Hibiscus sabdariffa (HS) and Lippia citriodora (LC) have attracted scientific interest, and they are recognized for their high content of polyphenols as these may prevent several disease factors, such as hypertension. The aim of the present study is to determine if supplementation with an HS-LC blend (MetabolAid®) may be effective for the treatment of type 1 hypertensive sedentary populations. A total of 80 type 1 hypertensive subjects of both sexes were included in the study and were treated with placebo or the HS-LC extract, and both groups were treated over 84 days. The blood pressure  was measured throughout the day, for each of the days of the study duration and determined using Ambulatory Blood Pressure Monitoring (ABPM). Physical activity was determined throughout the study to ensure similar conditions related to exercise. The results showed the capacity for reducing the blood pressure parameters in the case of the HS-LC extract. The daily consumption of the HS-LC extract but not the placebo over 84 days was able to reduce the daytime parameters related to blood pressure. The most remarkable results were observed in the measurements performed during the daytime, especially in the systolic blood pressure showing statistically significant variation.Hypertension is an important factor of cardiovascular diseases and contributes to their negative consequences including mortality. The World Health Organization estimated that 54% of strokes and 47% of cases of ischemic heart illness are related to high blood pressure. Recently,  Hypertension (HT) has become a major cause of mortality worldwide. An estimated 691 million people worldwide suffer from high blood pressure . The preThe World Health Organization estimated that 54% of strokes and 47% of cases of ischemic heart illness are connected with high blood pressure. This is due to the main risk factors for cardiovascular morbidity and mortality as well as HT . The decHT is a multifactorial disease that is strongly associated with lifestyle and especially with the consumption of alcohol, foods high in salt and fat, a sedentary lifestyle, and obesity among others . TobaccoHibiscus sabdariffa (HS) and Lippia citriodora (LC) have attracted scientific interest for their potential use in the treatment of metabolic syndrome [Polyphenols are natural extracts that have been extensively studied over recent years due to their antioxidant, antihypertensive, and anti-inflammatory capacities, in addition to their possible role in the prevention and management of several diseases, such as cardiovascular diseases, HT, diabetes, cancer, and neurodegenerative diseases ,11,12. Rsyndrome . In partsyndrome ,15.®, comprised of HS and LC extracts highly purified in anthocyanins and verbascoside polyphenols, respectively, previously reported a significant hypotensive effect, albeit using single blood pressure measurements in placebo-controlled clinical trials. Overweight and obesity are associated with higher blood pressure figures. Several studies, including the Framinghan study, have shown the high prevalence of hypertension in the obese population. Similarly, research demonstrated that weight loss with a hypocaloric diet in obese patients was associated with reductions in blood pressure levels and reductions in the pharmacological therapy necessary to keep it under control [Previous studies using a product called MetabolAid control ,17.® as part of antihypertensive treatment, due to the limited number of clinical studies linking LC and HS polyphenols with hypertension. Both plants that contain the ingredient are recognized for their high content of polyphenols, powerful antioxidant molecules that may be useful in many diseases such as HT, oxidative stress, dyslipidemia, lipid mobilization, and endothelial stiffness [The basis of the present work is the use of MetabolAidtiffness . The aimp = 0.516). Likewise, the diastolic blood pressure (DBP) also showed similar values when comparing the control and experimental groups, leading to 86.13 ± 7.6 mmHg and 90.27 ± 8.05 mmHg, respectively.The characteristics of the volunteers of the study are displayed in The determination of the blood pressure with ambulatory blood pressure monitoring (ABPM) allowed for multiple interpretations of the results, leading to reliable parameters that reflect the cardiovascular capacity.p < 0.05). This was not observed for the placebo, which showed similar values throughout the whole study (p > 0.05). The comparison between the placebo and HS-LC groups along the whole study led to significant differences in the SBP (p < 0.02). Therefore, the HS-LC extract appeared to improve the SBP to a greater extent compared with the placebo, which was observed from the first 56 days of treatment.p = 0.19). In contrast, the DBP remained stable throughout the whole study regardless of the HS-LC extract or placebo consumption . TherefoThe cardiovascular system is strongly influenced by circadian patterns. The incidence of cardiac events is clearly associated with daytime hours .The comparison between both the HS-LC and placebo groups revealed significant differences when the measurements of the daytime hours of the day were selected, as can be observed in p < 0.29). Remarkably, the treatment with placebo did not lead to variations on the systolic or DBP (p > 0.05).The HS-LC extract was able to reduce the daytime SBP but the daytime DBP remained at similar values as with the baseline (p > 0.05). The treatment with placebo was not able to reduce either the daytime systolic or DBP. However, the HS-LC extract appeared to be effective in reducing daytime SBP.From a wide point of view, MBP determined for the daytime maintained similar values from baseline to day 84 in both the placebo and HS-LC groups (p > 0.05). Similarly, placebo-controlled group showed a higher DBP (p > 0.05) at day 84 compared with at the baseline (+1.69 ± 1.21 mmHg). Therefore, no relevant changes were observed  and a decrease in those consuming the HS-LC extract (−2.24 ± 2.11 mmHg at day 84). However, the changes were not statistically significant in any case . There was a downward trend for the cholesterol and LDL values after the consumption of the product under study; however, the HS-LC extract did not improve (p > 0.05) the lipid profile of the subjects. The evolution of the lipid profile was similar (p > 0.05) between the subjects who consumed the placebo and those who consumed the HS-LC extract (As shown in  extract . As obse extract .p = 0.418) from 1.7 ± 0.3 MET at the baseline to 1.8 ± 0.3 MET at the end of the study. The experimental group showed similar values (p = 0.842) both at the baseline (1.7 ± 0.4 MET) and at the end of the study (1.7 ± 0.3 MET).Changes that may occur due to intrapersonal variation regarding physical activity can lead to errors in the interpretation of the results obtained . The meaTherefore, during the 84 days of treatment with the placebo or the HS-LC extract, the subjects maintained similar physical activity. This supports that the changes observed in subjects consuming the HS-LC extract were a consequence of the consumption and not a consequence of modified physical activity habits.The consumption of HS-LC extract significantly decreased the SBP compared to the control group, especially during the daily measurements. Habitually, the calyxes of HS have been used as a hypertension treatment . In factA study with 54 moderate hypertensive patients (similar to the present study) treated with sour HS tea revealed a noticeable reduction in blood pressure (systolic by 11.2% and diastolic by 10.7%). However, the length of the treatment (12 days) was not sufficient to draw firm conclusions . A studyNatural products, such as plant derivates are characterized by the presence of high content of polyphenols  with proScientific evidence has shown that certain plant-derived extracts, such as HS and LC, can modulate different metabolic pathways and activate the AMPK pathway favoring lipolysis and, therefore, fat loss , which cThe SBP was reduced, which may be explained by the vasodilator capacity of polyphenols . HoweverDue to their synergistic action, certain combinations of polyphenol metabolites exert greater antihypertensive effects compared with individually. Quercetin derivates, such as 3,4-dihydroxyphenylacetic acid (DHPA), 4-methylcatechol (4MC), and 3-(3-hydroxyphenyl) propionic acid (3HPPA), show different hypotensive effects if they act together . DespiteTherefore, the synergistic effect may be attributed to the different mechanisms of action of each metabolite . The mecH. sabdariffa has a compound that causes nitric oxide release from the vascular endothelium followed by kidney filtration increase, a mechanism that clears its diuretic effect on the blood pressure [In addition, research showed that pressure ,37. AnotIn addition, researchers reported that the polyphenols derived from HS-LC extract might be able to increase the adiponectin gene expression and PPAR-α, while reducing the NF-kB protein, which regulates the genes that mediate immune and inflammatory responses ,39. AdipFinally, the morning has also been associated with a greater risk for cardiovascular events compared with the rest of the day, due to fluctuations in the blood pressure flow and hemostatic changes ,41.The study consisted of a double-blind, randomized, placebo-controlled clinical trial, with two parallel branches to study depending on the extract consumed  and single-center. A total of 80 pre-hypertensive or type 1 hypertensive subjects of both sexes were included in the study after matching all the including criteria  and none of the exclusion criteria . After full disclosure of the implications and restrictions of the protocol, the subjects were required to sign an informed consent. The determination of blood pressure was done following the ESC/ESH criteria ,42. The ®) consisted of a capsule, including a mixture of 500 mg of HS-LC extracts (175 mg of HS and 325 mg of LC), leading to high quantities of verbascoside and anthocyanins, respectively [® was provided by Monteloeder S.L.  (Patent application number WO2019058011A1). The polyphenolic composition of the product was quantified and reported in previous studies [The product under study  and anthocyanins . Four main phenolic compounds were identified; two phenylpropanoids (verbascoside and isoverbascoside) and two anthocyanins (delphinidin-3-O-sambubioside and cyanidin-3-O-sambubioside). Regarding the phenylpropanoids, 15% corresponded to verbascoside  and 1% to isoverascoside (representing 6.25%). For the anthocyanins, 2.27% corresponded to delphinidin-3-O-sambubioside and 1.23% to cyanidin-3-O-sambubioside representing 65% and 35% of the total anthocyanin content, respectively. The length of the present study was 84 days, during which the subjects consumed the botanical mixture or the placebo daily depending on the previous randomization. Therefore, 40 subjects were distributed in the placebo group, and the other 40 subjects were allocated in the HS-LC group. Each subject that joined the study was assigned a code (generated by a number software generator (Epidat v4.1)) assigning them to one of the two study groups. Both the researchers and the participants themselves did not know the group they belonged to.As displayed in The blood pressure was determined using an oscillometer sphygmomanometer to determine the systolic and diastolic blood pressures, necessary for the inclusion criteria of the study . HoweverThe influence of the HS-LC extract on blood pressure was determined with an ABPM. The measurement of blood pressure was performed at baseline (prior to product consumption), at days 14, 56, and 84 from the beginning of the study. The ABPM method was done using a Holter Spacelabs Healthcare (holter) device . The cufThe volunteers were instructed to be quiet every time the cuff expanded. The holter was programmed to measure every hour for 24 h, and thus, after this time, the subjects returned the device. The values were displayed as the mean values of the measurements performed over 24 h, obtaining systolic and DBP determinations. Depending on the moment of the day, the daytime blood pressure and nighttime blood pressure were determined considering the morning hours and nighttime hours.Other parameters related to blood pressure were also reported as the MBP that measures systemic irrigation providing information on the effectiveness with which blood reaches from the heart to the organs. The MBP was obtained from the values obtained along 24 h and as an hourly measurement, resulting from the following formula: MBP = DP + ((SBP-DBP)/3) ,48.Additionally, due to the importance of exercise on cardiovascular system, physical activity can be partly-determinant of the possible observed effects during the study. Therefore, in order to prove if some strategies are effective for the treatment of obesity, physical exercise must be measured and regulated. For this purpose, the metabolic equivalent of the task (MET) was determined throughout the whole length of the study. That fact led to the determination of metabolic equivalents that relates the intensity of physical activity with the kilocalories consumed by subjects, in order to standardize the exercise throughout the study. MET values were determined in accordance with the “Compendium of Physical Activities” .Categorical variables were expressed as frequencies and percentages, and the continuous variables were expressed as the means and standard errors (SEs). The chi-square (χ2) test or the Fisher’s exact probability test was used for the comparison of categorical variables between the experimental and placebo groups. Quantitative variables were assessed using the analysis of variance (ANOVA) for repeated measures with two factors: time , as within-subject factors and intervention  as the between-subject factor with Bonferroni’s correction for pairwise comparisons. We considered 0.05 as the level of significance. Statistical analysis was carried out with the SPSS 21.0 software.The daily consumption of the HS-LC extract but not the placebo over 84 days was able to reduce the daytime parameters related to blood pressure. These parameters were established as leading indicators of hypertensive patients, and their reduction is key for the treatment of hypertension and related pathologies. Specifically, the supplementation with HS-LC extract reduced the SBP and MBP as measured using ABMP. The most remarkable results were observed in the daily measurements and particularly in the SBP, which showed a descent of 3%. The nocturnal measurements were less noticeable but revealed that the supplementation with the HS-LC extract was able to reduce all the parameters under study.


