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Background: The renin-angiotensin-aldosterone system (RAAS) is an important driver of blood pressure (BP), but the association of the RAAS with ambulatory BP (ABP) and ABP monitoring phenotypes among African Americans has not been assessed.Methods: ABP and ABP monitoring phenotypes were assessed in 912 Jackson Heart Study participants with aldosterone and plasma renin activity (PRA). Multivariable linear and logistic regression analyses were used to analyze the association of aldosterone and PRA with clinic, awake, and asleep systolic BP and diastolic BP (DBP) and ABP monitoring phenotypes, adjusting for important confounders.Results: The mean age of participants was 59±11 years and 69% were female. In fully adjusted models, lower log-PRA was associated with higher clinic, awake, and asleep systolic BP and DBP (all P<0.05). A higher log-aldosterone was associated with higher clinic, awake, and asleep DBP (all P<0.05). A 1-unit higher log-PRA was associated with lower odds of daytime hypertension (odds ratio [OR] 0.59 [95% CI, 0.49-0.71]), nocturnal hypertension (OR, 0.68 [95% CI, 0.58-0.79]), daytime and nocturnal hypertension (OR, 0.59 [95% CI, 0.48-0.71]), sustained hypertension (OR, 0.52 [95% CI, 0.39-0.70]), and masked hypertension (OR 0.75 [95% CI, 0.62-0.90]). A 1-unit higher log-aldosterone was associated with higher odds of nocturnal hypertension (OR, 1.38 [95% CI, 1.05-1.81]). Neither PRA nor aldosterone was associated with percent dipping, nondipping BP pattern, or white-coat hypertension. Patterns for aldosterone:renin ratio were similar to patterns for PRA.Conclusions: Suppressed renin activity and higher aldosterone:renin ratios were associated with higher systolic BP and DBP in the office and during the awake and asleep periods as evidenced by ABP monitoring. Higher aldosterone levels were associated with higher DBP, but not systolic BP, in the clinic and during the awake and asleep periods. Further clinical investigation of novel and approved medications that target low renin physiology such as epithelial sodium channel inhibitors and mineralocorticoid receptor antagonists may be paramount in improving hypertension control in African Americans. [ABSTRACT FROM AUTHOR]

Rationale: The renin-angiotensin-aldosterone system is a major pathway in regulating blood pressure, glomerular filtration, and fluid homeostasis. During inflammatory diseases, generation of angiotensin II might be disturbed, leading to increased renin concentrations. Cardiac surgery and the use of cardiopulmonary bypass both induce inflammatory response and cardiovascular instability, which can contribute to acute kidney injury (AKI).Objectives: To investigate whether renin concentrations are associated with hypotension and AKI.Methods: This is a single-center, prospective, observational study among patients undergoing cardiac surgery.Measurements and Main Results: The primary endpoint was the occurrence of AKI within 72 hours after cardiac surgery. A total of 197 patients were available for the primary analysis. The median renin serum concentration was 40.2 μU/ml (quartile 1 [Q1]-Q3, 9.3-144.4) at baseline and 51.3 μU/ml (Q1-Q3, 19.1-167.0) 4 hours after cardiac surgery, whereas the difference between postoperation and preoperation concentrations (Δ-renin) was 3.7 μU/ml (Q1-Q3, -22.7 to 50.9). Patients with an elevated Δ-renin developed an AKI significantly more often (43% vs. 12.2%; P < 0.001). High Δ-renin after cardiac surgery was associated with a significantly lower mean arterial pressure, longer time on vasopressors, and longer length of ICU and hospital stay. The area under the curve (AUC) of Δ-renin for the prediction of AKI (AUC, 0.817; 95% confidence interval, 0.747-0.887) was significantly greater compared with the AUC of the postoperative renin concentrations (AUC, 0.702; 95% CI, 0.610-0.793; P = 0.007).Conclusions: Elevated renin concentrations were associated with cardiovascular instability and increased AKI after cardiac surgery. Elevated renin concentrations could be used to identify high-risk patients for cardiovascular instability and AKI who would benefit from timely intervention that could improve their outcomes. [ABSTRACT FROM AUTHOR]

