Lean body mass and the cardiovascular system constitute a female-specific relationship.

Abstract

Recent evidence points toward a link between lean body mass (LBM) and cardiovascular capacity in women. This study aimed at determining the sex-specific relationship of LBM with central and peripheral circulatory variables in healthy women and men (<i>n</i>=70) matched by age (60±12 years versus 58±15 years), physical activity, and cardiovascular risk factors. Regional (legs, arms, and trunk) and whole-body (total) body composition were assessed via dual-energy x-ray absorptiometry. Cardiac structure, function, and central/peripheral hemodynamics were measured via transthoracic echocardiography and the volume-clamp method at rest and peak incremental exercise. Regression analyses determined sex-specific relationships between LBM and cardiovascular variables. Regional and total LBM were lower in women than men (<i>P</i><0.001), with little overlap between sexes. Leg and arm LBM positively associated with left ventricular (LV) internal resting dimensions in women (<i>r</i>≥0.53, <i>P</i>≤0.002) but not men (<i>P</i>≥0.156). Leg, arm, and total LBM only associated with LV relaxation in women (<i>r</i>≥0.43, <i>P</i>≤0.013). All LBM variables strongly associated with LV volumes at peak exercise in women (<i>r</i>≥0.54, <i>P</i>≤0.001) but not men and negatively associated with total peripheral resistance at peak exercise in women (<i>r</i>≥0.43, <i>P</i>≤0.023). Adjustment by adiposity-related or cardiovascular risk factors did not alter results. In conclusion, leg and arm LBM independently associate with internal cardiac dimensions, ventricular relaxation, and systemic vascular resistance in a sex-specific manner, with these relationships exclusively present in women.