Age- and sex-specific reference ranges are needed for the aldosterone/renin ratio

Associated lifestyle factors of elevated plasma aldosterone concentration in community population, gender-stratified analysis of a cross-sectional survey

BACKGROUND

Aldosterone plays important parts in development of cardio-metabolic diseases as end product of renin-angiotensin-aldosterone system. However, factors elevating circulating aldosterone are not clear, and lifestyle-related factors are suggested to be involved, whereas less studied. Therefore, we aimed to explore the association of lifestyle factors with plasma aldosterone concentration (PAC) in community population.

METHODS

In this cross-sectional study, we recruited participants using multistage random sampling from Emin China in 2019, and collected data and fasting blood samples. The considered lifestyle factors included obesity parameters (neck circumference, abdominal circumference), alcohol consumption, blood pressure (BP), physical activity, sleep duration, sleep quality, mental state (depression and anxiety), fasting blood glucose (FBG), and lipid profiles (total cholesterol and triglyceride). PAC was measured using radioimmunoassay. We performed sex-stratified linear and logistic regressions to explore associated factors of PAC. Component analysis was further performed to identify the main factors affecting PAC.

RESULTS

Twenty-seven thousand four hundred thirty-six participants with 47.1% men were included. Obesity parameters (neck circumference, abdominal circumference), glucose metabolism (FBG), psychological status (anxiety status in men and women, depression status in men), BP, liver function (in men), lipid metabolism (TC and TG in men), sleep parameters (sleep quality in women), and renal function (in women) are the main factors associated with elevated PAC.

CONCLUSION

lower physical activity, alcohol consumption, higher BP, fat accumulation, dyslipidemia, higher fasting blood glucose, and presence of depression and anxiety were the main factors associated with eleveated PAC.

Ex Vivo 13C-Metabolic Flux Analysis of Porcine Circulating Immune Cells Reveals Cell Type-Specific Metabolic Patterns and Sex Differences in the Pentose Phosphate Pathway

In general, females present with stronger immune responses than males, but scarce data are available on sex-specific differences in immunometabolism. In this study, we characterized porcine peripheral blood mononuclear cell (PBMC) and granulocyte energy metabolism using a Bayesian 13C-metabolic flux analysis, which allowed precise determination of the glycolytic, pentose phosphate pathway (PPP), and tricarboxylic acid cycle (TCA) fluxes, together with an assessment of the superoxide anion radical (O2•-) production and mitochondrial O2 consumption. A principal component analysis allowed for identifying the cell type-specific patterns of metabolic plasticity. PBMCs displayed higher TCA cycle activity, especially glutamine-derived aspartate biosynthesis, which was directly related to mitochondrial respiratory activity and inversely related to O2•- production. In contrast, the granulocytes mainly utilized glucose via glycolysis, which was coupled to oxidative PPP utilization and O2•- production rates. The granulocytes of the males had higher oxidative PPP fluxes compared to the females, while the PBMCs of the females displayed higher non-oxidative PPP fluxes compared to the males associated with the T helper cell (CD3+CD4+) subpopulation of PBMCs. The observed sex-specific differences were not directly attributable to sex steroid plasma levels, but we detected an inverse correlation between testosterone and aldosterone plasma levels and showed that aldosterone levels were related with non-oxidative PPP fluxes of both cell types.

A randomized vagus nerve stimulation study demonstrates that serum aldosterone levels decrease with age in women, but not in men

In this randomized, sham-controlled study, we explored the effects of acute transcutaneous vagus nerve stimulation (tVNS) on serum aldosterone in 20 younger (21-26 years) and 19 older (40-70 years) healthy participants. Blood samples were collected on two different days before and after a 20-min application of active tVNS at the inner tragus or sham stimulation of the earlobe. Irrespective of the stimulation mode, aldosterone levels decreased from pre- to post-stimulation in both the young (active: β = - 1.610 (- 2.855, - 0.365), p = 0.022; sham: β = - 0.857 (- 2.102, 0.388), p = 0.257) and the old cohort (active: β = - 1.969 (- 3.234, - 0.703), p = 0.005; sham: β = - 1.334 (- 2.600, - 0.069), p = 0.063). Although this decline was significant during active tVNS, the difference in estimated β-coefficients between active and sham stimulation was not statistically significant in either cohort. Nevertheless, aldosterone concentrations showed a significant interaction effect between sex and age (p = 0.001). Among all study participants, younger women (23.3 ± 1.6 years) had the highest mineralocorticoid levels (pre active: 172.1 ± 102.0 pg/ml, pre sham: 214.3 ± 82.3 pg/ml), whereas the lowest were observed in older females (59.4 ± 9.4 years) (pre active: 104.9 ± 85.8 pg/ml, pre sham: 81.1 ± 53.8 pg/ml). This post hoc analysis did not suggest that active auricular tVNS reduces serum aldosterone levels compared to sham stimulation in healthy subjects. However, serum aldosterone levels differed among subjects depending on their age and sex, irrespective of tVNS.

