV and ocular biometry, refractive errors or age. There was no correlation between avgGCC, supGCC, infGCC, FLV, GLV and NT-proBNP or LVEF. There were no significant differences in the studied parameters between the sexes. There were no significant differences in the studied parameters between the left and right eye. Conclusion: Our study seems to be the first to analyse ganglion cell complex in paediatric patients with dilated cardiomyopathy. We have demonstrated no changes in the ganglion cell complex thickness parameters in children with chronic heart failure due dilated cardiomyopathy, as compared to their healthy peers.Purpose: To assess ganglion cell complex (GCC) thickness in children with chronic heart failure (CHF) due to dilated cardiomyopathy (DCM) using optical coherence tomography (OCT). Methods: Sixty eyes of 30 patients with chronic heart failure (CHF) due to dilated cardiomyopathy (DCM) and 60 eyes of 30 age- and sex-matched healthy volunteers (control group) were enrolled. The mean age of the patients and controls was 9.9 ± 3.57 (range 5–17) years and 10.08 ± 3.41 (range 4–16) years, respectively. All patients underwent a complete ophthalmic assessment and OCT imaging using RTVue XR Avanti (Optovue). The following OCT-based parameters were analysed: average ganglion cell complex thickness (avgGCC), superior ganglion cell complex thickness (supGCC), inferior ganglion cell complex thickness (infGCC), global loss of volume (GLV) and focal loss of volume (FLV). Results: There were no significant differences in avgGCC (98.13 μm vs. 99.96 μm,  The retinal ganglion cells (RGCs) are the sole output neurons responsible for the integration and transmission of all visual information from the retina to the brain . Axons, The retinal ganglion cell complex thickness can be measured using a non-invasive, in vivo retinal imaging method: optical coherence tomography (OCT) ,4,5. OCTThe GCC parameters may serve as markers of diseases involving nerve tissue damage, and recently neurodegenerative diseases as well ,7,8. TheRetinal ganglion cells are known for their exceptional susceptibility to mild, transient and acute systemic hypoxic stress ,11. HypoThe retinal ganglion cell loss causing progressive damage to the optic nerve and visual impairment is a well-known phenomenon in such conditions as glaucoma, hereditary optic neuropathy, optic neuritis and ischemic optic neuropathy ,17,18,19Dilated cardiomyopathy (DCM) is defined as left ventricular (LV) dilatation and LV systolic dysfunction in the absence of abnormal loading conditions or coronary artery abnormalities sufficient to cause the abnormality ,26. It iThe aim of the study was to assess GCC thickness in children with CHF secondary to DCM and in healthy children using the OCT. It aimed to determine whether changes to systemic circulation observed in chronic heart failure due to dilated cardiomyopathy affect GCC thickness.This observational cross-sectional study was conducted at the Children’s Memorial Health Institute in Warsaw between February 2019 and March 2020. It adhered to the tenets of the Declaration of Helsinki and was approved by the Bioethics Committee of the Children’s Memorial Health Institute in Warsaw on 11 September 2019—No 33/KBE/2019. All subjects gave their informed consent for inclusion before they participated in the study. All participants above 16 years of age and legal guardians of those below 16 years of age were provided explanations as to the nature and possible consequences of the study and expressed their written, informed consent to participate in the study.A total of 60 eyes of 30 children  with chronic heart failure (CHF) due to dilated cardiomyopathy (DCM) and treated in the Department of Cardiology at the Children’s Memorial Health Institute were enrolled. The study group inclusion criteria included confirmed CHF due to DCM lasting more than six months with a left ventricular ejection fraction (LVEF) ≤ 55%. The control group consisted of 60 eyes of 30 healthy children, without diagnosed heart failure or other systemic as well as ocular disease, matched for sex (16M/14F) and age . The exclusion criteria in both groups included ocular diseases, such as hereditary retinal dystrophy, glaucoma, uveitis, vitreoretinal diseases; previous ocular trauma, retinal laser photocoagulation, eye surgery, significant refractive error , other systemic comorbidities, such as diabetes mellitus, hypertension, kidney disease, neurological diseases or a history of prematurity. Additionally, patients reluctant to cooperate during assessments and eyes with low-quality scans were excluded.Clinical parameters collected in patients with DCM included serum level of N-terminal (NT)-prohormone BNP (NT-proBNP), a biomarker of heart failure, and left ventricular ejection fraction (LVEF) measured using the Simpson method during the 2D transthoracic echocardiography. Each patient underwent a full ophthalmic assessment, including best-corrected visual acuity (BVCA) assessed with Snellen’s chart, anterior segment slit lamp biomicroscopy, fundus examination, ocular axial length measurement and cycloplegic (1% Tropicamide) refraction testing.The spectral domain OCT (SD-OCT) was performed in all participants using commercially available RTVue XR Avanti OCT system with AngioVue imaging system . The GCC scan consisting of a series of B-scans centred at 1 mm temporally to the fovea was taken in all cases. The GCC protocol consisted of 15 vertical lines with a 7 mm scanning length and a 0.5 mm interval, and one horizontal line with a 7 mm scanning length. Having analysed the scans, the device automatically calculated the GCC thickness defined as the distance between the internal limiting membrane (ILM) and the external boundary of the inner plexiform layer (IPL) . The RTVp < 0.05 was considered statistically significant for all calculated comparisons. All statistical analyses were performed using R 3.5.1 software (R Core Team 2018).The presented variables were expressed as means, standard deviations, 95% confidence intervals and ranges. The Wilcoxon two-way test for two independent samples  was used to determine the presence of statistical differences between the experimental group and the controls. It is a non-parametric alternative to Student’s t-test, which could not be used in the analysis due to the failure to meet the assumptions about the normal distribution of tested samples. Linear relationships between selected quantitative variables were calculated using the Pearson correlation coefficient of the product and angular momentum. The level p = 0.11). The detailed characteristics of the entire study cohort are presented in The data for 60 eyes of 30 patients with CHF in DCM (mean age 9.9 years ± 3.57) and 60 eyes of 30 healthy, sex- and age-matched controls (mean age 10.08 years ± 3.41) were included in the analyses. The mean NT-proBNP level in the study group was 568.1 pg/mL ± 1045.27 , while the mean LVEF was 49.03% ± 6.63 . All participants had normal BCVA, as well as normal findings on anterior and posterior segment examination. The average axial eyeball length was 22.17 mm (± 0.88) in the DCM group and 22.46 mm (±0.65) in the control group (p = 0.21), supGCC  or infGCC  between patients with chronic heart failure due to dilated cardiomyopathy and healthy children .There were no significant differences in avgGCC . There was also no interconnection between avgGCC, supGCC, infGCC, FLV, GLV and LVEF   . There wDilated cardiomyopathy is a myocardial disease characterised by systolic dysfunction with concomitant tissue remodelling, which leads to heart failure . It is tProper function of all retinal structures depends on regular and adequate oxygen supply . The retChoi et al.  observedKergoat et al.  investigThe majority of published studies carried out in patients with heart diseases, including heart failure, evaluated and analysed changes in the retinal nerve fibre layer (RNFL) only, not addressing GCC thickness changes ,49,50. BGlycolysis, angiogenesis, vasodilatation and erythropoiesis are autoregulatory, cellular and systemic response mechanisms which protect the human body in critical situations . In hearOn the other hand, a number of studies confirmed the association between GCC thickness and parameters such as ocular axial length, patient age and sex ,60,61,62Studies regarding the correlation between GCC and sex are inconclusive. Whereas there have been reports of the male sex being associated with higher GCC thickness ,63, otheMost studies report a negative correlation between GCC thickness and age, indicating that GCC tends to be thinner in older patients ,62,64,65The retinal ganglion cell complex thickness was not reduced in children with chronic heart failure due to dilated cardiomyopathy as compared to their healthy peers. In our study group, no relationship was found between reduced systemic circulation associated with chronic heart failure and damage to retinal ganglion cells. Therefore, it can now be concluded that there is no clinical indication for standard evaluation of retinal ganglion cell complex in patients with dilated cardiomyopathy. Further longitudinal studies on a larger group of patients and with a longer follow- up of disease progression are needed to confirm the absence of changes to ganglion cell complex thickness in chronic heart failure in the paediatric population.


