Age-related changes in the renin-aldosterone system. Physiological effects and clinical implications

The Balance Between the Natriuretic Peptides and the Renin-Angiotensin-Aldosterone System in the Preservation of Ideal Cardiovascular Health

A healthy lifestyle plays a key role for maintaining the cardiovascular health (CVH) status and prevent cardiovascular disease occurrence. In fact, a healthy lifestyle was included in the AHA Cardiovascular Health score (Life's Simple 7 [LS7]), subsequently updated to Life's Simple 8 [LS8]. Apart from the importance of controlling conventional cardiovascular risk factors, increasing evidence supports the contributory role of cardiovascular hormones. Higher levels of natriuretic peptides (NPs) and lower levels of renin and aldosterone were significantly associated to CVH. NT-proBNP levels showed a direct relationship with CVH scores in large general Caucasian populations, being also a marker of CVH changes and a predictor of future adverse events. On the other hand, renin and aldosterone were inversely related to CVH scores. In contrast, the counter-regulatory angiotensins [Ang (1-7) acting through Mas receptor, Ang (1-9) acting through Angiotensin Type 2 receptor, and alamandine] strengthen the beneficial properties of NPs. This evidence can be explained by both the effects on systemic hemodynamic and possible pleiotropic local functions regulating different pathways involved in the maintenance of CVH. Based on the current evidence, circulating levels of NT-proBNP, renin and aldosterone may affect CVH in apparently asymptomatic individuals and represent additional markers of residual cardiovascular risk.

Genome-wide sequencing identified extrachromosomal circular DNA as a transcription factor-binding motif of the senescence genes that govern replicative senescence in human mesenchymal stem cells

Introduction

Mesenchymal stem cells (MSCs) have long been postulated as an important source cell in regenerative medicine. During subculture expansion, mesenchymal stem cell (MSC) senescence diminishes their multi-differentiation capabilities, leading to a loss of therapeutic potential. Up to date, the extrachromosomal circular DNAs (eccDNAs) have been demonstrated to be involved in senescence but the roles of eccDNAs during MSC.

Methods

Here we explored eccDNA profiles in human bone marrow MSCs (BM-MSCs). EccDNA and mRNA was purified and sequenced, followed by quantification and functional annotation. Moreover, we mapped our datasets with the downloading enhancer and transcription factor-regulated genes to explore the potential role of eccDNAs.

Results

Sequentially, gene annotation analysis revealed that the majority of eccDNA were mapped in the intron regions with limited BM-MSC enhancer overlaps. We discovered that these eccDNA motifs in senescent BMSCs acted as motifs for binding transcription factors (TFs) of senescence-related genes.

Discussion

These findings are highly significant for identifying biomarkers of senescence and therapeutic targets in mesenchymal stem cells (MSCs) for future clinical applications. The potential of eccDNA as a stable therapeutic target for senescence-related disorders warrants further investigation, particularly exploring chemically synthesized eccDNAs as transcription factor regulatory elements to reverse cellular senescence.

Assessment of Phthalate Esters and Physiological Biomarkers in Bottlenose Dolphins (Tursiops truncatus) and Killer Whales (Orcinus orca)

There is growing concern about the potential adverse health effects of phthalates (PAEs) on human health and the environment due to their extensive use as plasticizers and additives in commercial and consumer products. In this study, we assessed PAE concentrations in serum samples from aquarium-based delphinids (Tursiops truncatus, n = 36; Orcinus orca, n = 42) from California, Florida, and Texas, USA. To better understand the physiological effects of phthalates on delphinids, we also explored potential correlations between phthalates and the biomarkers aldosterone, cortisol, corticosterone, hydrogen peroxide, and malondialdehyde while accounting for sex, age, and reproductive stage. All PAEs were detected in at least one of the individuals. ΣPAE ranges were 5.995-2743 ng·mL-1 in bottlenose dolphins and 5.372-88,675 ng·mL-1 in killer whales. Both species displayed higher mean concentrations of DEP and DEHP. PAEs were detected in newborn delphinids, indicating transference via placenta and/or lactation. Linear mixed model results indicated significant correlations between aldosterone, month, location, status, and ΣPAEs in killer whales, suggesting that aldosterone concentrations are likely affected by the cumulative effects of these variables. This study expands on the knowledge of delphinid physiological responses to PAEs and may influence management and conservation decisions on contamination discharge regulations near these species.

Cellular Senescence as a Targetable Risk Factor for Cardiovascular Diseases: Therapeutic Implications: JACC Family Series

The prevalence of cardiovascular diseases markedly rises with age. Cellular senescence, a hallmark of aging, is characterized by irreversible cell cycle arrest and the manifestation of a senescence-associated secretory phenotype, which has emerged as a significant contributor to aging, mortality, and a spectrum of chronic ailments. An increasing body of preclinical and clinical research has established connections between senescence, senescence-associated secretory phenotype, and age-related cardiac and vascular pathologies. This review comprehensively outlines studies delving into the detrimental impact of senescence on various cardiovascular diseases, encompassing systemic atherosclerosis (including coronary artery disease, stroke, and peripheral arterial disease), as well as conditions such as hypertension, congestive heart failure, arrhythmias, and valvular heart diseases. In addition, we have preclinical studies demonstrating the beneficial effects of senolytics-a class of drugs designed to eliminate senescent cells selectively across diverse cardiovascular disease scenarios. Finally, we address knowledge gaps on the influence of senescence on cardiovascular systems and discuss the future trajectory of strategies targeting senescence for cardiovascular diseases.

Life's Essential 8: Optimizing Health in Older Adults

The population worldwide is getting older as a result of advances in public health, medicine, and technology. Older individuals are living longer with a higher prevalence of subclinical and clinical cardiovascular disease (CVD). In 2010, the American Heart Association introduced a list of key prevention targets, known as "Life's Simple 7" to increase CVD-free survival, longevity, and quality of life. In 2022, sleep health was added to expand the recommendations to "Life's Essential 8" (eat better, be more active, stop smoking, get adequate sleep, manage weight, manage cholesterol, manage blood pressure, and manage diabetes). These prevention targets are intended to apply regardless of chronologic age. During this same time, the understanding of aging biology and goals of care for older adults further enhanced the relevance of prevention across the range of functions. From a biological perspective, aging is a complex cellular process characterized by genomic instability, telomere attrition, loss of proteostasis, inflammation, deregulated nutrient-sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication. These aging hallmarks are triggered by and enhanced by traditional CVD risk factors leading to geriatric syndromes (eg, frailty, sarcopenia, functional limitation, and cognitive impairment) which complicate efforts toward prevention. Therefore, we review Life's Essential 8 through the lens of aging biology, geroscience, and geriatric precepts to guide clinicians taking care of older adults.

Diagnostic predictivity of transtubular potassium gradient for primary hypoadrenocorticism in hyperkalemic dogs: a cross-sectional study

OBJECTIVES

Transtubular potassium gradient has never been evaluated in the diagnosis of primary hypoadrenocorticism in dogs. The objective of this study is to evaluate the diagnostic utility of transtubular potassium gradient for the diagnosis of primary hypoadrenocorticism in dogs with serum K+  > 5.5 mol/L.

MATERIALS AND METHODS

Cross-sectional study including dogs with primary hypoadrenocorticism and dogs with other disease. Differences in signalment and laboratory parameters between groups were assessed by binary logistic regression modelling. Variables significantly associated with primary hypoadrenocorticism were evaluated for their diagnostic accuracy of this condition by receiver operator characteristic curve analysis and by multivariable logistic regression analysis, respectively.

RESULTS

Dogs with primary hypoadrenocorticism (n=39) were significantly younger than hyperkalemic dogs without primary hypoadrenocorticism (n=41). Moreover they had higher serum and urinary concentrations of Na+ and Na+ :K+ , but lower transtubular potassium gradient than hyperkalemic dogs without hypoadrenocorticism. Serum Na+ (sNa+ ) had the highest diagnostic accuracy (area under the curve [AUC]: 0.87, 95% confidence interval, 0.78 to 0.96), followed by the transtubular potassium gradient (AUC: 0.81, 0.72 to 0.91), however the accuracy of the two AUCs was not statistically different. The transtubular potassium gradient-sNa+ additive index (i.e. transtubular potassium gradient+sNa+ /10) had a greater accuracy (AUC: 0.88, 0.79 to 0.94) than transtubular potassium gradient or sNa+ , although it was not statistically superior to the latter. The multivariable logistic regression model showed that transtubular potassium gradient (adjusted odds ratio [aOR]: 0.51, 0.3 to 0.84), sNa+ (aOR: 0.86, 0.78 to 0.95) and spayed female (aOR: 24.96, 2.32 to 267.66) were associated with primary hypoadrenocorticism.

