Abstract
BACKGROUND: Adiposity is associated with arterial stiffness, and both adiposity and arterial stiffness independently predict morbidity and mortality. Because adipocytes account for most adipokine production, the objectives of this study were to examine the influence of adipokines such as leptin, adiponectin, and resistin on the relationship between abdominal adiposity and arterial stiffness. METHODS: This is a cross-sectional analysis of data from the Baltimore Longitudinal Study of Aging (BLSA). Adiposity was measured as kilograms of abdominal adipose tissue using dual-energy X-ray absorptiometry (DXA). Arterial stiffness was assessed as carotid-femoral pulse wave velocity (PWV). Leptin, adiponectin, and resistin were assayed in fasting serum samples. The influence of adipokines on the relationship between adiposity and arterial stiffness by adipokines was examined using standard mediation pathway analysis. RESULTS: Among 749 participants ages 26-96 years (mean age 67, 52% men, 27% black), abdominal adiposity was positively associated with PWV (relative ratio (RR) = 1.04, P = 0.02), after adjusting for potential confounders but was attenuated and no longer significant after adjusting for leptin (RR = 0.99, P = 0.77). The relationship between adiposity and PWV was not substantially influenced by adiponectin (RR = 1.03, P = 0.06) or resistin (RR = 1.05, P = 0.010). Leptin (RR = 1.02, P < 0.001), resistin (RR = 0.92, P < 0.0001), and adiponectin (RR = 0.97, P = 0.004), but not abdominal adiposity (RR = 1.00, P = 0.94), retained significant associations with PWV when adjusting for each other and confounders. CONCLUSIONS: Our findings are consistent with the hypothesis that leptin explains, in part, the observed relationship between abdominal adiposity and arterial stiffness. Adiponectin, leptin, and resistin are independent correlates of PWV.