Relationship between subcutaneous fatness and leptin in male athletes

Purpose: Circulating leptin is low in trained subjects and closely related to body fat content. However. data are scarce as to whether differences exi st in the relationship between different estimates of adiposity, metabolic parameters. and leptin in endurance- and resistance -trained male athletes. We investigated this relationship with special emphasis on subcutaneous fa tness and its distribution. Methods: 20 endurance (ET) and 17 resistance (R T) athletes recruited from different kind of sports were studied. Fat-free mass (FFM) was estimated by means of impedance and fat mass (FM) was calcul ated. Subcutaneous fat (SAT) and its distribution was measured by means of the optical device Lipometer at 15 body sites (SAT-lavers: from 1-neck to 1 5-calf) on the right side of the body. Fifteen SAT-lavers were summed to ca lculate SAT. Blood samples were obtained for determination for leptin, insu lin. and glucose. Insulin resistance was calculated through the fasting ins ulin resistance index (FIRI [insulin x glucose/25]). Results: RT-athletes h ad a greater body mass and body fat content than ET-athletes. but no differ ences were found for leptin and metabolic parameters. In all athletes, esti mates of adiposity were correlated to leptin. However. in ET-athletes FM (P < 0.05). FFM (P < 0.05), and SAT (P < 0.001) but not metabolic parameters were correlated to leptin. In RT-athletes, SAT (P < 0.0001), metabolic para meters (all P < 0.05). but not FM and FFM were in significant relationship with leptin. Stepwise regression revealed SAT as the main determinant for t he variation in leptin in all athletes (adj. R-2 = 0.52, P < 0.0001). Concl usion: The results suggest that estimates of adiposity and metabolic parame ters are associated with leptin in a sport-specific manner. Whereas leptin might be regulated by overall subcutaneous fatness in athletes. our study d oes not imply a main influence of fat patterning on leptin in this group of trained subjects.