Serum leptin concentrations in obese women with Down syndrome and Prader–Willi syndrome

Abstract

We have evaluated serum leptin concentrations in two forms of genetic obesity. The subjects examined were eight women with Down syndrome and eight women with Prader-Willi syndrome. All patients were in the reproductive age range and were obese (body mass index ≥ 21 kg/m2). Plasma leptin values ,analyzed as a function of body mass index showed a statistically significant correlation in both Prader-Willi (r = 0.985; p < 0.001) and Down syndrome patients (r = 0.943; p < 0.001). Obese Down syndrome women exhibited significantly lower leptin values (10.8 ± 1.1) as compared to patients with Prader-Willi syndrome (31 ± 2.6; p < 0.01). The linear correlation between leptin and insulin in the two groups of patients was not statistically significant. The data suggested that obesity in Prader-Willi subjects could be caused by failure of leptin to reach its target in the brain ,as a consequence of defects in the receptor or in postreceptor processing ,whereas data on obese patients with Down syndrome could be due to a different pathogenetic origin.