The kidney is the first target organ of heavy metal toxicity due to its capacity to reabsorb and accumulate divalent metals. Hemodialysis therapy is used to purify the blood of individuals with impaired kidney function.The aim of the present study was to evaluate the relationship between dialysis fluid quality and the health of hemodialysis patients.A field sampling program was conducted to collect blood samples from 320 hemodialysis patients  in order to examine the concentrations of heavy metals that typically occur in municipal water in Baghdad , copper (Cu), lead (Pb), and zinc (Zn)), and explore associations with the same metals in dialysis fluid collected from four major dialysis centers in Baghdad hospitals for a period of one year (2018).The results showed that the dialysis fluid quality was not in compliance with international standards. The dialysis fluid in 63% of the samples contained high Al concentrations, while Cu and Zn concentrations were within international standards. Lead concentrations were elevated in dialysis fluid in some hospitals as well.The average blood levels of biologically important heavy elements were significantly varied in hemodialysis patients when compared with local reference values.Since both deficiency and excess elements are potentially harmful, the hypothesis that heavy element status affects the risk of adverse clinical outcomes is a worthy investigation.ObtainedThe study was approved by the Baghdad Ethics Committee of the Iraqi Ministry of Health and Environment.The authors declare no competing financial interests. Chronic kidney disease is a form of kidney disease in which kidney function is gradually lost over a period of time, and has a major impact on health-related quality of life and medical service use.5Aluminum (Al) can be toxic to those with chronic renal failure due to modified Al metabolism and present several health risks, including dementia.9Aluminum compounds are the conventional coagulant used in the treatment of the municipal water, while the other metals  can be found in municipal water due to their existence in most water pipes and fittings used in Baghdad.During hemodialysis, essential functions of the kidney, such as elimination of water and metabolic waste, as well as electrolyte and acid/base correction, are replaced by an artificial purification system or a dialyzer.12Dialysis fluid or dialysate is used in dialysis to adjust the composition of extracellular fluid and maintain homeostasis of the body. Dialysate is produced by mixing clean reverse osmosis water with acid and base concentrate.13During treatment, hemodialysis patients are typically exposed to an extremely large amount of water, more than 90 to 192 L of water per session, two or three times a week.16Epidemiological studies have shown a strong correlation between exposure to toxic elements and chronic kidney injury.18At present, there is no national dialysis fluid quality standard in Iraq. Thus, the standards set by the ISO 23500-2:2019 were adopted to compare the results of the present study evaluating the quality of dialysis water used for hemodialysis treatment and the relationship to hemodialysis patient health.19The present study was carried out in 2018, with voluntary participation of 320 hemodialysis patients identified as having chronic kidney disease without hepatitis virus infection. Viral hepatitis patients were excluded because they were treated in isolation units.ISOInternational Organization for StandardizationLSDLeast significant differenceStudy participants included male and female subjects registered for regular hemodialysis treatment in four hemodialysis centers in Baghdad, Iraq: Al-Kindi, Baghdad Teaching, Kadhimiya , and Al-Yarmouk. The study took place during one year across the four seasons: Spring , Summer , Autumn , and Winter , including 20 patients from each hospital during each of these four seasons.The study was approved by the Baghdad Ethics Committee of the Iraqi Ministry of Health and Environment. All participants in the study gave their written permission to access their medical records, blood sampling, and anonymous use of their samples.Participant demographic information was collected using a researcher-made questionnaire. Information was further verified by cross checking with medical records.Blood samples were collected once from each patient during the hemodialysis session. The samples were collected from the venous port of the hemodialysis catheter before adding heparin to the whole blood samples of regular hemodialysis patients. The first 5 IU/ml of blood were discarded to avoid activation of coagulation due to puncture trauma.Water samples were collected once from the same four dialysis centers from which blood samples were taken at the same time. Water samples (250 ml) were collected and transported to the laboratory for chemical analysis in a cool box.The analysis of heavy metals was done using the graphite furnace atomic absorption spectrometry method  in the laboratories of the Iraqi Ministry of Science and Technology.Statistical analysis was carried out using analysis of variance and least significant difference (LSD) methods to compare different factors in study parameters at a p-value of 0.05. Microsoft Excel 2010 was used to calculate the results. The statistical correlation coefficient was calculated between the heavy metal concentrations across all blood samples with their concentration in the dialysis fluid. The calculations took into consideration patient gender  and calculations were performed separately for each gender. Data were expressed as mean±SD and percentage (%).21The results showed that 63% of dialysis fluid samples had aluminum (Al) levels exceeding the international standard guideline, while all copper (Cu) and zinc (Zn) concentrations were within the international standard at an acceptable level. Approximately 6% of the samples showed lead (Pb) concentrations higher than the international standard.The statistical analysis showed no significant differences in Al, Cu or Zn concentrations across the four hospitals, with the exception of Pb concentrations in the spring, where LSD=0.068 (p <5%). In addition, seasonal variation showed no significant differences with the exception of Al in Al-Kindi, and Pb in Al-Imamain Al-Kadhimain, with LSD values of 0.044 and 0.068, respectively.22The results showed that 81% of the blood samples had elevated Al concentrations (0.13±0.08 mg/l) when compared to normal values. The statistical analysis showed significant differences in Al levels among the hospitals in the summer and autumn . Furthermore, seasonal significant differences in mean blood Al levels were detected in Al-Kindi and Baghdad Teaching hospital at p <5%, with LSD of 0.166 and 0.149, respectively.The levels of Cu (0.26±0.10 mg/l) in blood samples were lower than normal values. The statistical analysis showed significant differences in mean Cu levels across the studied hospitals during the study period, and there were significant seasonal differences in all the studied hospitals, except in Baghdad Teaching hospital, at p <5%.All Pb concentration results (0.013±0.01 mg/l) were within normal levels compared with local normal values, and there were no significant differences across seasons and hospitals at p <5%.Finally, Zn levels were observed to fluctuate, as 18% of the tested samples were higher than the normal range, and 25% of the samples were lower than the normal range. Statistical analysis showed significant differences in mean Zn levels across hospitals except in the autumn period, and there were significant seasonal differences among all the hemodialysis centers studied at p <5%.The results of the present study showed that the concentrations of each of the heavy metals in the two types of samples  had different trends. There have been no previous studies assessing the relationship between dialysis water quality and the health of hemodialysis patients in the study area.According to 24Finally, the results showed that the majority of patients in the present study had low levels of formal education.Patients on chronic hemodialysis are at high risk of developing heavy metal imbalances.18The majority of the dialysis fluid samples were within the acceptable level for Pb concentration at Baghdad hospitals, which contributed to normal Pb concentration values in hemodialysis patients' blood samples. However, in the Spring (March to May) two hospitals showed elevated Pb concentrations and blood samples from male patients from these hospitals were elevated as well. 26The prevalence of Cu in the dialysis fluid was in compliance with the international standards, and there was an insignificant correlation with the Cu concentration in blood samples. This result disagrees with previous studies of water samples conducted by the same author, which found that Cu levels exceeded international standards.28et al. which showed non-compliance with international standards for the same hospitals.29Zinc concentrations were in compliance with the international standard during the entire study period and in all the hospitals in the present study. The results for Zn levels disagree with a previous study by Al-Naseri There is a need to study pre- and post-dialysis serum biochemical measurements, and the relationship to morbidity risk indicators in hemodialysis patients.The average blood levels of biologically important heavy elements were significantly varied in hemodialysis patients when compared with local reference values. Since both deficiency and excess elements are potentially harmful, the hypothesis that heavy element status affects the risk of adverse clinical outcomes is a worthy investigation. There were insignificant correlations between Cu, Zn, and Al in dialysis fluid and blood samples, while Pb concentration showed a significant correlation with blood samples collected from males only.


