Measurement Of Renin Research Articles

Screening for primary aldosteronism in pregnancy.

Primary aldosteronism, the most common secondary cause of hypertension is likely to be significantly underdiagnosed in pregnancy and is associated with high rates of adverse maternal and fetal outcomes. Normal pregnancy is associated with a rise in aldosterone and renin levels early in pregnancy making the aldosterone:renin ratio which is normally used to screen for primary aldosteronism, difficult to interpret. Additionally, many laboratories have moved from performing plasma renin activity to measurements of direct renin. Aldosterone, direct renin and aldosterone: renin ratios were determined in 9 women with primary aldosteronism and compared to levels in 33 women with chronic hypertension. All women with primary aldosteronism had a direct renin levels of less than 20mU/L together with aldosterone:renin ratio of greater than 40. Values for direct renin were significantly lower, and the aldosterone:renin ratio was significantly higher in pregnancy in women with primary aldosteronism compared to women with chronic hypertension. Pregnant women with chronic hypertension who have a direct renin level less than 20mU/L and aldosterone:renin ratio of greater than 40 should have close surveillance for maternal and fetal complications, and follow-up postpartum should be ensured for definitive testing.

Gynaecomastia in a male neutered cat with an adrenal tumour and associated hyperprogesteronism, hypercortisolism and hyperaldosteronism.

Case summaryA 7-year-old male neutered domestic longhair cat was presented with chronic progressive gynaecomastia, polydipsia, polyphagia, weight loss and poor fur regrowth. Sexualised behavioural changes were not reported and virilisation was not present on physical examination. Pertinent haematology, biochemistry and urinalysis findings at the time of referral included mild hypokalaemia. Left adrenomegaly and mild prostatomegaly were identified on a CT scan. Evaluation of adrenal hormones with a low-dose dexamethasone suppression test, serum progesterone, testosterone, oestradiol, plasma aldosterone, renin, plasma metanephrine and normetanephrine measurement supported a diagnosis of hyperprogesteronism, hyperaldosteronism and hypercortisolism. Adrenalectomy was performed and histopathology was consistent with an adrenocortical tumour. Clinical signs and hormone elevations resolved postoperatively.Relevance and novel informationTo our knowledge, this is the second report of gynaecomastia secondary to an adrenal tumour in a male neutered cat and the first associated with hyperprogesteronism.

In PICU acute kidney injury stage 3 or mortality is associated with early excretion of urinary renin.

Urinary renin is proposed to be a novel prognostic biomarker of acute kidney injury (AKI) in adults. The intention of our study was to evaluate the early predictive value of urinary renin for AKI and pediatric intensive care unit (PICU) mortality in critically ill children. The first available urine sample during the first 24 h after admission was collected upon PICU admission for the measurement of renin using ELISA. Urinary renin concentrations were corrected for urinary creatinine (urinary renin-to-creatinine ratio, uRenCR). AKI was defined based on KDIGO criteria. Of the 207 children, 22 developed AKI, including 6 with stage 1, 6 with stage 2, and 10 with stage 3, and 14 died during PICU stay. There was a significant difference in uRenCR between non-AKI children and those with AKI stage 3 (P = 0.001), but not with AKI stage 1 or 2. The uRenCR remained associated with AKI stage 3 and PICU mortality after adjustment for potential confounders. The area under the receiver operating characteristic curve of uRenCR for discrimination of AKI stage 3 was 0.805, and PICU mortality was 0.801. Urinary renin was associated with the increased risk for AKI stage 3 and PICU mortality in critically ill children. Urinary renin is proposed to be a novel prognostic biomarker of AKI in adult patients. There are some differences between children and adults in physiological and pathophysiological characteristics. This study demonstrated that urinary renin was associated with the increased risk for AKI stage 3 and PICU mortality in critically ill children. Accurate identification of patients with severe renal injury or at high risk for mortality early in the disease course could augment the efficacy of available interventions and improve patient outcomes.

Mineralocorticoid Receptor Antagonist Effect on Aldosterone to Renin Ratio in Patients With Primary Aldosteronism.

