[Effect of age, gender, and body fat distribution on serum leptin concentrations]

The aim of this study was to clarify the relationship between serum leptin concentration and age, gender and body fat distribution. Serum leptin concentrations were determined 267 subjects (138 men and 129 women), aged 30 to 91. The thicknesses of the preperitoneal fat layer (Pmax) and subcutaneous fat layer (Smin) in the abdomen were measured by ultrasonography. Fat mass and percent fat were measured by the bioelectrical impedance analysis method. Women had higher leptin and leptin/fat mass values than men in all BMI groups (BMI < 20, 20-23.9, 24-25.9, > or = 26). The leptin concentration correlated significantly with BMI, fat mass, percent fat, waist, hip, waist/hip ratio (W/H), Pmax, Smin and serum Cr in both men and women. The leptin concentration correlated significantly with age in men only and P/S in female only. Leptin/fat mass values significantly correlated with age, fat mass, and percent fat, but not with BMI, waist, hip, W/H, Pmax, Smin and P/S in men. In women, leptin/fat mass values significantly correlated with BMI, fat mass, percent fat, waist, hip, Pmax, Smin and P/S, but not with age or W/H. Multiple regression analysis showed that fat mass and serum creatinine were significant determinants of the leptin and leptin/fat mass values both in men and women, but that age was a significant determinant of these values only in men. These results suggest that the influence of aging on serum leptin concentration exists only in men.