We aimed to evaluate whether the reduction in serum high-sensitivity C-reactive protein (hs-CRP) favors kidney outcomes.  This study was a subanalysis including patients with impaired fasting glucose or diabetes of the Kailuan cohort study. The predictor was based on two consecutive visits of hs-CRP levels in 2006 and 2008. A total of 3924 patients with hs-CRP ≥ 3 mg/L in 2006 were divided into two groups according to whether the levels of hs-CRP were reduced in 2008: Group 1: no reduction: hs-CRP ≥ 3 mg/L in 2008; Group 2: reduction: hs-CRP < 3 mg/L in 2008. Kidney outcomes include kidney function decline and development and progression of proteinuria and were followed up until the end of 2015. P = 0.002) and development of proteinuria  after controlling for potential confounders as compared to those with no reduction in hs-CRP levels.  There were 3905, 2049, and 493 patients included into our analysis for the outcomes of kidney function decline and the development and progression of proteinuria, respectively. A total of 398, 297, and 47 events occurred after 5 years of follow-up, respectively. Cox regression revealed that patients with reduction in hs-CRP have lower risk of kidney function decline (HR 0.71, 95% CI 0.57-0.89, and  Reduction in serum hs-CRP levels favors kidney outcomes in patients with impaired fasting glucose or diabetes. Chronic kidney disease (CKD) has become a common public health problem all over the world, with diabetes as the main etiology . Even peInflammation plays a relevant role in the development of CKD. The most commonly used biomarker of inflammation is high-sensitivity C-reactive protein (hs-CRP), which could predict all-cause and cardiovascular mortality . PreviouTherefore, we conducted this study aiming to evaluate whether the reduction in serum hs-CRP levels favors kidney outcomes in patients with impaired fasting glucose (IFG) or diabetes.Our study was based on the healthcare database from the Kailuan cohort , which wWe have obtained data on 30,016 patients with IFG or diabetes. According to the American Diabetes Association criterion, IFG was defined by fasting blood glucose (FBG) ≥ 100 and < 126 mg/dL  , with noIn the current study, we selected 3924 patients with IFG or diabetes and with hs-CRP ≥ 3 mg/L at baseline, a frequently used cut-off point for identifying high-risk population . The floThe Kailuan cohort study was approved by the Ethics Committee of Kailuan General Hospital. All participants provided informed consent in order to obtain their data for research purposes.2) was computed as weight/height2. Blood pressure (BP) was taken twice with a standardized mercury sphygmomanometer at a five-minute timespan after taking at least a five-minute break. If the difference between the two measurements was greater than 5 mmHg, one more BP was taken and the mean value of the three readings was adopted.During the face-to-face survey, a questionnaire including the sociodemographic information, medical history, and living habits was accomplished by all participants. Height, weight, and waist circumference (WC) were measured in line with the protocol. Body mass index . The CKD Epidemiology Collaboration equation was performed for calculating the estimated glomerular filtration rate (eGFR) . A cleanhs-CRP was tested by the immunoturbidimetry method , and the lower bound of measurement was 0.1 mg/L. Precision was assessed by measuring hs-CRP concentration in two common serum samples twice a day, greater than or equal to a 2-hour interval for 20 days, and the within- and between-assay coefficients of variation of this method were 6.53% and 4.78%, respectively. The interday and overall coefficients of variation were 6.61% and 9.37%, respectively .Patients with hs-CRP ≥ 3 mg/L at the first visit were divided into two groups according to whether the hs-CRP level was reduced or not at the second visit: Group 1: no reduction: hs-CRP ≥ 3 mg/L at the second visit; Group 2: reduction: hs-CRP < 3 mg/L at the second visit.2); (2) development of proteinuria, defined as the conversion from negative to micro- or overt proteinuria; and (3) progression of proteinuria, defined as the conversion from micro- to overt proteinuria.Kidney outcomes include the following: (1) kidney function decline, defined as eGFR decline ≥ 30% in two years , or doub2. Central obesity was defined as WC ≥ 90 cm for men and ≥ 80 cm for women. The definition of dyslipidemia includes a combination of increased total cholesterol (≥ 200 mg/dL (5.2 mmol/L)), and/or low-density lipoprotein cholesterol (≥ 130 mg/dL (3.4 mmol/L)), and/or triglyceride levels (> 150 mg/dL (1.7 mmol/L)), and/or decreased high-density lipoprotein cholesterol (< 40 mg/dL (1.0 mmol/L)), and/or taking lipid-lowering drugs [μmol/L in males and ≥ 360 μmol/L in females. “Inactive physical exercise” includes “no” or “occasional” (once or twice a week) exercise, and “active physical exercise” was considered “regular” (at least three times a week and each time continue at least 30 minutes). Current cigarette users were regarded as regular smoking (≥ 1 cigarette a day) in the last year, and current drinkers were identified by average alcohol consumption at least 100 mL a day for more than one year.Hypertension was defined as BP ≥ 140/90 mmHg, or having a history of hypertension, or currently taking antihypertensive drugs. BMI was classified into groups of < 18.5, 18.5-23.9, 24.0-27.9, and ≥ 28 kg/mng drugs . Hyperurt-test or Mann-Whitney U for continuous variables depending on the data distribution and χ2 test for classified variables.The characteristics of patients with IFG and diabetes were examined by whether or not the hs-CRP level was reduced. The normally distributed variables, the skewed distributed variables, the classified variables, and the incidence ratio were separately presented as mean ± standard deviation, median (interquartile range), number (proportion), and per 100,000 person-years. Baseline characteristics between groups were compared using the 2) were included into model 2 as potential confounders. For the outcome of kidney function decline, proteinuria (yes/no) was also included in model 2. We conducted a sensitivity analysis by removing participants who had a baseline eGFR < 60 mL/min/1.73 m2 in order to avoid the potential impact of reverse causality between the low eGFR and hs-CRP levels. The proportional hazard assumption was checked by the Schoenfeld residual test.Cox proportional hazard regression models were used to estimate the effect of reduction in hs-CRP levels on kidney outcomes. Model 1 controls for age and sex. Then, BMI (categories), FBG (per 1 mmol/L), dyslipidemia (yes/no), hypertension (yes/no), antihypertensive medicine (yes/no), hyperuricemia (yes/no), cigarette use (current yes/no), alcohol use (current yes/no), exercise (active/inactive), and baseline eGFR . Statistical significance was defined as alpha < 0.05 with the two-sided test.N = 3013) were male. Patients with reduced levels of hs-CRP tended to be younger, were more likely to be male, and have lower levels of BP, BMI, WC, FBG, triglycerides, and baseline hs-CRP and less proportion of proteinuria.Firstly, there were 3924 patients that were suitable for analysis . As showAccording to the inclusion and exclusion criteria, 3905 patients  were included into analysis after further removing 19 patients with missing information of eGFR at baseline or subsequent visits for the outcome of kidney function decline. After the mean follow-up of 5.0 ± 1.6 years , 398 (10.2%) patients experienced kidney function decline .For the outcome of the development of proteinuria, 2049 patients without proteinuria  at baseline were included into analysis. After the mean follow-up of 5.0 ± 1.6 years , 297 (14.5%) patients developed proteinuria .For the outcome of the progression of proteinuria, 493 patients with microproteinuria  were included into analysis. After the mean follow-up of 4.8 ± 1.6 years (2370 person-years), 47 (9.5%) patients experienced the progression of proteinuria .P = 0.003) and development of proteinuria , but not progression of proteinuria  after adjusting for age and sex (model 1) as compared to those with no reduction in hs-CRP levels. The results were essentially unchanged after adjusted for potential confounders (model 2).As shown in 2. In the fully adjusted models, the results did not change substantially: for kidney function decline  and for development of proteinuria .The sensitivity analysis was conducted by rerunning the Cox proportional hazard models after removing patients with eGFR > 60 mL/min/1.73 mBased on a subgroup of patients with IFG or diabetes and high level of hs-CRP from the Kailuan cohort study, we found that reduction in hs-CRP levels was associated with the decreased risk of kidney function decline and development of proteinuria.Previous studies focused on the effects of high level of hs-CRP at baseline on the kidney outcomes, while whether the reduced hs-CRP level is beneficial to kidney outcomes remains to be evaluated. Our study verified that the reduction in hs-CRP levels was beneficial to kidney outcomes from another perspective. This finding supports the efficacy of treatment targeting at inflammation in improving kidney outcomes.Nonimmunosuppressive treatment lowering the level of hs-CRP has been shown to be beneficial to kidney outcomes and cardiovascular disease in patients with CKD . A cliniBesides statin use, there are several nonimmunosuppressive ways to decrease hs-CRP levels. A systematic review and meta-analysis indicated that the natural soybean protein products may decrease plasma hs-CRP levels as compared with isoflavones from other sources . RegardiγRII on apoptotic cells and exacerbate epithelial-mesenchymal transition via the Wnt/β-catenin and ERK1/2 signal paths, which could promote the incidence of diabetic kidney disease [Despite the fact that hs-CRP is a practical indictor for risk assessment, many experimental investigations indicated that CRP itself is difficult to be a target for therapy. Following upstream of the inflammatory response from CRP to IL-6 to IL-1, increasing the availability of novel opportunities inhibits the activation of NLRP3 inflammasomes . In addi disease . HoweverThere were certain limitations in our study. Firstly, the current study was an observational study instead of a randomized controlled trial, so the probability of residual confounding factors cannot be ruled out. Secondly, males account for about 80% of the patients that could limit the applicability of the findings to females. Thirdly, this study is based on employees and relatives of the Kailuan Coal Mine Group, which limits the generalizability of our study. Further studies are needed to validate our results among other populations. Finally, eGFR and proteinuria were tested by using a urine sample, which can lead to the inaccuracy of the classification. Despite these limitations, this study determined that the reduction in hs-CRP levels did favor kidney outcomes.In conclusion, reduction in serum hs-CRP levels favors kidney outcomes in patients with IFG or diabetes. However, randomized controlled clinical trials are warranted to further confirm this association.