CLINICAL SIGNIFICANCE

Transtubular potassium gradient-sNa+ additive index can contribute to decision-making on diagnosis of primary hypoadrenocorticism in dogs presenting with hyperkalaemia.

Effect of Oral Contraception on Screening Tests for Primary Aldosteronism: A 10-Year Longitudinal Study

CONTEXT

Primary aldosteronism (PA) and oral contraception (OC) can both cause hypertension in young women. However, the effect of OC on the screening test for PA, the aldosterone to renin ratio (ARR), is not clear.

OBJECTIVE

We evaluated the impact of OC on the screening test for PA.

METHODS

In this retrospective cohort study, we analyzed data from the female offspring (Gen2) of women enrolled in the Raine Study, a population-based birth cohort, who had blood pressure (BP) measurements, blood samples, and information about OC use at age 17 years (N = 484) and/or age 27 years (N = 486).

RESULTS

Aldosterone concentration was significantly higher in OC users than nonusers at 17 years (median 486 pmol/L vs 347 pmol/L, P < 0.001). Renin concentration was significantly lower in OC users at both 17 years (13.4 mU/L vs 20.6 mU/L) and 27 years (9.2 mU/L vs 11.8 mU/L), hence the ARR was significantly higher in OC users compared to nonusers at both 17 years (31.5 vs 18.3) and 27 years (27.3 vs 21.1). The proportion of participants with ARR > 70 pmol/mU (current threshold for PA detection) was significantly higher in OC users at both 17 years (12.6% vs 2.1%) and 27 years (6.4% vs 0.4%); however, they had comparable BP to those with ARR < 70. OC use at any age abolished the relationship between ARR and BP that is observed in nonusers.

CONCLUSION

OC can increase the ARR and cause a false positive PA screening result. Until more reliable criteria for PA screening in OC users are established, alternative contraception should be considered during screening.

Impact of Admission of Patients With Syncope in Non-Teaching Hospitals Versus Teaching Hospitals: A Nationwide Analysis

Syncope is a common condition affecting many individuals, and it remains uncertain whether admission to academic medical centers (AMCs) leads to better outcomes than non-AMCs. This study is aimed to investigate whether there is a difference in mortality, length of stay (LoS), and total hospital charges between patients admitted with syncope to AMCs and non-AMCs. This retrospective cohort study used the National Inpatient Database (NIS) to examine patients aged 18 years and older admitted with a primary diagnosis of syncope to AMCs and non-AMCs from 2016 to 2020. Univariate and multivariate logistic regression analyses were conducted, adjusting for confounders, to assess the primary outcome of all-cause in-hospital mortality and secondary outcomes, including hospital LoS and total cost of admission. Patient characteristics were also described. Of the 451,820 patients who met the inclusion criteria, 69.6% were admitted to AMCs and 30.4% to non-AMCs. Patient age was similar between the two groups (68 years in AMC versus 70 years in non-AMC; p < 0.001), as was sex distribution (52% female in AMC versus 53% in non-AMC; 48% male in AMC versus 47% in non-AMC; p < 0.002). Most patients in both groups were white, while the percentages of black and Hispanic patients were slightly higher in non-AMCs. The study found no difference in all-cause mortality between patients admitted to AMCs and non-AMCs (p = 0.33). However, LoS was marginally longer in AMC patients (2.6 days in AMC versus 2.4 days in the non-AMC group; p < 0.001), and the total cost was higher for AMCs by $3,526 per admission. The estimated total economic burden related to syncope was over 3 billion USD per year. This study suggests that the teaching status of hospitals did not significantly affect the mortality of patients admitted with syncope. However, it may have contributed to marginally longer hospital LoS and higher total hospital charges.

The effect of age, sex and BMI on the aldosterone-to-renin ratio in essential hypertensive individuals

OBJECTIVE

The aldosterone-to-renin ratio (ARR) is widely used as a screening test for primary aldosteronism, but its determinants in patients with essential hypertension are not fully known. The purpose of the present investigation is to identify the impact of age, sex and BMI on renin, aldosterone and the ARR when measured under strict, standardized conditions in hypertensive patients without primary aldosteronism.

METHODS

We analysed the data of 423 consecutive hypertensive patients with no concomitant cardiac or renal disorders from two different hospitals (Rotterdam and Maastricht) who had been referred for evaluation of their hypertension. Those who were diagnosed with secondary causes of hypertension, including primary aldosteronism, were excluded from analysis. Patients who used oral contraceptives or had hormonal replacement therapy were excluded as well. Plasma aldosterone concentration (PAC), active plasma renin concentration (APRC) and the ARR were measured under standardized conditions. All measurements were taken in the supine position at 10.00 h in the morning, with one subgroup of patients adhering to a sodium-restricted diet (55 mmol/day) for no less than 3 weeks, and the other subgroup maintaining an ad libitum diet. In those who were receiving antihypertensive treatment, all medications were discontinued at least 3 weeks before testing.

RESULTS

In neither group did aldosterone correlate with age. Renin, however, was inversely related to age both during low-salt diet ( P  < 0.001) and during ad lib salt intake ( P  = 0.05). This resulted in a significant positive correlation between age and the ARR in both groups. Although on both dietary regimens, PAC and APRC were significantly higher in men when compared with women, the ARR was not significantly different between the two sexes. The age-relationships of renin and the ARR were comparable in men and women on both diets, albeit with greater variability in women. There was an upward trend between BMI and the ARR, which reached statistical significance only in men on low-salt diet. In multivariable regression analysis, age remained the only independent determinant of the ARR.

CONCLUSION

In our essential hypertensive population, the ARR increased significantly with age but was not affected by sex or BMI.

Longitudinal changes in blood pressure are preceded by changes in albuminuria and accelerated by increasing dietary sodium intake

BACKGROUND

Dietary sodium is a well-known risk factor for cardiovascular and renal disease; however, direct evidence of the longitudinal changes that occur with aging, and the influence of dietary sodium on the age-associated alterations are scarce.

METHODS

C57BL/6 mice were maintained for 13 months on a low (LS, 0.02 % Na+), normal (NS, 0.3 % Na+) or high (HS, 1.6 % Na+) salt diet. We assessed 1) the longitudinal trajectories for two markers of cardiovascular and renal dysfunction (blood pressure (BP) and albuminuria), as well as hormonal changes, and 2) end-of-study cardiac and renal parameters.

RESULTS

The effect of aging on BP and kidney damage did not reach significance levels in the LS group; however, relative to baseline, there were significant increases in these parameters for animals maintained on NS and HS diets, starting as early as month 7 and month 5, respectively. Furthermore, changes in albuminuria preceded the changes in BP relative to baseline, irrespective of the diet. Circulating aldosterone and plasma renin activity displayed the expected decreasing trends with age and dietary sodium loading. As compared to LS - higher dietary sodium consumption associated with increasing trends in left ventricular mass and volume indices, consistent with an eccentric dilated phenotype. Functional and molecular markers of kidney dysfunction displayed similar trends with increasing long-term sodium levels: higher renovascular resistance, increased glomerular volumes, as well as higher levels of renal angiotensin II type 1 and mineralocorticoid receptors, and lower renal Klotho levels.

CONCLUSION

Our study provides a timeline for the development of cardiorenal dysfunction with aging, and documents that increasing dietary salt accelerates the age-induced phenotypes. In addition, we propose albuminuria as a prognostic biomarker for the future development of hypertension. Last, we identified functional and molecular markers of renal dysfunction that associate with long-term dietary salt loading.

Importance of Micromilieu for Pathophysiologic Mineralocorticoid Receptor Activity-When the Mineralocorticoid Receptor Resides in the Wrong Neighborhood

The mineralocorticoid receptor (MR) is a member of the steroid receptor family and acts as a ligand-dependent transcription factor. In addition to its classical effects on water and electrolyte balance, its involvement in the pathogenesis of cardiovascular and renal diseases has been the subject of research for several years. The molecular basis of the latter has not been fully elucidated, but an isolated increase in the concentration of the MR ligand aldosterone or MR expression does not suffice to explain long-term pathologic actions of the receptor. Several studies suggest that MR activity and signal transduction are modulated by the surrounding microenvironment, which therefore plays an important role in MR pathophysiological effects. Local changes in micromilieu, including hypoxia, ischemia/reperfusion, inflammation, radical stress, and aberrant salt or glucose concentrations affect MR activation and therefore may influence the probability of unphysiological MR actions. The surrounding micromilieu may modulate genomic MR activity either by causing changes in MR expression or MR activity; for example, by inducing posttranslational modifications of the MR or novel interaction with coregulators, DNA-binding sites, or non-classical pathways. This should be considered when developing treatment options and strategies for prevention of MR-associated diseases.

