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 40-69 years enrolled to CARTaGENE between 2009 and 2010 (N=3,687).

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<0.05). Aldosterone (p=0.02), but not renin (p=0.43), was associated with increased ectopic cardiac adiposity in males. In contrast, higher renin (p<0.05), but not aldosterone (p≥0.05), 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<0.05) but were not associated with lean body mass or muscle mass (p≥0.05). All aforementioned associations were independent of body weight.

Conclusions: 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.