Evidence concerning the potential repurposing of antihypertensives for Alzheimer’s disease prevention is inconclusive. We used Mendelian randomization, which can be more robust to confounding by indication and patient characteristics, to investigate the effects of lowering systolic blood pressure, via the protein targets of different antihypertensive drug classes, on Alzheimer’s disease.We used summary statistics from genome-wide association studies of systolic blood pressure and Alzheimer’s disease in a two-sample Mendelian randomization analysis. We identified single-nucleotide polymorphisms (SNPs) that mimic the action of antihypertensive protein targets and estimated the effect of lowering systolic blood pressure on Alzheimer’s disease in three ways: (i) combining the protein targets of antihypertensive drug classes, (ii) combining all protein targets and (iii) without consideration of the protein targets.calcium channel blockers had an odds ratio (OR) per 10 mmHg lower systolic blood pressure of 1.53 . We also found limited evidence for an effect when combining all protein targets  and without consideration of the protein targets .There was limited evidence that lowering systolic blood pressure, via the protein targets of antihypertensive drug classes, affected Alzheimer’s disease risk. For example, the protein targets of Mendelian randomization suggests that lowering systolic blood pressure via the protein targets of antihypertensive drugs is unlikely to affect the risk of developing Alzheimer’s disease. Consequently, if specific antihypertensive drug classes do affect the risk of Alzheimer’s disease, they may not do so via systolic blood pressure. This is the first study to use Mendelian randomization to estimate the effects of the protein targets of the 12 most common antihypertensive drug classes on Alzheimer’s disease.Mendelian randomization suggests that lowering systolic blood pressure via the protein targets of antihypertensive drugs is unlikely to affect the risk of developing Alzheimer’s disease.If specific antihypertensive drug classes do affect Alzheimer’s disease risk, they may not do so via systolic blood pressure. ,Drug repurposing applies existing drugs to novel indications to identify potential treatments in a more rapid and cost-effective manner than traditional drug development. This approach is of interest for Alzheimer’s disease, as there are currently no preventative or disease-modifying therapies, despite investment in 1120 unique drug targets between 1995 and 2014.Mendelian randomization has been proposed to predict drug repurposing opportunities and overcome some of the issues associated with conventional observational studies.In this study, we use SNPs as instruments, selected to mimic the action of the protein targets of antihypertensive drug classes, in a two-sample Mendelian randomization analysis of systolic blood pressure on Alzheimer’s disease. Our rationale is to understand whether there are differences between specific antihypertensive drug classes on Alzheimer’s disease risk, which could inform the prioritization of repurposing candidates, and provide evidence at the drug class level that could be triangulated with that from other sources.We conducted a two-sample Mendelian randomization analysis using summary data on SNPs from GWAS. We identified SNPs to proxy the protein targets of antihypertensive drugs on the basis that they mimicked the action of that drug on the target. For example, angiotensin-converting enzyme inhibitors work by inhibiting the enzyme angiotensin-converting enzyme. We therefore selected SNPs in the angiotensin-converting enzyme gene to use as a genetic proxy for the protein targets of this drug class. Effect sizes for these SNPs were then extracted from a GWAS of systolic blood pressure to estimate the instrument–exposure association.,The systolic blood pressure phenotype was defined using a GWAS of the UK Biobank cohort.The Alzheimer’s disease phenotype was defined using the International Genomics of Alzheimer's Project (IGAP) GWAS Stage 1 results. These data were from a European ancestry meta-analysis of 17 008 Alzheimer’s disease cases, which were a mixture of clinically and autopsy-confirmed, and 37 154 controls.adrenergic neurone blocking drugs; alpha-adrenoceptor blockers, angiotensin-converting enzyme inhibitors, angiotensin-II receptor blockers, beta-adrenoceptor blockers, calcium channel blockers, centrally acting antihypertensive drugs, loop diuretics; potassium-sparing diuretics and aldosterone antagonists, renin inhibitors, thiazides and related diuretics, and vasodilator antihypertensives. Using the drug substance information, we were able to identify pharmacologically active protein targets and the corresponding genes in the DrugBank database .p-value for a variant-gene pair) in any tissue were selected for analysis.We identified 12 antihypertensive drug classes in the British National Formulary.IJE online.To validate the SNPs as instruments for the protein targets of the antihypertensive drugs, we estimated their effect on systolic blood pressure using two-sample Mendelian randomization. The SNP-expression association, extracted from GTEx as described above, was on the scale of a standard deviation change in ribonucleic acid (RNA)-expression levels for each additional effect allele. The SNP–systolic blood pressure association was extracted from the systolic blood pressure GWAS in UK Biobank and represented the standard-deviation change in systolic blood pressure for each additional effect allele. These associations were then used to estimate the effect of the protein target on systolic blood pressure (i.e. the standard deviation change in systolic blood pressure per standard deviation change in RNA-expression levels). SNPs with evidence of an effect on systolic blood pressure were retained for the main analysis. This instrument selection process is presented in We used two-sample Mendelian randomization to estimate the effect of lowering systolic blood pressure on Alzheimer’s disease in three ways. First, we estimated the effect of the protein targets of specific drug classes by combining their effects. This used the instruments defined in the previous section. Second, we estimated the effect of all protein targets of antihypertensive drugs as a whole on Alzheimer’s disease. Again, this used the instruments defined in the previous section. Finally, we estimated the overall effect of systolic blood pressure on Alzheimer’s disease by combining the effects of any genome-wide significant SNPs for systolic blood pressure.,R-squared value of 0.8 and palindromic SNPs were permitted if their minor allele frequency was <0.3.When multiple SNPs were being used as an instrument, ‘clumping’ was performed to identify nearly independent SNPs using the linkage disequilibrium between them. SNPs absent in the outcome data were replaced by proxy SNPs in high linkage disequilibrium from the 1000 Genomes Project European data where possible.Prior to the analysis, data were harmonized to represent an increase in systolic blood pressure. Mendelian randomization was then performed using the inverse variance weighted method or, for single SNP instruments, the Wald ratio.Mendelian randomization estimates may be subject to horizontal pleiotropy, whereby the SNP(s) chosen to proxy the exposure affect the outcome by a different mechanism to that intended.To examine heterogeneity within the drug classes, we also considered the effects of individual protein targets on Alzheimer’s disease. This analysis allowed us to ascertain whether certain targets were driving the combined effects we considered. Combined effects with very heterogeneous protein target results can be considered to have less reliable estimates than those where the protein targets were more homogeneous.https://github.com/venexia/MR-antihypertensives-AD).The analysis used R version 3.4.4.IJE online). Among these targets, 68 had an effect in one or more GTEx tissues and 58 of those 68 provided evidence that the target affected systolic blood pressure (IJE online). IJE online, summarizes the results of the Mendelian randomization analysis of expression on systolic blood pressure. A further six targets were excluded prior to the main analysis because neither the genetic instrument nor a suitable proxy was available in the outcome GWAS. Consequently, 52 unique protein targets were ultimately analysed (IJE online).We identified a total of 73 unique protein targets of antihypertensive drugs (IJE online). For example, calcium channel blockers had an OR of 1.53  and loop diuretics an OR of 0.78  per 10 mmHg lower systolic blood pressure. The exceptions to this were angiotensin-converting enzyme inhibitors  and potassium-sparing diuretics and aldosterone antagonists .There was limited evidence that reducing systolic blood pressure affected the risk of Alzheimer’s disease, via the protein targets, at the drug class level, with most estimates providing little evidence to exclude the null  (IJE online).We found little evidence for an overall effect of lowering systolic blood pressure on Alzheimer’s disease, via the protein targets, when combining them all  per 10 mmHg lower systolic blood