Despite current practice, patients with chronic kidney disease (CKD) are at increased risk of progression to end-stage renal disease and cardiovascular events. Neprilysin inhibition (NEPi) is a new therapeutic strategy with potential to improve outcomes for patients with CKD. NEPi enhances the activity of natriuretic peptide systems leading to natriuresis, diuresis and inhibition of the renin–angiotensin system (RAS), which could act as a potentially beneficial counter-regulatory system in states of RAS activation such as chronic heart failure (HF) and CKD. Early NEPi drugs were combined with angiotensin-converting enzyme inhibitors but were associated with unacceptable rates of angioedema and, therefore, withdrawn. However, one such agent (omapatrilat) showed promise of NEP/RAS inhibition in treating CKD in animal models, producing greater reductions in proteinuria, glomerulosclerosis and tubulointerstitial fibrosis compared with isolated RAS inhibition. A new class of drug called angiotensin receptor neprilysin inhibitor (ARNi) has been developed. One such drug, LCZ696, has shown substantial benefits in trials in hypertension and HF. In CKD, HF is common due to a range of mechanisms including hypertension and structural heart disease (including left ventricular hypertrophy), suggesting that ARNi could benefit patients with CKD by both retarding the progression of CKD  and reducing the risk of cardiovascular disease. LCZ696 is now being studied in a CKD population. Patients with chronic kidney disease (CKD) face many hazards including increased risk of progression to end-stage renal disease (ESRD) and premature mortality from cardiovascular disease (CVD) , 2. WherRandomized trials have shown that renin–angiotensin system (RAS) inhibitors  reduce the risk of ESRD in patients with diabetic and non-diabetic proteinuric CKD –6. In thAlthough dual ACEi/ARB therapy reduces albuminuria more than either agent alone, trials have shown that this does not translate into either cardiovascular benefit or additional renal protection –13. IndeThe lack of benefit associated with dual RAS blockade highlights the need for new therapeutic strategies in CKD. The natriuretic peptide (NP) system is a neurohormonal system that counter-regulates the RAS. Therefore, enhancing the activity of NPs may be beneficial in states of RAS activation, such as cardiovascular and kidney disease.NPs are a family of three peptides that include atrial, brain and c-type NPs  . ANP andANP and BNP have a range of renal and cardiovascular effects contributing to natriuresis, diuresis and BP regulation , 17. CNPAnimal models lacking the proANP gene develop salt-sensitive hypertension . Gene deNeprilysin [also known as neutral endopeptidase (NEP)] is the key enzyme responsible for degradation of NPs . NEP is The broad range of potential therapeutic actions of NPs led to development of agents that inhibit NEP. Neprilysin inhibition (NEPi) results in potent natriuresis and vasodilation; in the kidney, this vasodilatory effect reduces intraglomerular pressure and proteinuria , 25. ChrDual NEPi/ACEi are also known as vasopeptidase inhibitors (VPIs). Many compounds have been produced and trialled in humans Table . OmapatrOmapatrilat was well tolerated in studies of healthy volunteers among whom it significantly increased urinary excretion of ANP and cGMP (i.e. markers of NEPi). Omapatrilat also produced potent ACE inhibition with decreased levels of angiotensin II and reduced systemic BP. Renal effects of omapatrilat included marked increases in renal blood flow without associated change in glomerular filtration rate (GFR) and decreased filtration fraction. This haemodynamic profile could translate into renal protection and slower progression of CKD, as discussed further below , 25.Despite the promising cardiorenal and neurohormonal findings seen with VPIs, omapatrilat was associated with excess rates of angioedema. In 723 patients with CVD, omapatrilat reduced BP but six cases of angioedema occurred . In the Angioedema is an uncommon complication of ACEi therapy which is seen in 0.1–0.3% of treated patients and can occur at any interval after starting these drugs . It can Given the low incidence of angioedema associated with ACEi, it is thought that individuals are only affected if they have an additional risk factor, such as smoking (due to reduced NEP and dipeptidyl peptidase IV activity in smokers), black race (due to ACE gene polymorphisms) or hereditary angioedema (for example due to C1 inhibitor deficiency) , 30. WitWhilst ACEi induce RAS blockade by inhibiting the conversion of angiotensin I to angiotensin II, angiotensin II receptor blockers (ARBs) elicit similar effects by blocking the activation of angiotensin II Type 1 receptors by angiotensin II. However, ARBs have minimal effect on bradykinin activity and, therefore, are much less likely to cause angioedema. This led to the development of dual-acting angiotensin receptor neprilysin inhibitors (ARNi), which combine the beneficial effects of ARBs and NEPi without excess risk of angioedema Figure . LCZ696 In studies of healthy volunteers, AHU377 reached peak plasma concentrations in 0.5–1.1 h and the active moiety LBQ657 in 1.8–3.5 h . LCZ696 NEPi was originally studied using VPIs in a range of animal models of hypertension including salt-sensitive hypertension, stroke-prone spontaneous hypertensive rats and renovascular hypertension.In the OCTAVE trial involving 25 302 hypertensive patients , compareA trial of 1328 hypertensive patients compared increasing doses of LCZ696 , valsartan , AHU377 (200 mg) or placebo . The priPlasma ANP and cGMP levels increased significantly with LCZ696. LCZ696 reduced albuminuria more than placebo, but not more than the equivalent dose of valsartan . HoweverA recent trial has demonstrated similar efficacy in Asian patients  with hypertension, who are generally less responsive to isolated RASi . The ProIn early HF, NP levels increase to counteract salt and water retention. Over time the effects of NPs are negated by up-regulation of neurohormonal pathways, including RAS and the sympathetic nervous system, which cause further salt and water retention. Increasing levels of NPs with NEPi may help counteract up-regulation of these pathogenic pathways, when combined with RAS blockade.The Omapatrilat Versus Enalapril Randomized Trial of Utility in Reducing Events (OVERTURE) trial randomized 5770 patients with New York Heart Association (NYHA) Classes II–IV HF to either omapatrilat or enalapril . Non-sigThe Prospective comparison of ARNi with ARB on Management Of heart failUre with preserved ejectioN fracTion (PARAMOUNT) trial randomized 301 patients with HF with preserved ejection fraction (HFpEF) to maximum tolerated daily doses of LCZ696 or valsartan . The pri2] and 37% of participants had an eGFR <60 mL/min/1.73 m2 at enrolment [The Prospective comparison of ARNi with ACEi to Determine Impact on Global Mortality and morbidity in Heart Failure trial (PARADIGM-HF), the largest ever trial in HF with reduced ejection fraction (NYHA Classes II–IV) randomized 8436 patients to maximum daily tolerated doses of LCZ696 or enalapril , 39. TheThe trial was closed early on the recommendation of the Data Monitoring Committee, having met the primary end point with overwhelming efficacy in favour of LCZ696 . The fulThe Prospective comparison of ARni with Arb Global Outcomes in heart failure with preserved ejection fraction (PARAGON-HF) will soon start recruiting about 4300 patients with HFpEF and compare LCZ696 with valsartan. The primary outcome will be a composite of cardiovascular death and total (first and recurrent) hospitalizations for HF .The evidence for a potential role of NEPi in CKD comes from the study of NEPi in animal models of renal disease and the results of renal outcomes from trials in HF. However, no large-scale human trials have been conducted with this class of agents in a CKD cohort.In an animal model of hypertension, long-term administration of omapatrilat led to dose-dependent reductions in BP and proteinuria that halted progression of glomerulosclerosis, tubulointerstitial fibrosis and renal injury . In a 5/Candoxatrilat, an isolated NEPi, was compared with placebo in 24 patients with normal, moderately or severely reduced GFR in a cross-over study . CompareIn the Inhibition of Metallo Protease by Omapatrilat in a Randomized Exercise and Symptoms Study of Heart Failure (IMPRESS) trial (comparing omapatrilat with lisinopril), creatinine levels were reported as being raised more frequently in patients treated with lisinopril than omapatrilat  . Similar2). The trial will be the first test of an ARNi in a proteinuric population, and will assess the short-term safety and efficacy of LCZ696 in CKD with a primary outcome of the difference in change in measured GFR from baseline to 6 months between the two arms.These studies highlight the potential advantages of combined NEPi/RASi in slowing the progression of CKD. However, the current data are indirect as they are based on animal models or HF populations. The UK Heart And Renal Protection III (UK HARP-III) trial (ISRCTN11958993) will compare LCZ696 against irbesartan in 360 patients with proteinuric CKD (urine ACR >20 mg/mmol and eGFR ≥20 <60 mL/min/1.73 mNPs act as a potentially beneficial counter-regulatory system in states of excess RAS activation such as seen in hypertension, HF and CKD. In hypertension and HF, inhibition of neprilysin with LCZ696 has been shown to provide substantial clinical benefit. For patients with CKD, NEPi could be beneficial for two reasons: first, it may reduce the risk of CVD; second, it may retard the progression of CKD itself and delay the need for renal replacement therapy. A large randomized trial of an ARNi in a CKD population will be required to investigate this potential, but—if positive—such a trial would have a substantial impact on clinical practice.The UK HARP-III trial has been funded by Novartis. It will be conducted and interpreted independently of the principal funder. The Clinical Trials Service Unit and Epidemiological Studies Unit, which is part of the University of Oxford, has a staff policy of not accepting honoraria or consultancy fees.