Aldosterone secretion during the day: Salivary aldosterone awakening response and daytime levels

BACKGROUND

The mineralocorticoid hormone aldosterone is a key regulator of the sodium-potassium balance and blood pressure. In excess, aldosterone relates to hypertension and cardiovascular disease (CVD). Here, we systematically investigated aldosterone secretion during the day in terms of salivary aldosterone awakening response (AldAR) and salivary aldosterone daytime levels (AldDay) under controlled conditions in participants' natural environment including assessment of potential confounding variables.

METHODS

In 40 healthy young men, saliva samples for AldAR were collected immediately after awakening and 15, 30, 45, and 60 min thereafter. AldDay levels were measured in 1 h intervals from 9:00-22:00 h. Analyses were complemented by salivary cortisol assessment. Fluid and food intake was standardized and as potential confounders, we assessed awakening time and sleep duration, age, BMI and MAP, as well as chronic stress.

RESULTS

Awakening was followed by significant increases in salivary aldosterone (p = .004, f= 0.31), returning to baseline levels > 60 min later. Longer sleep duration was associated with lower AldAR (p < .001, f= 0.36). Over the course of the day we observed a continuous decrease of AldDay (p < .001, f= 0.45). Longer sleep duration (p = .097, f= .21), later time of awakening (p < .001, f= .29), and higher chronic stress (p = .041, f= .23) were associated with AldDay characteristics. Circadian aldosterone secretion was positively associated with most cortisol measures.

CONCLUSIONS

We observed an awakening response in salivary aldosterone and could confirm a decrease in aldosterone levels during the day, comparable to cortisol. Significant confounders were sleep-related variables and chronic stress. Clinical implications of circadian aldosterone secretion with respect to CVD risk remain to be elucidated.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

Urinary renin was associated with the increased risk for AKI stage 3 and PICU mortality in critically ill children.

IMPACT

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.

Determinants and Mechanisms of the Renin-Aldosterone Stress Response

OBJECTIVE

The renin-angiotensin-aldosterone system (RAAS) plays a relevant role in regulating blood pressure and thus maintaining cardiovascular homeostasis. Although it was recently shown that RAAS parameters are responsive to acute psychosocial stress, the psychobiological determinants of the acute stress-induced RAAS activation have not yet been investigated. In a randomized placebo-controlled design, we investigated potential psychological and physiological determinants of the RAAS response and underlying mechanisms.

METHODS

Fifty-seven young healthy male participants underwent either an acute standardized psychosocial stress test or a nonstress placebo task. We measured aldosterone in plasma and saliva, as well as renin, and the stress-reactive endocrine measures adrenocorticotropic hormone (ACTH), epinephrine, and norepinephrine in plasma at rest, immediately after the task and several times up to 3 hours thereafter. Moreover, we assessed stress-reactive psychological (anticipatory cognitive stress appraisal, mood, physical discomfort) and basal demographic-physiological measures (age, body mass index, blood pressure).

RESULTS

Acute psychosocial stress elicited changes in all assessed endocrine (p values ≤ .028, ηp2 values ≥ 0.07) and stress-reactive psychological measures (p values ≤ .003, ηp2 values ≥ 0.15). The basal parameter body mass index, the stress-reactive endocrine parameters ACTH and norepinephrine, and the psychological parameter anticipatory stress appraisal were identified as determinants of higher RAAS parameter reactivity to acute psychosocial stress. The association between anticipatory cognitive stress appraisal and plasma RAAS measures was fully mediated by ACTH increases (p values ≤ .044, ηp2 values ≥ 0.05).

CONCLUSIONS

Cognitive stress appraisal processes seem to modulate RAAS stress reactivity. This points to potential clinical implications for psychoeducative therapeutical interventions targeting stress appraisal processes to reduce endocrine stress reactivity.

Predictive factors of clinical success after adrenalectomy in primary aldosteronism: A systematic review and meta-analysis

BACKGROUND

Unilateral adrenalectomy is the mainstay treatment for unilateral primary aldosteronism (PA). This meta-analysis aimed to systematically analyse predictors of clinical success after unilateral adrenalectomy in PA.

METHODS

A search was performed using PubMed/Medline, Scopus, Embase and Web of Science from their inception to February 2022. Observational studies in adult PA patients which reported predictors of clinical success after unilateral adrenalectomy were included. A random-effects model was employed to pool the fully adjusted odds ratio (OR) or standardized mean difference (SMD) with 95% confidence interval (95% CI).

RESULTS

Thirty-two studies involving 5,601 patients were included. Females had a higher clinical success rate (OR 2.81; 95% CI 2.06-3.83). Older patients, patients with a longer duration of hypertension and those taking a higher number of antihypertensive medications had lower clinical success rates (OR 0.97; 95% CI 0.94-0.99, OR 0.92; 95% CI 0.88-0.96 and OR 0.44; 95% CI 0.29-0.67, respectively). Compared to non-clinical success cases, patients with clinical success had a lower body mass index (SMD -0.49 kg/m²; 95% CI -0.58,-0.39), lower systolic (SMD -0.37 mmHg; 95% CI -0.56,-0.18) and diastolic blood pressure (SMD -0.19 mmHg; 95% CI -0.33,-0.06), lower serum potassium (SMD -0.16 mEq/L; 95% CI -0.28,-0.04), higher eGFR (SMD 0.51 mL/min/1.73m²; 95% CI 0.16,0.87), a lower incidence of dyslipidemia (OR 0.29; 95% CI 0.15-0.58) and a lower incidence of diabetes mellitus (OR 0.36; 95% CI 0.22-0.59).

CONCLUSIONS

Multiple predictors of clinical success after unilateral adrenalectomy in PA were identified which can help improve the quality of care for PA patients. Systematic Review Registration: INPLASY, identifier 202240129.

Associations of trauma and posttraumatic stress disorder with aldosterone in women

BACKGROUND

Posttraumatic stress disorder (PTSD) has been associated with increased cardiovascular risk, however, underlying mechanisms have not been fully specified. PTSD is associated with stress-related hormones, including dysregulated glucocorticoid activity. Dysregulation of aldosterone, a mineralocorticoid activated by psychological stress and implicated in cardiovascular damage, may be a relevant pathway linking PTSD and cardiovascular risk. Few studies to date have evaluated the association between PTSD and aldosterone, none with repeated measures of aldosterone. We examined if trauma and PTSD were associated with altered aldosterone levels relative to women unexposed to trauma.

METHODS

The association of trauma exposure and chronic PTSD with plasma aldosterone levels was investigated in 521 middle-aged women in the Nurses' Health Study II. Aldosterone was assessed at two time points, 10-16 years apart, and trauma exposure and PTSD were also ascertained for both time points. Regarding exposure assessment, women were characterized based on a structured diagnostic interview as: having chronic PTSD (PTSD at both time points; n = 174); being trauma-exposed (trauma exposure at first time point but no PTSD; n = 174); and being unexposed (no trauma exposure at either time point; reference group for all analyses; n = 173). Linear mixed models examined associations of trauma and PTSD status with log-transformed aldosterone levels, adjusting for covariates and health-related variables that may confound or lie on the pathway between PTSD and altered aldosterone levels.

RESULTS

Across the sample, mean aldosterone concentration decreased over time. Adjusting for covariates, women with chronic PTSD had significantly lower aldosterone levels averaged over time, compared to women unexposed to trauma (β = - 0.08, p = 0.04). Interactions between trauma/PTSD group and time were not significant, indicating change in aldosterone over time did not differ by trauma/PTSD status. Post-hoc exploratory analyses suggested that menopausal status partially mediated the relationship between chronic PTSD status and aldosterone level, such that postmenopausal status explained 7% of the effect of PTSD on aldosterone.

CONCLUSIONS

These findings indicate that PTSD is associated with lower levels of aldosterone. Further work is needed to understand implications of this type of dysregulation in a key biological stress system for cardiovascular and other health outcomes previously linked with PTSD.