pressure (IJE online).We also found little evidence for an overall effect of lowering systolic blood pressure on Alzheimer’s disease, without consideration of the associated protein targets, as indicated by the OR of 1.04 . In addition, the estimates from the inverse variance weighted and MR-Egger methods were similar for all analyses with both the point estimate and CI for the inverse variance weighted method almost contained within the CI for the MR-Egger method (IJE online).The Egger intercepts were close to zero for almost all analyses where they could be calculated (IJE online). For example, the target NR3C2 is estimated to be extremely protective  and is therefore likely to have contributed to the extremely protective effect observed for potassium-sparing diuretics and aldosterone antagonists .The analysis of individual targets identified some targets that were likely to be driving the drug class effects . There was also limited evidence that lowering systolic blood pressure via the protein targets of specific antihypertensive drug classes affected Alzheimer’s disease. For example, calcium channel blockers had an OR of 1.53  and vasodilator antihypertensives had an OR of 0.98  per 10 mmHg lower systolic blood pressure. This was reflected in the overall effect of lowering systolic blood pressure on Alzheimer’s disease when combining all identified protein targets, which had an OR of 1.14  per 10 mmHg lower systolic blood pressure. Despite this, we also report some extreme results, such as that for the protein targets of angiotensin-converting enzyme inhibitors, which were associated with an increased Alzheimer’s disease risk . Note that, as with all studies that make multiple inferences simultaneously, multiple testing should be considered when interpreting the evidence presented here.We found limited evidence to support an overall effect of lowering systolic blood pressure on Alzheimer’s disease risk when combining the effects of any genome-wide significant SNPs for this exposure  and have independent effects on amyloid beta.potassium-sparing diuretics and aldosterone antagonists, the protein targets of which were also estimated to have an extreme effect , have previously been suggested to have a role, independently of blood pressure, in preventing cognitive decline.In our analysis, we found a small effect of systolic blood pressure on Alzheimer’s disease and our extreme results were for the protein targets of drug classes that may well act through competing mechanisms. For instance, returning to the example of ,et al. study found higher systolic blood pressure to be associated with a reduced risk of Alzheimer’s disease, whereas Larsson et al. found little evidence of an effect of systolic or diastolic blood pressure with Alzheimer’s disease. Our results agree with Larsson et al. in that there is unlikely to be an overall effect of systolic blood pressure on risk of Alzheimer’s disease. Gill et al. recently conducted a study that combined Mendelian randomization using genetic variants related to the protein targets of antihypertensive drugs with a PheWAS conducted in UK Biobank, although their analysis was restricted to beta-adrenoceptor blockers and calcium channel blockers.et al. for Alzheimer’s disease. There was a small overlap in the choice of SNPs used to instrument systolic blood pressure between our study and those previously reported, although there was less overlap when considering our instruments for the protein targets of specific drug classes (IJE online). Using the previously reported instruments with our data, we were able to reproduce the previously reported results (IJE online).Two previous Mendelian randomization studies have studied the overall effect of systolic blood pressure on Alzheimer’s disease to date. These studies used different instruments and different systolic blood pressure GWAS, both to us and each other.et al. recently conducted a systematic review and meta-analysis, which identified five randomized controlled trials that have investigated whether antihypertensives prevent dementia .p = 0.10). It is worth highlighting that most studies described in the meta-analysis were from populations with high cardiovascular morbidity and were designed around cardiovascular-related primary outcomes. In these trials, the proportion of dementia cases that derived from vascular mechanisms might be disproportionately high compared with other study populations.,calcium channel blocker Nilvadipine) as a direct intervention in Alzheimer’s disease has been published—it found no benefit of the treatment among patients with mild to moderate probable Alzheimer's disease.Larsson et al., the primary outcome for the SPRINT trial was cardiovascular, meaning participants in SPRINT-MIND are more likely to have cognitive impairment and dementia outcomes derived from vascular mechanisms. Finally, Mendelian randomization estimates are of lifelong exposure, whereas this trial intervened on blood pressure for a median of 3.34 years in people with a mean age of 67.9 years. It is therefore possible that the trial has identified a critical period in which altering blood pressure has a beneficial impact on cognitive outcomes, which we cannot distinguish. Overall, while not directly comparable to our study, the findings from these recent trials, as well as the Larsson et al. meta-analysis, provide further evidence concerning the repurposing of antihypertensives for Alzheimer’s disease that can be considered together in a triangulation framework.The results of the SPRINT-MIND trial, which assessed the effect of intensive vs standard blood pressure control using a range of antihypertensive medications on probable dementia, mild cognitive impairment and a composite outcome combining probable dementia and mild cognitive impairment, have also been released.A strength of our study was the use of two-sample Mendelian randomization that meant we were able to utilize the IGAP GWAS for our outcome data, which contains information on 17 008 Alzheimer’s disease cases and 37 154 controls.potassium-sparing diuretics and aldosterone antagonist may have seemed more protective due to the particularly large protective effect observed for one of the three targets under consideration: NR3C2. We were also limited by the fact that Mendelian randomization estimates the effect of lifelong exposure, whereas drugs typically have much shorter periods of exposure and systolic blood pressure may have age-dependent effects. This means that the effect sizes that we have estimated will not directly reflect what is observed in trials or clinical practice and may not be able to identify critical periods of exposure.The limitations of this study included the risk of horizontal pleiotropy. We addressed this by conducting sensitivity analyses using MR-Egger when possible and by using the information concerning the existing indication of these drugs, i.e. alterations in systolic blood pressure, to inform our analysis. While the latter offers many benefits, it does restrict the inference we could make about the protein target effects that do not occur as a result of altering systolic blood pressure. Sensitivity analyses that considered the individual protein target effects also identified some heterogeneity that may have affected our combined estimates—e.g. the estimate for Further limitations of this study relate to the populations used. For example, there is potentially ‘healthy volunteer’ bias in the UK Biobank study population, which would make the study unrepresentative of the UK population and may restrict the generalizability of our results.This study helps to inform the growing knowledge around repurposing antihypertensive drugs for Alzheimer’s disease prevention by using a different method, subject to different biases, to assess this research question. Combining the effects of all genome-wide significant SNPs for systolic blood pressure, we found little evidence to suggest that lowering systolic blood pressure itself will affect the risk of developing Alzheimer’s disease. This was accompanied by limited evidence for many of the protein targets of antihypertensive drug classes that we tested. This suggests that, if protein targets of specific antihypertensive drug classes do affect risk of Alzheimer’s disease, they may not do so via systolic blood pressure. Future research should consider this study, with other sources of evidence, in a triangulation framework to obtain a reliable answer concerning the potential repurposing of antihypertensives for Alzheimer’s disease prevention.This work was supported by the Perros Trust and the Integrative Epidemiology Unit. The Integrative Epidemiology Unit is supported by the Medical Research Council and the University of Bristol . Conflict of interest: Walker is currently working on a manuscript in collaboration with GlaxoSmithKline plc that explores whether Mendelian randomization can predict drug success but does not receive financial support from the company. Davies has worked on unrelated projects funded as part of the Global Research Awards For Nicotine Dependence, which is an independent grant giving body funded by Pfizer. dyz155_Supplementary_DataClick here for additional data file.