Introduction: Prorenin, a precursor of renin, and renin play an important role in regulation of the renin-angiotensin system. More recently, receptor-bound prorenin has been shown to activate intracellular signaling pathways that mediate fibrosis, independent of angiotensin II. Prorenin and renin may thus be of physiologic significance in CKD, but their plasma concentrations have not been well characterized in CKD.Methods: We evaluated distribution and longitudinal changes of prorenin and renin concentrations in the plasma samples collected at follow-up years 1, 2, 3, and 5 of the Chronic Renal Insufficiency Cohort (CRIC) study, an ongoing longitudinal observational study of 3,939 adults with CKD. Descriptive statistics and multivariable regression of log-transformed values were used to describe cross-sectional and longitudinal variation and associations with participant characteristics.Results: A total of 3,361 CRIC participants had plasma available for analysis at year 1. The mean age (±standard deviation, SD) was 59 ± 11 years, and the mean estimated glomerular filtration rate (eGFR, ± SD) was 43 ± 17 mL/min per 1.73 m2. Median (interquartile range) values of plasma prorenin and renin at study entry were 4.4 (2.1, 8.8) ng/mL and 2.0 (0.8, 5.9) ng/dL, respectively. Prorenin and renin were positively correlated (Spearman correlation 0.51, p < 0.001) with each other. Women and non-Hispanic blacks had lower prorenin and renin values at year 1. Diabetes, lower eGFR, and use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, statins, and diuretics were associated with higher levels. Prorenin and renin decreased by a mean of 2 and 5% per year, respectively. Non-Hispanic black race and eGFR <30 mL/min/1.73 m2 at year 1 predicted a steeper decrease in prorenin and renin over time. In addition, each increase in urinary sodium excretion by 2 SDs at year 1 increased prorenin and renin levels by 4 and 5% per year, respectively.Discussion/conclusions: The cross-sectional clinical factors associated with prorenin and renin values were similar. Overall, both plasma prorenin and renin concentrations decreased over the years, particularly in those with severe CKD at study entry. [ABSTRACT FROM AUTHOR]

Context: The corpus luteum (CL) secretes prorenin, renin's inactive precursor. It may thus contribute to the renin-angiotensin-aldosterone-system (RAAS) activation that is required for maternal adaptation in pregnancy. Whether this activation is disturbed in pregnancies lacking a CL is unknown.Objective: The objective of this work is to investigate maternal RAAS determinants in early pregnancy.Design and Setting: Two observational prospective cohort studies.Took Place At: 2 tertiary referral hospitals.Patients and Intervention(s): Pregnancies (n = 277) were stratified by CL number and in vitro fertilization (IVF) protocol: 0 CL (programmed cycle frozen embryo transfer [FET], n = 28), 1 CL (natural cycle FET, n = 41 and spontaneous conceptions, n = 139), and more than 1 CL (ovarian stimulation and fresh embryo transfer, n = 69).Methods: Quantification was performed for maternal prorenin, renin, and aldosterone blood levels at 5, 9, and 11 weeks of gestation.Results: Prorenin and renin were lower in the absence of a CL at all time points when compared to 1 CL, whereas prorenin, renin, and aldosterone were higher in the presence of more than 1 CL vs 1 CL (P < .05). Ovarian stimulation with menopausal gonadotropin resulted in higher prorenin, renin, and aldosterone concentrations during the late first trimester than recombinant follicle-stimulating hormone (P < .05). Prorenin, and to a lesser degree renin, correlated positively with serum progesterone and relaxin, but not serum estradiol. Total follicle diameter, body mass index (BMI), polycystic ovary syndrome (PCOS), and antimüllerian hormone (AMH) were additional determinants of circulating prorenin. Finally, pregnancies conceived in the absence of a CL were more disposed to develop preeclampsia.Conclusions: CL number, IVF protocol, BMI, PCOS, and AMH affect maternal RAAS activation in early pregnancy, and may thus contribute to pregnancy complications. [ABSTRACT FROM AUTHOR]