Posttranslational Modifications of the Mineralocorticoid Receptor and Cardiovascular Aging

During aging, the cardiovascular system is especially prone to a decline in function and to life-expectancy limiting diseases. Cardiovascular aging is associated with increased arterial stiffness and vasoconstriction as well as left ventricular hypertrophy and reduced diastolic function. Pathological changes include endothelial dysfunction, atherosclerosis, fibrosis, hypertrophy, inflammation, and changes in micromilieu with increased production of reactive oxygen and nitrogen species. The renin-angiotensin-aldosterone-system is an important mediator of electrolyte and blood pressure homeostasis and a key contributor to pathological remodeling processes of the cardiovascular system. Its effects are partially conveyed by the mineralocorticoid receptor (MR), a ligand-dependent transcription factor, whose activity increases during aging and cardiovascular diseases without correlating changes of its ligand aldosterone. There is growing evidence that the MR can be enzymatically and non-enzymatically modified and that these modifications contribute to ligand-independent modulation of MR activity. Modifications reported so far include phosphorylation, acetylation, ubiquitination, sumoylation and changes induced by nitrosative and oxidative stress. This review focuses on the different posttranslational modifications of the MR, their impact on MR function and degradation and the possible implications for cardiovascular aging and diseases.

Measured sodium excretion is associated with CKD progression: results from the KNOW-CKD study

BACKGROUND

Diet is a modifiable factor of chronic kidney disease (CKD) progression. However, the effect of dietary salt intake on CKD progression remains unclear. Therefore, we analyzed the effect of dietary salt intake on renal outcome in Korean patients with CKD.

METHODS

We measured 24-h urinary sodium (Na) excretion as a marker of dietary salt intake in the prospective, multi-center, longitudinal KoreaN cohort study for Outcome in patients With CKD (KNOW-CKD). Data were analyzed from CKD patients at Stages G3a to G5 (n = 1254). We investigated the association between dietary salt intake and CKD progression. Patients were divided into four quartiles of dietary salt intake, which was assessed using measured 24-h urinary Na excretion. The study endpoint was composite renal outcome, which was defined as either halving the estimated glomerular filtration rate or developing end-stage renal disease.

RESULTS

During a median (interquartile range) follow-up of 4.3 (2.8-5.8) years, 480 (38.7%) patients developed the composite renal event. Compared with the reference group (Q2, urinary Na excretion: 104.2 ≤ Na excretion < 145.1 mEq/day), the highest quartile of measured 24-h urinary Na excretion was associated with risk of composite renal outcome [Q4, urinary Na excretion ≥192.9 mEq/day, hazard ratio 1.8 (95% confidence interval 1.12-2.88); P = 0.015] in a multivariable hazards model. Subgroup analyses showed that high-salt intake was particularly associated with a higher risk of composite renal outcome in women, in patients <60 years of age, in those with uncontrolled hypertension and in those with obesity.

CONCLUSIONS

High salt intake was associated with increased risk of progression in CKD.

Aging and Allostasis: Using Bayesian Network Analytics to Explore and Evaluate Allostatic Markers in the Context of Aging

Allostatic load reflects the cumulative strain on organic functions that may gradually evolve into overt disease. Our aim was to evaluate the allostatic parameters in the context of aging, and identify the parameters that may be suitable for an allostatic load index for elderly people (>60 years). From previously published studies, 11 allostatic (bio)markers could be identified that sustain sufficient variability with aging to capture meaningful changes in health status. Based on reported statistics (prevalence of a biomarker and its associated outcome, and/or an odds/risk ratio relating these two), seven of these could be adopted in a Bayesian Belief Network (BBN), providing the probability of “disturbed” allostasis in any given elder. Additional statistical analyses showed that changes in IL-6 and BMI contributed the most to a “disturbed” allostasis, indicating their prognostic potential in relation to deteriorating health in otherwise generally healthy elderly. In this way, and despite the natural decline in variance that irrevocably alters the prognostic relevance of most allostatic (bio)markers with aging, it appeared possible to outline an allostatic load index specifically for the elderly. The allostatic parameters here identified might consequently be considered a useful basis for future quantitative modelling in the context of (healthy) aging.

Factors affecting the urinary aldosterone-to-creatinine ratio in healthy dogs and dogs with naturally occurring myxomatous mitral valve disease

BACKGROUND

Chronic renin-angiotensin-aldosterone system (RAAS) activation in course of heart diseases contributes to cardiac remodeling and heart failure. Myxomatous mitral valve disease (MMVD) is characterized by different stages of severity and trend of RAAS activity during the course of the disease is still uncertain. The urinary aldosterone-to-creatinine ratio (UAldo:C) has been proven to reflect RAAS activation in dogs and might be a useful marker in monitoring therapy and disease progression, but data about this parameter need to be expanded. The objective of this study was to evaluate the UAldo:C in healthy dogs and dogs with naturally occurring MMVD, and to investigate the relationships between this parameter and clinical, echocardiographic and laboratory variables.

RESULTS

The study population consisted of 149 dogs: 49 healthy and 100 MMVD dogs (45 stage B1, 13 stage B2 and 42 stage C). Urinary aldosterone-to-creatinine ratio was not significantly different among healthy and MMVD dogs of any stages. Breed, sex and age showed a significant impact on UAldo:C. In particular, Chihuahua and Cavalier King Charles spaniel showed significantly higher UAldo:C than other breeds, as well as intact females than other genders. In stage C dogs, UAldo:C appeared to be increased by spironolactone and was positively associated with furosemide dose (P = 0.024). Aldosterone breakthrough (ABT) appeared to occur in 36% (8/22) of stage C dogs not receiving spironolactone. A significant positive association between UAldo:C and left atrium-to-aortic root ratio (LA/Ao) was found.

CONCLUSIONS

Individual factors such as breed, sex and age appeared to influence UAldo:C, and therapy seemed to add further variability. In the light of these results, comparing the UAldo:C of a single patient with a population-based reference value might lead to wrong interpretations and an individual monitoring should be considered. The prevalence of ABT in the present study (36%) was in line with those previously reported. However, due to the high individual variability of UAldo:C found in the study, even this result should be re-evaluated in the setting of an individual longitudinal approach. The positive association between UAldo:C and LA/Ao supports the mutual relationship between RAAS and cardiac remodeling.

Severe neurological outcomes after very early bilateral nephrectomies in patients with autosomal recessive polycystic kidney disease (ARPKD)

To test the association between bilateral nephrectomies in patients with autosomal recessive polycystic kidney disease (ARPKD) and long-term clinical outcome and to identify risk factors for severe outcomes, a dataset comprising 504 patients from the international registry study ARegPKD was analyzed for characteristics and complications of patients with very early (≤ 3 months; VEBNE) and early (4–15 months; EBNE) bilateral nephrectomies. Patients with very early dialysis (VED, onset ≤ 3 months) without bilateral nephrectomies and patients with total kidney volumes (TKV) comparable to VEBNE infants served as additional control groups. We identified 19 children with VEBNE, 9 with EBNE, 12 with VED and 11 in the TKV control group. VEBNE patients suffered more frequently from severe neurological complications in comparison to all control patients. Very early bilateral nephrectomies and documentation of severe hypotensive episodes were independent risk factors for severe neurological complications. Bilateral nephrectomies within the first 3 months of life are associated with a risk of severe neurological complications later in life. Our data support a very cautious indication of very early bilateral nephrectomies in ARPKD, especially in patients with residual kidney function, and emphasize the importance of avoiding severe hypotensive episodes in this at-risk cohort.

Pathophysiology and Prevention of Paracentesis-induced Circulatory Dysfunction: A Concise Review

Annually, 10% of cirrhotic patients with ascites develop refractory ascites for which large-volume paracentesis (LVP) is a frequently used therapeutic procedure. LVP, although a safe method, is associated with circulatory dysfunction in a significant percentage of patients, which is termed paracentesis-induced circulatory dysfunction (PICD). PICD results in faster reaccumulation of ascites, hyponatremia, renal impairment, and shorter survival. PICD is diagnosed through laboratory results, with increases of >50% of baseline plasma renin activity to a value ≥4 ng/mL/h on the fifth to sixth day after paracentesis. In this review, we discuss the pathophysiology and prevention of PICD.