Although type 2 diabetes mellitus (T2DM) is one of the most frequent comorbidities in patients with chronic heart failure (CHF), the effects of T2DM on the exercise capacity of CHF patients are fully unknown. Here, we tested the hypothesis that the coexistence of T2DM lowers CHF patients’ peak aerobic capacity.We retrospectively analyzed the cases of 275 Japanese CHF patients with non-reduced ejection fraction (left ventricular ejection fraction [LVEF] ≥ 40%) or reduced EF (LVEF < 40%) who underwent cardiopulmonary exercise testing. We divided them into diabetic and nondiabetic groups in each CHF cohort.2) value was 16.87 mL/kg/min in the non-reduced LVEF cohort and 15.52 mL/kg/min in the reduced LVEF cohort. The peak VO2 was lower in the diabetics versus the nondiabetics in the non-reduced LVEF cohort with the mean difference  of − 0.93 (− 1.82 to − 0.04) mL/kg/min and in the reduced LVEF cohort with the mean difference of − 1.05 (− 1.96 to − 0.15) mL/kg/min, after adjustment for age-squared, gender, anemia, renal function, LVEF, and log B-type natriuretic peptide (BNP). The adjusted VO2 at anaerobic threshold (AT), a submaximal aerobic capacity, was also decreased in the diabetic patients with both non-reduced and reduced LVEFs. Intriguingly, the diabetic patients had a lower adjusted peak O2 pulse than the nondiabetic patients in the reduced LVEF cohort, but not in the non-reduced LVEF cohort. A multivariate analysis showed that the presence of T2DM was an independent predictor of lowered peak VO2 in CHF patients with non-reduced LVEF and those with reduced LVEF.The mean peak oxygen uptake (VO2 in CHF patients with non-reduced or reduced LVEF. The presence of T2DM has a negative impact on CHF patients’ exercise capacity, and the degree of impact is partly dependent on their LV systolic function.T2DM was associated with lowered peak VO In particular, a lowered peak oxygen uptake  , 10 or aWe retrospectively analyzed the cases of a total of 275 stable Japanese patients with CHF who underwent cardiopulmonary exercise testing (CPET) between January 2009 and March 2016 at Hokkaido University Hospital. Before the CPET, all of the patients had a history of one or more hospital admissions due to worsening HF diagnosed on the basis of the American College of Cardiology Foundation (ACCF)/American Heart Association (AHA) Task Force on Practice guidelines . In part2 was defined as the maximal VO2 attained during the symptom-limited incremental exercise, and the anaerobic threshold (AT) was determined by the V-slope method [2) to VO2. We calculated the ΔVO2/Δworkload as the ratio of the peak VO2 to the peak workload. The peak O2 pulse was calculated as the ratio of the peak VO2 to the peak heart rate (HR). We defined HR reserve as: HR reserve = peak HR − resting HR. The chronotropic index (CI) was defined as: CI = (peak HR − resting HR) / , where the predicted maximal HR was calculated as: the predicted maximal HR = 220 − age. The lowest minute ventilation (VE)/VCO2 during exercise was evaluated to assess patients’ ventilatory efficiency.Each of the patients exercised on an upright cycle ergometer  using a ramp protocol (5–25 watts/min). A respiratory gas analysis was simultaneously performed with a breath-by-breath apparatus  as described . Peak VOe method . The RER−1.094 × −0.287 × .We reviewed the patients’ medical records to collect their demographic and clinical data including age, gender, body mass index (BMI), New York Heart Association (NYHA) functional class, primary cause of HF, cardiovascular risk factor(s), and medication(s). Each patient’s echocardiographic parameters and laboratory data were acquired within 30 days before or after he or she underwent the CPET. The left ventricular end-diastolic diameter (LVEDD) of each patient was evaluated from the parasternal long-axis view, and the LVEF was measured by the biplane method of disks using echocardiography. To assess LV diastolic function, we measured the peak early-diastolic and atrial systolic transmitral flow velocities  and the deceleration time of the E wave using pulsed-Doppler echocardiography, and the peak early-diastolic mitral annular velocity (e′) at the septal and lateral sides of the annulus with tissue-Doppler imaging. The e′ was averaged, and then, E/e′ was calculated. Hemoglobin, plasma B-type natriuretic peptide (BNP), and the estimated glomerular filtration rate (eGFR) were determined by routine in-house analyses. The eGFR was calculated from the serum creatinine values and age using the Japanese equation : eGFR = 2 in the CHF patients, including T2DM , LVEF, log BNP, age-squared, gender, hemoglobin, and eGFR. All analyses were performed using the JMP 12.2.0 program . A confidence level was set at 95%. Probability (P)-values < 0.05 were considered significant.Data are presented as the mean ± standard deviation (SD) for continuous variables and as numbers (percentages) for categorical variables. We divided the CHF patients into diabetic and nondiabetic groups based on the presence/absence of T2DM. We also conducted a subgroup analysis defined by the patients’ non-reduced LVEF (LVEF ≥ 40%) or reduced LVEF (LVEF < 40%). We compared the CPET parameters between the diabetic and nondiabetic groups in each subgroup after adjustment for age-squared, gender, hemoglobin, eGFR, LVEF, and log BNP, all of which are considered confounders. We performed a multivariate analysis to determine the independent variables of peak VOThe baseline data of the total population of CHF are summarized in Table As expected, the HbA1c level was higher in the diabetic patients than in the nondiabetic patients. Renal function was impaired in the diabetic patients with higher serum creatine and lower eGFR compared to the nondiabetic patients. The mean level of plasma BNP, a marker of the severity of HF, was 291.6 pg/dL in the total CHF population, 321.0 pg/dL in the diabetic patients with CHF, and 280.5 pg/dL in the nondiabetic patients with CHF. Regarding medications, 83% of the total CHF population were being treated with an angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB), and 80% received β-blockers; 9% of the diabetic patients with CHF were treated with insulin.We divided the total CHF population into two subgroups: the patients with non-reduced LVEF  and the patients with reduced LVEF . The baseline data of each subgroup are summarized in Table We further divided the non-reduced LVEF cohort into the preserved LVEF  and the mid-range LVEF cohorts , which is summarized in Additional file 2 value was 16.87 mL/kg/min in the LVEF ≥ 40% group and 15.52 mL/kg/min in the LVEF < 40% group. After the adjustment for age-squared, gender, anemia, renal function, LVEF, and log BNP, the peak VO2 was lower in the diabetics compared to the nondiabetics among the patients with LVEF ≥ 40%, with the mean difference (95% CI) of − 0.93 (− 1.82 to − 0.04) mL/kg/min; the peak VO2 was also lower in the diabetics compared to the nondiabetics among the patients with LVEF < 40%, with the mean difference of − 1.05 (− 1.96 to − 0.15) mL/kg/min. The O2 pulse  at peak exercise was decreased in the diabetics compared to the nondiabetics only in the LVEF < 40% group. The AT VO2, a marker of the body’s submaximal aerobic capacity, was also lower in the diabetics than in the nondiabetics in the LVEF ≥ 40% group, with the adjusted mean difference of − 0.65 (− 1.18 to − 0.12) mL/kg/min, and in the LVEF < 40% group with the adjusted mean difference of − 0.66 (− 1.11 to − 0.21) mL/kg/min. In contrast, there was no difference in the lowest VE/VCO2 between the diabetics and nondiabetics in either LVEF group. When we further divided the non-reduced LVEF cohort into the preserved LVEF and the mid-range LVEF cohorts, the peak VO2 and the AT VO2 were lowered in the diabetics in the LVEF 40-49% group, but not in the LVEF ≥ 50% group, after adjustment for age-squared, gender, anemia, renal function, LVEF, and log BNP  [Exercise intolerance is a cardinal symptom of HF regardless of the LVEF . It is w (< 40%) , 10 or a (< 40%) . To the 2 between the diabetics and the non-diabetics was 0.93 mL/kg/min  and 1.05 mL/kg/min  in the patients with non-reduce LVEF and in those with reduced LVEF, respectively, and the difference of absolute value of peak VO2 between the diabetics and the nondiabetics appears to be small. However, a large clinical trial has reported that every 6% increase of peak VO2 after exercise training results in a 5% lower risk of all-cause mortality or all-cause hospitalization and an 8% lower risk of cardiovascular mortality or HF-related hospitalization in CHF patients [2 is clinically relevant in the prevention of HF development.In the present study, the adjusted mean difference of peak VOpatients . Accordi2 is defined by the Fick equation: VO2 = cardiac output × arteriovenous O2 difference, where arteriovenous O2 difference is determined by peripheral factors. Low aerobic capacity may be generally caused by cardiac, vascular, or skeletal muscle dysfunction, which results in reduced O2 delivery or O2 utilization. Recent studies have shown that predominantly peripheral  factors contribute to reduced peak VO2 in CHF patients [2 utilization for energy production during exercise, and it has been demonstrated that skeletal muscle dysfunction characterized by impaired mitochondrial oxidative capacity and fiber-type switch  is a common feature of CHF patients with both preserved and reduced LVEFs [2 difference at peak exercise is reported to be reduced in association with lowered peak VO2 in patients with T2DM [2 via skeletal muscle dysfunction in CHF patients with non-reduced or reduced LVEF.The VOpatients , 20. In ed LVEFs , 21, 22.ith T2DM , and a sith T2DM , 7, 24. 