Although current international guidelines recommend to avoid mineralocortcoid receptor antagonists in patients undergoing screening test for primary aldosteronism, a recent report suggested that mineralocorticoid receptor antagonist treatment can be continued without significant influence on screening results. We aimed to evaluate the effect of mineralocorticoid receptor antagonists on the aldosterone to renin ratio in patients with primary aldosteronism. We prospectively enrolled 121 patients with confirmed primary aldosteronism who started mineralocorticoid receptor antagonist (canrenone) treatment. Eighteen patients (11 with unilateral and 7 with bilateral primary aldosteronism) constituted the short-term study cohort and underwent aldosterone, renin, and potassium measurement after 2 and 8 weeks of canrenone therapy. The long-term cohort comprised 102 patients (16 with unilateral and 67 with bilateral primary aldosteronism, and 19 with undetermined subtype) who underwent hormonal and biochemical re-assessment after 2 to 12 months of canrenone therapy. Renin and potassium levels showed a significant increase, and the aldosterone to renin ratio displayed a significant reduction compared with baseline after both a short- and long-term treatment. These effects were progressively more evident with higher doses of canrenone and after longer periods of treatment. We demonstrated that canrenone exerted a deep impact on the diagnostic accuracy of the screening test for primary aldosteronism: the rate of false negative tests was raised to 16.7%, 38.9%, 54.5%, and 72.5% after 2 weeks, 8 weeks, 2 to 6 months, and 7 to 12 months of mineralocorticoid receptor antagonist treatment, respectively. Mineralocorticoid receptor antagonists should be avoided in patients with hypertension before measurement of renin and aldosterone for screening of primary aldosteronism.

Comparison of the Chemiluminescence Immunoassay LIAISON® with the Radioimmunoassay for Aldosterone and Renin Measurement.

Determination of renin plasma levels is useful in the diagnosis of hypertension and in the therapeutic follow-up of hypertensive patients. Plasmatic concentration of renin decreases in patients with hypertension due to a primary hyperaldosteronism, contrary to renovascular hypertension where concentrations of renin and aldosterone are both elevated. Blood samples (serum, EDTA plasma) were analysed using two different chemiluminiscent methods CLIA LIAISON® and radioimmunoassay for aldosterone (IMMUNOTECH Beckman Coulter) and renin (Cisbio Bioassay) measurements were compared. We used both methods to ascertain the correlation between serum vs. EDTA plasma levels of aldosterone (RIA, CLIA) and renin (IRMA, CLIA) and to compare aldosterone to renin ratios for CLIA and for radioimmunoassay: serum aldosterone to plasma renin and plasma aldosterone to plasma renin. We compared serum aldosterone CLIA vs. RIA (rP=0.933, P<0.001) and plasma renin determined using CLIA vs. IRMA (rP=0.965, P=0.062). Furthermore, we used both methods to establish the correlation between the serum vs. plasma levels of aldosterone: RIA (rP=0.980, P<0.001); CLIA (rP=0.994, P=0.353) and serum vs. plasma levels of renin: IRMA (rP=0.948, P<0.001); CLIA (rP=0.921, P=0.011). Aldosterone (serum, plasma) to plasmatic renin ratios for CLIA (rP=0.999, P=0.286) and for radioimmunoassay (rP=0.992, P=0.025). Our data demonstrate that renin and aldosterone concentrations obtained using CLIA correlate with renin and aldosterone concentrations using radioimmunoassay methods. Correlation coefficients of pair results ranged from 0.921 to 0.994. Aldosterone (serum, EDTA plasma) to plasmatic renin ratios are comparable and any of them can be used with no significant differences found.

Intraindividual Variability of Aldosterone Concentrations in Primary Aldosteronism: Implications for Case Detection.