A Critical Evaluation of Wet Biomarkers for Huntington's Disease: Current Status and Ways Forward

There is an unmet clinical need for objective biomarkers to monitor disease progression and treatment response in Huntington's disease (HD). The aim of this review is, therefore, to provide practical advice for biomarker discovery and to summarise studies on biofluid markers for HD. A PubMed search was performed to review literature with regard to candidate saliva, urine, blood and cerebrospinal fluid biomarkers for HD. Information has been organised into tables to allow a pragmatic approach to the discussion of the evidence and generation of practical recommendations for future studies. Many of the markers published converge on metabolic and inflammatory pathways, although changes in other analytes representing antioxidant and growth factor pathways have also been found. The most promising markers reflect neuronal and glial degeneration, particularly neurofilament light chain. International collaboration to standardise assays and study protocols, as well as to recruit sufficiently large cohorts, will facilitate future biomarker discovery and development.

Reference intervals of nine steroid hormones over the life-span analyzed by LC-MS/MS: Effect of age, gender, puberty, and oral contraceptives

New reference intervals need to be established for a new analytical method with improved sensitivity and specificity. We aimed to establish the new reference intervals from infancy to senescence of nine steroid hormones (cortisol, cortisone, progesterone, 17-hydroxyprogesterone (17-OHP), androstenedione, testosterone, estradiol, DHEAS, and aldosterone) for LC-MS/MS method. Serum samples from 4678 reference individuals (age range: 0.3-79 years) were measured with LC-MS/MS. Samples were collected between 7 a.m. and 10 a.m. Exclusion criteria were concomitant endocrine diseases and body mass index ≥ 33. Generalized additive model for location, scale and shape, the nonparametric or robust method was applied. We established the reference intervals of the nine steroid hormones by sex, age, and pubertal stage. Below the age of one, we observed the surge of androgen and estrogen which implied mini-puberty. At the same period of life, aldosterone and cortisone levels were very high reflecting physiological hyperaldosteronism. An increase of steroid hormones during the pubertal development and slow decrease towards senescence after the peak at early adulthood were observed. Due to the increase of CBG synthesis, cortisol levels were increased under oral contraceptives (OC) significantly (p < 0.0001), while OC suppressed progesterone, 17-OHP, androstenedione, and estradiol (p < 0.0001). Our results will facilitate the interpretation of patient data in routine diagnostics with the use of LC-MS/MS method. Since LC-MS/MS methods have shown good comparability among the different laboratories, our reference intervals can be further adopted in other laboratories equipped with LC-MS/MS, once the validation with a small number of reference samples is performed.

Serum Aldosterone Is Related to Left Ventricular Geometry and Function in Young Adults with Never-Treated Primary Hypertension

Background: Although aldosterone has been demonstrated to induce left ventricular (LV) hypertrophy not only in primary aldosteronism but also in primary hypertension (HT), it can be affected by multiple factors, including age, and the effect of aldosterone on LV function is controversial. This study was to investigate the relationship of aldosterone to changes in LV geometry and function in young adults with never-treated HT. Methods: Seventy-five consecutive patients (age, 29.8 ± 6.3 years) with never-treated HT and 45 normal controls were enrolled. Echocardiographic values and LV global longitudinal strain (LVGLS) were obtained. Serum aldosterone concentration (SAC) and serum procollagen type III amino-terminal peptide (PIIINP) level were obtained in HT patients. Results: HT patients had higher LV mass index, higher relative wall thickness (RWT), and worse LV function than normal controls. LVGLS and e’ velocity were worse in HT patients with normal geometry than in normal controls. SAC was well correlated with LV mass index, RWT, e’ velocity, LVGLS, and PIIINP (all p < 0.05). LV geometry pattern was most related to SAC among clinical parameters (p = 0.019). LVGLS was most related to LV geometry and diastolic blood pressure. In contrast, e’ velocity was most related to PIIINP. Conclusion: Our findings may indicate that in young patients with never-treated HT, aldosterone significantly contributes to changes in LV geometry and functional impairment through its pro-hypertrophic and myocardial fibrosis effects beyond blood pressure.

Genotype/phenotype correlations in 538 congenital adrenal hyperplasia patients from Germany and Austria: discordances in milder genotypes and in screened versus prescreening patients

Congenital adrenal hyperplasia (CAH) due to CYP21A2 gene mutations is associated with a variety of clinical phenotypes (salt wasting, SW; simple virilizing, SV; nonclassical, NC) depending on residual 21-hydroxylase activity. Phenotypes and genotypes correlate well in 80-90% of cases. We set out to test the predictive value of CAH phenotype assignment based on genotype classification in a large multicenter cohort. A retrospective evaluation of genetic data from 538 CAH patients (195 screened) collected from 28 tertiary centers as part of a German quality control program was performed. Genotypes were classified according to residual 21-hydroxylase activity (null, A, B, C) and assigned clinical phenotypes correlated with predicted phenotypes, including analysis of Prader stages. Ultimately, concordance of genotypes with clinical phenotypes was compared in patients diagnosed before or after the introduction of nationwide CAH-newborn screening. Severe genotypes (null and A) correlated well with the expected phenotype (SW in 97 and 91%, respectively), whereas less severe genotypes (B and C) correlated poorly (SV in 45% and NC in 57%, respectively). This was underlined by a high degree of virilization in girls with C genotypes (Prader stage >1 in 28%). SW was diagnosed in 90% of screening-positive babies with classical CAH compared with 74% of prescreening patients. In our CAH series, assigned phenotypes were more severe than expected in milder genotypes and in screened vs prescreening patients. Diagnostic discrimination between phenotypes based on genotypes may prove overcome due to the overlap in their clinical presentations.

Role of Aldosterone and Mineralocorticoid Receptor in Cardiovascular Aging

The mineralocorticoid receptor (MR) was originally identified as a regulator of blood pressure, able to modulate renal sodium handling in response to its principal ligand aldosterone. MR is expressed in several extra-renal tissues, including the heart, vasculature, and adipose tissue. More recent studies have shown that extra-renal MR plays a relevant role in the control of cardiovascular and metabolic functions and has recently been implicated in the pathophysiology of aging. MR activation promotes vasoconstriction and acts as a potent pro-fibrotic agent in cardiovascular remodeling. Aging is associated with increased arterial stiffness and vascular tone, and modifications of arterial structure and function are responsible for these alterations. MR activation contributes to increase blood pressure with aging by regulating myogenic tone, vasoconstriction, and vascular oxidative stress. Importantly, aging represents an important contributor to the increased prevalence of cardiometabolic syndrome. In the elderly, dysregulation of MR signaling is associated with hypertension, obesity, and diabetes, representing an important cause of increased cardiovascular risk. Clinical use of MR antagonists is limited by the adverse effects induced by MR blockade in the kidney, raising the risk of hyperkalaemia in older patients with reduced renal function. Therefore, there is an unmet need for the enhanced understanding of the role of MR in aging and for development of novel specific MR antagonists in the context of cardiovascular rehabilitation in the elderly, in order to reduce relevant side effects.

Aldosterone and aldosterone/cortisol ratio is higher in serum of long-term compared to first episode schizophrenia patients: A pilot study

We have previously shown that patients with severe depressive episode exhibit higher aldosterone concentrations compared to those with moderate depressive episode. The present study was undertaken to test the hypothesis that circulating concentration of aldosterone reflect the clinical state in patients with schizophrenia. The sample consisted of 36 hospitalized patients (25 men, 11 women) with the first episode or long-term course of schizophrenia. The severity of psychopathology was evaluated using the Positive and Negative Syndrome Scale (PANSS). Samples for measurement of serum aldosterone were obtained immediately after awakening. The results showed that serum aldosterone concentrations were lower in patients with the first episode compared to those in patients with long-term course of schizophrenia. Importantly, lower aldosterone concentrations observed in patients with the first episode were associated with more severe clinical symptoms as indicated by all subscales of PANSS. Serum cortisol concentrations did not differ between the groups, while the aldosterone/cortisol ratio showed similar pattern as aldosterone concentrations. The present pilot study suggests that circulating aldosterone in patients with schizophrenia may reflect the severity of clinical symptoms but in an opposite direction than in patients with major depressive disorder.