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.

Renin, Aldosterone, and Cortisol in Pregnancy-Induced Hypertension

INTRODUCTION

We aimed to assess renin, aldosterone, and cortisol in the early stages of pregnancy-induced hypertension (PIH), i. e., at the time of diagnosis.

METHODS

During the postural test, we measured aldosterone, renin [Liason DiaSorin Inc. (Italy)], as well as cortisol, sodium, potassium, and 24-h urinary sodium and potassium excretion in 62 women with newly diagnosed PIH, 70 healthy women during the 3rd trimester of pregnancy, and in 22 healthy non-pregnant women.

RESULTS

In all groups, there was a significant increase in aldosterone and renin in upright versus supine posture (p<0.01). Both supine and upright aldosterone concentrations were higher in healthy pregnant women than in women with PIH and the lowest in healthy not-pregnant [supine (median±intequartile range): 25.04±18.4 ng/dL, 18.03±12.58 ng/dL, and 7.48±4.78 ng/dL, p<0.001, upright: 31.60±21.32 ng/dL, 25.11±13.15 ng/dL, and 12.4±12.4 ng/dL, p<0.001, for healthy pregnant, pregnant with PIH, and non-pregnant, respectively]. Supine renin concentrations were higher only in healthy pregnant (p<0.001), while in the upright position, there was a difference only between healthy pregnant and women with PIH (p=0.002). Both in supine and upright positions, there was no difference in the aldosterone-to-renin ratio between healthy pregnant women and women with PIH, though, in both groups, the ratio was higher than in non-pregnant women (p<0.001). Morning cortisol concentrations and 24-h urinary sodium excretion were lower in women with PIH than in healthy pregnant (p<0.001, p=0.002, respectively).

CONCLUSION

Hyperaldosteronism is not involved in the etiology of PIH. In PIH, there is also a tendency towards lower sodium excretion and lower morning cortisol concentrations.

Aldosterone, Renin, and Aldosterone-to-Renin Ratio Variability in Screening for Primary Aldosteronism

CONTEXT

The plasma aldosterone concentration (PAC), renin, and aldosterone-to-renin ratio (ARR) are used to screen for primary aldosteronism (PA). Substantial intra-individual variability of PAC and ARR using plasma renin activity in the context of usual antihypertensive therapy has been described, but there is no data on ARR variability calculated using direct renin concentration (DRC).

OBJECTIVE

To describe the intra-individual variability of PAC, DRC, and ARR in the absence of interfering medications in patients with and without PA.

DESIGN

Retrospective cohort study.

PATIENTS

Hypertensive patients referred for investigation of PA, with at least 2 ARR measurements while off interfering medications.

SETTING

Endocrine hypertension service of a tertiary center, from May 2017 to July 2021.

MAIN OUTCOME MEASURES

PAC, DRC, and ARR variability was calculated as coefficient of variation (CV) and percent difference (PD).

RESULTS

Analysis of 223 patients (55% female, median age 52 years), including 162 with confirmed PA, demonstrated high variability with a sample CV of 22-25% in the PAC and sample CV of 41% to 42% in the DRC and ARR in both the PA and non-PA groups. The degree of variability was substantially higher than the assays' analytical CV. Sixty-two patients (38%) with PA had at least one ARR below 70 pmol/L:mU/L (2.4 ng/dL:mU/L), a cut-off for first-line screening of PA.

CONCLUSIONS

Significant intra-individual variability in PAC, DRC, and hence ARR occurs in a large proportion of patients being investigated for PA. These findings support the need for at least 2 ARR before PA is excluded or further investigated.

Establishing Reference Ranges for Aldosterone, Renin and Aldosterone-to-Renin Ratio for Women in the Third-Trimester of Pregnancy

OBJECTIVE

Diagnosis of primary hyperaldosteronism in pregnancy is complicated due to lack of reference ranges for aldosterone, renin and aldosterone-to-renin ratio. We have endeavoured to establish third-trimester reference ranges for the above-mentioned parameters.