The relationship between chronic inflammation and the incidence of chronic kidney disease (CKD) remained not-clear in patients with rheumatoid arthritis (RA). This study aims to examine the relationship between persistently high C-reactive protein (CRP), a marker of inflammation, and the incidence of CKD in RA.2 and/or positive dipstick testing for proteinuria for ≥3 months. We defined high CRP, as >3.0 mg/L. On the basis of three measurements of CRP for 6-months period, patients were divided into three groups: group 1, including patients with no high CRP values; group 2, patients with transient high CRP values (once or twice) and group 3, patients with persistently high CRP values.We retrospectively examined the relationship between the levels of CRP and incidence of CKD in 345 RA patients. The outcome of interest was incidence of CKD, defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 mDuring a median follow-up period of 89 months, 14% of all patients developed CKD. The cumulative incidence of CKD was 7% in group 1, 14% in group 2 and 22% in group 3 . In a multivariate analysis, including classical risk factors for CKD, persistently high CRP was an independent predictor of the incidence of CKD .Persistently high CRP was a significant risk factor for the incidence of CKD. Results suggest that persistent inflammation is a marker for the high risk of CKD in RA. Chronic kidney disease (CKD) is common–5 in patC-reactive protein (CRP), a marker of inflammation, is associated with RA disease activity; a persistently active form of the disease is characterised by elevated CRP levels and is associated with a more rapid radiological progression, 9. It hTherefore, in the present study, we examined the relationship between persistent elevation of CRP during 6 months and the incidence of CKD in patients with RA.2 and/or proteinuria for less than three months at baseline for this study  after obtaining a permissions of Ethical Committee of Tomishiro Central Hospital. The data from medical records were anonymized before access for this study. As a baseline for this study, we screened 487 adult patients (≥18 years of age) who visited the hospital in April 2006 and fulfilled the 1987 American College of Rheumatology criteria for RA. Of thes n = 16; . Finally2. We also analysed clinical characteristics of RA, including RA duration, and the continuous use of anti-rheumatic medication for at least 6 months during the period of the first to third measurement of CRP for this study  based on medical records. In DMARDs, nephrotoxic DMARDs were defined as drugs which have potential renal toxicity include the following: bucillamine, D-penicillamine, auranofin and tacrolimus. Serum creatinine level was measured using the enzymatic method .At outpatient department, nurses or doctors dispensed a lifestyle and medical history questionnaire, collected blood and urine samples and measured blood pressure levels. Classical CKD risk factors at baseline for this study were hypertension (defined as more than two resting blood pressure measurements of ≥140 mm Hg systolic and/or ≥90 mm Hg diastolic or treatment with antihypertensive agents), diabetes mellitus  and dyslipidemia  was calculated using the Japanese Society of Nephrology formula as follows:eGFR . CRP levels were measured using the latex agglutination immunoassay method using the Nanopia CRP . The normal range of this assay was ≤3 mg/L. Measurements of blood glucose, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides were obtained using a HITACHI 7170 autoanalyser . Rheumatoid factor was measured using the latex agglutination test .In this study, we used CRP as a marker of inflammation. High CRP was defined as >3.0 mg/L. To diagnose persistently high CRP, we chose CRP at three time points: at baseline for this study, at 3 months (range of 2–4 months) and at 6 months (range of 5–7 months) from the baseline for this study. On the basis of CRP measurements, patients were divided into three groups: group 1, those with no high CRP values ; group 2, those with transient high CRP values  and group 3, those with persistently high CRP values .2 and/or proteinuria for ≥3 months, according to the criteria of the Japanese Society of Nephrology. Incidence of CKD was defined as the new development of CKD.CKD was defined as an eGFR <60 mL/min/1.73 m2); Model 3) covariates included in mode2 plus classical risk factors for CKD ; Model 4) covariates included in model 3 plus baseline medication use which may have a toxic effect on the kidney . The time starts after the third measurement of CRP for the cumulative incidence rates and Cox proportional hazard analysis. The relationship between the median CRP values along the entire follow-up and the median CRP values during the first 6 months of follow-up was examined using Pearson’s correlation coefficient with log-transformation of variables because of non-normal distribution of values. Receiver operating characteristic (ROC) analysis was conducted to determine the cut-off value of the median CRP values along the entire follow-up that predicts incidence of CKD. Analyses were performed using the JMP software package . Continuous data are expressed as mean ± standard deviation, and skewed distributions are presented as the median with 25th and 75th percentiles. P < 0.05 was considered statistically significant.Parametric analyses were performed by analysis of variance with the Tukey–Kramer test as a post hoc test to analyze differences in discrete variables between groups. Nonparametric analyses were performed by Kruskal–Wallis test with the Steel–Dwass test. Categorical variables were examined with the Pearson’s chi–square test. Cumulative incidence rates were calculated using the Kaplan–Meier method, and differences between groups were assessed using the log-rank test. Patients were censored at time of event, at death, at lost to follow-up, or at the end of follow-up, whichever came first. The Cox proportional hazard analysis was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of developing CKD in crude and adjusted models. We used four models of multivariate analysis to examine the association between the incident CKD and persistent elevation of CRP. Covariates included in the adjusted models were as follows: Model 1) age (every 10 years), sex, and CRP subgroups; Model 2) covariates included in model 1 plus baseline eGFR  were included in group 1 , 100 (29%) in group 2  and 144 (42%) in group 3 . The CRP values were significantly higher in groups 2 and 3 than those in group 1 at all three points. The prevalence of rheumatoid factor-positive, methotrexate, corticosteroids and NSAIDs use were higher in groups 2 and 3 than group 1. Patients in group 3 had significantly higher CRP values at all three time points and had a higher prevalence of hypertension than groups 1 and 2. There were no significant differences in eGFR among the three groups at the baseline.Baseline characteristics of the patients are summarised in 2 without proteinuria, n = 37; proteinuria without eGFR <60 mL/min/1.73 m2, n = 8 and eGFR <60 mL/min/1.73 m2 with proteinuria, n = 2). The median follow-up period from the third measurement of CRP was 89 months . Over this period, 16 patients (5%) died, 22 (6%) were lost to follow-up and 41 (12%) were unable to follow-up due to changing hospital. A total of 47 patients (14%) developed CKD .It was not clear whether the CRP levels during the first 6 months of follow-up represented the CRP levels along the entire follow-up. Therefore, we examined the relationship between the median CRP values along the entire follow-up and the CRP values during the first 6 months of follow-up using Pearson’s correlation coefficient with log-transformation of variables because of non-normal distribution of values. . There wIt is important to define the clinically relevant levels of CRP during the entire follow-up for increasing risk of CKD. We used the area under the curve of the median CRP values along the entire follow-up to predict CKD. Clinically significant inflammation for prediction of incidence of CKD was defined as CRP > 3.6 mg/L, based on the ROC curve .We further analyzed an association between incidence of CKD and the median CRP values along the entire follow-up using Cox proportional regression analysis. On the basis of the median CRP values along the entire follow-up, patients were divided into two groups: Low CRP  and High CRP . As shown in Previous studies conducted within the general population have not demonstrated an association between elevated CRP and the incidence of CKD, 17. To 2 [In a population-based study, several markers of inflammation, such as interleukin-6 and tumour necrosis factor-alpha receptor 2 levels, predicted declining kidney function–18. Mean2 , 17. RA Several mechanisms might be involved in the association between inflammation and incidence of CKD. First, a previous study showed that elevated CRP was positively related to blood pressure, glucose, lipids and BMI in a dose-dependent fashion among non-diabetic patients with CKD. TherefoSecond, renal involvement can be caused by drugs for RA. Patients with RA need often long term therapy with the drugs that are associated with nephrotoxicity such as NSAIDs and DMARDs. Chronic use of NSAIDs is associated with declining eGFR in RA patients. In DMARThird, it is well known that patients with longstanding inflammation may develop secondary amyloidosis in RA, 25. On 2 and/or positive dipstick testing for proteinuria in association with a hyperfiltration state.Alternatively, alteration in glomerular hemodynamic derived from endothelial dysfunction might be responsible for the CRP-related increased risk for incidence of CKD. It has been reported that CRP was independently associated with endothelial dysfunction in patients with RA, and proOur results have important clinical implications. The prevalence of CKD has been shown to be higher in patients with RA than that in the general population, and its causes are likely to be multifactorial, 38. HowIn patients with RA, CVD is a leading cause of mortality–41. The This study had several limitations. First, we used data from dipstick testing for proteinuria but not albuminuria for evaluating urinary protein. Methods for evaluating urinary protein vary between countries; in Japan, dipstick testing for proteinuria is common, and we previously demonstrated its power for predicting cardiorenal outcomes in the general population. Kidney In conclusion, the present study shows that persistently high CRP for at least 6 months is a significant risk factor for CKD development, independent of classical risk factors in patients with RA. Results suggest that inflammation is important for the development of CKD and that strict control of inflammation is expected to have clinical benefits including the reduction of incidence of CKD in patients with RA.


