A study in the relationships between leptin, insulin, and body fat in Asian subjects

OBJECTIVE: To study the relationship of leptin concentrations with indices of obesity, fasting insulin, insulin resistance and lipid profiles (total c holesterol, low density lipoprotein (LDL)-cholesterol, high density lipopro tein (HDL)- cholesterol and triglyceride) in an Asian cohort. DESIGN: Cross sectional study. SUBJECTS: A total of 133 healthy volunteers were enrolled (64 female: age: 25-61 y, body mass index (BMI): 18.7-45.1 kg/m(2) and 69 male: age: 25-61 y , BMI: 19.3-35.0 kg/m(2)). MEASUREMENTS: Weight, height, waist and hip circumferences, blood pressure, lean body mass (by bioelectric impedence analysis (BIA)), plasma leptin an d lipid profiles were taken after a 10h fast, RESULTS: Percentage of body fat measured by bioelectric impedance was the s trongest determinant of plasma leptin (r= 0.844, P < 0.0001). Females had h igher leptin concentrations than males for the same fat mass. In a multiple linear regression model, body fat percentage, (percentage body fat gender) , hip circumference and fasting insulin were significant determinants of le ptin concentration (r = 0.882, P < 0.0001). CONCLUSION: Leptin concentration correlated closely with percentage body fa t in Asian subjects. Hip circumference as a corollary for peripheral obesit y, was better associated with leptin than waist circumference or waist-to-h ip ratio (WHR). Distribution of fat in females tended to be peripheral and may partly explain the gender difference. Fasting insulin level and central obesity were correlated with HDL-cholesterol, triglyceride and blood press ure, while fasting leptin had little correlation with these metabolic param eters. Therefore, insulin resistance was a better guide to cardiovascular r isk assessment than plasma leptin.