2 pulse (a parameter that relies on the stroke volume at peak exercise) was lower in the diabetics than in the nondiabetics in the group of CHF patients with a reduced LVEF, but not in those with a non-reduced LVEF. In addition, the multivariate analysis showed that the LVEF was an independent predictor of lowered peak VO2 in the CHF patients with reduced LVEF. Accordingly, in patients with reduced LVEF, a decrease in LV systolic function  may also underlie the association between T2DM and lowered peak aerobic capacity.On the other hand, we observed that the peak O2 supply to skeletal muscle. Insulin resistance is associated with decreased vasodilatation and capillary recruitment [2 was correlated with the muscle blood flow reserve in patients with T2DM [2 in these patients [Another possible explanation of the lowered peak aerobic capacity in diabetic CHF patients is reduced muscle blood flow, which results in low Oruitment , and a rith T2DM . In addipatients . Taken t2 delivery, O2 storage, and muscle oxidative metabolism, iron deficiency can be an independent predictor of reduced peak VO2 in patients with CHF irrespective of hemoglobin levels [Anemia, a determinant of lowered peak aerobic capacity, is known to be common in diabetic patients, and prevalence of anemia in diabetic patients could be doubled when they have an impaired renal function . In addin levels . In the 2 in CHF patients with a reduced LVEF via an impairment of the alveolar-capillary gas transfer, possibly due to microangiopathy, which may lead to decreased O2 uptake through the lungs during exercise [2, a parameter of ventilatory efficiency during exercise, did not differ between the CHF patients with and without T2DM, which is inconsistent with the previous report [2 perfusion to the depressed peak VO2 in CHF patients with T2DM.Guazzi et al. demonstrated that the coexistence of T2DM reduces the peak VOexercise , 31. In s report . However2 in CHF patients with non-reduced LVEF (≥ 40%). However, in the multivariate analysis to determine the independent variables of peak VO2 after division of the non-reduced LVEF cohort into the preserved LVEF (≥ 50%) and the mid-range LVEF (40–49%) cohorts, the presence of T2DM did not reach statistical significance in the CHF patients with preserved LVEF, which is inconsistent with a previous study [Our analyses demonstrated that T2DM is an independent predictor of lowered peak VOus study . There aIt has been shown that sedentary behavior and physical inactivity may induce exercise intolerance and increase risk of cardiovascular events in individuals with pre-diabetes or T2DM , 33 and 2. Second, our participants’ mean value of peak VO2 was higher than 14 mL/kg/min, a cut-off value of candidate of heart transplantation, indicating that most participants had a mild-to-moderate CHF. Third, some of the patients underwent echocardiography or blood testing on another day within 30 days before or after CPET, which might influence the data analysis, although all the participants were in stable condition. Finally, we could not eliminate patients with recovered or improved LVEF from the non-reduced LVEF cohort.There are some limitations in this study. First, we could not identify the causes of the lowered peak aerobic capacity in the CHF patients with T2DM, including cardiac and peripheral factors that determine the peak VO2 in CHF patients with non-reduced LVEF and in those with reduced LVEF. The comorbidity of T2DM has a negative impact on CHF patients’ exercise capacity, and the degree of impact is partly dependent on their LV systolic function. The prevention of T2DM is important not only for the reduction of cardiovascular risks but also for the maintenance of exercise capacity in HF management.T2DM is an independent predictor of the lower peak VOAdditional file 1. Table S1. Baseline characteristics of the CHF patients with preserved LVEF (≥50%) or mid-range LVEF (40-49%). Table S2. Cardiopulmonary exercise testing parameters of the CHF patients with preserved LVEF (≥50%) or mid-range LVEF (40-49%). Table S3. Multivariable analysis for peak VO2 in the CHF patients with preserved LVEF (≥50%) or mid-range LVEF (40-49%).


Our recently established measurement protocol for the Cellular Oxygen Metabolism (COMET) Monitor, a novel device employing the PpIX-TSLT, additionally allows the evaluation of oxygen consumption (mitoVO2) and delivery (mitoDO2). In the intensive care setting, these variables might provide new insight into mitochondrial oxygen metabolism and especially mitoDO2 might be a surrogate parameter of microcirculatory function. However, the feasibility of the PpIX-TSLT in critically ill patients has not been analyzed systematically. In this interim study analysis, we evaluated PpIX-TSLT measurements of 40 patients during the acute phase of sepsis. We assessed (a) potential adverse side effects of the method, (b) the rate of analyzable measurements, (c) the stability of mitoPO2, mitoVO2, and mitoDO2, and (d) potential covariates. Due to excessive edema in patients with sepsis, we specifically analyzed the association of patients' hydration status, assessed by bioimpedance analysis (BIA), with the aforementioned variables. We observed no side effects and acquired analyzable measurements sessions in 92.5% of patients (n = 37/40). Different measures of stability indicated moderate to good repeatability of the PpIX-TSLT variables within one session of multiple measurements. The determined limits of agreement and minimum detectable differences may be helpful in identifying outlier measurements. In conjunction with signal quality they mark a first step in developing a previously unavailable standardized measurement quality protocol. Notably, higher levels of hydration were associated with lower mitochondrial oxygen tension. We conclude that COMET measurements are viable in patients with sepsis. To validate the clinical and diagnostic relevance of the PpIX-TSLT using the COMET in the intensive care setting, future studies in critically ill patients and healthy controls are needed.The imbalance of oxygen delivery and oxygen consumption resulting in insufficient tissue oxygenation is pathognomonic for all forms of shock. Mitochondrial function plays an important role in the cellular oxygen metabolism and has been shown to impact a variety of diseases in the intensive care setting, specifically sepsis. Clinical assessment of tissue oxygenation and mitochondrial function remains elusive. The  Sepsis is defined as a life-threatening host response toward infection resulting in organ dysfunction . Despiteex vivo there may be pre-analytical confounders influencing the results. Also, the procedure is invasive and therefore unlikely to be used routinely for diagnostic purposes. Non-invasive direct measurements of mitochondrial function in patients could pose a feasible method to assess tissue oxygenation in patients with sepsis.In recent years, the mitochondrion has become a focus of medical research. The mitochondrion, as “powerhouse” of the cell, is responsible for the regulation of cellular oxygen metabolism and could therefore pose a potential target for the measurement of tissue oxygenation. Studies have demonstrated a pathophysiological involvement of mitochondrial function in, among others, cancer, heart, and age-related diseases –5. In se2)  for non-invasively measuring mitochondrial oxygen tension (mitoPO2) . In brie2)  and in h2) , 12.The primary objective of this study was to test how feasible the PpIX-TSLT measurements are in the acute phase of sepsis during the treatment at the critical care unit. The secondary objectives were to assess the distribution and the stability of PpIX-TSLT variables for single measurements and to identify potential covariates, in particular the patients' fluid status.Identification of cardiovascular and molecular prognostic factors for the medium- and long-term outcomes of sepsis . Patients with sepsis were recruited at the intensive care units of the Jena University Hospital. The inclusion and exclusion criteria of the study are presented in This study is an intermediate analysis of patients from the study 2 patch containing 5-ALA  was applied to the clavipectoral triangle at least 5 h before the planned measurement to ensure sufficient accumulation of PpIX. Before application, the skin was cleaned and prepared with an abrasive paste . For 48 h after application, the