The CO2 reactivity of the basilar and middle cerebral arteries increased significantly after ST36 acupuncture treatment, whereas the mean arterial blood pressure and pulse rate did not change significantly. The high-frequency power significantly increased after ST36 acupuncture treatment, and the percentage increase of high-frequency power correlated significantly with the percentage increase in the CO2 reactivity of the contralateral middle cerebral artery. These data suggest that ST36 acupuncture treatment increases CO2 reactivity, indicating improvement of vasodilatory potential of the cerebral vasculature to compensate for fluctuations caused by changes in external conditions. The increase in parasympathetic tone by ST36 acupuncture treatment is responsible for this therapeutic effect.This study was conducted to verify the effect of acupuncture on cerebral haemodynamics to provide evidence for the use of acupuncture treatment as a complementary therapy for the high-risk stroke population. The effect of ST36 acupuncture treatment on the hyperventilation-induced CO Cerebral vessels respond to changes in the arterial carbon dioxide concentration in order to maintain constant cerebral blood flow (CBF), and this compensatory vasodilatory capacity of cerebral vessels is referred to as cerebral vasomotor reactivity (CVR). A decreased CVR is correlated with increasing age , cognitiPrevious studies have shown that sympathetic activation affects cerebral haemodynamics . Increas2 reactivities of the anterior and posterior circulations show regional differences [2 reactivity and corrected cerebral flow velocities (at P2ETCO = 40 mmHg) of both middle cerebral arteries (MCAs) and basilar artery (BA). Moreover, to establish a theory explaining the mechanism of the improvement in CVR, heart rate variability (HRV) data were collected simultaneously for 10 healthy young male volunteers.Although the effect of acupuncture treatment on CVR has been studied , the eviferences , each teThis study included 10 healthy male volunteers  years; range, 23–27 years); all volunteers signed written consent forms. None of the subjects had a history of cerebrovascular disease, hypertension, diabetes mellitus, thyroid disease, or psychiatric disorders. Alcohol, coffee, smoking, or any other drugs were forbidden for 24 hours prior to examination. The Institutional Review Board of the Hospital of Korean Medicine, Kyung Hee Medical Center, approved the study protocol.All acupuncture procedures were performed by 1 experienced acupuncturist with a stainless steel acupuncture needle with a diameter of 0.25 mm and a length of 40 mm . The selected acupoint, ST36, is located on the tibialis anterior muscle 3-cun inferior to ST35, which is located on the anterior aspect of the knee, in the depression lateral to the patellar ligament . The nee2 reactivities of both MCAs and the BA were measured by transcranial Doppler sonography (TCD) using a Multi-Dop X4 system , as described in previous studies [The cerebral blood flow velocities and the CO studies , 16, 17.2 tension; thus, the corrected blood flow velocity was calculated at 40 mmHg of CO2 tension , as described previously [b is the CO2 reactivity, V1 is the velocity at P1CO2, and P2ETCO is the end-tidal CO2 partial pressure.The blood flow velocity is dependent on the arterial COeviously :(1)CV402 reactivity refers to the percent change in mean blood velocity per change in P2ETCO, as calculated by the following formula [Vrest is the blood flow velocity at rest, obtained during the most stable 10 seconds in the stable normocapnic condition, Vhypocapnia is the blood flow velocity obtained during the most stable 10 seconds of the latter half of the 1-minute hyperventilation period, and ΔP2ETCO is the change in P2ETCO from baseline to maximal hyperventilation. The CO2 reactivity was expressed as %/min.CO formula :(2)CO2 2ETCO, and transcutaneous (tc) PO2, were observed by using various modules of the Cardiocap S/5 collector . Blood pressure and heart rate were measured under normocapnic conditions before hyperventilation. Blood pressure was measured 4 times at 2-minute intervals to determine the mean blood pressure. Heart rate and tcPO2 were continuously monitored by an oximetry apparatus positioned on the subject's finger. A Cardiocap S/5 collector-connected nasal prong positioned in front of the subject's nostril monitored P2ETCO, and each subject was instructed to breathe only through the nose during the study. A snapshot function in the Cardiocap S/5 collector software program was used to calculate the mean heart rate, mean tcPO2, and P2ETCO at specific time points during the study. These 4 variables were monitored and the data were saved in the computer, which was connected to the Cardiocap S/5 collector. The measurements were performed before and after the 20-minute ST36 acupuncture treatment , high-frequency power , and the LF/HF ratio in the frequency domain [ECG data were obtained simultaneously by using an ECG monitoring system , with a sampling rate of 125 Hz. ECG monitoring was continued throughout the procedure, and the obtained ECG data were transferred to a PC from the IC card of the recorder. Power spectral analysis of the RR-interval variability was performed by 512-point fast Fourier transformation using SCM-510 , a HRV analysis software program, to obtain the following HRV parameters: low-frequency power . The data are summarized as the means ± standard deviation. The Wilcoxon signed-rank test was used for statistical comparisons between the values before and after ST36 acupuncture treatment. We correlated the changes in COP = 0.721 and P = 0.386, resp.). Significant increases were observed in the CO2 reactivities of both MCAs and the BA during hypocapnia (2ETCO = 40 mmHg) of the BA, whereas the CV40 of both MCAs showed a nonsignificant increasing trend after ST36 acupuncture treatment , but the correlation with increases in the CO2 reactivity of the ipsilateral MCA was slightly greater than the significance cut-off (P = 0.057). This suggests that acupuncture-induced activation of parasympathetic tone plays a role in the improvement of CO2 reactivity.The purpose of the present study was to verify the effect of ST36 on blood flow velocity and the COactivity , 20 and activity , the restic tone . In the 2ETCO = 40 mmHg) of the BA was observed after ST36 acupuncture treatment. We measured all of the variables that can influence CBF and blood flow velocities: mean blood pressure, heart rate, PCO2, and arterial oxygen content [2, mean blood pressure, and heart rate did not change significantly after ST36 acupuncture treatment. We assessed P2ETCO instead of PCO2 because if P2ETCO is not influenced by changes in arterial blood pressure, it represents a close approximation of the arterial PaCO2 [2ETCO response curves for the blood flow velocity of the MCA resemble those of the PCO2 response curves for CBF [2 in humans [2 reactivity is known to be directly related to the regional CBF and inversely related to blood pressure [2 reactivity of both MCAs suggests that the corresponding regional CBF had increased. Further, significant correlations between the increases in CV40 and CO2 reactivity of both MCAs and the BA were observed in this study, indicating that the CO2 reactivity shows a good correlation with both the CV40 and the regional CBF. Although the acupuncture-induced changes in the CV40 of the ipsilateral and contralateral MCAs only showed nonsignificant increasing trend , ST36 acupuncture treatment significantly increased CO2 reactivity of both MCAs, suggesting that the CBF had increased in both MCA territories. Further studies that are performed under similar conditions are needed to confirm the present findings.A significant increase in the mean corrected blood flow velocity  who took placebo drugs was measured by using a protocol similar to that of the current study, and no significant change was observed [2 reactivity of the ipsilateral MCA (P = 0.496) or the contralateral MCA (P = 0.191) in 15 healthy young male volunteers  when using methods and devices identical to those used in the present study to investigate CO2 reactivity. Therefore, although this study did not have a control group, data from our previous studies support the efficacy of ST36 acupuncture treatment on improvement of CO2 reactivity in both MCAs. Another limitation of our study is the small sample size and incomplete demonstration of the mechanism of acupuncture-induced improvement of CO2 reactivity. While the percentage changes in the HF power correlated with the percentage changes in CO2 reactivity in the contralateral MCA, the correlation between the percentage changes in HF power and CO2 reactivity of the ipsilateral MCA was not significant. A great number of subjects should be studied to confirm this theory. Further, other mechanisms such as improvement of endothelial function should be studied in the future. Our results should encourage further studies regarding the effectiveness of acupuncture treatment on improving cerebral haemodynamics in the high-risk stroke population.A limitation of the present study is the lack of a control group; however, we have obtained TCD-measured CVR data in our previous studies that can serve as a historical control group. The COobserved . In our 2 reactivity of both MCAs and the BA during hypocapnia in healthy subjects, which indicates increased vasodilatory potential of the cerebral vasculature to compensate for fluctuations caused by changes in external conditions. Further, the application of acupuncture treatment on ST36 increased the blood flow velocity of the BA, suggesting that the CBF in the BA territory had been increased. Changes in HRV parameters represent an increase in parasympathetic tone due to ST36 acupuncture, and increases in the CO2 reactivity of the contralateral MCA were significantly correlated with increases in the HF power, showing that autonomic nervous system activation plays a role in acupuncture-mediated improvement of cerebral haemodynamics.ST36 acupuncture treatment increased the CO


Supplemental Digital Content is available in the text. 2 sensitivity remain unknown. Here, we investigated potential mechanisms linking brainstem hypoxia and high systemic arterial blood pressure in the spontaneously hypertensive rat. Brainstem parenchymal PO2 in the spontaneously hypertensive rat was found to be ≈15 mm Hg lower than in the normotensive Wistar rat at the same level of arterial oxygenation and systemic arterial blood pressure. Hypoxia-induced activation of rostral ventrolateral medulla oblongata neurons was suppressed in the presence of either an ATP receptor antagonist MRS2179 or a glycogenolysis inhibitor 1,4-dideoxy-1,4-imino-d-arabinitol, suggesting that sensitivity of these neurons to low PO2 is mediated by actions of extracellular ATP and lactate. Brainstem hypoxia triggers release of lactate and ATP which produce excitation of C1 neurons in vitro and increases sympathetic nerve activity and arterial blood pressure in vivo. Facilitated breakdown of extracellular ATP in the rostral ventrolateral medulla oblongata by virally-driven overexpression of a potent ectonucleotidase transmembrane prostatic acid phosphatase results in a significant reduction in the arterial blood pressure in the spontaneously hypertensive rats . These results suggest that in the spontaneously hypertensive rat, lower PO2 of brainstem parenchyma may be associated with higher levels of ambient ATP and l-lactate within the presympathetic circuits, leading to increased central sympathetic drive and concomitant sustained increases in systemic arterial blood pressure.Systemic arterial hypertension has been previously suggested to develop as a compensatory condition when central nervous perfusion/oxygenation is compromised. Principal sympathoexcitatory C1 neurons of the rostral ventrolateral medulla oblongata  are highly sensitive to hypoxia, but the mechanisms of this O Despite significant progress in the diagnosis and treatment of hypertension, approximately only half of patients show satisfactory response to treatment.4 Vasomotor and cardiac activities of spinal sympathetic preganglionic neurons depend on tonic descending excitatory drive generated by sympathoexcitatory (presympathetic) neuronal networks residing in the hypothalamus and the brainstem9: the rostral ventrolateral medulla (RVLM), rostral ventromedial and midline medulla, the A5 cell group of the pons, and the paraventricular hypothalamic nucleus.12 Bulbospinal neurons of the RVLM which belong to the catecholaminergic C1 group are believed to be of a prime importance for the maintenance of vasomotor sympathetic tone.12The pathophysiology of systemic arterial hypertension