Abstract 3221: Association of the Leptin to Adiponectin Ratio with the Metabolic Syndrome in Older Adults: The Rancho Bernardo Study
Higher concentrations of leptin and lower adiponectin have each been implicated in the development of insulin-resistance, the metabolic syndrome (MetS) and increased risk of cardiovascular disease (CVD). These adipocytokines have opposing actions on several metabolic systems, thus their relative concentration may be more important than their individual levels in determining CVD risk. We examined the sex-specific association of serum leptin, adiponectin, and the leptin to adiponectin ratio (L/A) with ATPIII-defined MetS among 836 men and 678 women, ages 50 to 91 yrs (mean=72), who were not current users of hormone therapy; 18% met criteria for the MetS. Leptin, adiponectin and the L/A ratio (×103) were higher (p<.001) in women (medians=13.3 μg/l, 15.5 mg/l, 0.86) than men (medians=6.2 μg/l, 9.8 mg/l, 0.67). The L/A ratio correlated negatively with age (r=−0.17) and HDL cholesterol (r=−0.46) and positively with waist girth (r=0.62), triglycerides (r=0.47), fasting plasma glucose (FPG) (r=0.21), and diastolic blood pressure (r=0.15) adjusting for sex (all p<.001). In age and sex-adjusted logistic regressions comparing the highest and lowest sex-specific tertiles (Table⇓), the association of L/A with individual MetS components was not notably stronger than that of one of the adipocytokines alone, and was markedly lower than leptin for central adiposity. However, L/A was associated with stronger odds of having the MetS (3+ components) than either adipocytokine alone, before and after adjusting for adiposity. Compared to those in the lowest tertile, men and women in the highest L/A tertile were 24 times more likely to have the MetS; adjustment for waist girth reduced the odds ratio to 9, suggesting that a significant proportion, but not all, of this association was related to fat distribution. Overall, 73% of men and women in the highest tertile of L/A met criteria for the MetS, thus the adipocytokine ratio may be a biomarker for, or a component of, the metabolic syndrome.