Age-related hearing loss: prevention of threshold declines, cell loss and apoptosis in spiral ganglion neurons

Age-related hearing loss (ARHL) -presbycusis - is the most prevalent neurodegenerative disease and number one communication disorder of our aged population; and affects hundreds of millions of people worldwide. Its prevalence is close to that of cardiovascular disease and arthritis, and can be a precursor to dementia. The auditory perceptual dysfunction is well understood, but knowledge of the biological bases of ARHL is still somewhat lacking. Surprisingly, there are no FDA-approved drugs for treatment. Based on our previous studies of human subjects, where we discovered relations between serum aldosterone levels and the severity of ARHL, we treated middle age mice with aldosterone, which normally declines with age in all mammals. We found that hearing thresholds and suprathreshold responses significantly improved in the aldosterone-treated mice compared to the non-treatment group. In terms of cellular and molecular mechanisms underlying this therapeutic effect, additional experiments revealed that spiral ganglion cell survival was significantly improved, mineralocorticoid receptors were upregulated via post-translational protein modifications, and age-related intrinsic and extrinsic apoptotic pathways were blocked by the aldosterone therapy. Taken together, these novel findings pave the way for translational drug development towards the first medication to prevent the progression of ARHL.

Blood pressure response to metoprolol and chlorthalidone in European and African Americans with hypertension

Despite the availability of many antihypertensive drug classes, half of patients with hypertension have uncontrolled blood pressure (BP). The authors sought to assess the effect of age on BP response in European American and African American patients with hypertension. Clinic BP from the PEAR2 (Pharmacogenomics Evaluation of Antihypertensive Responses 2) study was used to estimate BP responses from baseline following sequential treatment with metoprolol 100 mg twice daily and chlorthalidone 25 mg daily for 8 to 9 weeks each, with a minimum 4-week washout between treatments. BP responses to both drugs were compared in 159 European Americans and 119 African Americans by age with adjustment for baseline BP and sex. European Americans younger than 50 years responded better to metoprolol than chlorthalidone (diastolic BP: -9.6 ± 8.0 vs -5.9 ± 6.8 mm Hg, adjusted P = .003), whereas patients 50 years and older responded better to chlorthalidone than metoprolol (systolic BP: -18.7 ± 13.8 vs -13.6 ± 14.8 mm Hg, adjusted P = .008). African Americans younger than 50 years responded similarly to both drugs, whereas those 50 years and older responded better to chlorthalidone than metoprolol (-17.0 ± 13.2/-9.6 ± 7.5 vs -7.0 ± 18.6/-6.7 ± 9.3 mm Hg, adjusted P<.0001/.008). Therefore, age should be considered when selecting antihypertensive therapy in European and African American populations with hypertension.

The expression of renin-angiotensin-aldosterone axis components in infantile hemangioma tissue and the impact of propranolol treatment

BackgroundPropranolol's mechanism of action for controlling infantile hemangioma (IH) remains unclear. We hypothesize that this nonselective beta antagonist downregulates renin-angiotensin-aldosterone (RAA) axis components, preventing angiogenic substrate induction of IH.MethodsIH tissue and serum were collected from children with propranolol-treated or -untreated IH during surgery. Normal skin and serum from demographically matched children were used as controls. Real-time PCR and western blot quantified RAA components in proliferative (n=10), involuting (n=10), propranolol-treated (n=12) IH, and normal specimens (n=11). Serum was analyzed by enzyme-linked immunosorbent assay (ELISA).ResultsThere were significantly greater messenger RNA (mRNA) levels of angiotensinogen (AGT) in proliferating IH, but not in involuting or treated IH, when compared with controls (P<0.05). Angiotensin-converting enzyme (ACE) and angiotensin II receptor 1 (AGTR1) mRNA expression was higher in all IH specimens when comparedwith controls (P<0.05). ACE and AGTR1 protein expression was greater in proliferating IH tissue compared with that in controls and in involuting and treated IH tissue (P<0.05). ELISA showed no significant difference in ACE serum levels but did show a significant reduction in renin in involuting compared with proliferating IH (P<0.05).ConclusionsThe protein and mRNA expression of several RAA pathway constituents is elevated in IH tissue when compared with that in normal tissue. The action of propranolol on IH may be the result of reductions in ACE and AGTR1.

Clinical aspects of changes in water and sodium homeostasis in the elderly

The population of elderly individuals is increasing worldwide. With aging, various hormonal and kidney changes occur, both affecting water homeostasis. Aging is a risk factor for chronic kidney disease (CKD) and many features of CKD are reproduced in the aging kidney. Dehydration and hyperosmolarity can be triggered by diminished thirst perception in this population. Elderly with dementia are especially susceptible to abnormalities of their electrolyte and body water homeostasis and should be (re-)assessed for polypharmacy. Hypo- and hypernatremia can be life threatening and should be diagnosed and treated promptly, following current practice guidelines. In severe cases of acute symptomatic hyponatremia, a rapid bolus of 100 to 150 ml of intravenous 3% hypertonic saline is appropriate to avert catastrophic outcomes; for asymptomatic hyponatremia, a very gradual correction is preferred. In summary, the body sodium (Na+) balance is regulated by a complex interplay of environmental and individual factors. In this review, we attempt to provide an overview on this topic, including dehydration, hyponatremia, hypernatremia, age-related kidney changes, water and sodium balance, and age-related changes in the vasopressin and renin-angiotensin-aldosterone system.

Isolated Systolic Hypertension: An Update After SPRINT

Isolated systolic hypertension is the most common hemodynamic form of hypertension in the elderly. With a rapidly aging population, the prevalence of hypertension, particularly isolated systolic hypertension, is expected to increase substantially. This phenomenon of increasing systolic pressure in the elderly is believed to be secondary to pathophysiological changes of aging as well as modifiable risk factors. Isolated systolic hypertension is associated with substantial mortality and morbidity, particularly of cerebrovascular disease. It is a rapidly growing public health concern and its management continues to remain a challenge to practicing physicians. Recent studies like the Systolic Blood Pressure Intervention Trial (SPRINT) and Heart Outcomes Prevention Evaluation (HOPE)-3 have implications for antihypertensive therapy in general and for the management of isolated systolic hypertension in particular. In this article we will review: 1) epidemiology and pathophysiologic mechanisms, 2) impact of isolated systolic hypertension on cardiovascular outcomes, 3) optimal management strategies, and 4) systolic blood pressure goals in the light of SPRINT and HOPE 3 trials.

Meta-analysis of effects of obstructive sleep apnea on the renin-angiotensin-aldosterone system

Background

Obstructive sleep apnea (OSA) is the most common cause of resistant hypertension, which has been proposed to result from activation of the renin–angiotensin–aldosterone system (RAAS). We meta-analyzed the effects of OSA on plasma levels of RAAS components.

Methods

Full-text studies published on MEDLINE and EMBASE analyzing fasting plasma levels of at least one RAAS component in adults with OSA with or without hypertension. OSA was diagnosed as an apnea-hypopnea index or respiratory disturbance index ≥ 5. Study quality was evaluated using the Newcastle-Ottawa Scale, and heterogeneity was assessed using the I² statistic. Results from individual studies were synthesized using inverse variance and pooled using a random-effects model. Subgroup analysis, sensitivity analysis, and meta-regression were performed, and risk of publication bias was assessed.

Results

The meta-analysis included 13 studies, of which 10 reported results on renin (n = 470 cases and controls), 7 on angiotensin II (AngII, n = 384), and 9 on aldosterone (n = 439). AngII levels were significantly higher in OSA than in controls [mean differences = 3.39 ng/L, 95% CI: 2.00–4.79, P < 0.00001], while aldosterone levels were significantly higher in OSA with hypertension than OSA but not with hypertension (mean differences = 1.32 ng/dL, 95% CI: 0.58–2.07, P = 0.0005). Meta-analysis of all studies suggested no significant differences in aldosterone between OSA and controls, but a significant pooled mean difference of 1.35 ng/mL (95% CI: 0.88–1.82, P < 0.00001) emerged after excluding one small-sample study. No significant risk of publication bias was detected among all included studies.

Conclusions

OSA is associated with higher AngII and aldosterone levels, especially in hypertensive patients. OSA may cause hypertension, at least in part, by stimulating RAAS activity.