is complex and in general poorly understood, but over the last 3 decades studies in animal models and patients with hypertension have provided significant evidence that activation of the sympathetic nervous system is linked to the development and maintenance of the condition.13 Although originally described as an autoresuscitation mechanism recruited under extreme pathological conditions such as brain ischemia, it is currently viewed as a physiological compensatory response to compromised brain perfusion or brain hypoxia.15 Brainstem vasculature of patients with hypertension and of animal models of hypertension  is considerably narrower (compared with the respective normotensive counterparts), resulting in high cerebral artery resistance.17 This is not a consequence of hypertension as it occurs prior to its development, at least in the SHR.16 Thus, the neuronal sympathoexcitatory networks that control the arterial blood pressure have been suggested to be hypoperfused/hypoxic.18 By increasing systemic arterial blood pressure in response to compromised brainstem perfusion, the Cushing mechanism would be expected to produce changes in the circulatory system to preserve oxygen delivery and maintain brain oxygenation at the expense of systemic hypertension.19One of the potential mechanisms which may be responsible for sympathetic activation in hypertension is based on the operation of a so-called Cushing response characterized by a triad of high blood pressure, irregular breathing, and bradycardia.22 but the mechanisms of their O2 sensitivity have never been addressed. Brain tissue hypoxia is expected to be associated with increases in the level of extracellular lactate, which was recently shown to have a profound excitatory effect on another notable population of brainstem catecholaminergic neurons residing in the pontine locus coeruleus.23 In addition, we have previously shown that hypoxia triggers release of ATP within the RVLM.24 Other pharmacological studies have revealed that activation of ATP receptors in the RVLM by microinjections of ATP or stable ATP analogues increases the excitability of C1 neurons and leads to the increases in the arterial blood pressure, heart rate, and renal sympathetic nerve activity.27The mechanisms underlying sympathetic activation associated with compromised brain tissue perfusion and hypoxia remain unknown. Presympathetic RVLM neurons are highly sensitive to hypoxia,l-lactate on sympathetic nerve activity and the arterial blood pressure, and determined the effect of blocking ATP-mediated signaling in the RVLM on systemic arterial blood pressure in the SHRs and their normotensive counterparts.This study was designed to test the hypothesis that brainstem hypoxia is associated with the pathogenesis of systemic arterial hypertension. We measured oxygen tension from within the presympathetic RVLM region of the brainstem in the SHRs and control Wistar rats, determined whether oxygen sensitivity of presympathetic C1 neurons is direct or mediated by prior release and actions of ATP and lactate, evaluated the effects of All animal experimentations were performed in accordance with the European Commission Directive 86/609/EEC  and the UK Home Office (Scientific Procedures) Act (1986) with project approval from the respective Institutional Animal Care and Use Committees. Detailed description of the Materials and Methods used in the current study is available in the online-only Data Supplement.O2 in anesthetized SHRs was found to be slightly lower compared with their age- and sex-matched normotensive Wistar rats , brainstem PO2 decreased to 11±1 mm Hg , brainstem PO2 increased to 35±3 mm Hg  was 16±2 mm Hg decreasing to 8±3 mm Hg  when the arterial blood pressure was lowered to the normotensive level. In age- and sex-matched normotensive Wistar rats (n=3), baseline nucleus of the solitary tract PO2 was 19±3 mm Hg (n=3) increasing to 30±5 mm Hg  when blood pressure was increased to the level recorded in the SHRs. These data confirm that the level of the arterial blood pressure determines PO2 of the brainstem parenchyma. The data also demonstrate that the brainstem PO2 in the SHR is ≈15 mm Hg lower than in the Wistar rat at the same level of the systemic arterial blood pressure.At baseline conditions, ventrolateral medullary PP<0.001, paired t test; Figure 24 and the next experiment examined whether the sensitivity of RVLM neurons to low PO2 is dependent on ATP- and lactate-mediated signaling.We next determined whether the sensitivity of RVLM neurons to hypoxia is direct or mediated by prior release and actions of ATP or lactate or both. In the acute brainstem slices of adult Wistar rats, hypoxia was associated with facilitated release of lactate Figure A. Lactat2+]i responses in putative C1 neurons were visualized in organotypic brainstem slices using the genetically encoded Ca2+ indicator TN-XXL expressed under the control of the PRSx8 promoter  with sustained depolarization  and increased rate of action potential firing  also triggered robust [Ca2+]i elevations in ≈60%  of the recorded putative C1 neurons expressing TN-XXL  with a complete recovery within ≈5 minutes of lactate washout , application of l-lactate  on the ventral surface of the medulla oblongata induced profound and sustained (lasting for at least 10 minutes) sympathoexcitatory response, characterized by significant increases in renal sympathetic nerve activity , systolic arterial blood pressure , diastolic arterial blood pressure , and heart rate  RVLM neurons expressing TMPAP , within the C1 area of the RVLM Figure C. This es Figure C. TMPAP P Figure A and a gP Figure B. Thus, O2 (100 mm Hg) and systemic arterial blood pressure (mean ≈95 mm Hg). PO2 measurements were taken from within the brainstem region that contains a major group of RVLM bulbospinal sympathoexcitatory (presympathetic) C1 neurons which generate vasomotor sympathetic tone.30 These neurons are known to be excited by low Po2,31 and our data indicate that their sensitivity to hypoxia is  indirect  and mediated by prior release and actions of ATP and lactate. Tissue hypoxia always leads to lactate release/accumulation32 , resulted in a significant lowering of the arterial blood pressure—the effect which was sustained for 3 weeks. The aim of this experiment was to achieve widespread and strong transgene expression in the general RVLM area. This would ensure effective ATP breakdown and blockade of ATP-mediated paracrine (volume) signaling. Although, only a proportion of the RVLM C1 neurons was transduced, expression of TMPAP by other cellular elements in the area was clearly sufficient to achieve significant reduction of the arterial blood pressure in the SHR. Together these data suggest that decreased parenchymal PO2 in the RVLM leads to higher levels of ambient ATP and lactate which increase the excitability of RVLM neurons, leading to enhanced vasomotor sympathetic tone and high systemic arterial blood pressure. We propose that in the SHR this serves as a compensatory condition needed to maintain adequate blood supply and oxygenation of the brain.This study tested the hypothesis that brainstem hypoxia contributes to the pathogenesis of systemic arterial hypertension. This hypothesis is difficult to test directly as this would require an experimental paradigm allowing differential precise manipulation of peripheral and cerebral oxygenation at different stages of development, including young prehypertensive SHRs. However, our evidence strongly supports the hypothesis. We found that the brainstem of the adult SHR is hypoxic PO2≈10 mm Hg) at physiological levels of the arterial P≈10 mm Hg33 In rats, increasing cerebral vascular resistance was shown to raise sympathetic activity and the arterial blood pressure.16 Moreover, in the SHR, development of hypertension is associated with progressive impairment of neurovascular coupling, elevated baseline capillary red blood cell velocity,34 and impaired autoregulation because of vascular hypertrophy.35 Our data are consistent with these observations and directly demonstrate that the brainstem of SHRs becomes hypoxic when systemic arterial blood pressure decreases to physiological levels.Several previous studies have shown that cerebral vascular resistance is high in patients with hypertension as well as in animal models of hypertension, including the SHRs.Histological analysis revealed robust TMPAP expression in the RVLM even at 6 weeks after the delivery of viral vectors (not shown). Therefore, fading TMPAP expression and declining activity are unlikely to be responsible for the recovery of the hypertensive phenotype in the SHR. Although TMPAP activity is effective in reducing systemic arterial blood pressure, our oxygen measurements suggest that this would also result in reduced cerebral oxygenation. We hypothesize that compensation is likely to develop over time to restore high arterial blood pressure by either recruitment of other mechanisms driving the activity of RVLM presympathetic neurons or by enhanced activity of presympathetic neurons residing in other regions of the central nervous system, not targeted to express TMPAP . Moreover, at later stages of hypertension development in this model, other factors  may become more significant in maintenance of the condition.− application).38 Confirming these reports, hypoxia was found to trigger robust and reproducible [Ca2+]i elevations in 100% of the recorded RVLM neurons. Hypoxia-induced responses in these putative C1 neurons were reduced to a similar extent either in the presence of an ATP receptor antagonist MRS2179  or after incubation of the slice with glycogenolysis inhibitor 1,4-dideoxy-1,4-imino-d-arabinitol. These data suggest that sensitivity of C1 neurons to decreases in PO2 is mostly indirect and mediated by prior release and actions of ATP and lactate. In this study, we demonstrate directly that hypoxia leads to a significant increase in lactate efflux detected at the ventral surface of the brainstem, whereas our previous study reported profound hypoxia-induced release of ATP in the medulla oblongata—an effect observed in anesthetized and artificially ventilated rats and in acute brainstem slices in vitro.24Earlier in vivo and in vitro studies have demonstrated that presympathetic C1 neurons are highly sensitive to hypoxia  in the RVLM41 and markedly enhanced sympathetic responses to microinjections of ATP into the RVLM.42C1 neurons are known to be sensitive to ATP. ATP or stable ATP analogues increase their activity, triggers sympathoexcitation, and increases arterial blood pressure in normotensive rats.23 Lactate is produced by activated astroglial cells and stimulates neurons of the locus coeruleus to release norepinephrine, and these effects are mimicked by application of exogenous lactate.23 As expected, hypoxia triggered release of lactate in the ventrolateral medulla  communicate predominantly via release of ATP.17 These observations in humans further support the hypothesis that brainstem hypoperfusion/hypoxia is an important contributor to the development of hypertension. Whether this is also the case in other cardiovascular diseases where central sympathetic drive is high is not known. However, we have recently shown that a similar mechanism involving facilitated ATP-mediated signaling in the RVLM contributes to sympathetic activation during the development of myocardial infarction-induced heart failure.43 Interestingly, a recent study using cerebral oximetry has demonstrated that cerebral tissue oxygen saturation in many heart failure patients is low, despite nearly normal levels measured in the arterial blood.47 It seems that the same mechanism activated by brainstem hypoxia might be responsible for heightened central sympathetic tone in both heart failure and systemic arterial hypertension.A major clinical problem associated with hypertension is stroke. Many strokes develop as a consequence of brain ischemia rather than hemorrhage. It is of interest that there is a significant association between hypertension before and after posterior cerebral artery infarction compared with anterior cerebral artery infarction.O2 results in higher levels of ambient ATP and lactate within the presympathetic areas of the brainstem leading to the increased activity of sympathoexcitatory neurons and concomitant sustained increases in the arterial blood pressure.The data obtained in the present study suggest that in the SHR low parenchymal PExperimental work described in this paper was funded by The Wellcome Trust (UK) and the British Heart Foundation. N. Marina is a British Heart Foundation Intermediate Basic Research Fellow (ref. FS/13/5/29927). A.V. Gourine is a Wellcome Trust Senior Research Fellow (ref. 095064).None.