Primary aldosteronism is an underdiagnosed cause of hypertension. Although inadequate screening is one reason for underdiagnosis, another important contributor is that clinicians may inappropriately exclude the diagnosis when screening aldosterone concentrations fall below traditionally established thresholds. We evaluated the intraindividual variability in screening aldosterone concentrations and aldosterone-to-renin ratios, and how this variability could impact case detection, among 51 patients with confirmed primary aldosteronism who had 2 or more screening measurements of renin and aldosterone on different days. There were a total of 137 screening measurements with a mean of 3 (range 2-6) per patient. The mean intraindividual variability, expressed as coefficients of variation, was 31% for aldosterone and 45% for the aldosterone-to-renin ratio. Aldosterone concentrations ranged from 4.9 to 51 ng/dL; 49% of patients had at least one aldosterone measurement below 15 ng/dL, 29% had at least 2 aldosterone measurements below 15 ng/dL, and 29% had at least one measurement below 10 ng/dL. Individual aldosterone-to-renin ratios ranged from 8.2 to 427 ng/dL per ng/mL·hour; 57% had at least one ratio below 30 ng/dL per ng/mL·hour, 27% had at least 2 ratios below 30 ng/dL per ng/mL·hour, and 24% had at least one ratio below 20 ng/dL per ng/mL·hour. Aldosterone concentrations and aldosterone-to-renin ratios are highly variable in patients with primary aldosteronism, with many screening values falling below conventionally accepted diagnostic thresholds. The diagnostic yield for primary aldosteronism may be substantially increased by recalibrating the definition of a positive screen to include more liberal thresholds for aldosterone and the aldosterone-to-renin ratio.

A Comparison of Urine Dilution Ability between Adult Dominant Polycystic Kidney Disease, Other Chronic Kidney Diseases, and Healthy Control Subjects: A Case-Control Study.

The final dilution of urine is regulated via aquaporin-2 water channels in the distal part of the nephron. It is unclear whether urine dilution ability in autosomal dominant polycystic kidney disease patients (ADPKD patients) differs from other patients with similar degree of impaired renal function (non-ADPKD patients). The purpose of this case control study was to measure urine dilution ability in ADPKD patients compared to non-ADPKD patients and healthy controls. Methods. Eighteen ADPKD, 16 non-ADPKD patients (both with chronic kidney disease, stage I-IV), and 18 healthy controls received an oral water load of 20 ml/kg body weight. Urine was collected in 7 consecutive periods. We measured free water clearance (CH2O), urine osmolality, urine output, fractional excretion of sodium, urine aquaporin2 (u-AQP2), and urine epithelial sodium channel (u-ENaC). Blood samples were drawn four times (at baseline, 2 h, 4 h, and 6 hours after the water load) for analyses of plasma osmolality, vasopressin, renin, angiotensin II, and aldosterone. Brachial and central blood pressure was measured regularly during the test. Results. The three groups were age and gender matched, and the patient groups had similar renal function. One hour after water load, the ADPKD patients had an increased CH2O compared to non-ADPKD patients (2.97 ± 2.42 ml/min in ADPKD patients vs. 1.31 ± 1.50 ml/min in non-ADPKD patients, p0.029). The reduction in u-AQP2 and u-ENaC occurred earlier in ADPKD than in non-ADPKD patients. Plasma concentrations of vasopressin, renin, angiotensin II, and aldosterone and blood pressure measurements did not show any differences that could explain the deviation in urine dilution capacity between the patient groups. Conclusions. ADPKD patients had a higher CH2O than non-ADPKD patients after an oral water load, and u-AQP2 and u-ENaC were more rapidly reduced than in non-ADPKD patients. Thus, urine-diluting capacity may be better preserved in ADPKD patients than in non-ADPKD patients.

Mineralocorticoid Receptor Antagonists Decrease the Rates of Positive Screening for Primary Aldosteronism

Mineralocorticoid receptor antagonists (MRAs) are effective in patients with resistant hypertension and/or primary aldosteronism (PA). Screening for PA should ideally be conducted after stopping medications that might interfere with the renin-angiotensin-aldosterone system, but this is challenging in patients with recalcitrant hypertension or hypokalemia. Herein, we aimed to evaluate the impact of MRAs on PA screening in clinical practice. We conducted a retrospective cohort study of patients with hypertension who had plasma aldosterone and renin measurements before and after MRA use in a tertiary referral center, over 19 years. A total of 146 patients, 91 with PA, were included and followed for up to 18 months. Overall, both plasma renin and aldosterone increased after MRA initiation (from median, interquartile range: 0.5 [0.1, 0.8] to 1.2 [0.6, 4.8] ng/mL/hour and from 19.1 [12.9, 27.7] to 26.4 [17.1, 42.3] ng/dL, respectively; P<.0001 for both), while the aldosterone/renin ratio (ARR) decreased from 40.3 (18.5, 102.7) to 23.1 (8.6, 58.7) ng/dL per ng/mL/hour (P<.0001). Similar changes occurred irrespective of the MRA treatment duration and other antihypertensives used. Positive PA screening abrogation after MRA initiation was found in 45/94 (48%) patients. Conversely, 17% of patients had positive PA screening only after MRA treatment, mostly due to correction of hypokalemia. An initially positive screening test was more likely altered by high MRA doses and more likely persistent in patients with confirmed PA or taking beta-blockers. MRAs commonly reduce ARR and the proportion of positive PA screening results. When PA is suspected, screening should be repeated off MRAs. ACEI = angiotensin-converting enzyme inhibitor; ARB = angiotensin receptor blocker; ARR = aldosterone/renin ratio; DRC = direct renin concentration; MRA = mineralocorticoid receptor antagonist; PA = primary aldosteronism; PAC = plasma aldosterone concentration; PRA = plasma renin activity; RAAS = renin-angiotensin-aldosterone system.