Long-term treatment with aldosterone slows the progression of age-related hearing loss

Age-related hearing loss (ARHL), clinically referred to as presbycusis, is one of the three most prevalent chronic medical conditions of our elderly, with the majority of persons over the age of 60 suffering from some degree of ARHL. The progressive loss of auditory sensitivity and perceptual capability results in significant declines in workplace productivity, quality of life, cognition and abilities to communicate effectively. Aldosterone is a mineralocorticoid hormone produced in the adrenal glands and plays a role in the maintenance of key ion pumps, including the Na-K(+)-Cl co-transporter 1 or NKCC1, which is involved in homeostatic maintenance of the endocochlear potential. Previously we reported that aldosterone (1 μM) increases NKCC1 protein expression in vitro and that this up-regulation of NKCC1 was not dose-dependent (dosing range from 1 nM to 100 μM). In the current study we measured behavioral and electrophysiological hearing function in middle-aged mice following long-term systemic treatment with aldosterone. We also confirmed that blood pressure remained stable during treatment and that NKCC1 protein expression was upregulated. Pre-pulse inhibition of the acoustic startle response was used as a functional measure of hearing, and the auditory brainstem response was used as an objective measure of peripheral sensitivity. Long-term treatment with aldosterone improved both behavioral and physiological measures of hearing (ABR thresholds). These results are the first to demonstrate a protective effect of aldosterone on age-related hearing loss and pave the way for translational drug development, using aldosterone as a key component to prevent or slow down the progression of ARHL.

Non-invasive assessment of endothelial function in children with obesity and lipid disorders

BACKGROUND

Digital tonometry is designed to non-invasively screen for endothelial dysfunction by the detection of impaired flow-induced reactive hyperaemia in the fingertip. We determined whether digital reactive hyperaemia correlated with risk factors for atherosclerosis in two groups of children at increased risk for endothelial dysfunction.

METHODS

A total of 15 obese children and 23 non-obese, dyslipidaemic children, 8-21 years of age, were enrolled, and their medical histories, anthropometric measurements, carotid wall thickness by means of ultrasonography, and fasting blood samples for cardiovascular risk factors were obtained. The standard endoPAT index of digital reactive hyperaemia was modified to reflect the true peak response or the integrated response of the entire post-occlusion period. In each group, age, sex, pubertal status, carotid wall thickness, and multiple cardiovascular risk factors were tested as predictors of endothelial dysfunction.

RESULTS

In the non-obese, dyslipidaemic group, but not in the obese group, both indices strongly correlated with height (r=0.55, p=0.007, by peak response) followed by weight, waist circumference, and age. In both groups, neither index of reactive hyperaemia significantly correlated with any other cardiovascular risk factor.

CONCLUSIONS

Contrary to the known age-related increase in atherosclerosis, digital reactive hyperaemia increased with age and its correlates in non-obese, dyslipidaemic children and was not related to other cardiovascular risk factors in either group. The reason for the lack of this relationship with age in obese children is unknown. The age-dependent physiology of digital microvascular reactivity and the endothelium-independent factors controlling the peak hyperaemic response need further study in children with a wide age range.

Renin gene rs1464816 polymorphism contributes to chronic kidney disease progression in ADPKD

Background

Autosomal dominant polycystic kidney disease (ADPKD) is a monogenic disorder and is a common genetic cause of chronic renal failure in children and adults. The enzyme renin plays a key role in the RAAS cascade and an important role in the development of hypertension and progression of renal disease in ADPKD. The present study is aimed to investigate the potential modifier effect of REN gene polymorphisms on the progression of chronic kidney disease (CKD) in ADPKD.

Methods

We analyzed 102 ADPKD patients and 106 healthy controls from the same geographic area. FRET-based KASPar single-nucleotide polymorphism (SNP) genotyping assays for REN gene tag-SNPs (rs2887284, rs2368564, rs1464816, rs7521667, rs10900555, rs6693954, rs6676670 and rs11571078) were performed. Cochran-Armitage trend test was used to assess the potential associations between these polymorphisms and CKD stages. Haplotype frequencies and LD measures were estimated by using the software Haploview. Mantel-Haenszel stratified analysis was used to explore confounding and interaction effects of these polymorphisms.

Results

Of the eight tag-SNPs genotyped, the rs10900555 polymorphism deviated from the Hardy-Weinberg equilibrium in controls. The presence of ADPKD in general was not significantly associated with the REN tag-SNPs included in this study. Linkage disequilibrium analysis yielded three haplotype blocks and the haplotypes of the respective blocks are not statistically different between ADPKD and controls. In multivariate analysis, the rs1464816 TG genotype showed a significant association with the advancement of CKD in ADPKD (OR = 4.80; 95 % CI = 1.30–17.82; p = 0.019).

Conclusions

The present study provides evidence that the rs1464816 polymorphism in REN is associated with CKD progression in ADPKD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12929-015-0217-0) contains supplementary material, which is available to authorized users.

The effect of puberty on diurnal sodium regulation

The aim of this study was to investigate the impact of sex and puberty stage on circadian changes in sodium excretion, sodium-regulating hormones, and hemodynamics. Thirty-nine healthy volunteers (9 prepuberty boys, 10 prepuberty girls, 10 puberty boys, and 10 puberty girls) were included. They all underwent a 24-h circadian in-patient study under standardized conditions regarding activity, diet, and fluid intake. Blood samples were drawn every 4 h, and the urine was collected in fractions. Blood pressure and heart rate were noninvasively monitored. Atrial natriuretic peptide (ANP), angiotensin II, aldosterone, and renin were measured in blood. Children in puberty had lower plasma levels of renin (P<0.05) and angiotensin II (P<0.05) and a 26% reduction in filtered sodium without changes in sodium excretion compared with prepuberty children. A circadian rhythm in sodium excretion, the renin-angiotensin system, ANP, and blood pressure was found with a midnight ANP peak (P<0.001), a nighttime decrease in hemodynamic parameters (P<0.001), an increase in plasma renin (P<0.001) and angiotensin II (P<0.001), and a decrease in sodium excretion (P<0.001) mainly on the basis of increased sodium reabsorption (P<0.001). The timing of the changes did not depend on sex or puberty group. There is a circadian rhythm of sodium excretion and sodium regulation in 7- to 15-yr-old children. This rhythm is similar in boys and girls. As an important new finding, puberty changes the plasma levels of renin and angiotensin II without changing the amount of sodium excreted or the day to night sodium excretion ratio.

Common genetic variants of the human steroid 21-hydroxylase gene (CYP21A2) are related to differences in circulating hormone levels

Purpose

Systematic evaluation of the potential relationship between the common genetic variants of CYP21A2 and hormone levels.

Methods

The relationships of CYP21A2 intron 2 polymorphisms and haplotypes with diverse baseline and stimulated blood hormone levels were studied in 106 subjects with non-functioning adrenal incidentaloma (NFAI). The rationale for using NFAI subjects is dual: i) their baseline hormone profiles do not differ from those of healthy subjects and ii) hormone levels after stimulation tests are available.

Results

The carriers (N = 27) of a well-defined CYP21A2 haplotype cluster (c5) had significantly elevated levels of cortisol (p = 0.0110), and 17-hydroxyprogesterone (p = 0.0001) after ACTH stimulation, and 11-deoxycortisol after metyrapone administration (p = 0.0017), but the hormone values were in normal ranges. In addition, the carriers (N = 33) of the C allele of the rs6462 polymorphism had a higher baseline aldosterone level (p = 0.0006). The prevalence of these genetic variants of CYP21A2 did not differ between NFAI and healthy subjects.

Conclusions

The common CYP21A2 variants presumably exert the same effect on hormone levels in the healthy and disease-affected populations. Therefore, they may contribute to complex diseases such as some cardiovascular diseases, and may influence the genotype-phenotype correlation in patients with congenital adrenal hyperplasia (CAH) including the individual need for hormone substitution.

Increasing complexity: which drug class to choose for treatment of hypertension in the elderly?

Treatment of hypertension in the elderly is expected to become more complex in the coming decades. Based on the current landscape of clinical trials, guideline recommendations remain inconclusive. The present review discusses the latest evidence derived from studies available in 2013 and investigates optimal blood pressure (BP) and preferred treatment substances. Three common archetypes are discussed that hamper the treatment of hypertension in the very elderly. In addition, this paper presents the current recommendations of the NICE 2011, JNC7 2013-update, ESH/ESC 2013, CHEP 2013, JNC8 and ASH/ISH guidelines for elderly patients. Advantages of the six main substance classes, namely diuretics, beta-blockers (BBs), calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), and direct renin inhibitors (DRIs) are discussed. Medical and economic implications of drug administration in the very elderly are presented. Avoidance of treatment-related adverse effects has become increasingly relevant. Current substance classes are equally effective, with similar effects on cardiovascular outcomes. Selection of substances should therefore also be based on collateral advantages of drugs that extend beyond BP reduction. The combination of ACEIs and diuretics appears to be favorable in managing systolic/diastolic hypertension. Diuretics are a preferred and cheap combination drug, and the combination with CCBs is recommended for patients with isolated systolic hypertension. ACEIs and CCBs are favorable for patients with dementia, while CCBs and ARBs imply substantial cost savings due to high adherence.