Chronic kidney disease (CKD) is increasingly common and under-recognized in primary care clinics, leading to low rates of stage-appropriate monitoring and treatment. Our objective was to determine whether electronic problem list documentation of CKD is associated with monitoring and treatment.2 separated by 90 days and collected between 2007-2008. We examined the association of problem list documentation with: 1) serum eGFR monitoring test, 2) urine protein or albumin monitoring test, 3) an angiotensin converting enzyme inhibitor or angiotensin receptor blocker (ACE/ARB) prescription, 4) mean systolic blood pressure (BP), and 5) BP control.This is a cross-sectional observational study of patients with stage 3 or 4 CKD, defined as two past estimated glomerular filtration rates (eGFR) 15-60 mL/min/1.73 mOut of 3,149 patients with stage 3 or 4 CKD, only 16% of patients had CKD documented on the problem list. After adjustment for eGFR, gender, and race/ethnicity and after clustering by physician, problem list documentation of CKD was associated with serum eGFR testing  and urine protein testing . After adjustment, problem list documentation was not associated with ACE/ARB prescription, mean systolic BP, or BP control.Documentation of CKD on the electronic problem list is rare. Patients with CKD documentation have better stage-appropriate monitoring of the disease, but do not have higher rates of blood pressure treatment or better blood pressure control. Interventions aimed at increasing documentation of CKD on the problem list may improve stage-appropriate monitoring, but may not improve clinical outcomes. Chronic kidney disease (CKD) is prevalent in the United States and successful approaches to treating the disease could reduce healthcare costs and save lives. Ninety-five percent of the 26 million Americans with CKD are in the early stages of disease and are cared for in primary care clinics by primary care physicians (PCPs) . NationaThe electronic problem list in an electronic health record  is a specialized tool which has been proven to improve the quality of care for chronic conditions -18. Seei2, separated by 90 days and collected during routine clinical care between January 1, 2007 to December 31, 2008 [We first gathered data on all of the patients who visited a primary care provider (PCP) at one of 12 primary care clinics in the Brigham and Women’s Primary Care Practice Based Research Network. These clinics serve a diverse set of patients and include hospital-based and community-based clinics, two of which are federally qualified health centers. We included adult patients with stage 3 or 4 CKD, defined as two past estimated glomerular filtration rates (eGFR) between 15-60 mL/min/1.73 m31, 2008 . Our labThe same EHR is used by all 12 clinics. The EHR is a homegrown system called the Longitudinal Medical Record which has been in use since July 2000 . When a We measured the proportion of patients who had CKD documented on the EHR problem list. We also determined the proportion of patients who had other renal diagnoses on the problem list. We examined the association of potential confounders of the relationship between problem list documentation and quality of care using the chi-squared test. We included demographic characteristics  and we accounted for CKD severity as a continuous variable by averaging two consecutive eGFR assessments 90 days apart. We could not account for PCP demographic characteristics, but we examined PCP panels to determine the clustering pattern of patients within panels.We used similar methods to extract data on the five outcomes of interest, while limiting the search to calendar year 2009. We assessed the association of problem list documentation with five stage-appropriate outcomes, taken from nationally accepted guidelines: 1) serum eGFR test , 2) urine albumin/protein test, 3) an ACE or ARB prescription, 4) mean systolic BP, and 5) BP control ,19. We aWe used multivariable logistic and linear regression to adjust for confounders and to produce weighted estimates . We first analyzed the data assuming that each event was independent. Then we conducted analyses accounting for clustering by PCP and found similar results. All unadjusted and adjusted estimates are presented after accounting for clustering by PCP.2 separated by 90 days. Patients had a mean age of 74 years (range 26-104 years) and were predominantly female (Table 2 (standard deviation ±10 mL/min/1.73 m2). Race/ethnicity rates were 67% White, 23% Black, 8% Hispanic, and 1.5% Asian.Of the 79,605 patients who made a visit to a PCP in 2009, there were 3,149 patients with stage 3 or 4 CKD as defined by two eGFR results between 15-60 mL/min/1.73 mOf the patients with a laboratory diagnosis of stage 3 or 4 CKD, 3,074 patients were assigned to one of the 269 PCPs within the Brigham and Women’s Primary Care Practice Based Research Network. Each PCP panel included 1 to 173 patients. We treated the 75 patients who were not assigned to a PCP as independent clusters.Out of 3,149 patients with laboratory evidence of stage 3 or 4 CKD, 488 patients (16%) had CKD on the problem list. Problem list documentation was more likely in patients with lower eGFR, male gender, Black race/ethnicity, or Hispanic race/ethnicity  serum eGFR test, 2) urine protein or albumin test, 3) an angiotensin converting enzyme inhibitor or angiotensin receptor blocker prescription, 4) mean systolic blood pressure, and 5) blood pressure control . The percentage of patients with a serum eGFR test during the one year study period was 94% and there was an association with CKD documentation after adjusting for clustering by PCP . A model adjusting for eGFR, gender, and race/ethnicity, showed a significant association as well . However, the association was no longer significant after adjustment for eGFR, gender, and race. The rate of urine protein or albumin testing in patients with diabetes was 77% and there was no significant association with CKD problem list documentation. This is compared to a rate of 26% in the 2283 patients without diabetes, where there is a significant association of urine protein or albumin testing with CKD documentation , but the association was no longer significant after adjustment for eGFR, gender, and race. The rate of ACE/ARB prescription in patients with diabetes was 86% and there was no significant association with CKD problem list documentation. There were no significant associations between CKD documentation and blood pressure outcomes within the diabetes subgroup.We found that one out of every six patients with laboratory evidence of stage 3 or 4 CKD had CKD documented as a diagnosis on the problem list. The low documentation of this chronic illness shows that there are opportunities to improve the quality of care for CKD patients. Documentation was associated with certain patient characteristics such as disease severity, suggesting that there is a severity threshold above which PCPs are more likely to document CKD on the problem list.We also found that demographic characteristics  are associated with CKD documentation, which is consistent with prior studies. One possibility is that CKD documentation is more common in groups that have higher serum creatinine levels for a given eGFR (men and Black patients ); this fEncouragingly, patients with CKD on the EHR problem list were more likely to receive stage-appropriate monitoring including serum eGFR testing and urine protein testing. The higher rate of urine protein testing is important because recent evidence and expert opinion support the idea that urine protein testing in addition to serum creatinine-based measures provide superior risk stratification ,27. WhenWe did not find a significant relationship between CKD documentation and higher quality treatment, specifically ACE/ARB treatment, after adjustment for age, race and eGFR. Finally, the mean systolic and diastolic BP values were not associated with CKD documentation and when we examined BP control as a dichotomous outcome we found that CKD documentation was not associated with the likelihood of blood pressure control.The low rate of documentation is in agreement with studies that examined CKD documentation using billing codes rather than the EHR problem list. For example, a study which examined billing codes found that CKD was included as a billing code only 14% of the time . AnotherThe strength of this study of electronic problem list documentation was the large dataset from the clinical information system of a primary care network serving a diverse population. Despite these strengths, our study has several limitations. Though we utilized longitudinal data, we analyzed the data in a cross-sectional fashion. Therefore, we cannot assume that associations are causal in nature. PCPs may choose not to add CKD as a separate diagnosis when a patient already has a renal diagnosis . It is possible that certain PCPs characteristics  confound the association between documentation and quality of care, but we chose to cluster patients within PCP panels for this reason. When considering limitations of measures, data on laboratory tests was limited to those performed in our hospital’s affiliated laboratories, but the population only included patients who had seen one our affiliated PCPs during the study period and all lab orders are automatically routed through our central laboratory. We attempted to control for severity of CKD by adjusting for eGFR as a continuous measure, but this may not accurately reflect severity of disease. Similarly, we only captured ACE/ARB prescriptions written using our electronic prescribing module, but all PCPs were using this module almost exclusively during the study period. We did not include serum creatinine tests unless an eGFR was reported by the lab as well, but eGFR has been routinely reported by our lab for the past decade. We used the last BP reading rather than a synthesis of multiple blood pressure readings over the study period, which may affect the validity of the measure . Due to Documentation of CKD on the electronic problem list was uncommon and more likely in patients with certain demographic characteristics and more severe CKD. CKD documentation was positively associated with stage-appropriate monitoring, both serum eGFR testing and urine protein testing. However, CKD documentation was not associated with higher rates of blood pressure treatment or better blood pressure control. Therefore, interventions aimed at increasing documentation of CKD can improve monitoring, but documentation alone is not sufficient to improve treatment or intermediate clinical outcomes.The authors declare that they have no competing interests.LS had complete access to data, performed the statistical analysis, and drafted the manuscript. JAL, DWB, and AW have each made substantial contributions to conception and design, and interpretation of data; have been involved in revising the manuscript; and have given final approval of the version to be published. All authors read and approved the final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2369/15/70/prepubA. Options provided within the electronic medical record to add renal diagnoses to the problem list. B. Data Validation study.Click here for file