DESIGN & PATIENTS

We performed postural tests for aldosterone and renin (chemiluminescence immunoassay Liason® DiaSorin Inc., Italy) in 70 healthy pregnant women (age 30.53±4.51 years), at 32.38±4.25 weeks of gestation and in 22 non-pregnant healthy women (age 33.08±8.72 years).

RESULTS

Aldosterone reference ranges were 6.51-73.97 ng/dl and 12.33-86.38 ng/dl, for supine and upright positions, respectively and that for renin were 6.25-59.36 µIU/ml and 11.12-82.55 µIU/ml, respectively. Aldosterone and renin concentrations were higher in an upright position (p=0.000459 and p=0.00011, respectively). In contrast, aldosterone-to-renin ratio was not affected by posture (i. e. 0.497-3.084 ng/dl/µIU/ml versus 0.457-3.06 ng/dl/µIU/ml, p=0.12), but was higher (p=0.00081) than in non-pregnant controls. In comparison to manufacturer-provided non-pregnant reference range, supine aldosterone concentrations increased by 556% (lower cut-off) and 313% (upper cut-off), while upright aldosterone concentrations increased by 558% (lower cut-off) and 244% (upper cut-off). The reference range for supine renin concentrations increased by 223% (lower cut-off) and 48.7% (upper cut-off), while upright renin concentrations increased by 253% (lower cut-off) and 79% (upper cut-off).

CONCLUSIONS

There is an upward shift in aldosterone and renin reference ranges in the third-trimester of pregnancy accompanied by an increase in an aldosterone-to-renin ratio, that is not influenced by posture. It remains to be established whether the aldosterone-to-renin ratio may be used as a screening tool for primary hyperaldosteronism in pregnancy.

Higher Plasma Aldosterone Concentrations Are Associated With Elevated Risk of Aortic Dissection and Aneurysm: a Case-Control Study

BACKGROUND

Animal models demonstrate circulating aldosterone leads to aortic dissection and aneurysm, whereas data from humans are lacking. Therefore, we aimed to examine the associations of plasma aldosterone concentrations (PAC) with aortic dissection and aneurysm.

METHODS

We identified patients with aortic dissection and aneurysm with assessed PAC before disease onset from hospital-based electronic database and set as case group. Simultaneously, age and gender-matched cohort with PAC measurement whereas without aortic dissection and aneurysm were selected as control group using ratio of 1:4. Multi-variable logistic regression analysis was used to assess the relationship of PAC with aortic dissection and aneurysm.

RESULTS

Totally, 133 cases and 531 controls (all hypertensive) were enrolled between 2004 and 2021, with 77.9% men, mean age of 55.5 years and PAC of 13.9 ng/dL. Case group showed significantly higher PAC(14.51 versus 13.65 ng/dL, P=0.012) than did control group. In logistic regression analysis, higher PAC exhibited 1.68-fold higher odds (95% CI, 1.14-2.48, P=0.008) for presence of aortic dissection and aneurysm, significant in adjusted model (odds ratio, 1.69 [95% CI, 1.11-2.57], P=0.015). In stratified analysis, the association between the 2 was observed in women of all ages and in men with coronary artery disease. Sensitivity analysis by excluding those under interfering agents at PAC measurement and those with primary aldosteronism did not change the relationship of the 2.

CONCLUSIONS

Higher PAC is associated with the increased odd for aortic dissection and aneurysm in patients with hypertension, even in the absence of primary aldosteronism, implying that PAC might be a target for prevention.

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.

Relationship Between the Aldosterone-to-Renin Ratio and Blood Pressure in Young Adults: A Longitudinal Study

[Figure: see text].

The Age-Dependent Changes of the Human Adrenal Cortical Zones Are Not Congruent

BACKGROUND

While previous studies indicate that the zonae reticularis (ZR) and glomerulosa (ZG) diminish with aging, little is known about age-related transformations of the zona fasciculata (ZF).

OBJECTIVES

To investigate the morphological and functional changes of the adrenal cortex across adulthood, with emphasis on (i) the understudied ZF and (ii) sexual dimorphisms.