Treatment and health outcomes in adults with congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is a genetic disorder caused by defective steroidogenesis that results in glucocorticoid deficiency; the most common underlying mutation is in the gene that encodes 21-hydroxylase. Life-saving glucocorticoid treatment was introduced in the 1950s, and the number of adult patients is now growing; however, no consensus has been reached on the management of CAH beyond childhood. Adult patients are prescribed a variety of glucocorticoids, including hydrocortisone, prednisone, prednisolone, dexamethasone and combinations of these drugs taken in either a circadian or reverse circadian regimen. Despite these personalized treatments, biochemical control of CAH is only achieved in approximately one-third of patients. Some patients have a poor health status, with an increased incidence of obesity and osteoporosis, and impaired fertility and quality of life. The majority of poor health outcomes seem to relate to inadequate treatment rather than the genotype of the patient. Patients receiving high doses of glucocorticoids and the more potent synthetic long-acting glucocorticoids are at an increased risk of obesity, insulin resistance and a reduced quality of life. Further research is required to optimize the treatment of adult patients with CAH and improve health outcomes.

Hypertension and depressed symptomatology: a cluster related to the activation of the renin-angiotensin-aldosterone system (RAAS). Findings from population based KORA F4 study

CONTEXT

Preliminary evidence points to aldosterone being not only prominently involved in the systemic regulation of the blood pressure but also to play a role in the pathophysiology of depression.

OBJECTIVE

We evaluated whether the combination of hypertension and depressed symptomatology is useful to screen for individuals suffering an activation of the renin-angiotensin-aldosterone system (RAAS).

DESIGN

We conducted a cross-sectional analysis in participants from the Cooperative Health Research in the Region of Augsburg (KORA) F4 Study conducted between 2006 and 2008 in Southern Germany. A total of 1805 participants of the F4 study were included in the study.

METHODS

The association between aldosterone and renin levels and the different combinations of hypertension and depressed symptomatology was examined in four different models of multiple linear regression adjusted for age, sex, creatinine levels, potassium levels, body mass index (BMI) and behavioural risk factors.

RESULTS

Individuals suffering both, depressed symptomatology and hypertension exhibited highly significantly increased aldosterone levels (p<0.001) and slightly, not significantly increased renin levels (p=0.08) compared to individuals with no depressed symptomatology and no hypertension. No significant activation of the RAAS was seen in only depressed or only hypertensive individuals.

CONCLUSIONS

The finding of highly significantly increased aldosterone levels and increased renin levels in individuals suffering both, depressed symptomatology and hypertension provides further evidence for the involvement of the RAAS in the pathogenesis of depressed symptomatology. These findings have important implications for future research concerning the pathophysiological pathways that link depression and cardiovascular disease.

Acute kidney injury, sodium disorders, and hypercalcemia in the aging kidney: diagnostic and therapeutic management strategies in emergency medicine

This article summarizes the current literature regarding the structural and functional changes of the aging kidney and describes how these changes make the older patient more susceptible to acute kidney injury and fluid and electrolyte disorders. It discusses the clinical manifestations, evaluation, and management of hyponatremia and shows how the management of hypernatremia in geriatric patients involves addressing the underlying cause and safely correcting the hypernatremia. The current literature regarding evaluation and management of hypercalcemia in older patients is summarized. The management of severe hypercalcemia is discussed in detail. The evaluation and management of acute kidney injury is described.

To live alone and to be depressed, an alarming combination for the renin-angiotensin-aldosterone-system (RAAS)

INTRODUCTION

The renin-angiotensin-aldosterone-system (RAAS) is one of the most important systems involved in the pathogenesis of cardiovascular diseases. Its role in stress response has been generally neglected, although the progression of cardiovascular disease is considerably increased in the presence of stress and especially in the presence of depression risk. With the present analysis we aimed to evaluate whether the activity of the RAAS correlates with depressive symptomatology and with chronic stress. Moreover, we aimed to analyse whether stress response is altered in the presence of depressed symptomatology. We chose "living alone" to be our paradigm of chronic stress.

METHODS AND RESULTS

Aldosterone and renin levels were assessed in 1743 (829 men, 914 women) from the population-based KORA study (Cooperative Health Research in the Region of Augsburg). The relationship between aldosterone, renin levels and the different combinations of living alone and depressive symptomatology was examined in three different multiple linear regression models adjusted for age, sex, creatinine levels, potassium levels, body mass index (BMI) and bio-behavioural factors. Neither "living alone" nor depressive symptomatology alone were associated with an activation of the RAAS, but the combination of living alone and depressive symptomatology yielded a highly significant increase in the aldosterone (p<0.01) and renin level (p=0.03).

CONCLUSION

Our findings show that depressive symptomatology is associated with a hyper-responsiveness to chronic stress. Under the condition of chronic stress depressed individuals have an activated RAAS. Activation of the RAAS might explain the known increased risk of negative cardiovascular disease outcomes in this group.

Kidney aging--inevitable or preventable?

The aging process affects all organs, including the kidneys. As part of this process, progressive scarring and a measurable decline in renal function occur in most people over time. The improved understanding of the processes that can lead to and/or hasten scarring and loss of renal function over time parallels advances in our understanding of the aging process. Clinical factors, including hypertension, diabetes mellitus, obesity, abnormal lipid levels and vitamin D deficiency, have been associated with increasing renal sclerosis with age. In addition, tissue factors such as angiotensin II, advanced glycation end products, oxidative stress and Klotho are associated with renal aging. These associations and possible interventions, including the control of blood pressure, blood sugar, weight, diet and calorie restriction might make renal aging more preventable than inevitable.

Podocyte dysfunction in aging--related glomerulosclerosis

We review podocyte molecular structure and function, consider the underlying mechanisms related to podocyte dysfunction and propose that podocyte dysfunction be considered in the evaluation and management of age-associated glomerulosclerosis. With aging, progressive sympathetic activation, increased intrarenal renin-angiotensin system (RAS) activity, endothelin system and oxidative stress and reduced nitric oxide (NO)-availability can damage podocytes. Apoptosis and proliferation are the principal podocyte changes following injury with the latter leading to sclerosis and loss of nephrons. Podocyte loss can be evaluated by either determining their average number in biopsed glomeruli or by estimating podocyte number or their associated molecules in urine sediment. Podocyturia may be considered a marker of active glomerular disease. Preliminary data suggest that antiadrenergic drugs, angiotensin converting enzyme (ACE) inhibitors, RAS blocking drugs, endothelin system inhibitors and reduced oxidative stress can protect podocytes. Thus podocytes appear to play an important role in the pathogenesis, evaluation and therapy of age related glomerulosclerosis.

Aldosterone, Plasma Renin Activity, and Aldosterone/Renin Ratio in a Normotensive Healthy Pediatric Population

Primary aldosteronism is an important cause of secondary hypertension and is suspected in adults with an aldosterone/renin ratio ≥25. The normal aldosterone/renin ratio is unknown in children. The aim was to establish serum aldosterone, plasma renin activity, and aldosterone/renin ratio values in a healthy pediatric population. A cross-sectional study was performed in 211 healthy normotensive children (4 to 16 years old). Two subgroups of normotensive children were obtained: with hypertensive parents (NH) (n=113) and normotensive parents (n=98). Blood samples for measuring serum aldosterone, plasma renin activity, aldosterone/renin ratio, and DNA were collected. In subjects with aldosterone/renin ratio ≥25, the chimeric CYP11B1/CYP11B2 gene was investigated by long-extension PCR. Results are expressed as median [Q 1 –Q 3 ]. NH and normotensive parents groups were similar in serum aldosterone (6.5 [3.6 to 9.0] ng/dL versus 6.5 [2.9 to 9.7] ng/dL; P =0.968) and plasma renin activity (2.3 [1.6 to 3.1] versus 2.4 [1.7 to 3.7] ng/mL per hour; P =0.129). The aldosterone/renin ratio was higher in the NH group, but this difference did not reach statistical significance (2.8 [1.9 to 4.1] versus 2.5 [1.4 to 4.0], P =0.104). In one subject of the NH group, the chimeric CYP11B1/CYP11B2 gene was detected. We demonstrated that normal aldosterone/renin ratio values in a healthy pediatric population without NH were lower than those reported for an adult normotensive population.