Clinical Evaluation of Assays for Plasma Renin Activity and Aldosterone Measurement by Liquid Chromatography-Tandem Mass Spectrometry.

Aldosterone and renin are pivotal hormones in the regulation of salt and water homeostasis and blood pressure. Measurement of renin and aldosterone in serum/plasma is essential for the investigation of primary hyperaldosteronism (PA) and monitoring of glucocorticoid replacement therapy. We report 2 LC-MS/MS methods developed to measure aldosterone and plasma renin activity (PRA). PRA was determined by endogenous enzymatic generation of angiotensin I using 150 µL of sample. Generated angiotensin I was purified by solid phase extraction prior to chromatographic separation and mass spectrometry. Aldosterone measurement required 300 μL of sample extracted with MTBE prior to LC-MS/MS analysis. The PRA method was linear (1.2-193 nmol/L), sensitive (LLOQ = 1.2 nmol/L), precise (CV = 4.1%), and specific (no cross reactivity for a number of structurally similar steroids). Dilutional linearity and recovery (84%) were acceptable. Accuracy was confirmed by comparison against our current RIA method. The aldosterone method had equally acceptable performance characteristics. Reference ranges in 110 healthy normotensive subjects were: PRA 0.2-3.7 nmol/L/h and aldosterone 50-950 pmol/L. Consecutive patients (n = 62) with adrenal incidentalomas shown to have no functional adrenal disease; their post overnight 1 mg dexamethasone test values were: PRA 0.2-2.6 nmol/L/h and aldosterone 55-480 pmol/L. Serum aldosterone values after 2 liter saline suppression were-normal subjects (n = 17): 78-238 pmol/L and confirmed primary hyperaldosteronism (n = 25): 131-1080 pmol/L. We have developed robust assays for PRA and aldosterone with appropriate clinical evaluation. These assays are now in routine practice in the UK.

Plasma renin measurements are unrelated to mineralocorticoid replacement dose in patients with primary adrenal insufficiency

Plasma renin measurements are unrelated to mineralocorticoid replacement dose in patients with primary adrenal insufficiency

SAT-564 Effectiveness of Treatment with Mineralocorticoid Receptor Antagonistsin Primary Aldosteronism