Supplemental Digital Content is available in the text. P<8.9×10−5). Replication was conducted in 2 independent cohorts KORA (n=1494) and Hertfordshire (n=1515). Three independent animal experiments were performed to establish causality: (1) blood pressure change after increasing circulating metabolite levels in Wistar–Kyoto rats; (2) circulating metabolite change after salt-induced blood pressure elevation in spontaneously hypertensive stroke-prone rats; and (3) mesenteric artery response to noradrenaline and carbachol in metabolite treated and control rats. Of the15 metabolites that showed an independent significant association with blood pressure, only hexadecanedioate, a dicarboxylic acid, showed concordant association with blood pressure  and mortality  in TwinsUK. The blood pressure association was replicated in KORA and Hertfordshire. In the animal experiments, we showed that oral hexadecanedioate increased both circulating hexadecanedioate and blood pressure in Wistar–Kyoto rats, whereas blood pressure elevation with oral sodium chloride in hypertensive rats did not affect hexadecanedioate levels. Vascular reactivity to noradrenaline was significantly increased in mesenteric resistance arteries from hexadecanedioate-treated rats compared with controls, indicated by the shift to the left of the concentration–response curve (P=0.013). Relaxation to carbachol did not show any difference. Our findings indicate that hexadecanedioate is causally associated with blood pressure regulation through a novel pathway that merits further investigation.High blood pressure is a major contributor to the global burden of disease and discovering novel causal pathways of blood pressure regulation has been challenging. We tested blood pressure associations with 280 fasting blood metabolites in 3980 TwinsUK females. Survival analysis for all-cause mortality was performed on significant independent metabolites ( More importantly, 54% of stroke and 47% of ischemic heart disease are directly attributable to hypertension, thus primarily responsible for one quarter of the 52.8 million deaths recorded globally in 20102. The causation of hypertension is multifactorial and is related to perturbations in the pathways that regulate BP through renal, renin–angiotensin–aldosterone and autonomic systems. Despite the availability of numerous drugs for the treatment of hypertension, only one third of treated patients achieve target and this can be partially explained by the complexity of BP regulatory mechanisms that are different in each individual.3 New drug development for hypertension has essentially stalled during the past 10 years and there is a need to discover novel biological pathways for hypertension that will help identify novel drug targets or enable effective targeting of therapy.4 The hypothesis generating approach using genome-wide association studies while successful at identifying common variants associated with blood pressure6 have resulted in few tractable loci and novel pathways.8 Recent advances in metabolomics enable the capture of a snap-shot of the metabolic profile of the individual, allowing for the potential identification of novel pathogenic pathways.11Hypertension is the most prevalent modifiable risk factor for cardiovascular morbidity and mortality, with the World Health Organization estimating that the current 1 billion people with high blood pressure (BP) worldwide will rise to 1.5 billion by 2020In this study, we performed nontargeted metabolomic screening to discover metabolites associated with BP integrating data from dietary intake and mortality outcomes in a large female twin cohort from the United Kingdom and replicated our findings in 2 independent populations from Germany and England. Finally, we use animal models to establish causality.12 without renal impairment (estimated glomerular filtration rate >60 mL/min per 1.73 m2) and not on any BP-lowering medications. The study was approved by St. Thomas Hospital Research Ethics Committee. All participants provided informed written consent. Further details are available in the online-only Data Supplement. TwinsUK metabolomics, and phenotypic data are publicly available on request on the department website (http://www.twinsuk.ac.uk/data-access/accessmanagement/).Metabolomic data were analyzed for 3980 female participants from TwinsUK9Nontargeted detection and quantification of 280 structurally named biochemicals was conducted by Metabolon, Inc  on 1052 serum and 5003 plasma fasting samples from TwinsUK participants as previously described.2) from the population-based KORA S4 study .13We included 1494 individuals comprising nearly equal numbers of males and females, with BP, metabolomics data and without renal impairment  rats  were used. Eleven-week-old male WKY rats were treated with hexadecanedioic acid  or vehicle control (n=6) for 4 weeks. Twelve-week-old male SHRSP rats received 1% NaCl in drinking water for 3 weeks (n=6). Systolic BP (SBP) was measured by tail plethysmography in conscious, restrained animals.18 BP recordings were carried out before salt challenge or hexadecanedioic acid treatment and during the final week of treatment. An average of 6 to 8 pressure readings were taken for each rat per sitting. Statistical comparisons were made using Student t test. In addition, telemetry probes  were implanted at 10 weeks of age with 1 week of recovery before administration of hexadecanedioic acid  or vehicle control (n=5) for 3 weeks in WKY rats. Statistical analysis of the radiotelemetry data was carried out using appropriate summary measures followed by Student t test.19All animal procedures performed were approved by the UK Home Office. Male spontaneously hypertensive stroke-prone (SHRSP) ratsL1) to achieve optimal contraction. Internal diameter was calculated using the following equation: L1=0.0×L100 . After further 60 minutes, contractile responses to 10 μmol/L KCl were examined, followed by washout. A cumulative concentration–response curve to noradrenaline, 10 nmol/L to 30 μmol/L was performed. In addition, vessels were preconstricted to the effective concentration (EC50) of noradrenaline and a concentration–response curve for carbachol (10 nmol/L–10 μmol/L) was obtained. Area under the curve data were calculated from the mesenteric artery response curves (n=10 hexadecanedioate treated and n=9 control) and statistical comparisons were made using Student t test.Mesenteric resistance artery function was assessed by wire myography. Resistance arteries were dissected from connective tissue and segments (≈2 mm in length) were mounted as ring preparations on 2 stainless steel wires in a 4-channel small vessel myograph . One wire was attached to a force transducer and the other to a micrometer. After a 30-minute rest period, vessels were set to normalized internal diameter  were included in a backward regression model reducing the number of predictors for SBP and DBP.Metabolites associated with SBP and diastolic BP (DBP) were identified by linear regression adjusting for age,20 we tested their effect on the association between the metabolites represented independent variables using random intercept linear regressions.As dietary factors  and genotype risk scores are known to affect BP to varying levels,2 sex, and body mass index.In KORA and Hertfordshire, the covariates in the regression model included age,Kaplan–Meier survival analysis (univariate) and Cox proportional hazards modeling  were used to study association of tertiles of metabolites on all-cause mortality in TwinsUK.The overall analysis pipeline is presented in Figure S1 in the online-only Data Supplement.P<8.9×10−5 after multivariate adjustment; Table S1 in the online-only Data Supplement). Backward linear regressions identified 15 metabolites independently associated with SBP or DBP—14 metabolites for SBP (R2=32%), 7 for DBP (R2=21%) with 6 in common , and caffeine are shown in the Kaplan–Meier plots . Multivariate-adjusted Cox proportional hazard models showed hexadecanedioate , dihomo-linoleate , and caffeine  significantly associated with all-cause mortality  was significantly associated with both SBP and DBP in the KORA S4 population after adjusting for covariates. Hexadecanedioate was also significantly associated with both SBP and DBP in the Hertfordshire cohort .The replication KORA S4 cohort included 1494 individuals , whereas the Hertfordshire cohort included 1515 individuals . Hexadecanedioate  compared with untreated controls when measured by tail-cuff plethysmography , but did not show any separation with DBP or heart rate . Vascular reactivity to noradrenaline was significantly increased in mesenteric resistance arteries from hexadecanedioate-treated rats compared with controls, indicated by the shift to the left of the concentration response curve  with a causal role supported by in vivo studies in rats. After screening 280 metabolites in the discovery TwinsUK cohort, we identified 77 metabolites significantly associated with SBP or DBP. To limit the number of metabolites to take forward for replication, we narrowed the list down to 15 independent metabolites through a series of sequential analytic steps to address the observed correlations between metabolite levels. These 15 metabolite signals were also independent of fruit/vegetable or alcohol intake and BP genome-wide association study risk score all of which affect BP to varying levels.21 but this was not evident in our study.Only 3 metabolites (dihomo-linoleate (20:2n6), hexadecanedioate, and caffeine) showed significant associations with mortality in TwinsUK. More importantly, only 1 metabolite (hexadecanedioate) of the 3 showed directionally consistent and significant associations with both BP and mortality suggesting a possible sustained detrimental effect of higher levels of the metabolite through increased BP. This is in contrast to the other 2 metabolites, dihomo-linoleate (20:2n6) and caffeine, which did not increase mortality, despite showing positive associations with BP. In addition, we performed survival analysis on other dicarboxylic acids  and none of them showed significant concordant association with mortality. Although our discovery analysis included only women who were not on any BP-lowering medications, we are able to demonstrate generalizability of our results for hexadecanedioate through replication in the KORA and Hertfordshire study, both of which included male and female subjects and hypertensive subjects on treatment. Our discovery results are maintained even after inclusion of individuals from the TwinsUK cohort who were on BP-lowering medications (Table S5 in the online-only Data Supplement). We recognize that the lack of concordant mortality effect with BP association for dihomo-linoleate (20:2n6) and caffeine does not conclusively exclude a pathological effect, but we think further analyses of dihomo-linoleate (20:2n6) in larger cohorts with more events is warranted before further functional studies are conducted. The lack of a detrimental effect on survival for caffeine levels reflects the acute effect of caffeine on blood pressure, which varies with intake. We had a priori excluded individuals with renal impairment in our analysis and adjusting for estimated glomerular filtration rate did not alter the BP hexadecanedioate association. There is evidence that long-chain fatty acids, such as docosahexaenoic acid influence BP potentially through an effect on large-conductance Ca(2+)- and voltage-activated K+ (BK) channels,We performed 3 in vivo experiments to establish causality of hexadecanedioate on BP regulation. In the first, after oral intake of hexadecanedioate, normotensive WKY rats showed an increase in circulating hexadecanedioate levels along with an increase in BP, both of which were statistically significant. In the second experiment, we measured hexadecanedioate levels in the SHRSP rat before and after administration of salt, which resulted in a further increase in BP but no change in circulating hexadecanedioate levels. Interestingly hexadecanedioate levels in the SHRSP rats were higher than that of WKY rats at baseline, and levels were similar between SHRSP and posthexadecanedioate WKY rats. We used radio-telemetry to provide confirmation of our tail-cuff plethysmography data and to determine the time course of the hexadecanedioate-induced rise in blood pressure. From the radio-telemetry data, the increase in SBP and mean arterial pressure is not immediate after hexadecanedioate administration, with separation of SBP and mean arterial pressure between control and hexadecanedioate-treated animals occurring after day 15 of treatment. This suggests that the mechanism by which hexadecanedioate affects BP is probably through secondary downstream pathways activated by higher hexadecanedioate levels. The increased vascular reactivity to noradrenaline shown by mesenteric arteries of hexadecanedioate-treated rats point to a vascular mechanism underlying the association of hexadecanedioate and blood pressure. Although these are preliminary data, overall they provide strong corroborative evidence of a causal role for hexadecanedioate in modulating blood pressure and support further research in validating and elucidating the mechanisms.23 A lack of carnitine can lead to increased ω-oxidation.24 In our data, we find that levels of hexadecanedioate are indeed negatively correlated with carnitine , as well as disturbances in β-oxidation.