Background: Overactivation of renin-aldosterone-angiotensin system (RAS) is part of the pathogenesis of obesity-associated hypertension. Evidences have shown that weight loss can result in reduction in blood pressure and RAS. This study was aim to investigate changes of plasma aldosterone concentration (PAC) after bariatric surgery. Methods: A prospective study was done in 14 morbidly obese patients undergoing bariatric surgery. Patients who were taking medications that can interfere with PAC and renin levels were excluded. Collection of blood samples were done at baseline and at 3 and 6-month post-bariatric surgery. Results: Four out of 14 patients had hypertension at baseline. Mean body mass index (BMI) was 56.7 ± 13.5 kg/m2. PAC were significantly decreased at 3-and 6-month post-bariatric surgery from 14.3 ± 8.0 to 7.5 ± 5.5 [reduction of 36% from baseline (P < 0.01)] and 8.0 ± 6.6 ng/dl [reduction of 32% from baseline (P < 0.05)] respectively. The reduction of PAC at 3-month post-surgery was correlated with the reduction of body weight (r = 0.46, P < 0.05), waist circumference (r = 0.73, P < 0.05) and percent of body fat (r = 0.58, P < 0.05). Conclusions: Maximal reduction of PAC in obese patients underwent bariatric surgery occurred during the first 3 months after bariatric surgery. The reduction of PAC was associated with the reduction of body weight, waist circumference and percent of body fat suggesting the link between RAS and obesity-mediated hypertension. [ABSTRACT FROM AUTHOR]

Background: Previous studies suggested that exposure to traumatic events during childhood and adulthood and post-traumatic stress disorder (PTSD) are associated with a dysregulation of different neuroendocrine systems. However, the activity of the renin–angiotensin–aldosterone-system (RAAS) in relation to trauma/PTSD has been largely neglected. Methods: Traumatization, PTSD, and plasma concentrations of renin and aldosterone were measured in 3092 individuals from the general population. Subgroups according to the status of traumatization ('without trauma'; 'trauma, without PTSD', 'PTSD') were formed and compared regarding renin and aldosterone concentrations. Additionally, we calculated the associations between the number of traumata, renin, and aldosterone concentrations. Finally, associations of PTSD with renin/aldosterone levels were controlled for the number of traumata ('trauma load'). Results: Levels of renin, but not aldosterone, were increased in traumatized persons without PTSD (p = 0.02) and, even stronger, with PTSD (p < 0.01). Moreover, we found a dose–response relation between the number of traumata and renin levels (β = 0.065; p < 0.001). Regression analyses showed PTSD as a significant predictor of renin (β = 0.38; p < 0.01). This effect was only slightly attenuated when controlled for trauma load (β = 0.32; p < 0.01). Conclusions: Our results suggest that traumatization has lasting and cumulative effects on RAAS activity. Finding elevated renin levels in PTSD independent from trauma load supports the concept of PTSD as a disorder with specific neuroendocrine characteristics. Alternatively, elevated renin levels in traumatized persons may increase the risk for developing PTSD. Our findings contribute to explain the relationship between traumatic stress/PTSD and physical disorders. [ABSTRACT FROM AUTHOR]

Abstract: Imarikiren hydrochloride (TAK‐272/ SCO‐272) is a novel direct renin inhibitor. This randomized, double‐blind, phase I study evaluated the safety and pharmacokinetics/pharmacodynamics of multiple oral administrations of imarikiren in healthy nonelderly (aged 20‐45 years) and elderly (aged 65‐85 years) Japanese male subjects. Subjects were randomized within 1 of 3 cohorts to receive imarikiren or placebo: Cohort 1 (imarikiren 80 mg; nonelderly), Cohort 2 (imarikiren 160 mg; nonelderly), or Cohort 3 (imarikiren 80 mg; elderly). Imarikiren or placebo was administered orally, once daily, for 7 days. Accumulation of imarikiren did not occur during the 7‐day treatment period. Area under the plasma‐concentration time curve and maximum plasma concentration of imarikiren were higher in elderly than in nonelderly subjects (52% and 39% higher, respectively). Inhibition of plasma renin activity was observed for 7 days and was maintained for at least 71 hours after the last imarikiren administration at the 80‐mg (nonelderly and elderly) and 160‐mg (nonelderly) doses. Plasma active renin concentration increased in nonelderly and elderly subjects; peak concentrations were higher on day 7 than on day 1. Increase from baseline in plasma active renin concentration was smaller in elderly than in nonelderly subjects during the 7‐day treatment period and until 71 hours after last imarikiren administration. Treatment‐emergent adverse events were reported in 33.3% (elderly) and 22.2% (nonelderly) of imarikiren subjects. Multiple oral administrations of imarikiren for 7 days were safe and well tolerated with no drug accumulation and strong and sustained suppression of plasma renin activity. [ABSTRACT FROM AUTHOR]