Background: Medical treatment with mineralocorticoid receptor antagonists (MRAs) is preferred for patients with primary aldosteronism (PA) who are not surgical candidates. Adequate mineralocorticoid receptor blockade, as suggested by renin elevation above suppression levels, has been associated with lower rates of cardiovascular and renal complications as compared with PA with sustained renin suppression. Objectives: To assess the timeline and rates of achieving target renin levels in patients with PA and low renin hypertension treated with MRAs. Patients and Methods: We conducted a retrospective cohort study of adult patients with hypertension who were treated with MRAs in an academic center between 2003-2019. Of these, we included patients who had suppressed renin at baseline, and repeated renin measurement(s) during MRAs therapy. Renin suppression was defined as plasma renin activity (PRA) 1.0 ng/mL/h or direct renin concentration (DRC) 8.0 pg/mL. We excluded patients with adrenal cancer, end-stage renal disease, exogenous glucocorticoids, and critically ill. Mann-Whitney test, Wilcoxon signed rank test, Chi-Square test and multiple logistic regression analysis were employed, as appropriate. Results: So far, 89 patients (45 men), median age 56 (range, 19-84), have been included. Of these, 46% had confirmed PA; 25% had positive PA screening, but no confirmatory tests; and 29% had other forms of low-renin hypertension. On average, patients were on 2.9 1.6 antihypertensive agents; 62% of patients were prescribed beta blockers, and 38% were on K+ supplements. Overall, renin (PRA in 69 cases, and DRC in 20 cases) increased after MRA treatment (from 0.40 [0.10, 0.60] ng/mL/h to 1.10 [0.60, 2.23] ng/mL/h; and from 2.1 [2.1, 3.7] pg/mL to 5.7 [2.9, 16.7] pg/mL, respectively, p<0.0001 for both). The cumulative proportions of patients in whom renin reached target levels during MRA treatment were: 25% at 2 weeks; 38.9% at 1 month; 34.2% at 3 months; 39.5% at 6 months; and 47.2% at 1 year. Age, sex, race, blood pressure, use of beta blockers, renal function, serum K+ and aldosterone concentrations were similar between patients with target vs. suppressed renin. Multiple logistic regression analysis suggested that after adjusting for age and sex, higher MRA dose and higher BMI were associated with higher likelihood of achieving target renin during MRA therapy (odds ratio (95%CI): 1.021 (1.001-1.041) and 1.097 (1.008-1.193), respectively, p<0.05 for both); conversely, beta blockers use tended to be less often associated with target renin (odds ratio, 0.37 (0.13-1.008), p=0.052). Conclusion: Although raising renin above suppression levels is important for reducing the cardiovascular risk associated with PA, this goal is achieved in less than half of patients, even after one year of treatment with MRAs, in an academic setting. Strategies for optimizing PA treatment are critically needed.

Clinical determinants and prognostic implications of renin and aldosterone in patients with symptomatic heart failure.

AimsActivation of the renin–angiotensin–aldosterone system plays an important role in the pathophysiology of heart failure (HF) and has been associated with poor prognosis. There are limited data on the associations of renin and aldosterone levels with clinical profiles, treatment response, and study outcomes in patients with HF.Methods and resultsWe analysed 2,039 patients with available baseline renin and aldosterone levels in BIOSTAT‐CHF (a systems BIOlogy study to Tailored Treatment in Chronic Heart Failure). The primary outcome was the composite of all‐cause mortality or HF hospitalization. We also investigated changes in renin and aldosterone levels after administration of mineralocorticoid receptor antagonists (MRAs) in a subset of the EPHESUS trial and in an acute HF cohort (PORTO). In BIOSTAT‐CHF study, median renin and aldosterone levels were 85.3 (percentile25–75 = 28–247) μIU/mL and 9.4 (percentile25–75 = 4.4–19.8) ng/dL, respectively. Prior HF admission, lower blood pressure, sodium, poorer renal function, and MRA treatment were associated with higher renin and aldosterone. Higher renin was associated with an increased rate of the primary outcome [highest vs. lowest renin tertile: adjusted‐HR (95% CI) = 1.47 (1.16–1.86), P = 0.002], whereas higher aldosterone was not [highest vs. lowest aldosterone tertile: adjusted‐HR (95% CI) = 1.16 (0.93–1.44), P = 0.19]. Renin and/or aldosterone did not improve the BIOSTAT‐CHF prognostic models. The rise in aldosterone with the use of MRAs was observed in EPHESUS and PORTO studies.ConclusionsCirculating levels of renin and aldosterone were associated with both the disease severity and use of MRAs. By reflecting both the disease and its treatments, the prognostic discrimination of these biomarkers was poor. Our data suggest that the “point” measurement of renin and aldosterone in HF is of limited clinical utility.

Plasma Renin Measurements are Unrelated to Mineralocorticoid Replacement Dose in Patients With Primary Adrenal Insufficiency.