+K+-ATPase activity in vascular smooth muscle cells through increase in intracellular Na+ and decrease of passive Na+/Ca2+ exchange or through partial depolarization of cell membrane and activation of voltage-dependent Ca2+ channels resulting in increased intracellular Ca2+ concentration and a relative elevation of vascular tone, thus promoting the development of hypertension.26Multiple strands of evidence from related pathways point to potential mechanisms that can inform future studies to dissect the hexadecanedioate BP association. Nonesterified fatty acids reduce Na27 Indeed metabolic dysfunction and acquired mitochondrial abnormalities leading to abnormal glycolytic and fatty acid metabolism are now recognized as a potential biological mechanism leading to both pulmonary vascular remodeling with aberrant cellular proliferation and apoptosis, and in the development of right ventricular failure.29 Fatty acid metabolism could offer a novel therapeutic pathway, which would potentially target both pulmonary vasculature and the right ventricle.Interestingly, a recent report showed multiple dicarboxylic acids, including hexadecanedioate, to be significantly accumulated in pulmonary arterial hypertension tissues indicating a disruption of β-oxidation and an increase of ω-oxidation in this condition and pointing to a putative role in elevating pressure in both the systemic and the pulmonary circulations.31 and has a liver-specific calorigenic-thyromimetic action characterized by a decrease in liver phosphate potential and liver redox potential with an increase in oxygen consumption, but its effect on BP has not been studied thus far.33 Endogenous hexadecanedioate may be a putative marker either for the perturbations in immunologic processes or lipid β-oxidation that lead to high blood pressure, and further studies are needed to clarify the mechanism. Human metabolomic studies are potentially confounded by diet or drug effects, as well as other comorbidities.34 In our discovery study, we tested for the effect of diet and alcohol intake, excluded individuals who were on antihypertensive therapy and looked for corroborative evidence of increased mortality.Some of the specific functional effects of hexadecanedioate have been studied using β,β′-tetramethylhexadecanedioic acid (MEDICA 16), which is not metabolized and hence the effects of downstream metabolic products that may mask the effects of hexadecanedioate are minimized. MEDICA 16 has been shown to be effective as a hypolipidemic and antiobesity/anti-insulin resistance agent in experimental models,We note some limitations to our study. All the human metabolomics analysis is cross-sectional so we cannot dissect causality from it alone. We used all-cause mortality rather than incident hypertension or cardiovascular mortality because of lack of data. Our 2-stage approach was designed to take forward a limited number of metabolites for replication to attenuate the multiple testing burden and the high false-positive rates seen in high-throughput discovery studies. We recognize that hexadecanedioate may be a low-hanging fruit and that there will exist other valid metabolites that are associated with BP. Although our in vivo studies support a role for hexadecanedioate in BP regulation, the exact causal pathway is not established. The increased vascular reactivity to noradrenaline in hexadecanedioate-treated rats may be either a consequence of hypertension or a cause, and this needs to be elucidated in future experiments.Using a multilayered approach comprising metabolomic profiling in twins followed by replication studies and in vivo experiments, we have uncovered a putative novel pathway of BP regulation involving a dicarboxylic acid, hexadecanedioate. Preliminary studies from pulmonary hypertension suggesting an accumulation of dicarboxylic acids in this condition supports a possible vascular role for dicarboxylic acids in increasing pressure in both the systemic and pulmonary circulation. Studies on fatty acid metabolism could offer a novel therapeutic pathway, which would potentially target both pulmonary and systemic hypertension. Our finding may indeed be a low-hanging fruit but as it points to a previously unknown pathway for blood pressure regulation these results should stimulate further studies specifically along 2 strands—(1) confirm and elucidate the mechanistic underpinnings of the role of fatty acid ω-oxidation in blood pressure regulation and (2) identify other true causal metabolite associations.We wish to express our appreciation to all study participants of the TwinsUK, KORA, and Hertfordshire studies.This work was supported by: the EU Framework Programme 7 small-scale focused research collaborative project EurHEALTHAging 277849; Metabolomic analysis was funded by Pfizer; TwinsUK was funded by the Wellcome Trust (Ref: 081878/Z/06/Z); European Community’s Seventh Framework Programme (FP7/2007–2013). The study also receives support from the National Institute for Health Research (NIHR) Clinical Research Facility at Guy’s and St. Thomas’ National Health Service (NHS) Foundation Trust and NIHR Biomedical Research Centre based at Guy’s and St Thomas’ NHS Foundation Trust and King’s College London. T. Spector is an NIHR senior Investigator and is holder of an ERC Advanced Principal Investigator award. S.-Y. Shin is supported by a Post-Doctoral Research Fellowship from the Oak Foundation. N. Soranzo team is supported by the Wellcome Trust (Grant Codes WT098051 and WT091310), the EUFP7 (EPIGENESYS Grant Code 257082 and BLUEPRINT Grant Code HEALTH-F5-2011–282510). The KORA research platform  was initiated and financed by the Helmholtz Zentrum München—German Research Center for Envirnomental Health, which is funded by the German Federal Ministry of Education and Research and by the State of Bavaria. Furthermore, KORA research was supported within the Munich Center of Health Sciences , Ludwing-Maximilians-Universität, as part of LMUinnovativ. The Hertfordshire Cohort Study was supported by the Medical Research Council (MRC) of Great Britain; Arthritis Research UK; and the International Osteoporosis Foundation. The work herein was also supported by the NIHR Nutrition Biomedical Research Centre, University of Southampton, and the NIHR Musculoskeletal Biomedical Research Unit, University of Oxford.R.P. Mohney is an employee of Metabolon, Inc. M.J. Brosnan is full time employee and share holder of Pfizer. J. Trimmer is a share holder of Pfizer. The other authors report no conflicts.


Physical activity is recommended as a part of a comprehensive lifestyle approach in the treatment of hypertension, but there is a lack of data about the relationship between different intensities of physical activity and cardiovascular parameters in hypertensive patients. The purpose of this study was to investigate the association between the time spent in physical activities of different intensities and blood pressure levels, arterial stiffness and autonomic modulation in hypertensive patients.In this cross-sectional study, 87 hypertensive patients (57.5 ± 9.9 years of age) had their physical activity assessed over a 7 day period using an accelerometer and the time spent in sedentary activities, light physical activities, moderate physical activities and moderate-to-vigorous physical activities was obtained. The primary outcomes were brachial and central blood pressure. Arterial stiffness parameters (augmentation index and pulse wave velocity) and cardiac autonomic modulation (sympathetic and parasympathetic modulation in the heart) were also obtained as secondary outcomes.P < 0.01), central systolic , brachial diastolic  and central diastolic  blood pressures, after adjustment for sex, age, trunk fat, number of antihypertensive drugs, accelerometer wear time and moderate-to-vigorous physical activities. Arterial stiffness parameters and cardiac autonomic modulation were not associated with the time spent in sedentary activities and in light physical activities (P > 0.05).Sedentary activities and light physical activities were positively and inversely associated, respectively, with brachial systolic (r = 0.56; Lower time spent in sedentary activities and higher time spent in light physical activities are associated with lower blood pressure, without affecting arterial stiffness and cardiac autonomic modulation in hypertensive patients. Hypertension affects 30 to 45% of adults worldwide, and hasAs part of a comprehensive lifestyle modification approach, hypertensive patients are advised to practice at least 30 min of moderate-to-vigorous physical activity (MVPA) on five to seven days per week, 4, 5. IStudies have shown controversial results on the influence of the time spent doing MVPA, light physical activities (LPA) and sedentary activities (SED) on cardiovascular health–16. MoreUnderstanding of how the time spent in physical activity of different intensities affects cardiovascular parameters in patients with hypertension is necessary to expand public health recommendations for these patients, including suggestions related to physical activity intensity. Thus, the purpose of this study was to investigate the association between the time spent in physical activity of different intensities and BP levels, arterial stiffness and autonomic modulation in hypertensive patients. Our hypothesis was that less time spent in SED and more time spent in physical activities are associated with better BP, arterial stiffness and cardiac autonomic modulation indicators in hypertensive patients.Patients were recruited for possible enrolment into a Randomized Clinical Trial (NCT02257268) related to a lifestyle modification program in hypertensive subjects. The data and analyses for the current cross-sectional study were part of the baseline assessments obtained for this Randomized Clinical Trial. The recruitment was carried out through local media advertisements and flyers distributed in hospitals and in the surrounding area of the University of Pernambuco, Recife, Pernambuco State (northeast of Brazil), in 2014. The study protocol was approved by the ethics committee of the Federal University of Santa Catarina (811.266) in compliance with the Brazilian National Research Ethics System Guidelines. Written informed consent was obtained from each patient prior to investigation.As inclusion criteria, participants were required to be 40+ years old, hypertensive and to have been taking antihypertensive drugs for at least three months prior to the study. Additionally, participants were required not to have diabetes, other cardiovascular diseases or physical disabilities, and not to be involved in regular physical activity programs.Physical activity was assessed by a GT3X or GT3X+ accelerometer  and Actilife software  was used to analyze collected data. Each participant was instructed to use the accelerometer for seven consecutive days, removing it only to sleep, bathe or perform activities involving water. The device was attached to an elastic belt and fixed to the right side of the hip. Data were collected with a 30 Hz sample frequency and were analyzed using 60 s epochs. Periods with consecutive values of zero (with a 2 min spike tolerance) for 60 min or longer were interpreted as “accelerometer not worn” and excluded from the analysis. PhysicaPrior to all outcome measurements, the patients were instructed to avoid physical exercise for at least 24 hours prior to the visit, avoid smoking, alcohol and caffeine ingestion for at least 12 hours and to eat a light meal before arriving at the laboratory. In the laboratory, a rest period of 10 min in the supine position prior to taking the measurements was instructed. All measurements were taken in the supine position in a quiet environment, with monitored temperature. The volunteers were asked to attend the laboratory twice. During the first visit the patients were submitted to anthropometry, heart rate variability and body composition assessments. At the end of this first visit, they received the accelerometer to use during