Periodontal disease has been associated with gestational complications and both conditions have a high prevalence in rural populations from developing regions. A cross-sectional study was carried out to explore the relationship between periodontal inflamed surface area (PISA), blood pressure (BP), and, serum uric acid levels (UA) in a group of rural North Chinese pregnant women in the third trimester of pregnancy.Three hundred and thirty-five rural women aged 20–34 years, with normal body mass index (BMI) were examined in a cross-sectional study during their third trimester of gestation. Exclusion criteria were history of pregnancy complications, multiple pregnancy, smoking habits, diabetes, hypertension or any known infectious disease. Socio-demographic variables, including age and socioeconomic status (SES), systolic blood pressure (SBP) and diastolic blood pressure (DBP) readings, serum UA levels, and PISA values were recorded. A structural equation model was implemented with two constructed latent variables including “Dem” (comprising of age and SES category to represent unobserved demographic variables) and, “BP” (comprising of SBP and DBP to account for measurement error and lack of multiple BP readings). The model accounted for co-variance of BP and UA, and implemented simultaneous regressions for BP and UA as outcomes, upon Dem and PISA values as exogenous variables.p < 0.001) and UA .The median PISA score was 1,081.7 (IQR = 835.01), reflecting high levels of periodontal inflammation in the sample. SEM showed a significant association of PISA with BP (estimate = 0.011, 95% CI = 0.009–0.012 Higher PISA values were significantly associated with higher blood pressure and uric acid levels among rural pregnant women in a cross-sectional sample from a center in North China after accounting for a latent demographic construct derived from age and SES. Hypertensive disorders of pregnancy affect more than 5% of women in China, with the highest incidence in North China . HypertePorphyromonas gingivalis with ensuing immuno-inflammatory sequelae  index was developed , represeThe present cross-sectional study aimed to explore the association of periodontal inflammatory burden assessed using PISA values with prenatal gestational blood pressure and serum uric acid levels in a sample of rural-living North Chinese women in the third trimester of pregnancy.https://cran.r-project.org/web/packages/epiR/index.html). Data for the estimated prevalence of gestational hypertension in North China (7.44%)   was usedA group of 335 eligible subjects in week 28 or beyond of pregnancy were recruited consecutively during their routine prenatal visit at The Heping Affiliated Hospital of Changzhi Medical College, Changzhi City, Shanxi Province, China, from January to April 2021. The inclusion criteria were; pregnant women aged between 18 and 34 years in the third trimester, Body Mass Index (BMI) of 18.5–24.9, presence of at least 20 teeth, with no history of periodontal or dental treatment in the past 1 year. Exclusion criteria were smoking or smoking habits, previous history of preterm delivery, previously diagnosed gestational hypertensive disorders, or other pregnancy complications, known systemic conditions or diseases such as chronic hypertension, diabetes, renal disease, polyhydramnios or known congenital malformation in fetus, infections during pregnancy such as bacterial vaginosis and chorioamnionitis, other bacterial or viral illnesses, or antibiotic use during pregnancy. All subjects provided written and oral informed consent before any study procedure. Oral health counseling was provided to all screened subjects by a dental professional irrespective of their study participation. Appropriate referral for dental or medical management was also provided when deemed necessary based on the clinical findings.Medical records were the source of demographic variables; age, socioeconomic level (SES), scored as high, medium or low, where to assess SES, monthly family income was noted and grouped into; low , moderate  or High  , and retAll data analysis was performed in the R statistical environment. Prior to modeling, variable distribution was examined for normality using the Shapiro Wilk test. Structural equation modeling (SEM) was applied using the “lavaan” package (v 0.5-9)  using a r > 0.6, p < 0.001, all) were noted between the three endogenous dependent variables DBP, SBP, and UA. Among the exogenous variables, age was significantly but weakly correlated with DBP , lower SES was weakly correlated with SBP , DBP  and UA . PISA score was moderately correlated with DBP  and strongly correlated with SBP  and UA . Very weak but significant correlations were noted for lower SES with Age  and PISA score . The SEM model outcomes are summarized in p < 0.001) and also significantly predicted by Dem . UA was also significantly predicted by PISA  and also significantly predicted by Dem .Descriptive data pertaining to the cross-sectional sample are presented in 2 has been found to indicate periodontitis at very high sensitivity and specificity . The patients/participants provided their written informed consent to participate in this study.SH conceptualized the research idea, carried out data analysis, and led the paper writing. FY and HJ performed the data analysis. WS and HM were responsible for study design and data collection. SL, JZ, and HX initiated the idea of the study, supervised the project, and edited the manuscript. All authors contributed to the article and approved the submitted version.simin.li.dentist@gmail.com).We appreciate the funding by the Science Research Cultivation Program of Stomatological Hospital, Southern Medical University (No. PY2020004), which was provided to support the postdoc research of Dr.rer.med., SL ( 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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Synchrotron deep ultraviolet imaging highlighting pathological calcium oxalate detection in kidney is presented. n = 11) and secondary hyperoxaluria , seven samples from PHO patients who received combined kidney and liver transplants, and 16 controls. For all oxalocalcic hydrates samples, a fluorescence signal is detected at 420 nm. These spectra were used to identify standard oxalocalcic crystals in patients with PHO or SHO. They also revealed micrometric crystallites as well as non-aggregated oxalate accumulation in tubular cells. A nine-points histological score was established for the diagnosis of renal oxalosis with 100% specificity (76–100) and a 73% sensitivity (43–90). Oxalate tubular accumulation and higher histological score were correlated to lower estimated glomerular filtration rate and higher urinary oxalate over creatinine ratio.Renal oxalosis is a rare cause of renal failure whose diagnosis can be challenging. Synchrotron deep ultraviolet (UV) fluorescence was assayed to improve oxalosis detection on kidney biopsies spatial resolution and sensitivity compared with the Fourier transform infrared microspectroscopy gold standard. The fluorescence spectrum of synthetic mono-, di- and tri-hydrated calcium oxalate was investigated using a microspectrometer coupled to the synchrotron UV beamline DISCO, Synchrotron SOLEIL, France. The obtained spectra were used to detect oxalocalcic crystals in a case control study of 42 human kidney biopsies including 19 renal oxalosis due to primary (PHO,  PHO diagnosis was either confirmed by genetic analysis and/or decreased alanine:glyoxylate aminotransferase activity on liver biopsy. SHO diagnosis was proposed when renal oxalosis was diagnosed in the context of either ethylene glycol intoxication or digestive malabsorption and in the absence of familiar evidence orienting towards PHO. Delay between biopsy and combined liver/kidney transplantation is specified in Table S1. As stipulated in Table S1, kidney biopsies used as control came from our standard clinical activity and included various profiles of normal and pathological native or transplanted kidneys.et al., 1999et al., 2009The estimated glomerular filtration rate (eGFR) was estimated using the closest available serum creatinine (within one month) to the biopsy, and the modification diet in renal disease formula for adults and the Schwartz formula for children  for 3 h. Dehydration was performed in a carousel (Microm France STP MM 120) before paraffin (Leica/ParaplastSurgipath) inclusion. Three-micrometre-thick slices were spread on low-e microscope slides . A first drying was operated at 56°C for two hours followed by two successives 15 min baths in xylene (Carlo Erba) to remove paraffin. Synthetic CaOx powders  were deposited on quartz coverslips .2.3.et al., 2009DUV fluorescence microspectroscopy was performed on a UV microspectrometer coupled to the monochromated synchrotron beam at the SOLEIL DISCO beamline  equipped with a polarizing system and a compensatory lens.−1, each spectrum being acquired after 64 accumulations at 8 cm−1 resolution. Images used for oxalosis diagnosis were acquired with a 6.25 µm spatial resolution, the maximal resolution allowed by refraction within this wavelength regimen . Spectra were collected in reflection mode between 4000 and 700 cmFIJI  images were blindly analysed by two independent readers. Biopsies were considered positive for macrocrystals if one crystal >10 µm was seen. Microcrystal presence was estimated on a semiquantitative four-point scale .2.4.GraphPad Prism version 8.00 for Windows .All statistics analysis was performed using Sensitivity and specificity are presented with a 95% confidence interval. The statistical significance of contingency tables was evaluated using two-sided Fisher’s exact test. As the percentage of positive tubular sections does not seem to follow a normal distribution, statistical significance was evaluated using the Kruskal-Wallis test followed by comparison of the mean rank using Dunn’s multiple comparisons test. To avoid pseudoreplication and artificial statistical power, tubular fluorescence ratio were compared using nested t-test. Medians are presented with 25% and 75% percentile.Correlations between the oxaluria, eGFR and WFUV results were analysed using linear regression. 