Aims: The direct renin inhibitor, aliskiren, is known to reduce plasma renin activity (PRA), but whether the efficacy of aliskiren varies based on an individual's baseline PRA in patients hospitalized for heart failure (HF) is presently unknown. We characterized the prognostic value of PRA and determined if this risk is modifiable with use of aliskiren.Methods and Results: This pre-specified neurohormonal substudy of ASTRONAUT analysed all patients hospitalized for HF with ejection fraction (EF) ≤40% with available baseline PRA data (n = 1306, 80.9%). Risk associated with baseline PRA and short-term changes in PRA from baseline to 1 month was modelled with respect to 12-month clinical events. Median baseline PRA was 3.0 (interquartile range 0.6-16.4) ng/mL/h. Aliskiren significantly reduced PRA early after treatment initiation through 12-month follow-up compared with placebo (P < 0.001). The lowest baseline PRA quartile (<0.6 ng/mL/h) was independently predictive of lower all-cause mortality [adjusted hazard ratio (HR) 0.50, 95% confidence interval (CI) 0.31-0.81] and the composite of cardiovascular mortality and HF hospitalization (adjusted HR 0.57, 95% CI 0.40-0.79). Delta log-normalized PRA (from baseline to 1 month) was not predictive of either primary endpoint at 12 months (P ≥ 0.43). The prognostic value of baseline PRA and short-term changes in PRA did not vary by randomization to aliskiren or placebo (interaction P ≥ 0.13).Conclusions: Plasma renin activity is reduced early and durably by aliskiren, but this did not translate into improved clinical outcomes in ASTRONAUT. Baseline PRA or short-term reduction in PRA do not identify a subgroup who may preferentially benefit from direct renin inhibition. Clinical Trial Registration ClinicalTrials.gov Unique Identifier: NCT00894387. [ABSTRACT FROM AUTHOR]

Background: Activation of the renin-angiotensin-aldosterone-system (RAAS) has been proposed to contribute to development of vascular complications in type 2 diabetes (T2D). The aim of the present study was to determine if plasma renin levels are associated with the severity of vascular changes in subjects with and without T2D.Methods: Renin was analyzed by the Proximity Extension Assay in subjects with (n = 985) and without (n = 515) T2D participating in the SUMMIT (SUrrogate markers for Micro- and Macro-vascular hard endpoints for Innovative diabetes Tools) study and in 205 carotid endarterectomy patients. Vascular changes were assessed by determining ankle-brachial pressure index (ABPI), carotid intima-media thickness (IMT), carotid plaque area, pulse wave velocity (PWV) and the reactivity hyperemia index (RHI).Results: Plasma renin was elevated in subjects with T2D and demonstrated risk factor-independent association with prevalent cardiovascular disease both in subjects with and without T2D. Renin levels increased with age, body mass index, HbA1c and correlated inversely with HDL. Subjects with T2D had more severe carotid disease, increased arterial stiffness, and impaired endothelial function. Risk factor-independent associations between renin and APBI, bulb IMT, carotid plaque area were observed in both T2D and non-T2D subjects. These associations were independent of treatment with RAAS inhibitors. Only weak associations existed between plasma renin and the expression of pro-inflammatory and fibrous components in plaques from 205 endarterectomy patients.Conclusions: Our findings provide clinical evidence for associations between systemic RAAS activation and atherosclerotic burden and suggest that this association is of particular importance in T2D. [ABSTRACT FROM AUTHOR]