the following seven days. After this period, they returned with the accelerometer to the laboratory for the second visit, at the same time of the day as the first visit and brachial and central BP and arterial stiffness were evaluated, in this order.Brachial systolic and diastolic BP were measured on the left arm using an automatic oscillometric instrument . Measurements were taken on two non-consecutive days, and three measurements were performed on each day, with a one minute interval between measurements. The mean of all BP values measured was used for analysis. All the measurements were taken by the same evaluator (systolic BP: ICC = 0.85 and diastolic BP: ICC = 0.92).Central systolic and diastolic BP were obtained by the pulse wave analysis that was recorded in the left radial artery using applanation tonometry  and the validated transfer function algorithm provided by the Sphygmocor® software. All measurements were performed by the same evaluator (systolic BP: ICC = 0.84 and diastolic BP: ICC = 0.72), according to guidelines specified by the Clinical Application of Arterial stiffness, Task Force III. To enhaBody mass was measured with participants wearing light clothes and barefoot, using an automatic scale  accurate to the nearest 0.1 kg. Height was measured using a stadiometer connected to a scale accurate to the nearest 0.5 cm. Demographic information and a list of current antihypertensive drugs used were obtained by individual interview.Total body fat and trunk fat were estimated by densitometry scans for dual-energy X-ray absorptiometry . Scans were performed with patients in the supine position along the longitudinal centerline axis of the table. The software generated standard lines that separated the limbs from the trunk and head. For the assessment, participants were instructed to remain clothed, but were asked to remove any metallic objects. The procedure lasted five to ten minutes for each individual and was carried out by the same technician who calibrated the device. All the procedures were carried out following the manufacturer’s recommendations. The percentage of fat was calculated by dividing the amount of fat by the weight of the segment analyzed .The arterial stiffness and wave reflection parameters were obtained through carotid-femoral pulse wave velocity (cfPWV) and augmentation index respectively. For these measurements, the applanation tonometry  method was used. The measurement of these parameters was performed by the same evaluator (cfPWV: ICC = 0.91 and AI: ICC = 0.80) according to guidelines specified by the Clinical Application of Arterial Stiffness, Task Force III. The augFor cardiac autonomic modulation assessment, R-R interval was obtained using a heart rate monitor . Participants remained in the supine position for 10 minutes, after approximately 10 minutes at rest. All analyses were performed with Kubios HRV software  by a single evaluator (ICC = 0.99), following the recommendations of the Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. The freThe data were stored and analyzed using the Statistical Package for the Social Sciences (SPSS Version 17.0 for Windows). Normality was checked using the Shapiro-Wilk test and the Levene test was used to analyze the homogeneity of variances. Continuous variables were summarized as mean and standard deviations or in median and inter-quartile range, whereas categorical variables were summarized as relative frequencies.st tertile: < 492.42; 2nd tertile: 492.42–570.67; 3rd tertile: > 570.67 min/day) and LPA . Comparison among patients classified according to tertiles of minutes spent in MPA  was also tested by ANCOVA one-way, with sex, age, trunk fat, number of antihypertensive drugs, accelerometer wear time and LPA as covariables.Mean values of cardiovascular risk factors were compared using the ANCOVA one-way test with sex, age, trunk fat, number of antihypertensive drugs, MVPA and accelerometer wear time as covariables, according to the level of physical activity, categorized by low, moderate and high, according to tertiles, for SED  and also including MVPA (model 2). The same approach was employed to analyze the relationship between MPA and cardiovascular parameters adjusting for sex, age, trunk fat, number of antihypertensive drugs used and accelerometer wear time with and without including LPA. A residual analysis was performed, and adherence to the normal distribution was tested using the Shapiro-Wilk test. Multicollinearity analysis was performed assuming variance inflation factors less than five and tolerance below 0.20. For all the statistical analyses, significance was accepted at The required sample size (n = 51) for linear multiple regression test was calculated using the software GPower (3.1.9), considering the brachial systolic BP as the main variable, an alpha of 95%, a power of 80%, an effect size of 0.33 predicted by a squared correlation coefficient of 0.25, and seven variable predictors.Eighty-seven patients  participated in this study . MinutesP < 0.05), while the group with higher time in LPA presented lower systolic  and diastolic  BP (P < 0.05) .After adjustments it was observed that the patients with higher time in SED presented higher systolic  and diastolic  BP (P > 0.05)  .P = 0.01). Those classified in the first tertile (< 12.7 min/day of MPA) had LF and HF higher and lower (Δ = 7.5 (n.u.)), respectively, than those in the 3rd tertile (> 23.1 min/day of MPA). Considering MVPA, the results of this analysis were similar.Regarding the comparison among patients classified according tertiles of minutes spent in MPA, significant differences were observed only for LFnu and HFnu  after adjustment for sex, age, trunk fat, number of antihypertensive drugs and accelerometer wear time (model 1). When MVPA was included in the adjusted analysis (model 2) the relationships between LPA and all the BP measurements remained significant (P < 0.05) . Arterial stiffness parameters and cardiac autonomic modulation were not related to LPA in both models of adjusted analysis (P > 0.05).Inverse relationships were observed between LPA and BP  (P < 0.05) and model 2 . There were no relationships between SED and arterial stiffness and cardiac autonomic modulation (P > 0.05).Inversely to results seen with LPA, time spent in SED was positively associated with brachial and central systolic and diastolic BP both in model 1 , arterial stiffness  or cardiac autonomic modulation  after adjustment for confounders.Time spent in MPA was not associated with BP (bSBP: ß = 0.07 and P > 0.05), before or after adjustment for confounders.No significant association was observed between SED, LPA or MPA and the number of antihypertensive drugs used (The main findings of the present study were: (i) SED and LPA were related to both brachial and central BPs in hypertensive patients; (ii) arterial stiffness and cardiac autonomic modulation parameters were not associated with the time spent in SED and LPA. The BP results concurred with our hypothesis, while the findings regarding arterial stiffness and cardiac autonomic modulation parameters did not.The strengths of the study include the use of scientifically recognized techniques to assess physical activity, brachial and central BPs. Brachial BP was measured twice in non-consecutive days and only hypertensive patients were included in the study, contributing to a better comprehension about the influence of different physical activity intensities on hypertension. In addition the inclusion of the trunk fat as a confounder factor should be highlighted, since it was assessed by one of the best techniques to evaluate body composition, and becThe relationship between the time spent in SED and BP observed in this study is in agreement with a previous study of hypertensive patients. AdditioAssociations between higher time spent in LPA and improvements in several cardiovascular risk factors such as triglycerides, HDL choInterestingly, LPA was also inversely associated with central BP, indicating that LPA influences both peripheral and central arteries. Hypertensive patients present increased BP in both central and peripheral arteries, however antihypertensive treatment strategies have shown different effects on brachial and central BP, most of them acting mainly in peripheral arteries, 29. As The time spent in MPA was not associated with BP. Although these results are in disagreement with previous studies, 33 whicIn addition neither SED, LPA nor MPA were associated to arterial stiffness parameters and cardiac autonomic modulation, which does not concur with previous studies, 14, 35.The positive and inverse relationship between SED and LPA, respectively, and brachial and central BP show the importance of LPA in hypertensive patients. Thus, physical activity prescription should consider the recommendation of LPA for BP control, especially because it is easier to include in daily activities. TherefoThe cross-sectional design is the major limitation of this study. Interventional studies are required to confirm these findings and to make inferences about causality. Additionally, we suggest for future studies the rigorous control of antihypertensive drugs. The patients were using different antihypertensive drugs. Although the lack of association between SED, LPA or MPA and the number of antihypertensive drugs used may be related to other factors related to cardiovascular control , specific influence of the type and dose can have occurred, which was not controlled in the study. The small sample size and the impossibility to access cfPWV of all participants due to technical difficulties, should also be considered as limitations of this study, and could partially help to explain why the expected association between SED and LPA and arterial stiffness and cardiac autonomic modulation was not seen. Finally, as the subjects of this study were not engaged in regular exercise programs, the results could not be extrapolated for patients who are engaged in such programs.In conclusion, this study indicated that lower time spent in SED and higher time spent in LPA are associated with lower brachial and central BP, without affecting arterial stiffness and autonomic modulation in hypertensive patients.S1 FigSED = sedentary activities; LPA = light physical activities; bSBP = brachial systolic blood pressure; bDBP = brachial diastolic blood pressure; cSBP = central systolic blood pressure; cDBP = central diastolic blood pressure.(XLS)Click here for additional data file.S2 FigLPA = light physical activities; bSBP = brachial systolic blood pressure; bDBP = brachial diastolic blood pressure; cSBP = central systolic blood pressure; cDBP = central diastolic blood pressure.(XLS)Click here for additional data file.


Severe asthma are linked with high morbidity, significant mortality and high treatment costs. Omalizumab has been shown to decrease the risk of hospitalization or Emergency Department (ED) visits in patients with uncontrolled severe allergic asthma. We aim to describe the conditions under Omalizumab was prescribed in patients followed in a Reference Center for Severe Asthma Treatment in Nova Iguaçu, Rio de Janeiro; and assess the effects of Omalizumab through the Asthma Control Test (ACT) in those patients who had at least a 16 week course.Asthmatic patients treated with omalizumab between February 2013 and June 2014 were evaluated retrospectively. The conditions under Omalizumab was prescribed and ACT improvements were evaluated.A total of 19 patients  were prescribed omalizumab. Prescribing criteria were: one or more ED visits in the last year (100%); high dose inhaled corticosteroid and long-acting beta2agonist use (94.7%); systemic corticosteroid use more than 3 times the last year (89.5%); FEV<80% (78.9%); daily short-acting beta2agonist use (68.4%); fast pulmonary function deterioration after systemic corticosteroid withdrawal (52.6%); death threatening asthma exacerbation episode (42%). Seven of these patients had a 16 week course of omalizumab with a significant improvement in ACT total score in six of them (86%).In our casuistic, the main criteria omalizumab was prescribed for severe asthma was ED visits. Omalizumab promoted a significant improvement in most patients' ACT total score.