95% confidence interval of the slope is represented by dashed lines.Uric acid and calcium oxalate mono- and di-hydrate kidney stone fluorescence spectra were treated using lowess spline fitting using 20 points in the smoothing window.3.3.1.−1 massif typical of oxalate vibrations  and 327–353 nm (attributed to aromatic amino acid) , one patient with suspected autosomal dominant tubulointerstitial kidney disease  . They were almost always observed in tubular lumen or in tubular cells. We performed scanning electron microscope (SEM) analysis to confirm that the large positive formations matched big stone-like formations located in severely injured tubular sections . They were frequently found in the tubular lumen (24/26) and in the cytoplasm of tubular cells (21/26), but they could also be observed in the interstitium (18/26), small vessels (2/26) and glomeruli (5/26). On higher magnification, some of these microdeposits were shown to be intracellular  but no control biopsy was scored above 1. A 2 or 3 microcrystallite density score was granted in 8/11 (73%) PHO, 4/8 (50%) SHO and 4/7 (57%) KLTPHO biopsies , 5/8 SHO [median of positive tubular section 10% (IQ25-75: 0–68)], and 4/7 KLTPHO [median of positive tubular section 5% (IQ25-75: 0–75)] biopsies. The percentage of involved tubules ranged from 5 to 100%  compared with patients with high scores (5–9)   [Fig. 7Fig. S2(B)].Patients presenting the lowest nine-points histological score, Given the low number of patients and scarce data, we could not perform multivariate analysis and rule out confounding bias.p < 0.05] [Fig. 7p < 0.0001) [Fig. 7We could only retrieve urinary oxalate/creatinine ratios from nine oxalosis patients. Patients with high nine-points histological score (5–9) had higher urinary oxalate creatinine ratio [median 0.25 mmol/mmol IQ25-75 (0.18–0.26)] than patients with lower score [median 0.12 mmol/mmol IQ25-75 (0.11–0.13), 4.In this study, we show that oxalate fluorescence emission around 420 nm after 275 nm synchrotron DUV excitation can be used to identify oxalate in kidney biopsies. This method allows detection of the expected macrocrystals but also numerous tubular and extratubular microcrystals in renal oxalosis patients. Furthermore, we identified for the first-time oxalate accumulation in the cytoplasm of tubular cells. These findings could be combined in a nine-points histological score.et al., 2013Standard microscopy using chemical or immunological staining of kidney biopsy has led to a better understanding and classification of kidney diseases . Large areas of the biopsy can be investigated. Unlike mass spectrometry, it is not destructive and can be conveniently coupled with other standard microscopic techniques . This diffuse signal was histologically very different. It covered all tissue regardless of underlying kidney architecture suggesting diffuse impregnation. The fluorescence ratio was significantly lower than in any other biopsy suggesting excitation of a different fluorophore. Biopsies were not processed the same day. They were sent to Tenon hospital from various institutions – therefore pre-analytical flaw is not likely. Interestingly, all these patients shared urate metabolism abnormalities, and uric acid fluorescence spectra seem to potentially overlap oxalate fluorescence spectra  which calls for a dedicated study. Identification of these biopsies was in fact quite easy to the expert eye although it raises concern regarding signal specificity.Four biopsies were excluded before analysis due to diffuse positive signal suggestive of non-oxalate related fluorescence .The large tubular deposits evocative of CaOx macrocrystals detected by subtracting the 327–353 nm channel signal from the 412–438 nm ones correlate with usual CaOx crystals in size, number, and localization. As clinically expected, they were more common in PHO than in SHO biopsies and were inconstant in KLTPHO samples. Other tested crystals  were not underlined by this fluorescence signal. There were no macrocrystals identified, nor >1 microcrystallite scoring in those patients . It also correlated with the estimated glomerular filtration rate (eGFR) and urinary oxalate over creatinine ratio whereas there were no statistical links between these measurements and eGFR in control patients.Given the low number of patients we cannot exclude confounding bias such as variations due to accumulation of other fluorescent compounds such as uric acid due to renal dysfunction. However, no tubular accumulation was spotted in stage 4 chronic kidney diseases (CKD4) control patients . One of the two tubular diffuse signal positive control biopsies is patient 34 in which subsequent analysis found a FTIR-confirmed CaOx microcrystal suggesting potential oxalate metabolism disturbance.Altogether these elements strongly support that the observed fluorescence is indeed attributable to oxalate.et al., 2020et al., 2005et al., 2009et al., 2019The ability to ‘see’ intracellular oxalate accumulation could lead to major progress in the understanding of the oxalate mediated kidney injury mechanism. In our experience, there is often a poor correlation between histological findings  and severe renal failure in renal oxalosis. Oxalate identification on a kidney allograft biopsy is associated with poorer renal survival (Palsson et al., 2014et al., 2014While it is established that oxalate calcium crystals are noxious for tubular epithelia (Thamilselvan & Khan, 1998Tubular accumulation was often heterogeneous from one tubular section to another within the same biopsy. Determinants of this heterogeneity and correlation with markers of tubular injury would be of great interest.et al., 2018et al., 2008et al., 2020Standard renal histology is not always sufficient to affirm the diagnosis of renal oxalosis. High urinary oxalate, genetic testing, enteric oxalate hyperabsorption enabling underlying condition and exclusion of another cause of tubulointerstitial disease are almost as important, if not more so, to formally establish a proper diagnosis (Lumlertgul et al., 2020et al., 2019et al., 2020et al., 2019et al., 2017et al., 2020et al., 2020et al., 2020Major progress has been made towards potential treatment of hyperoxaluric patients (Burns The main limitation of our study is the relatively low number of biopsies that we could analyse and incomplete clinical and biological information, due the fact that Tenon Hospital is a tertiary reference centre with late referral of patients. Since renal oxalosis is a rare disease, we could not test the diagnostic performance of our new technique in a naive population and could not determine positive and negative predictive values. A prospective larger study with better patient phenotyping is needed to support our observations.Owing to its unique potential to identify crystallized and non-crystallized oxalate in kidney biopsies, synchrotron DUV fluorescence could not only help improve renal oxalosis diagnosis in litigious cases but open new paths of research towards the understanding of oxalate participation in kidney diseases and assess incoming hyperoxaluria treatment efficiency.10.1107/S1600577521011371/yn5078sup1.pdfFigure S1-S3 and table of patients with details. DOI:


No significant differences in plasma A and V AA concentrations nor in A-V differences were found between patients with mild kidney damage  and patients with moderate-severe kidney damage . Several plasma arterial AAs correlated with hemodynamic variables, but not with GFR. The study showed that patients with CRS 2 had very low concentrations of circulating AAs, independent of the degree of GFR damage.The goal of this retrospective study was to document any alterations in plasma amino acids (AAs) in subjects with cardiorenal syndrome type 2 (CRS 2). We analyzed data from sixteen patients with CRS 2 and eight healthy subjects , whose plasma arterial (A) and venous (V) AA concentrations had been measured. Compared to C, the group of CRS 2 patients showed significant reductions by more than 90% in A ( The complication of chronic heart failure (CHF) with chronic kidney disease (CKD) identifies the cardiorenal syndrome (CRS) which is classified as CRS type 2 (CRS 2) ,2. The pWe hypothesized that the development of renal dysfunction in patients with CHF may amplify the alterations of amino acid (AA)/protein metabolism, as reflected by plasma AA concentrations, already documented in CHF alone  and in pThe presence of an abnormal plasma amino acid (PAA) profile in patients with CRS 2 may be clinically important given that it has the potential to impair the metabolic activities of all body districts, including the heart and the kidney themselves, thus acting as additive damage. Moreover, abnormal PAAs may lead the physician to two therapeutic dilemmas: (a) when patients are stable, how could their dietary protein intake be reduced in relation to glomerular filtration rate (GFR) damage  and, at Using the data from a previous study where we had analyzed arterial and venous PAA profile in CHF patients , we perfWe re-analyzed the data from chronic heart failure (CHF) patients who had participated in a previous study on Plasma Amino Acid Abnormalities . These p2) for the previous three months, absence of hypoglycemic agents, normal liver function , absence of kidney dysfunction preceding the diagnosis of CHF, absence of primary endocrine disturbances.The diagnosis of CRS 2 was established following the indication of the American Heart Association Statement . In addiFollowing the routine protocol of the Institute, 2D-echocardiography