No consensus exists for optimization of mineralocorticoid therapy in patients with primary adrenal insufficiency. To explore the relationship between mineralocorticoid (MC) replacement dose, plasma renin concentration (PRC), and clinically important variables to determine which are most helpful in guiding MC dose titration in primary adrenal insufficiency. Observational, retrospective, longitudinal analysis. A total of 280 patients (with 984 clinical visits and plasma renin measurements) with primary adrenal insufficiency were recruited from local databases and the international congenital adrenal hyperplasia (CAH) registry (www.i-cah.org). Thirty-seven patients were excluded from the final analysis due to incomplete assessment. Data from 204 patients with salt-wasting CAH (149 adults and 55 children) and 39 adult patients with Addison disease (AD) were analysed. PRC, electrolytes, blood pressure (BP), and anthropometric parameters were used to predict their utility in optimizing MC replacement dose. PRC was low, normal, or high in 19%, 36%, and 44% of patients, respectively, with wide variability in MC dose and PRC. Univariate analysis demonstrated a direct positive relationship between MC dose and PRC in adults and children. There was no relationship between MC dose and BP in adults, while BP increased with increasing MC dose in children. Using multiple regression modeling, sodium was the only measurement that predicted PRC in adults. Longitudinally, the change in MC dose was able to predict potassium, but not BP or PRC. The relationship between MC dose and PRC is complex and this may reflect variability in sampling with respect to posture, timing of last MC dose, adherence, and concomitant medications. Our data suggest that MC titration should not primarily be based only on PRC normalization, but also on clinical parameters such as BP and electrolyte concentration.

Renin as a Marker of Tissue-Perfusion and Prognosis in Critically Ill Patients.

To characterize renin in critically ill patients. Renin is fundamental to circulatory homeostasis and could be a useful marker of tissue-perfusion. However, diurnal variation, continuous renal replacement therapy and drug-interference could confound its use in critical care practice. Prospective observational study. Single-center, mixed medical-surgical ICU in Europe. Patients over 18 years old with a baseline estimated glomerular filtration rate greater than 30 mL/min/1.73 m and anticipated ICU stay greater than 24 hours. Informed consent was obtained from the patient or next-of-kin. Direct plasma renin was measured in samples drawn 6-hourly from arterial catheters in recumbent patients and from extracorporeal continuous renal replacement therapy circuits. Physiologic variables and use of drugs that act on the renin-angiotensin-aldosterone system were recorded prospectively. Routine lactate measurements were used for comparison. One-hundred twelve arterial samples (n = 112) were drawn from 20 patients (65% male; mean ± SD, 60 ± 14 yr old) with septic shock (30%), hemorrhagic shock (15%), cardiogenic shock (20%), or no circulatory shock (35%). The ICU mortality rate was 30%. Renin correlated significantly with urine output (repeated-measures correlation coefficient = -0.29; p = 0.015) and mean arterial blood pressure (repeated-measures correlation coefficient = -0.35; p < 0.001). There was no diurnal variation of renin or significant interaction of renin-angiotensin-aldosterone system drugs with renin in this population. Continuous renal replacement therapy renin removal was negligible (mass clearance ± SD 4% ± 4.3%). There was a significant difference in the rate of change of renin over time between survivors and nonsurvivors (-32 ± 26 μU/timepoint vs +92 ± 57 μU/timepoint p = 0.03; mean ± SEM), but not for lactate (-0.14 ± 0.04 mM/timepoint vs +0.15 ± 0.21 mM/timepoint; p = 0.07). Maximum renin achieved significant prognostic value for ICU mortality (receiver operator curve area under the curve 0.80; p = 0.04), whereas maximum lactate did not (receiver operator curve area under the curve, 0.70; p = 0.17). In an heterogeneous ICU population, renin measurement was not significantly affected by diurnal variation, continuous renal replacement therapy, or drugs. Renin served as a marker of tissue-perfusion and outperformed lactate as a predictor of ICU mortality.

Green peas protein hydrolyzed by bromelain in simple procedure to improve kidney function in cisplatin-induced rats

Context: Chronic kidney disease (CKD) can lead to terminal kidney failure. Previous study has shown that protein hydrolysate in yellow peas (Pisum sativum L.) can be used as a natural remedy for CKD. Aims: To obtain hydrolysate protein that is most effective in improving kidney function of cisplatin (CP)-induced Wistar rats, based on urea, creatinine, atrial natriuretic peptide (ANP), cyclooxygenase-1 (COX-1), and renin levels of CP-induced nephrotoxicity Wistar rats. Materials and Methods: Methods of Kjeldahl, Bradford, Kunitz, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis were used to determine the content of the eight types of protein hydrolysates. In in vivo experiment, the samples were administered to CP-induced nephrotoxicity Wistar rats, with urea, creatinine, ANP, COX-1, and renin as parameters. Results: Total neutrase activity was 40.65 U/mg, and bromelain was 35.77 U/mg. Total specific activities of both enzymes were almost identical. Protein hydrolyzed using bromelain had small fractions (<14.4 kDa). On the 30th day of treatment, urea and creatinine levels of all groups of treatment were significantly different from CP control (P < 0.01). The lowest level was shown by the group which was treated with bromelain-hydrolyzed green pea protein. Among ANP, COX-1, and renin measurements, only the result of COX-1 showed the promising result. Conclusions: Green peas protein hydrolysate hydrolyzed by bromelain are suggested as the most effective in improving kidney function based on urea, creatinine, and COX-1 levels of CP-induced nephrotoxicity Wistar rats.