Introduction: The addition of the direct renin inhibitor aliskiren is demonstrated to improve blood pressure (BP) control rate and reduce progression of organ damage in treated hypertensive patients in clinical trials with a relatively short follow-up period. Aim: The objective of this study was to assess the effectiveness, safety and tolerability of aliskiren as an add-on antihypertensive therapy in high-risk, treated, hypertensive patients, who were not controlled with concomitant treatment with at least two antihypertensive drugs under 'real-life' conditions, during a planned observation and treatment period of at least 12 months in Italy. Methods: Clinical data were derived from medical databases of treated, uncontrolled, hypertensive patients followed by specialized physicians operating in different clinical settings (hospital divisions or outpatient clinics) in Italy. Aliskiren was added to stable antihypertensive treatment, including at least two drug classes (independently of class or dosage) and unable to achieve BP control. Follow-up visits for measuring clinic BP levels and collecting data on drug safety and tolerability were planned at time intervals of 1, 6 and 12 months. At each predefined follow-up visit, aliskiren could be up-titrated from 150 to 300 mg daily if BP control was not achieved. Results: From May 2009 to June 2011, a total of 1186 treated, uncontrolled, hypertensive patients (46.3% female, aged 65.2 ± 11.7 years, mean duration of hypertension 13.2 ± 9.3 years, mean clinic BP levels 156.5 ± 15.9/90.3 ± 9.5mmHg) were enrolled. Systolic and diastolic BP levels were 141.1/82.4, 134.9/79.8 and 133.6/78.9 mmHg at 1-, 6- and 12-month follow-up visits, respectively (p < 0.0001 vs baseline for all comparisons). These effects were consistent in all predefined subgroups, including those with left ventricular hypertrophy, renal disease, diabetes mellitus, coronary artery disease or cerebrovascular disease. Reduced levels of microalbuminuria were also reported, without affecting other renal and electrolyte parameters. Overall, compliance to study medication was high (93.0%), with a very low proportion of patients experiencing adverse events leading to drug discontinuation (3.6%). Conclusions: In this observational, prospective, open-label, multicentre study, we reported the 12-month clinical effectiveness, safety and tolerability of adding aliskiren to treated, uncontrolled, hypertensive patients in a 'real-life' setting in Italy. This strategy leads to a significantly improved BP control rate and low incidence of drug-related side effects or discontinuations. [ABSTRACT FROM AUTHOR]

We assessed the association between (CA)n repeat polymorphism of angiotensinogen (AGT), 250 base pair (bp) insertion/deletion (I/D) of angiotensin-converting enzyme (ACE), tetranucleotide repeat polymorphism (TCTG)n of renin (REN), (CT)n repeat polymorphism of the natriuretic peptide receptor A (NPRA) genes, and the presence and extent of coronary artery disease (CAD) in Greek patients with a history of myocardial infarction (MI). A total of 158 post-MI patients referred for coronary angiography were compared with 144 controls. The SS genotype of the AGT gene was related with an increased risk for 3-vessel CAD (odds ratio [OR], 1.94; 95% confidence interval [CI], 1.05-3.61; P = .041), whereas the SL genotype was related with a decreased risk (OR, 0.44; 95% CI, 0.22-0.87; P = .019). Moreover, there was a trend for the SL genotype of the REN gene toward increased risk for CAD. There was a significant association between (CA)n polymorphism of the AGT gene and the extent of CAD in Greek patients with a history of MI. [ABSTRACT FROM AUTHOR]

Abstract: The first oral direct renin inhibitor, aliskiren, recently received approval for the treatment of hypertension. This article addresses the premise, promise, and potential limitations of this new class of renin-angiotensin system inhibitor. Although aliskiren adds to a list of more than 100 drugs approved for the treatment of hypertension, its introduction into clinical medicine is of particular interest because of the novel mechanism of action: inhibition of renin’s catalytic activity, the most proximal and rate-limiting step in renin-angiotensin system activation. By producing more complete renin-angiotensin system inhibition than with existing agents, direct renin inhibitors may afford greater protection from hypertensive complications. Other potential advantages include additional blood pressure reduction when used in combination therapy, a placebo-like side-effect profile, avid renal concentration, and long duration of action. Potential limitations include modest levels of blood pressure reduction that are equivalent to but not greater than angiotensin receptor blockers, reduced gastrointestinal absorption with a high-fat meal, and large reactive increases in renin secretion—the functional importance of which is under intense investigation. The results of outcomes trials are eagerly awaited. [Copyright &y& Elsevier]