and cardiopulmonary exercise testing was performed on CHF patients, and their venous N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) concentrations were measured.2) [2 (moderate-severe CKD: MS-CKD) (range 59–26) and 5 (31.2%) had eGFR ≥ 60 mL/min/1.73 m2 (range 60–88) (mild reduction: M-CKD). The patient characteristics have been reported in In the selected patients, CKD was diagnosed after transforming serum creatinine concentrations into GFR  (mL/min/1.73 m2) . The eGF2) . AccordiIn the patients, the PAAs had been determined as described elsewhere , and expWe used arterial (A) and venous (V) concentrations to calculate the AA (A-V) differences. A positive value indicated net muscle AA uptake ; a negative value indicated a net muscle AA release ; no positive–no negative (A-V) value indicated no AA net uptake, no net release .N = 8, 6 of whom males). The controls were selected for similar BMI (27.1 ± 2.2 kg/m2) and age (51 ± 9 years) and for absence of discretionary physical activity. The healthy subjects reported no significant past medical history. Examination of the control subjects confirmed that they were in good health. In healthy C, in the current study, we also considered the AA ornithine, which had not been considered in the previous study [PAA concentrations were determined in a group of healthy subjects , hypothesis testing was based on non-parametric statistics. Descriptive statistics for categorical variables were reported as N (percent frequency). Between-group comparisons were carried out by the Mann–Whitney U-test (two groups), or by the Kruskal–Wallis test (three groups) and by the Chi-square test for continuous and categorical variables, respectively. When the Kruskal–Wallis test was significant, post hoc analysis was carried out (Dunn–Sidak adjustment). The association between couples of variables was assessed by the Spearman’s correlation coefficient.p-value < 0.05 was considered statistically significant. All analyses were carried out using the SAS/STAT statistical package, release 9.4 .A p = 0.027) in CRS 2 than in C. Moreover, in CRS 2, significantly lower arterial and venous essential amino acid (EAA) and branched chain amino acid (BCAA) concentrations were found , whereas their muscle releases  had lower concentrations of arterial  patients had lower arterial . Several plasma AAs correlated with LVEF and other hemodynamic variables, but not with eGFR  and glutamic acid, and cysteine (NYHA III) were low . NotablyThe study results clearly indicate that it is clinically and metabolically important in every patient with CHF to convert the serum creatinine levels into eGFR.The non-dependence of AA alterations on the degree of GFR reduction clearly indicates that tubular dysfunction contributes to altered PAA concentrations. Under physiological conditions, proximal tubule cells reabsorb 80% of the filtrated AAs . In CHF,The complex interplay of several factors shared by CHF and CKD likely provides an explanation of the results of this study. These factors include neurohormonal activation , consistThe main contributions of these factors to abnormal PAAs in CRS will be discussed separately for arterial AA concentrations and A-V differences.AA concentrations in arterial plasma reflect body protein metabolism better than venous plasma .Under physiological conditions, arterial AA concentrations depend on both dietary protein intake and body protein metabolism .Due to the lack of information about patients’ nutritional intakes, the role of nutrition in deteriorating PAAs cannot be delineated. However, it would be reasonable to assume that even if the patients’ nutrition had been normal, it would have been inadequate to meet the body’s nitrogen requirements, as inferred by the reduction in circulating essential AAs (EAAs): substances which must be provided by exogenous sources.The combination of hemodynamic alterations, body AA overconsumption and intracellular metabolic acidosis (not determined in the study patients) may be responsible for the altered PAAs.Both in CHF and CKD, volume overload leads to intestinal wall congestion ,41, thus2) is associated with left ventricular remodeling [The heart, the lungs, the kidney and skeletal muscle are body districts with high AA consumption. In heart failure, there is AA overconsumption to sustain myocardium remodeling, a process requiring a high rate of protein synthesis and oxidative metabolism ,46,47. Rmodeling  and on tmodeling .In CHF, there is also AA overconsumption in the lungs , in partMetabolic acidosis lowers PAA concentrations by increasing renal AA uptake and, at the same time, suppressing renal proteolysis . MeasureSkeletal muscle AA utilization, particularly in mitochondria, occurs both in CHF and CKD as documented in bioptic specimens from the quadriceps muscle of CHF  and CKD At first glance, low arterial AAs could be due to low venous AA concentrations; however, this is not a major mechanism as the patients, unlike controls, had low arterial/venous AA ratios, indicating that muscle release of AAs, although in excess, was not enough to balance AA uptake by extramuscular body districts.In summary, the study suggests that in CRS 2 patients, the body’s AA requirements are greater than the amount of AAs provided by the skeletal muscle, which is the main store of AAs in the body.The net muscle AA releases, in particular phenylalanine, indirectly indicate the presence of muscle protein hypercatabolism , whose pInflammation is a potent condition causing muscle AA depletion. The overproduction of proinflammatory cytokines increases muscle protein degradation, inhibits both muscle protein synthesis and repair ,61,62,63Both in CHF and CKD, one source of cytokine production is venous hypertension .In CKD, metabolic acidosis leads to muscle AA overconsumption by accelerating protein degradation .Insulin and growth hormone (GH) resistances reduce anabolic activities both in CHF  and CKD The study confirms the positive correlations existing between most PAAs and cardiac function . On the Regarding the heart/kidney relationship, the positive association between renal filtration rate and arterial blood pressure (both systolic and diastolic pressures) indicates that an important determinant of GFR is the peripheral arterial pressure and consequently the renal perfusion pressure  and not The lack of information about patient nutritional intake does not allow us to understand the contribution of ingested salt and water intakes to the hyponatremia found in MS-CKD. Given that sodium is the most important osmotic solute of extracellular fluid, it would be reasonable to assume that serum osmolarity was low in MS-CKD, and low concentrations of circulating AAs likely contributed to reduce osmolarity. Notably, increased blood glucose and urea may help to maintain renal perfusion pressure, mitigate sodium-induced hypoosmolality, and limit the extravasation of intravascular hypotonic fluid towards the intracellular and interstitial spaces.The higher serum albumin in MS-CKD could be due to higher protein-calorie intakes  and/or aThe similar PAA alterations in M-CKD and MS-CKD indicate that the renal contribution to altered AA/protein metabolism starts in the early stages of renal damage in subjects with CHF.In CRS 2 patients, the alterations of AA/protein metabolism may potentially contribute to and accentuate the metabolic and functional alterations of several body districts .The hypoaminoacidemia in hyperazotemic CRS 2 patients raises the question of whether it is appropriate to prescribe a hypoproteic diet before improving circulating AAs. The authors’ opinion is that a hypoproteic diet should be prescribed in association with EAA supplementation for the following reasons. Firstly, a hypoproteic diet alone may further impair circulating AAs. Secondly, a bolus of oral 8 g EAAs has shown to increase EAA plasma concentrations in healthy subjects . ChronicIt would be prudent to improve plasma AA concentrations when the patients are clinically stable in order to limit metabolic damage following periods of acute events requiring continuous renal replacement therapy or during hemodynamic instability .This study suggests the importance of calculating nutritional intakes of patients with CHF as soon as CHF is first diagnosed, given the high prevalence of the development of renal damage.The study has several limitations that should be addressed by future research. The results of the study should be confirmed by a prospective investigation with a larger patient population.Patients’ nutritional intakes and body tissue composition were not available. The knowledge of nutritional intakes would have allowed us to better understand the contribution of diet to circulating AAs. Body composition analysis would have allowed us to diagnose a state of sarcopenia or cachexia. However, a depletion of skeletal muscle mass in the study patients may be likely, given their muscle hypercatabolism .A population of subjects with CHF alone was not considered in this study. For comparison aims, we referred to the abnormal plasma AA profile of subjects with CHF described in a previous investigation . SimilarRenal biomarkers  includinAnother limitation of the study is the lack of information about urine AA losses. This information would have strengthened the discussion. A future prospective study will address the balance between urine and plasma amino acid levels.The knowledge of patients’ acid-base state would have allowed us to better understand its contribution to muscle net AA releases. In addition, the determination of urinary AA losses would have suggested the role played by proximal tubular dysfunction in contributing to altered PAAs.The study shows that patients with cardiorenal syndrome type 2 had very low concentrations of circulating AAs, the rates of which were independent of the degree of GFR reduction.