skin was protected from light with an additional patch. The measurements were performed with the COMET measurement system . Before the measurement session, the sensor was shielded from light and applied to the prepared skin. During one session multiple measurements with the following parameters were performed . Finally, the pressure was released to evaluate the re-oxygenation (mitoDO2 : maximum and mitoDO2 : average) and post-re-oxygenation mitoPO2 (mitoPO2 : post). A single measurement took 105 s and was performed at least three times per session. We used two complementary sigmoid functions to fit the raw PpIX-TSLT signals of each single measurement:PpIX-TSLT measurements took place within 3 ± 1 days after the onset of sepsis. A 4 cmsee also : In the The estimation of these function parameters allows a direct inference of the PpIX-TSLT variables. For details please [see ].We used a self-developed program  under MATLAB  for data management, data preparation and PpIX-TSLT variable estimation./height, Xc/height) in meters . For bioimpedance vector analysis (BIVA), raw impedance variables, resistance (R) and reactance (Xc), were standardized to body height  are reported. For categorical and dichotomous variables we report absolute and relative frequencies. The distribution of the PpIX-TSLT variables was assessed using histograms, Q-Q-plots, Shapiro-Wilk-Tests, and an estimation of kurtosis and skewness with corresponding standard errors (SE) and kurtosis excess (kurtosis – 3).In descriptive analysis, means, standard deviations (SD), medians, as well as first and third quartiles  are reported.To analyze the repeatability, i.e., stability, of PpIX-TSLT variables during one measurement session we took the following steps: First, descriptive mean differences between measurement pairs and corresponding y strong . Third, y strong , 19. In y strong . At popuy strong . ICCs any strong . Finallyy strong  and the 2, hemoglobin, fluid balance), and treatment-associated data . Treatment-related variables were obtained from electronic patient records on ICU .Potential covariates for PpIX-TSLT variables were analyzed parametrically and non-parametrically with Pearson correlation coefficients and Spearman's rank correlation coefficients, respectively. PpIX-TSLT variables from multiple single measurements were averaged before correlative analysis. Results were additionally visualized with scatterplots and regression lines from the simple linear regression models (PpIX-TSLT variables served as dependent variables). We considered the following variables: sex, age, BIVA variables (see above), PpIX-TSLT-associated variables , physiological data  and R . We app2 could not be induced consistently during multiple measurements. We did not observe any side effects of the 5-ALA application or the PpIX-TSLT measurement itself in any patient.In 37 (92.5%) of the 40 included patients with sepsis, reliable PpIX-TSLT measurement sessions could be recorded. In the 3 patients with unreliable measurement sessions either the signal quality was too low and/or mitoVO2 variables were normally distributed (p > 0.05). The p-values of the Shapiro-Wilk tests for the other PpIX-TSLT variables were significant (p < 0.01). All PpIX-TSLT parameters were positively skewed and kurtosis excess values ranged between −2.4  to 3.0 . After removing outlier values  indicating normally distributed values.The descriptive statistics of the PpIX-TSLT variables are displayed in 2 : baseline values showed a mean difference of 4.42 mmHg between subsequent measurements, resulting in a significant p-value of the corresponding paired t-test (2 variables differed significantly between subsequent measurements (p < 0.01) with a mean difference of 1.07 (mitoDO2 : maximum) and 0.76 (mitoDO2 : average), respectively. MitoPO2 : Post and both mitoVO2 variables did not differ significantly between subsequent measurements. All variables were moderately (mitoDO2) to strongly  correlated between subsequent measurements  and ranged between 0.652 (moderate) for mitoDO2 variables and 0.805 (good) for mitoVO2 variables  of the fitting function. MitoDO2 variables were negatively correlated with the duration of 5-ALA application, the average signal quality during PpIX-TSLT measurement and body height. In addition, mitoDO2 variables were positively correlated with the room temperature. Finally, the mean signal quality of one measurement was positively correlated with the duration of the 5-ALA application and negatively correlated with the room temperature. All other tested covariates showed no statistically significant correlation coefficients with PpIX-TSLT variables (data not shown). MitoPO2 : baseline tended to differ between female  and male patients . In addition, we found significant sex differences between mitoDO2 : average with higher values for females  compared to males . Neither the ventilation status nor the catecholamine dosage was significantly associated with any of the PpIX-TSLT variables. After adjusting for multiple testing using the Bonferroni-Holm method, only the p-value for the association between mitoVO2 variables and the goodness of fit (R2) reached significance .Statistically significant associations between PpIX-TSLT variables and tested covariates are shown in in vivo assessment of mitochondrial oxygen metabolism by PpIX-TSLT measurements in a cohort of patients with sepsis. Thus far, only reports in healthy subjects or surgical patients have been published. In our cohort of 40 patients, PpIX-TSLT measurements yielded analyzable datasets in 92.5% of patients. Also, no side effects of the measurements were observed. We therefore conclude that PpIX-TSLT measurements with the COMET are feasible in patients with sepsis in the ICU setting. In our previous study, analyzable results were obtained from 75% of healthy subjects . Taken together, the stability of replicate measurements in one session can be seen as moderate to good. We nonetheless recommend multiple measurements in one session. Judging from the LOA and MDD, we can determine that an increase in mitoPO2 : baseline of 35 mmHg or a decrease of 25 mmHg between measurements is probably due to incorrect measurement and the measurement should be repeated. Similarly, absolute changes of 2 mmHg/s for mitoVO2 : average and 5 mmHg/s for mitoDO2 : average could indicate incorrect measurements. All these results are very similar to values determined in our previous study of healthy controls  and selective exclusion criteria . Furthermore, in correlative analysis for the identification of potential covariates we did not adjust for multiple testing. Thus, our results need to be confirmed in larger trials. Especially the potential influence of the patient's hydration status on PpIX-TSLT variables should be examined. A direct estimation of total body water using BIA may be useful but is strongly dependent on body weight and height. As measuring body weight accurately in intensive care patients is difficult, we restricted our analyses to the weight-independent BIA variables (BIVA). Due to the fluctuation of physiological variables in critically ill patients, we only analyzed the short-term stability of PpIX-TSLT variables, with iterative measurements within minutes. The long-term stability of PpIX-TSLT variables was not analyzed.The generalizability of the results for our secondary objectives are limited by the relatively small number of patients (We conclude that PpIX-TSLT measurements with the COMET are feasible in the critical care setting. Despite the moderate to good stability of the PpIX-TSLT variables using our protocol, we recommend the recording of multiple measurements during one session to increase the reliability of results. The determined limits of agreement and the minimum detectable differences may help to identify potential outlier measurements and additionally improve data quality. Future studies in larger cohorts of critically ill patients are needed to determine the clinical and diagnostic relevance of the PpIX-TSLT using the COMET. Furthermore, healthy controls should be measured to generate normal values for the PpIX-TSLT variables. This study poses a first step toward an evidence-based approach in the assessment of tissue oxygenation in the intensive care unit.The datasets generated for this study are available on request to the corresponding author.The studies involving human participants were reviewed and approved by Ethics Committee of the Friedrich Schiller University Jena. The patients/participants provided their written informed consent to participate in this study.SC, CN, and PB: conception and design of the study. CN, PB, AP, KS, JG, and CS-W: performance of measurements. PB, CN, AP, KS, and JG: clinical data collection. PB, KS, and AP: data analysis and statistical analysis. CN, PB, AP, KS, JG, CS-W, and SC: drafting the manuscript for important intellectual content. CN, CL, PB, and SC: revising the manuscript prior to submission. All authors carefully reviewed and approved the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.