Objective: Hyperreninemic hypoaldosteronism has been described in critically ill patients. The present study investigated the plasma aldosterone concentration (PAC) in septic shock patients and its relationship with clinical course.Design and Setting: Prospective descriptive study in a medical intensive care unit (ICU) of a university hospital.Patients: Forty-six consecutive patients with septic shock as defined by the ACCP/SCCM criteria.Intervention: A corticotropin stimulation test, followed by treatment with low doses of hydrocortisone and fludrocortisone.Measurements and Results: Plasma renin activity, PAC, and cortisol levels were measured before and after the test. PAC measurements were repeated for 1 week. Relevant clinical and laboratory variables were recorded for ICU stay. Patients were divided into two groups according to PAC/renin activity ratio: above 2 (n=24 patients) and below 2 n=22). Patients with PAC/renin activity less than 2 had higher total volume of infused fluid, serum creatinine level, and fractional excretion of sodium values; aldosterone and serum creatinine were negatively correlated. Hypoaldosteronism was reversible within 1 week. Duration of ICU stay (p=0.0026) and the need for renal replacement therapy (p=0.0021) were greater in the group with PAC/renin less than 2.Conclusions: Transient hyperreninemic hypoaldosteronism is common in patients with septic shock. These abnormal aldosterone levels are associated with greater sodium and fluid depletion and are followed by enhanced incidence of acute renal failure requiring renal replacement therapy and prolonged length of stay in ICU. [ABSTRACT FROM AUTHOR]

Background: In heart failure patients, diuretics cause renin–angiotensin–aldosterone system (RAS) activation, which may lead to increased morbidity and mortality despite short-term symptomatic improvement. Aim: To determine changes in RAS activation and clinical correlates following furosemide withdrawal in elderly heart failure patients without left ventricular systolic dysfunction. Methods and results: We performed clinical assessments and laboratory determinations of aldosterone, plasma renin activity (PRA), atrial natriuretic peptide (ANP), norepinephrine, and endothelin in 29 heart failure patients [aged 75.1±0.7 (mean±S.E.M.) years], before, 1 and 3 months after placebo-controlled furosemide withdrawal. Recurrent congestion occurred in 2 of 19 patients withdrawn, and in 1 of 10 patients continuing on furosemide. Three months after withdrawal, PRA had decreased −1.61±0.71 nmol/l/h (P<0.05). Decreases in aldosterone levels did not reach significance (−0.17±0.38 nmol/l). The decreases in PRA after withdrawal correlated with decreases in systolic (rs=0.61, P=0.020) and diastolic blood pressure (rs=0.80, P=0.01). Successful withdrawal was associated with increases in norepinephrine (+0.58±0.22 nmol/l) and ANP (+3.5±1.3 pmol/l) (P<0.05) after 1 month, but these changes did not persist after 3 months. Endothelin levels did not change in both groups. Conclusion: Successful furosemide withdrawal in elderly heart failure patients causes persistent decreases in RAS activation. [Copyright &y& Elsevier]

Objective: To characterize the chronology of hemodynamic changes in in vitro fertilization (IVF) cycles and its relationship with circulating ovarian steroids, cytokines, and their mediator nitric oxide.Design: Prospective, cross-sectional study.Setting: University teaching hospital.Patient(s): Eighty-eight IVF patients.Intervention(s): Ovarian stimulation with FSH under pituitary suppression.Main Outcome Measure(s): Circulating levels of estradiol, progesterone, nitrite/nitrate, interleukin-6, vascular endothelial growth factor, tumor necrosis factor alpha, aldosterone, norepinephrine, as well as measurements of plasma renin activity and mean arterial pressure.Result(s): The maximal stimulation of the renin-aldosterone and sympathetic nervous systems was seen 7 days after hCG administration, although values still remained elevated over normal control values on day of hCG + 11. Mean arterial pressure in IVF patients remained significantly reduced throughout the luteal phase. Changes in the stimulation of the renin-aldosterone system correlated temporally with progesterone but not estradiol levels. No significant changes were observed in circulating concentrations of cytokines investigated or nitric oxide.Conclusion(s): The circulatory changes and the homeostatic activation of the renin-aldosterone system and sympathetic nervous system that consistently develop in patients undergoing controlled ovarian hyperstimulation for IVF is a feature associated with the luteinization process. These hemodynamic changes occur in the absence of variations in the circulating levels of cytokines potentially involved in ovarian hyperstimulation syndrome. [ABSTRACT FROM AUTHOR]