Conclusion: This study found a significant positive association between magnesium and systolic blood pressure, but not diastolic blood pressure, among patients with hypertensive crises. This positive association of serum magnesium with systolic blood pressure was maintained after adjusting for covariates. This study’s findings suggest a potential role of magnesium in blood pressure among patients with hypertensive crises.The role of magnesium in blood pressure has been studied among hypertensive patients; however, there is a dearth of studies exploring the role of magnesium in hypertensive crises. The primary objective of this study was to evaluate the relationship between serum magnesium and blood pressure in patients with hypertensive crises. This was a single-center, retrospective, chart review, cross-sectional study of patients with hypertensive crises. Patients were included if they were eighteen years of age or older, with an international classification disease ninth revision (ICD-9) code of 401.9 (hypertensive crises: emergency or urgency) and a documented magnesium level on their electronic medical record. The primary outcome of the study was the correlation between serum magnesium and blood pressure (systolic blood pressure and diastolic blood pressure) in patients with hypertensive crises. Two hundred and ninety-three patients were included in the study. The primary outcome result showed that serum magnesium was positively correlated with systolic blood pressure (r = 0.143,  Hypertension is a condition characterized by elevation in the systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) ,2. CliniMagnesium is the second most abundant intracellular cation after potassium and the fourth most abundant cation in the body ,11,12. IMultiple clinical trials/reviews have shown, albeit inconsistently, that magnesium deficiency (serum and/or tissue) exist to some extent in hypertensive subjects, with decreased magnesium levels linked to undesirable effects on blood pressure ,17,18,19Multiple observational clinical studies and a meta-analysis have evaluated the relationship between serum magnesium and blood pressure in patients with and without hypertension ,26,27,28The primary objective of this study was to evaluate the relationship between serum magnesium and blood pressure (SBP and DBP) in hypertensive crises. The secondary objectives were to evaluate the association between serum calcium, corrected calcium, and serum potassium on blood pressure in patients with hypertensive crises, and to determine the influence of covariates on the relationship between serum magnesium and blood pressure in patients with hypertensive crises. Given that hypertensive crisis is a state of dysregulated high blood pressure, it is vital to study the role that factors such as serum magnesium play in the etiology of hypertensive crises. Data from these studies can be hypothesis-generating and provide evidence for studying potential innovative therapies to manage hypertensive crises, such as serum magnesium-modifying therapies.This was a single-center, retrospective, chart review, cross-sectional study conducted at the Interim Louisiana State University Hospital (ILH)—New Orleans, Louisiana. The study data were derived from patients who were admitted to ILH with hypertensive crises during a 2-year period from July 2012 to July 2014. This study was approved by the ILH Research Review Committee (RRC) and Xavier University of Louisiana Institutional Review Board (IRB).Patients eighteen years of age or older with an international classification disease ninth revision (ICD-9) code of 401.9 (hypertensive crises: emergency or urgency) and a documented serum magnesium level on their electronic medical record  were included in the study. Hypertensive crisis was defined as systolic blood pressure (SBP) greater than 180 mmHg and/or diastolic blood pressure (DBP) greater than 120 mmHg ,4. PatiePatients were excluded if they had conditions interfering with serum magnesium levels, such as chronic kidney disease (CKD) stages 4 and 5, end-stage renal disease (ESRD), hepatic cirrhosis, pheochromocytoma, chronic diarrhea, and hyperaldosteronism. Additionally, patients who received vasopressors or inotropes  during the hospital encounter were excluded from the study.® systems detection method and the Beckman DXC 600 instrument were used to measure the serum magnesium, serum calcium, and serum potassium levels. Additionally, maximum and minimum values of SBP and DBP were recorded within 24 h of the first recorded hypertensive crises’ blood pressure. All SBP and DBP measurements were taken at intervals specified by the medical unit/floor whereat each patient was admitted. Corrected calcium (mg/dL) was calculated using the formula: corrected calcium = patient’s measured serum calcium in mg/dL + ). The corrected calcium was only calculated for patients whose serum albumin was less than 4 gm/dL. Additional independent variables collected included home and hospital use of blood pressure medications  grouped in the electronic health record), at home use of proton pump inhibitors, home use of oral magnesium, hospital use of intravenous magnesium, and albumin levels (gm/dL).All patient data were obtained from ILH’s electronic medical record. The following demographic data were collected: age, sex, race, body mass index (BMI), and history of diabetes mellitus. The key variables obtained for our primary and secondary outcome analyses include serum magnesium (mg/dL), serum calcium (mg/dL), serum potassium (mEq/L), SBP (mmHg), and DBP (mmHg). These variables were obtained at a time closest to that at which blood pressure was measured in the first documented hypertensive crises during the hospital encounter, denoted as “at crises”. The SynchronThe primary outcome of the study was the correlation between serum magnesium and blood pressure (SBP and DBP) in patients with hypertensive crises. The secondary outcomes were the associations of serum calcium, corrected calcium, and serum potassium with blood pressure in patients with hypertensive crises, and the relationship between serum magnesium and blood pressure when adjusting for covariates . We selected these covariates to control for their potential confounding effects on the results of our study, since the covariates were variables that could potentially affect SBP, DBP, and serum electrolyte levels. An additional exploratory outcome was the correlation of serum magnesium, serum calcium, corrected calcium, and serum potassium with the two independent variables SBP and DBP, measured at different time points.2 (coefficient of determination) for the linear regression between serum magnesium and either SBP or DBP would range between of 0.06 and 0.56. Our power analysis revealed that the target sample size for this study will range between 140 and 180 subjects, to give us a power of 0.80 at a significance level of 5%.We performed a power analysis (based on findings from prior studies) on our key variables for the primary outcome of the study  ,29,31. B2) between serum magnesium, serum calcium, corrected calcium, and serum potassium in relation to blood pressure (SBP and DBP). A linear model analysis was conducted to evaluate the association between serum magnesium (and other electrolytes) and blood pressure (SBP and DBP) at the time of hypertensive crises while adjusting for covariates. Statistical analyses were performed using SAS® version 9.4. A p-value of less than 0.05 was considered statistically significant in the two-tailed test.Descriptive statistical analysis was performed on demographic characteristics. Measures of central tendency were obtained for continuous measures and frequency distribution for categorical measures. Simple linear regression was conducted to assess the correlation (r) and coefficient of determination  with SBP at crises, but not DBP at crises. The coefficient of determination (R2) reveals that 2% of the variability in SBP at crises can be attributed to serum magnesium. Besides serum magnesium, serum calcium was the only additional electrolyte significantly correlated with SBP at crises. Serum calcium was positively correlated with SBP at crises, with 3.5% of the variability in SBP at crises attributable to serum calcium. When evaluating DBP at crises, no electrolyte was significantly correlated with DBP at crises; however, serum potassium showed a slight trend towards a negative correlation with DBP at crises.The primary outcome result is presented in p-value = 0.017). Although a significant association was found with serum magnesium and SBP at crises after adjusting for covariates, no significant association was found with serum magnesium and DBP at crises after adjusting for covariates in the model.Variables that were significantly associated with SBP at the time of hypertensive crises was assessed using a linear model (adjusted for covariates), and the results are displayed on This study contributes much new knowledge on the role of magnesium in patients with hypertensive crises—a population where the role of magnesium has been sparsely evaluated. The primary objective of our study was to evaluate the relationship between magnesium and blood pressure (SBP and DBP) in patients with hypertensive crises.N = 5 out of 7, 71.4%) showed a negative relationship between serum magnesium and SBP [N = 4 out of 7, 57%) have shown a non-significant relationship, which is consistent with our study findings [Using correlation  and line and SBP ,19,25,28 and SBP , while o and SBP . With refindings ,17,22,28findings ,19,25. Ofindings . It is rfindings ,19,25,28N = 207) versus serum calcium (N = 293) may have led to the divergent direction of the relationship. Two hundred and seven patients had corrected calcium values because corrected calcium was only calculated for patients who had serum albumin levels less than 4 gm/dL. In the exploratory results, we found that corrected calcium was positively associated with both minimum SBP and DBP within 24 h of hypertensive crises. All the data with corrected calcium should be interpreted cautiously, given that we did not include 86 missing data points from among patients who did not have serum albumin levels less than 4 gm/dL. Potassium was also not significantly correlated with either SBP or DBP at crises, although there was a trend towards a negative correlation between potassium and DBP at crises. This finding is inconsistent with prior studies, which have predominantly shown a negative correlation between serum potassium and both SBP and DBP [When assessing the relationship between the additional electrolytes reviewed  and blood pressure, we observed that serum calcium was significantly positive correlated with SBP at crises, but not DBP at crises. After adjusting for covariates , we foun and DBP ,45,46,47um N = 29 may have and DBP ,20,21,22 and DBP ,48. It iThe strengths of our study include our use of statistical tests that explored associations between variables, the pilot nature of our study, and the attainment of our study’s desired sample size. We performed regression analysis to examine the association of magnesium and other electrolytes with blood pressure in hypertensive crises. The findings from the regression analysis provide us with useful information on the relationship between electrolytes and variables. This study is also a pilot/exploratory study, and is thus a hypothesis-generating study and can provide population estimates to help determine the appropriate sample size to study the effect of magnesium on hypertensive crises in future studies. Lastly, our study reached and exceeded our desired sample size, which decreased the probability of type II errors and improved the probability of detecting significant differences that may exist in the true population of patients from which our sample population was obtained.Several limitations impacting internal and external validity apply to our study. First, our study was a single-center study, and this limits the generalizability of our study to patients across institutions. Thus, the findings from this single-center study should be extrapolated cautiously to individual patients and patient populations with hypertensive crises. This study was a retrospective study, so variables available from the electronic medical record were not collected uniformly at specific times, as would be the case in a prospective study. Given the retrospective and non-randomized design of our study, notable variables were not collected or accounted for, which may confound our findings. Some of the potential confounding variables not accounted for include, but are not limited to, the use of calcium supplements, use of vitamin D, use of magnesium-containing antacids, use of diuretics, and renal function markers (SCr or estimated glomerular filtration rate). Our study was also a non-interventional/non-experimental study, which impacts the internal validity and limits our study’s ability to assess causation. Our study was not a randomized study, and confounding variables may have impacted our results. Sodium’s relationship with blood pressure was not assessed in our study, which is a limitation, given that an interaction has been found between magnesium and other electrolytes  in blood pressure reduction ,21. LastThis study found a significant positive association between magnesium and systolic blood pressure, but not diastolic blood pressure, among patients with hypertensive crises. This positive association of serum magnesium with systolic blood pressure was maintained after adjusting for covariates. This study’s findings suggest a potential role of magnesium in blood pressure among patients with hypertensive crises. However, when considering the limitations and strengths of our study, we do not recommend changing current clinical practice regarding the monitoring of magnesium in patients with hypertensive crises. We recommend monitoring magnesium levels based on clinical necessity. We recommend experimental studies with larger samples be conducted to evaluate the role of serum magnesium and/or serum magnesium-modifying therapies in controlling or regulating blood pressure in patients with hypertensive crises. Future studies should also evaluate the role of serum calcium-modifying therapies in blood pressure control in patients with hypertensive crises.