Keeping primary aldosteronism in mind: Deficiencies in screening at-risk hypertensives

BackgroundPrimary aldosteronism is a common but underdiagnosed cause of hypertension. Patients with this disorder have worse morbidity compared with those with essential hypertension, but with timely diagnosis and appropriate intervention these patients are potentially cured and may have reversal of target organ damage. The goal of this study was to determine if hypertensive patients considered high risk were checked for primary aldosteronism. MethodsWe reviewed electronic health records to identify patients age 18 years or older with coexisting hypertension and hypokalemia or hypertension and sleep apnea, then determined if they had been investigated with measurement of aldosterone or renin. We built regression models to identify explanatory variables for screening in these 2 high-risk groups. ResultsOf nearly 37,000 patients with hypertension and hypokalemia, only 2.7% were ever screened for primary aldosteronism. Most opportunities for case detection were during inpatient hospitalizations, yet in this setting, patients were less likely than clinic patients be screened. Similarly, 3.0% of hypertensive patients with sleep apnea were screened since the inclusion of this group in case detection recommendations. ConclusionUptake of practice guidelines by hospital physicians, fueled by support from their specialty societies, may help to identify many more patients with unrecognized primary aldosteronism.

Exploring the utility of renin measurements in the routine management of salt-wasting congenital adrenal hyperplasia

Exploring the utility of renin measurements in the routine management of salt-wasting congenital adrenal hyperplasia

Role of Corin in Neuro‐Circulatory and Renal‐Adrenal Control during Pregnancy in Humans

Corin (an atrial natriuretic peptide converting enzyme) represents a key regulator of cardiovascular and renal function through its influence on blood pressure (BP) and salt‐water balance, respectively. Recently, corin has been identified as a potential contributor to the pathogenesis of preeclampsia. However, the role of corin in BP regulation and renal function during pregnancy remains uncertain. Therefore, the objective of the current study was to investigate the role played by corin in the neuro‐circulatory adjustments and renal‐adrenal response during pregnancy. We evaluated prospectively, in 30 healthy women [30±4 (SD) yrs, 164±5 cm, 65±20 kg], BP (Suntech), heart rate (HR; electrocardiogram), and muscle sympathetic nerve activity (MSNA; microneurography) prior‐to pregnancy (mid‐luteal phase), during early‐(6.8±1.2 wks gestation) and late‐ (33.7±2.1 wks gestation) pregnancy, and post‐partum (8.3±1.2 wks post‐delivery). Venous blood samples were taken for the measurement of maternal serum corin content (ELISA) and direct renin (radio‐immunoassay) and aldosterone concentrations (chemiluminescent immunoassay). All women had singleton, full‐term pregnancies. Compared to pre‐pregnancy (1312±367 pg/mL), corin levels remained unchanged during early‐pregnancy (1368±351 pg/mL; P&gt;0.05), increased markedly during late‐pregnancy (2046±651 pg/mL; P&lt;0.001), and returned to pre‐pregnancy levels following delivery (1265±315 pg/mL; P&gt;0.05). During early‐ and late‐pregnancy, corin content was related moderately to mean arterial BP (R=0.510; P&lt;0.001). Similarly, corin levels were related, albeit modestly, to MSNA burst frequency (R=0.357; P&lt;0.01) and burst incidence (R=0.338; P=0.01), as well as direct renin (R=0.374; P&lt;0.05) and aldosterone (R=0.319; P&lt;0.05) concentrations. In a subset of eight women who developed gestational hypertensive disorders during their pregnancies, the change in corin levels from early‐ to late‐pregnancy tended to be greater than in those with normotensive pregnancies, although considerable individual variability existed (Δ 974±706 vs. Δ 493±457 pg/mL; P=0.06). Throughout pregnancy, mean arterial BP was greater in women with hypertensive pregnancies (Pre: 79±4; Early: 76±6; Late: 81±7; Post: 77±4 mmHg) compared to those with normotensive pregnancies (Pre: 77±4; Early: 71±5; Late: 76±6; Post: 74±4 mmHg; P&lt;0.01 for group). Similarly, MSNA burst frequency was greater in women with hypertensive pregnancies (Pre: 18±5; Early: 23±12; Late: 28±13; Post: 13±13 bursts/min) than in those with normotensive pregnancies (Pre: 10±6; Early: 14±9; Late: 22±14; Post: 9±7 bursts/min; P&lt;0.05 for group). In conclusion, corin increases during late pregnancy and appears to be moderately associated with BP regulation. Whether corin represents a key regulator of neuro‐circulatory control and renal‐adrenal responses during pregnancy, or plays a unique role in the development of gestational hypertensive disorders, remains uncertain but represents a novel target for future investigation.Support or Funding InformationNIH R21 (HLO88184); AHA Grant‐in‐Aid award (13GRNT16990064); Harry S. Moss Heart TrustThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Cure With Cryoablation of Arterial Hypertension Due to a Renin-Producing Tumor

