Effects of leptin replacement therapy on pancreatic beta-cell function in patients with lipodystrophy

OBJECTIVE: Leptin administration is known to directly modulate pancreatic ?-cell function in leptin-deficient rodent models. However, human studies examining the effects of leptin administration on ?-cell function are lacking. In this study, we examined the effects (16-20 weeks) of leptin replacement on ?-cell function in patients with lipodystrophy. RESEARCH DESIGN AND METHODS: In a prospective, open-label, currently ongoing study, we studied the effects of leptin replacement on ?-cell function in 13 patients with congenital or acquired lipodystrophy. Insulin secretory rate (ISR) was calculated by C-peptide deconvolution from plasma glucose and C-peptide levels measured during oral glucose tolerance tests (OGTTs) performed at baseline and after 16-20 weeks of leptin replacement. ?-Cell glucose sensitivity and rate sensitivity were assessed by mathematical modeling of OGTT. RESULTS: There was a significant decrease in triglycerides, free fatty acids, and glycosylated hemoglobin levels (A1C) after leptin therapy. Patients with lipodystrophy have high fasting and glucose-stimulated ISR. However, leptin therapy had no significant effect on fasting ISR, total insulin secretion during OGTT, ?-cell glucose sensitivity, rate sensitivity, or insulin clearance. CONCLUSIONS: In contrast to the suppressive effects of leptin on ?-cell function in rodents, 16-20-week treatment with leptin in lipodystrophy patients did not significantly affect insulin secretion or ?-cell function in leptin-deficient individuals with lipodystrophy. © 2014 by the American Diabetes Association.