Is there an interaction between baseline diastolic blood pressure and intensification of blood pressure–lowering therapy for survival and cardiovascular outcomes?In this cohort study of 14 094 patients from 2 large randomized clinical trials, baseline DBP of 80 and 90 mm Hg were associated with significant reductions in the risk of a composite cardiovascular end point that included cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke. The same was not true for the outcome of all-cause death.The findings of this study suggest that further work is needed to determine whether blood-pressure lowering therapy should be intensified in patients whose diastolic blood pressure is low. This cohort study evaluates whether there is an association of baseline diastolic blood pressure (DBP) and intensification of blood pressure–lowering therapy with all-cause death and cardiovascular events. Low diastolic blood pressure (DBP) has been found to be associated with increased adverse cardiovascular events; however, it is unknown whether intensifying blood pressure therapy in patients with an already low DBP to achieve a lower systolic blood pressure (SBP) target is safe or effective.To evaluate whether there is an association of baseline DBP and intensification of blood pressure–lowering therapy with the outcomes of all-cause death and cardiovascular events.This cohort study analyzed patients who were randomized to intensive or standard BP control in the Action to Control Cardiovascular Risk in Diabetes–Blood Pressure (ACCORD-BP) trial and Systolic Blood Pressure Intervention Trial (SPRINT). Data were collected from September 1999 to June 2009 (ACCORD-BP) and from October 2010 to August 2015 (SPRINT). Data were analyzed from December 2020 to June 2021.Baseline DBP as a continuous variable.All-cause death and a composite cardiovascular end point (CVE) that included cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke.P = .02) and the composite CVE  observed among all participants. Findings for the interaction between baseline DBP and treatment group assignment for all cause death did not reach statistical significance. For intensive vs standard therapy, the HR of death for a baseline DBP of 50 mm Hg was 1.80  and that for a baseline DBP of 80 mm Hg was 0.77 . Overall, there was no interaction found between baseline DBP and treatment group assignment for the composite CVE. Over the range of baseline DBP values, significant reductions in the composite CVE for patients assigned to intensive vs standard therapy were found for baseline DBP values of 80 mm Hg  and 90 mm Hg .A total of 14 094 patients  were included in this analysis. There were significant nonlinear associations between baseline DBP and all-cause death (eg, baseline DBP 50 vs 80 mm Hg: hazard ratio [HR], 1.48; 95% CI, 1.06-2.08; This pooled cohort study found no evidence of a significant interaction between baseline DBP and treatment intensity for all-cause death or for a composite CVE. These results are hypothesis generating and merit further study. However, this ignores observational data showing a J-shaped curve for diastolic blood pressure (DBP), where adverse cardiovascular events and mortality increase as DBP decreases below critical levels (<60 mm Hg).4 It has been postulated that pharmacological treatment to achieve a lower SBP target in persons whose DBP is already low may worsen patient outcomes. To test this hypothesis, we performed a pooled cohort analysis combining participants from SPRINT1 with those of the similarly designed Action to Control Cardiovascular Risk in Diabetes–Blood Pressure (ACCORD-BP) trial5 to assess whether there is an association between baseline DBP and treatment intensity on patient outcomes.Since the publication of the landmark Systolic Blood Pressure Intervention Trial (SPRINT),STROBE) reporting guideline. The study met all criteria for exemption by the institutional review board at Penn State College of Medicine. Informed consent was waived because data were deidentified.This cohort study was reported in adherence with the Strengthening the Reporting of Observational Studies in Epidemiology  or standard  BP control and followed for a median of 4.7 years. SPRINT randomized 9361 patients without diabetes with elevated cardiovascular risk to either intensive or standard BP control, using the same targets as ACCORD-BP, and followed them for a median of 3.3 years.The designs and outcomes of ACCORD-BPdf. The level of significance was set to a 2-sided P < .05, and the hazard ratios (HRs) and corresponding 95% CIs were reported from these models. We also showed the association in graphical form using the log hazard scale.We used a Cox proportional hazards model to test the association between baseline DBP as a continuous variable and the outcomes of interest. These outcomes were all-cause mortality and a composite cardiovascular end point (CVE) that included cardiovascular death, nonfatal myocardial infarction (MI), or nonfatal stroke. This composite CVE was chosen because it was the primary composite end point of the ACCORD-BP trial and because each of these individual end points was included in the composite primary end point of the SPRINT trial. The completed analysis included the following variables measured at baseline: DBP, age, sex, history of MI, history of congestive heart failure, history of peripheral vascular disease, history of stroke, estimated glomerular filtration rate at baseline, treatment group (intensive vs nonintensive), stratification factor for study (SPRINT vs ACCORD-BP), and stratification factor for site. To allow for nonlinear associations with outcomes, we used a restricted cubic spline with 4 df. The level of significance was set to P < .05, and the HRs and corresponding 95% CIs were reported from these models. We also showed the associations in graphical form using the log hazard scale.A separate Cox proportional hazards regression model was used to test for an interaction between baseline DBP as a continuous variable and treatment group assignment. The outcomes were all-cause mortality and the aforementioned composite CVE. The completed analysis included all variables used in the model described already but included the additional variable of interaction between treatment group and DBP. To allow for nonlinear associations with outcomes, we used a restricted cubic spline with 4 For representative purposes, baseline characteristics are presented for all patients stratified by baseline DBP less than 60 mm Hg and greater than or equal to 60 mm Hg. The change in SBP and DBP values from baseline to 12 months is also presented for these DBP subgroups based on treatment group assignment (intensive vs nonintensive).Analyses were generated using SAS STAT software version 9.4 for Windows (SAS Institute). Data were analyzed from December 2020 to June 2021.P = .02; baseline DBP 110 vs 80 mm Hg: HR, 2.15; 95% CI, 1.30-3.56; P = .003) and the composite CVE . The resulting estimated associations were U-shaped , with 4733 (33.6%) coming from ACCORD and 9361 (66.4%) coming from SPRINT. The overall number of patients who died was 672 (4.8%), and the number experiencing the combined CVE was 893 (6.3%). More patients died from noncardiovascular causes (392 patients) than cardiovascular causes (280 patients) . The medU-shaped .P values from the Cox model are provided in When analyzed as a continuous variable, findings for the association between baseline DBP and treatment group assignment for the outcome of all-cause death did not reach statistical significance . No inteP = .07); for 60 mm Hg, the HR was 1.12 ; for 70 mm Hg, the HR was 0.82 ; for 80 mm Hg, the HR was 0.77 ; for 90 mm Hg, the HR was 0.85 , for 100 mg Hg, the HR was 0.79 ; for 110 mm Hg, the HR was 0.64  (P = .03) and 90 mm Hg   . For intP = .04) .There were 800 participants with baseline DBP less than 60 mm Hg and 13 277 with baseline DBP greater than or equal to 60 mm Hg. Individuals with baseline DBP less than 60 mm Hg were older  and had 3-fold higher risk of dying (74 patients [9.3%] vs 598 patients [4.5%]) than those with baseline DBP greater than or equal to 60 mm Hg . BaselinIn this pooled cohort analysis of patients from the ACCORD-BP and SPRINT trials, we tested the association between baseline DBP and patient outcomes. We also tested for an association between baseline DBP and treatment group assignment with respect to patient outcomes. Our results confirm prior observations of a nonlinear association between DBP and patient outcomes that appears U-shaped. No statistically significant interactions were observed, however, with respect to DBP and treatment group assignment for all-cause mortality or the composite CVE. This undermines the traditional J-curve hypothesis relating low DBP with reduced coronary perfusion and events.8 In individuals with lower baseline DBP values, factors unrelated to blood pressure may be associated with death more so than for individuals with higher DBP. Patients whose baseline DBP was less than 60 mm Hg compared with those with higher values were at 3-fold higher risk of dying (9% vs 3%), were significantly older (73.6 vs 65.7 years), and had higher rates of all comorbid conditions  the risk of the primary study outcome, (2) competing risk, (3) the risk of treatment-related harm, and (4) direct treatment-effect modification.nditions . It is a9 where there was a significant association of heart failure class and implantable cardioverter-defibrillator therapy with mortality. Patients with New York Heart Association class III heart failure derived no benefit from implantable cardioverter-defibrillator therapy but those with New York Heart Association class II heart failure benefited greatly. The 5-year mortality rates in the New York Heart Association classes III and II placebo groups were 46% and 32%, respectively.9 This same dynamic can be seen across trials as well. In the Study to Evaluate the Use of Rosuvastatin in Subjects on Regular Hemodialysis trial,10 a high-risk population of dialysis patients derived no benefit from statin therapy. The rates of death and nonfatal MI in the control group of this population were 14 per 100 person-years and 2.5 per 100 person-years, respectively.10 Contrary to this, in the Justification for the Use of Statins in Prevention: An International Trial Evaluating Rosuvastatin trial,11 a much lower risk population of patients who were in generally good health derived a significant benefit from statin therapy. The same rates of death and nonfatal MI in the control group of this population were 1.25 per 100 person-years and 0.33 per 100 person-years, respectively.11The notion of treatment effect heterogeneity for common interventions in high-risk patients is not unprecedented in cardiovascular medicine. An example of this within an individual trial can be found in the Sudden Cardiac Death in Heart Failure Trial,13 patients with advanced chronic kidney disease derived no benefit from an invasive compared with conservative strategy and were more likely to experience a stroke or a composite of death from any cause or initiation of dialysis. The 3-year rates of death and nonfatal MI in the control group of this population were 27.8% and 15.9%, respectively.13 In the main trial,15 which excluded CKD patients with chronic kidney disease, fewer events were experienced in the invasive group, and there was a significant reduction in angina and no evidence of harm. The 3-year rates of death and nonfatal MI in the control group of this population were 4.3% and 8.5%, respectively.15In the recently published International Study of Comparative Health Effectiveness with Medical and Invasive Approaches-Chronic Kidney Disease trial,16 did not find an interaction between baseline DBP and all-cause death, the composite CVE, or chronic kidney disease events when DBP subgroups were analyzed on the basis of quintiles, or when the lowest quintile was compared with the remaining cohort. There are several notable differences between this study16 and ours. First, the use of SPRINT-only patients would reduce power to detect any subgroup interactions, if present. Second, their method only considered baseline DBP as a dichotomous variable (based on quintiles) and in doing so, they included many patients with DBPs much greater than 60 mm Hg in their lowest quintile (the mean [SD] DBP of this group was 61 [5] mm Hg).16 Our analysis of DBP as a continuous variable suggests the interaction occurs very near the 60 mm Hg mark. Finally, in their analysis they do report a P value for the interaction between baseline DBP and treatment intensity on all-cause death of .29.16 Although this is far from the traditional bounds of what is considered statistically significant, it may not be trivial. P values for testing interactions may be considered hypothesis-generating at lower thresholds than the 95% mark used for hypothesis testing and confirmation.Our study is not the first to look for an interaction between intensive therapy and baseline DBP in an intention-to-treat fashion. In a reanalysis of SPRINT-only patients, Beddhu et al17 studied the association between DBP and outcomes for patients in the ACCORD-BP and SPRINT trials among patients who achieved a SBP less than 130 mm Hg. Among such patients, those with treated DBP lower than 60 mm Hg had higher rates of events. Their findings are consistent with our study and many others in the past that have looked at baseline and achieved DBP levels and found associations between lower values and outcomes. We did this by looking at baseline DBP as a continuous variable and found significant nonlinear associations with all-cause death and a composite CVE among patients in the ACCORD-BP and SPRINT trials (16 address this question directly.Li and colleaguesT trials . HoweverIt should not be construed from our data or the other studies mentioned here that patients with low DBP should have deintensification of therapy with the aim of increasing DBP. The question addressed by our study is whether therapy can be safely intensified to lower SBP in such patients.Our study has both strengths and limitations. The main strength is the use of individual patient data from 2 large, randomized clinical trials conducted in the same manner, including both patients with and without diabetes. Limitations include the lack of a significant number of patients with stroke at baseline and the low number of patients whose baseline DBP was less than 60 mm Hg.In conclusion, this pooled cohort analysis of patients enrolled in the ACCORD-BP and SPRINT trials supports the existence of a nonlinear association between baseline DBP and patient outcomes as previously reported. More importantly, it suggests that among patients whose baseline DBP was greater than 60 mm Hg, intensifying therapy to achieve an SBP target of 120 mm Hg could reduce death and cardiovascular events. It does not allow us to conclude the same for patients whose baseline DBP is 60 mm Hg or below since intensifying therapy may not reduce the risk of dying and could possibly increase it. This topic merits further investigation.