We herein report on a 20 years old woman with stage I hypertension, who was found to carry a renin-producing tumor (RPT). Due to her young age, the patient underwent screening measurement of plasma renin and aldosterone, abdominal computed tomography (CT) angiography, and selective renal vein renin assessment to identify secondary hypertension. The patient was screened for secondary causes of hypertension and was diagnosed with secondary aldosteronism. Therefore, she underwent an abdominal computed tomography (CT) angiography that was reported as unremarkable. Selective renal vein renin studies showed overproduction of renin in the right kidney and a re-evaluation of her CT allowed detection of an 8-mm mass in her right kidney, suggesting the presence of a RPT. Considering the technical difficulty of renal sparing surgery a CT-guided cryoablation was undertaken, which provided long-term cure of arterial hypertension and normalization of plasma active renin concentration. RPTs usually present with a clinical phenotype featuring stage III and/or malignant hypertension and are held to be exceptionally rare. This case is unique in that it presented with stage I hypertension and a mild clinical phenotype. Moreover, to our knowledge this is the first case of RPTs shown to be safely treated with CT-guided cryoablation and found to be cured at long-term.

Associations between glycaemic control and activation of the renin-angiotensin-aldosterone system in participants with type 2 diabetes mellitus and hypertension.

Introduction Hyperglycaemia increases succinate concentrations and succinate receptor activation in the kidney resulting in renin release. The aim of our study was to determine if there is an association between glycaemic control as evidenced by glycated haemoglobin values and activation of the renin-angiotensin-aldosterone system in patients with type 2 diabetes mellitus and hypertension. Methods A cross-sectional study was conducted at Galway University Hospitals between December 2014 and March 2015. Participants ( n = 66) were identified following interrogation of the electronic database for patients with type 2 diabetes mellitus. Baseline clinical demographics, aldosterone, plasma renin activity, direct renin concentration, urea and electrolytes, glycated haemoglobin, cholesterol, urine sodium and albumin creatinine ratio were recorded. Results There was a significant positive linear correlation between glycated haemoglobin and renin (both plasma renin activity [ P = 0.002] and direct renin concentration [ P = 0.008]) and between serum creatinine and aldosterone measured using both radioimmunoassay ( P = 0.008) and immunochemiluminometric assay ( P = 0.008). A significant negative linear correlation was demonstrated between serum sodium and plasma renin activity ( P = 0.005) and direct renin concentration ( P = 0.015) and between estimated glomerular filtration rate and aldosterone measured using radioimmunoassay ( P = 0.02) and immunochemiluminometric assay ( P = 0.016). A significant negative linear correlation existed between urine sodium and plasma renin activity ( P = 0.04) and aldosterone measured using radioimmunoassay ( P = 0.045). Conclusions There is a direct positive association between glycaemic control and renin. We advocate for renin measurement to be part of the diabetologist's armamentarium to assess, guide and optimize therapeutic strategies in patients with diabetes.