Sex-specific Associations of Aldosterone and Renin With Body Composition: A Population-based Cohort Study.

Context: Renin-angiotensin-aldosterone system (RAAS) activation is closely linked to obesity; however, the sex-specific associations between RAAS activity and body composition among individuals without obesity are not well understood.

Objective: To investigate the associations of aldosterone and renin with body composition according to sex in the general population.

Design: Population-based cohort study.

Setting: Québec (Canada).

Participants: Adults aged 40 to 69 years enrolled in CARTaGENE between 2009 and 2010 (N = 3687).

Exposures: Plasma aldosterone and renin concentrations.

Main outcome measures: Body composition assessed via anthropometrics (waist circumference and waist-to-hip ratio), bioelectrical impedance (lean body mass, fat mass, and muscle mass), and cardiac magnetic resonance imaging (epicardial and pericardial adipose tissue volumes).

Results: The mean (SD) age and body mass index were 55 (8) years and 27.3 (4.8) kg/m2, respectively. Among males, higher aldosterone and renin were associated with increased waist circumference, increased waist-to-hip ratio, increased fat mass, decreased lean body mass, and decreased muscle mass (P < .05). Aldosterone (P = .02), but not renin (P = .43), was associated with increased ectopic cardiac adiposity in males. In contrast, higher renin (P < .05), but not aldosterone (P ≥ .05), was associated with increased waist circumference, increased waist-to-hip ratio, and increased cardiac adiposity in females. Among females, higher renin and aldosterone were associated with increased fat mass (P < .05) but were not associated with lean body mass or muscle mass (P ≥ .05). All aforementioned associations were independent of body weight.

Conclusion: Independent of body weight, increased RAAS activity is associated with unfavorable differences in body composition; however, the strength and pattern of association varies by sex.