Lipolysis, fatness, gender and plasma leptin concentrations in healthy, normal-weight subjects

Background: Relationship between plasma leptin and adiposity and gender has been reported in adults. Effect of age on plasma leptin is unclear and reg ulation of leptin production by white adipose tissue is still poorly unders tood. Objectives: To study if age and parameters of lipolysis are related to plas ma leptin concentrations. Methods: Seventy-seven healthy, normal-weight subjects (age range 19-82 y.) had measurements of body composition ((18)oxygen dilution technique) and o f fasting plasma levels of leptin, glycerol, and nonesterified fatty acids (NEFA). Results: Plasma leptin was correlated to NEFA (r = 0.28) and glycerol (r = 0.48) concentrations. The relationship between %fat and plasma leptin was b est fitted by an exponential (r(2) = 0.82). In multiple regression %fat, bo dy mass index, glycerol, and gender, but not fat mass, age or NEFA contribu ted independently to the variation in log plasma leptin. Log plasma leptin was higher in women than in men for a given glycerol concentration. Conclusion: Adiposity, lipolysis, and gender are related to plasma leptin i n healthy humans.