The Plasma Leptin Concentration Is Closely Associated with the Body Fat Mass in Nondiabetic Uremic Patients

Plasma leptin is associated with the body mass index and, more precisely, with the body fat mass. Plasma leptin has been found to be elevated in uremic patients. This study aimed at investigating the plasma leptin concentration and associations between plasma leptin, body fat mass, and glomerular filtration rate in nondiabetic predialysis uremic patients and in nondiabetic patients on chronic hemodialysis. Plasma leptin, body fat mass, and creatinine clearance were measured in 22 predialysis uremic patients, 18 hemodialysis patients, and 24 healthy control subjects. The logarithmically transformed plasma leptin concentration was closely associated with the body fat mass in all groups (r = 0.93, r = 0.83, and r = 0.72, respectively; p < 0.000001, < 0.000002 and p < 0.001, respectively). In predialysis uremic patients the plasma leptin concentration was slightly elevated as compared with controls 10.4 (3.1–59.5) ng/ml versus 5.4 (1.6–47.5) ng/ml (median and range in parentheses; p < 0.05), whereas the plasma leptin concentration was normal in hemodialysis patients. Plasma leptin was not significantly associated with the creatinine clearance in predialysis patients. In conclusion; the glomerular filtration rate seemed to have a limited influence on the plasma leptin concentration in nondiabetic uremic subjects matched by body fat mass to controls. The plasma leptin concentration was closely associated with the body fat mass, and the leptin level might, therefore, be useful as an indicator of the fat mass in nondiabetic uremic patients.