METHODS

We used immunohistochemistry to evaluate the expression of aldosterone synthase (CYP11B2), visinin-like protein 1 (VSNL1), 3β-hydroxysteroid dehydrogenase type II (HSD3B2), 11β-hydroxylase (CYP11B1), and cytochrome b5 type A (CYB5A) in adrenal glands from 60 adults (30 men), aged 18 to 86. Additionally, we employed mass spectrometry to quantify the morning serum concentrations of cortisol, 11-deoxycortisol (11dF), 17α-hydroxyprogesterone, 11-deoxycorticosterone, corticosterone, and androstenedione in 149 pairs of age- and body mass index-matched men and women, age 21 to 95 years.

RESULTS

The total cortical area was positively correlated with age (r = 0.34, P = 0.008). Both the total (VSNL1-positive) and functional ZG (CYP11B2-positive) areas declined with aging in men (r = -0.57 and -0.67, P < 0.01), but not in women. The CYB5A-positive area declined with age in both sexes (r = -0.76, P < 0.0001). In contrast, the estimated ZF area correlated positively with age in men (r = 0.59, P = 0.0006) and women (r = 0.49, P = 0.007), while CYP11B1-positive area remained unchanged across ages. Serum cortisol, corticosterone, and 11-deoxycorticosterone levels were stable across ages, while 11dF levels increased slightly with age (r = 0.16, P = 0.007).

CONCLUSION

Unlike the ZG and ZR, the ZF and the total adrenal cortex areas enlarge with aging. An abrupt decline of the ZG occurs with age in men only, possibly contributing to sexual dimorphism in cardiovascular risk.

Gender differences in human adrenal cortex and its disorders

The adrenal cortex plays pivotal roles in the maintenance of blood volume, responsiveness to stress and the development of gender characteristics. Gender differences of human adrenal cortex have been recently reported and attracted increasing interests. Gender differences occur from the developing stage of the adrenal, in which female subjects had more activated stem cells with higher renewal capacity resulting in gender-associated divergent structures and functions of cortical zonations of human adrenal. Female subjects generally have the lower blood pressure with the lower renin levels and ACE activities than male subjects. In addition, HPA axis was more activated in female than male, which could possibly contribute to gender differences in coping with various stressful events in our life. Of particular interest, estrogens were reported to suppress RAAS but activate HPA axis, whereas androgens had opposite effects. In addition, adrenocortical disorders in general occur more frequently in female with more pronounced adrenocortical hormonal abnormalities possibly due to their more activated WNT and PRK signaling pathways with more abundant activated adrenocortical stem cells present in female adrenal glands. Therefore, it has become pivotal to clarify the gender influence on both clinical and biological features of adrenocortical disorders. We herein reviewed recent advances in these fields.

A Multicenter Study of Neutrophil-to-Lymphocyte Ratio in Primary Aldosteronism

Background

Hypertensive patients with primary aldosteronism (PA) have a higher risk of cardiovascular complications than those with blood pressure-matched essential hypertension. The excess cardiovascular consequences of PA can be attributed to the proinflammatory effect of excessive aldosterone and mineralocorticoid receptor activation in a range of peripheral tissues and cell types. The neutrophil-to-lymphocyte ratio (NLR) is a widely available marker of inflammation which has been shown to predict cardiovascular outcome in the general population. This study aims to evaluate the use of NLR as a potential biomarker of PA and PA severity.

Methods

Patients with PA (n = 355) were identified from 2 large PA databases in Australia and China, while controls (n = 222) were patients with hypertension who were referred for assessment but did not meet the diagnostic criteria for PA. The NLR was retrospectively collected from routine full blood examination, prior to commencement of targeted treatment for PA.

Results

The NLR did not differ between PA patients and hypertensive controls (median 2.3 and 2.4, P = 0.563). However, among patients with PA, the NLR was positively correlated with baseline and post-saline aldosterone levels (r = 0.22 and P < 0.001 for both) and negatively correlated with serum potassium (r = -0.15, P = 0.006). Furthermore, in a logistic regression analysis of data from patients with PA, the NLR predicted the presence of comorbid chronic kidney disease (CKD) (defined as estimated glomerular filtration rate <60 mL/min/1.73m²) with an odds ratio of 1.5 (P = 0.003).

Conclusion

While the NLR did not distinguish PA from controls, it was a marker of PA severity, being associated with aldosterone concentration as well as the presence of CKD. A prospective study is needed to further clarify the role of NLR in predicting end-organ damage associated with PA.