The impact of left ventricular diastolic dysfunction (LVDD) on cardiovascular (CV) outcomes in patients with pre-dialysis chronic kidney disease (CKD) has been rarely unveiled. We here investigated the association of LVDD with CV outcomes and all-cause mortality in patients with pre-dialysis CKD.E/e′) > 14.A total of 2,135 patients with pre-dialysis CKD from the Korean Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD) cohort were dichotomized by the absence or presence of LVDD, which was defined as the ratio of the early transmitral blood flow velocity to early diastolic velocity of the mitral annulus  and all-cause mortality , suggesting that the impact of LVDD on the outcomes in patients with CKD is independent of LV systolic function. Subgroup analyses revealed that the associations were not modified by various clinical contexts, such as age, sex, burden of comorbid conditions, body mass index, estimated glomerular filtration rate, and albuminuria.Cox regression analysis revealed that LVDD was significantly associated with increased risk of composite CV events  and all-cause mortality . Restricted cubic splines visualized stringent linear correlations of LVDD is independently associated with adverse CV outcomes and all-cause mortality in patients with pre-dialysis CKD. Heart failure (HF) is a major cause of cardiovascular (CV) mortality in patients with chronic kidney disease (CKD) , which iThe LVDD is prevalent in patients with CKD, where chronic hypertension (HTN) and anemia may promote the development of LVH . PreviouAs LVDD is prevalent even among patients with early-stage CKD , 8, we hhttp://www.clinicaltrials.gov) (E/e′), a total of 2,135 subjects were finally included for the analyses (The Korean Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD) is a nationwide prospective cohort study involving 9 tertiary-care general hospitals in Korea  . Korean analyses . The stuDemographic information was collected from all eligible participants, including age, gender, comorbid conditions, smoking history, and medication history . Trained staff members measured the height, weight, and waist circumference (WC) of study participants. Body mass index (BMI) was calculated as weight divided by the height squared. Systolic and diastolic blood pressures (SBPs and DBPs) were measured by an electronic sphygmomanometer after seated rest for 5 min. Venous samples were collected following overnight fasting, to determine hemoglobin, albumin, total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), fasting glucose, high-sensitivity C-reactive protein (hs-CRP), 25-hydroxyvitamin D [25(OH) vitamin D], and creatinine levels at the baseline. The estimated glomerular filtration rate (eGFR) was calculated by the Chronic Kidney Disease Epidemiology Collaboration equation . CKD stavia standard approaches by cardiologists at the participating hospitals who were blinded to the clinical data. M-mode examination was performed according to the American Society of Echocardiography guidelines . LVDD was defined as E/e′ > 14 , left atrium volume index >34 ml/m2, and peak tricuspid regurgitation velocity >2.8 m/s, are also commonly used to evaluate LVDD , myocardial infarction , or coronary intervention/surgery ], hospitalization for HF, ischemic or hemorrhagic stroke, or symptomatic arrhythmia.E/e′ (E/e′ ≤ 14 vs. E/e′ > 14), the Student's t-test and χ2 test were used for continuous and categorical variates, respectively. In the primary analysis, the participants with any missing data were excluded for further analyses. To evaluate the association between LVDD and study outcomes, Cox proportional hazard regression models were analyzed. Patients lost to follow-up were censored at the date of the last visit. Models were constructed after adjusting for the following variables: Model 1 represents crude hazard ratios (HRs); Model 2 was adjusted for age, sex, Charlson comorbidity index, smoking history, medication , BMI, SBP, and DBP; Model 3 was further adjusted for hemoglobin, albumin, fasting glucose, HDL-C, TG, 25(OH) vitamin D, hs-CRP, GFR, and spot urine ACR; and Model 4 was additionally adjusted for LVEF at the baseline. The results of Cox proportional hazard models were presented as HRs and 95% confidence intervals (CIs). Cumulative incidences of composite CV events and all-cause mortality were estimated using Kaplan-Meier analyses and were compared using the log-rank test. Restricted cubic splines were used to visualize the association between E/e′ as a continuous variable and HRs for study outcomes. To validate our findings, we performed sensitivity analyses. First, we excluded the subjects with eGFR <15 ml/min/1.73 m2, because those were relatively small in number and may exaggerate the association between LVDD and study outcomes due to far advanced CKD. Second, we excluded the subjects with eGFR ≥ 90 ml/min/1.73 m2, because those were considered close to normal kidney function and may not represent the CKD population well. Third, we excluded the subjects with LVEF < 50% to examine whether the association between LVDD and study outcomes is independent of LV systolic dysfunction. Finally, we replaced the missing values in primary analyses with multiple imputations and further conducted the Cox regression analyses. To examine whether the association of LVDD with the study outcomes is modified by certain clinical contexts, we conducted prespecified subgroup analyses. Subgroups were defined by age (<60 vs. ≥60 years), sex , Charlson comorbidity index (≤3 vs. ≥4), BMI (<23 vs. ≥23 kg/m2), eGFR (<45 vs. ≥45 ml/min/1.73 m2), and spot urine ACR (<300 vs. ≥300 mg/gCr). Two-sided P-values <0.05 were considered statistically significant. Statistical analysis was performed using SPSS for Windows version 22.0  and R .Continuous variables were expressed as mean ± standard deviation or median [interquartile range]. Categorical variables were expressed as the number of participants and percentage. The normality of distribution was ascertained by the Kolmogorov-Smirnov test. To compare the baseline characteristics according to E/e′ (≤14 vs. >14)  vitamin D, and eGFR were lower in the subjects with E/e′ > 14, while TG, hs-CRP, and spot urine ACR were higher in the subjects with E/e′ > 14. Echocardiographic findings  . The meafindings  revealedE/e′ > 14 . To determine the independent association of LVDD with study outcomes, Cox regression models were analyzed  and all-cause mortality  was still valid  and all-cause mortality  remained robust (–3.000) and all-cause mortality   , suggest3–2.754) .Subgroup analyses revealed that the association of LVDD with adverse CV outcome is not modified by age, sex, burden of comorbid conditions, BMI, eGFR, or albuminuria . These cIn this study, we demonstrated that LVDD is significantly associated with adverse CV outcomes and all-cause mortality in patients with pre-dialysis CKD. We also discovered that the association is robust even among the subjects with preserved LVEF, suggesting that the impact of LVDD on the CV outcomes in CKD is independent of LV systolic function.2 were included for the analyses. As LVH contributes to the pathogenesis of LVDD, the findings indicate a possible association between LVDD and adverse CV outcomes in patients with CKD (E/e′ ratio (E/e′ > 15) can predict mortality and CV events and all-cause mortality in patients with CKD  is a simplified and modified one. Nevertheless, E/e′ is a feasible and reproducible index to assess the LV filling pressure , Eunkyeong Jung (Project Officer), Suyeon Jeong, Eunmi Ahn, and Sil-Hea Sung.SS designed and helped in the data analysis and manuscript writing. SS, TO, and HC contributed to the conception of the study. SS and CK performed the data analyses and wrote the manuscript. EB, K-HO, KC, YO, and SK collected the data. SM and SK helped perform the analysis with constructive discussions. All authors contributed to the article and approved the submitted version.This study was supported by the Research Program funded by the Korea Centers for Disease Control and Prevention , by the National Research Foundation of Korea (NRF) funded by the Korean Government (MSIT) (NRF-2019R1A2C2086276), and a Grant (BCRI21046) of Chonnam National University Hospital Biomedical Research Institute.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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Assessment of fluid responsiveness is problematic in intensive care unit patients. Lung recruitment maneuvers (LRM) can be used as a functional test to predict fluid responsiveness. We propose a new test to predict fluid responsiveness in mechanically ventilated patients by analyzing the variations in central venous pressure (CVP) and systemic arterial parameters during a prolonged sigh breath LRM without the use of a cardiac output measuring device.Prospective observational cohort study.Intensive Care Unit, Saint-Etienne University Central Hospital.Patients under mechanical ventilation, equipped with invasive arterial blood pressure, CVP, pulse contour analysis (PICCO™), requiring volume expansion, with no right ventricular dysfunction.Interventions.None.p = 0.022, p = 0.014, p = 0.006 and p = 0.038, respectively). PP and CVP slopes during STEP-UP were strongly predictive of fluid responsiveness with an AUC of 0.926 , sensitivity = 100%, specificity = 89% and an AUC = 0.901 , sensibility = 78%, specificity = 100%, respectively. Combining sensitivity of PP and specificity of CVP, prediction of fluid responsiveness can be achieved with 100% sensitivity and 100% specificity . One patient showed inconclusive values using the grey zone approach (5.5%).CVP, systemic arterial parameters and stroke volume (SV) were recorded during prolonged LRM followed by a 500 mL fluid expansion to asses fluid responsiveness. 25 patients were screened and 18 patients analyzed. 9 patients were responders to volume expansion and 9 were not. Evaluation of hemodynamic parameters suggested the use of a linear regression model. Slopes for systolic arterial pressure, pulse pressure (PP), CVP and SV were all significantly different between responders and non-responders during the pressure increase phase of LRM (STEP-UP)  The baseline was 5 cmH2O PEEP and 20 cmH2O inspiratory pressure for all patients. The maximum pressure level reached was 30 cmH2O PEEP and 45 cmH2O inspiratory pressure. PEEP de-escalation was performed following the same pattern , as described in the literature , 17, 19.5 cmH2O, We recorded demographic data including weight, age, gender, Simplified Acute Physiology Score (SAPS II), medical history, criteria of admission to ICU and comorbidities. Respiratory parameters , hemodynamic parameters , pulse pressure (PP = SAP-DAP), CVP, heart rate, PPV, and PICCO data (stroke volume and cardiac output (CO)) were also recorded. Baseline PPV was displayed on Phillips monitors. Pharmacological data (vasoactive infusions) and biological data (lactate) were recorded..When a patient met the inclusion criteria, the investigating physicians collected a set of demographic, ventilatory and hemodynamic data. Central venous catheter were inserted in right internal jugular vein, tip position was controlled to be in the right atrium using chest X-ray before inclusion. Zero of CVP was made at 0 degrees inclination. A transcardiopulmonary thermodilution was performed. Three injections of 20 mL cold fluid bolus were used for SV and CO calculations at baseline (mean of the three bolus). The LRM was then performed following the STEP-PEEP pattern as described above. A video of the hemodynamic monitoring was recorded during the LRM, with the clinician announcing the time and pressure level for each step. Hemodynamic values were later documented by pausing on the video during the two last seconds of each LRM step as announced by the physician. Next, a fluid expansion of Plasmalyte 500 mL over 10 min was performed. A second transcardiopulmonary thermodilution was done between 2 to 4 min after fluid expansion, using the same method. Responders (R) and Non-Responders (NR) were defined with regard to the change in SV (expressed as percentage) after fluid expansion. A fluid responder was defined as a 15% increase in SV after fluid expansion [th to 75th). We used the Student T-test for continuous variables. Slope values were obtained using a linear regression calculation are expressed in degrees for the angle (α) between the horizontal axis and the linear regression curve calculated between the drop of pressure (mmHg) and the PEEP level (cmH2O). The threshold for statistical significance was set to P < 0.05. A receiver-operating characteristic (ROC) curve was drawn for αSAP, αMAP, αDAP, αPP and αCVP for STEP-UP and STEP-DOWN during LRM, respectively. We selected the threshold that gave the highest Youden index. We defined the grey zone for which inconclusive conclusions could not be obtained for values with a sensitivity lower than 90% or specificity lower than 90% according to Cannesson et al [A sample size of 18 patients (9 responders and 9 non-responders) was calculated to be sufficient to demonstrate that CVP and PP variations can predict fluid responsiveness with an area under curve (AUC) of 0.85, a power of 80% (beta risk = 0.2) and an alpha risk of 0.05. Data are expressed as mean (SD) or median , ejection fraction less than 50% (1 patient) and presence of arrythmia (3 patients). Two patients were excluded due to absence of fluid expansion performed after LRM. A total of 18 patients were analyzed  than in the Non-Responders (NR) group . Baseline PPV was higher in the R than in the NR group . R and NR did not differ for baseline values of SV, CO, MAP, CVP or lactate level. Static pulmonary compliance was not statistically different between R and NR.SV values for baseline, maximum lung recruitment pressure, and before and after volume expansion are represented in Fig. Six data points were available for each parameter for STEP-UP and STEP-DOWN. Figure Evaluation of all hemodynamic variables suggested the use of a linear regression model, especially during STEP-UP LRM. Slope calculations are shown in Table Slope calculations showed greater absolute values for the Responder compared to the Non-Responder group for STEP-UP and STEP-DOWN LRM Table . The abiαPP during STEP-UP was strongly predictive of fluid responsiveness with an AUC of 0.926 , and a sensitivity and a specificity of 100% and 89% respectively. Cut-off value was -42.8°. Inconclusive values ranged from -42.8° to -52.1° using the grey zone approach (35% of the patients).αCVP during STEP-UP was also strongly predictive of fluid responsiveness with an AUC of 0.901  and a sensitivity and a specificity of 78% and 100% respectively. The cut-off value was 20.1°. Inconclusive values ranged from 13.8° to 20.1° using the grey zone approach (44% of the patients).By combining sensitivity of αPP and specificity of αCVP if both measures are available, taking for each angle the specificity value of αCVP and sensitivity value of αPP, fluid responsiveness prediction can be obtained with 100% sensitivity and 100% specificity during STEP-UP LRM . One patient (5.5%) showed inconclusive values using the grey zone approach Fig. . Index cAbsolute variations for SAP, PP, MAP, DAP, SV and CVP between baseline  and maximum pressure level  are reported as ∆SAP, ∆PP, ∆MAP, ∆DAP, ∆SV and ∆CVP. Their ability to predict fluid responsiveness is shown in Table PPV at baseline was available for 11 patients. A PPV of more than 12% before LRM predicted responders with an AUC of 0.711  and a sensitivity and a specificity of 63% and 100% respectively. Inconclusive values ranged from 4 to 10% using the grey zone approach (45% of the patients)  recruitment maneuver are the best hemodynamic parameters for the prediction of fluid responsiveness in mechanically ventilated patients in ICU, with or without neuromuscular blockade.STEP-PEEP LRM offered the ability to evaluate the effects of LRM using a different approach from usual bi-level sustained insufflation LRM. Six data points were available for STEP-UP and STEP-DOWN for all parameters, following a linear evolution especially during STEP-UP, allowing a linear regression analysis. Absolute variations of PP and CVP between PEEP = 5cmH2O and PEEP = 30cmH2O during STEP-UP provide interesting results with respect to discrimination of fluid responders and non-responders. PPV was significantly different between Responders and Non-Responders at baseline but showed inferior statistical values compared to slope analysis. PPV and CVP follow a linear evolution during STEP-UP LRM and there is a possibility that the LRM method for fluid responsiveness prediction could offer a similar statistical performance using lower pressure LRM.During LRM, a transient increase in intra-pulmonary pressure is transmitted to the adjacent intra-thoracic compartments. This increase in intrathoracic pressure most impacts the right ventricle, however no patients in our study had right ventricular cardiac dysfunction as they were excluded. Preload and afterload of the right ventricle are also affected by high intra-thoracic pressure. High intra-thoracic pressure increases the right ventricular afterload and ejectional impedance . These e. Pressure transmission from lung and pleural space to the heart and mediastinum can be affected by many physiological and physio-pathological conditions. Compliance loss in acute respiratory distress syndrome for patients in intensive care units or catecholamine use can also lead to changes in cardio-pulmonary interactions. Therefore, it is important for clinicians not to oversimplify this physiology and to take into account the characteristics of the underlying pathologies before making any decision based on the scientific literature.Cardio-pulmonary interactions are widely studied and used in clinical practice, especially with PPV analysis and more recently with LRM hemodynamic response analysis –14 or enPP slope calculation (αPP) after linear regression during STEP-PEEP showed excellent sensitivity. This can be explained by the fact that if a transient increase in intra-thoracic pressure does not impact systemic arterial pressure, the right ventricular preload is likely to be sufficient to avoid collapse. αPP variation below cut-off value during STEP-UP could therefore exclude fluid responsiveness with a 100% sensitivity in our study.CVP slope calculation (αCVP) during STEP-LRM showed excellent specificity. This can be explained by the fact that if a transient increase in intra-thoracic pressure induces a significant variation in CVP, the right ventricular preload is likely to be low and easily affected external pressure. αCVP above cut-off value during STEP-UP can confirm fluid responsiveness with 100% specificity in our study.Clinicians may therefore benefit from the sensitivity of αPP using only an arterial catheter, or the specificity of αCVP using a central venous catheter for fluid responsiveness prediction. For patients equipped with both, combination of αPP and αCVP during STEP-UP allows clinicians to predict fluid responsiveness with 100% sensitivity and specificity.This study has several limitations. This pilot study was monocentric and 18 only patients have been studied. Statistical results are highly significant but further larger studies are needed to confirm our preliminary results. Next, SV during LRM was calculated with pulse contour analysis. Surprisingly, the SV results for absolute variation and angle analysis were inferior to results for SAP, PP and CVP. SV calculated from pulse contour analysis may have been imprecise due to increasing levels of pressure and variation of systemic vascular resistances from baseline initial transcardiopulmonary thermodilution. Of note, thermodilution is the method of choice for cardiac output measurement and was used before LRM, and after fluid challenge.Baseline norepinephrine differed between the R and NR groups. Differences of norepinephrine dosage may have had an effect on the stressed and unstressed fluid volume, potentially leading to bias in interpretation of CVP for evaluation of fluid responsiveness.All included patients required fluid expansion as determined by the clinician in charge, based on vasopressor requirements, echocardiographic evidence or clinical judgement. Half of the patients included were found to have received suboptimal fluid management, illustrating the need for a specific tool for evaluation of fluid responsiveness.Calculation of the slope may be challenging at bedside but a calculation of the α angle according to the successive values of CVP and PP can easily be automated on a computer or smartphone.All patients were not consecutive patients, introducing a potential selection bias. Before inclusion, all patients required a fluid expansion as determined by the clinician in charge based on vasopressor requirements, echocardiographic evidence or clinical judgement. Inclusions were conducted exactly the same way for all patients, Responder or Non-Responder status being determined offline only after fluid expansion. The fact that half of the included patients were Non-Responders shows that our current tools are not accurate enough to discriminate Responders and Non-Responders..The use and format of LRM can be debated. High intrathoracic pressures can have harmful effects on patients without lung disease. The STEP-PEEP lung recruitment maneuver was chosen from the literature as it showed lesser increase in transpulmonary pressure for a longer period of time and improved lung aeration as effectively as sustained inflation does, with less risk of hemodynamic compromise and hyperinflation , 18.In mechanically ventilated patients, a progressive STEP-PEEP lung recruitment maneuver could predict fluid responsiveness using the slope analysis of pulse pressure (αPP) and central venous pressure (αCVP) evolutions. αPP variation below cut-off value during STEP-UP can exclude fluid responsiveness. αCVP above cut-off value during STEP-UP can affirm fluid responsiveness. In this pilot study, the association of αPP and αCVP during STEP-UP recruitment maneuver provides a high sensitivity and high specificity and seems to offer a very promising method for fluid responsiveness prediction without the use and cost of a cardiac output measurement device.