Endocrine Abstracts

Kisspeptin is a neuropeptide secreted in anteroventral-periventricular and arcuate hypothalamic nuclei involved pubertal onset and in other functions of adult life. Kisspeptin levels are sex dependent, so they are higher in prepubertal girls and in adult women compared to age-matched male. This sex-related pattern has been reported in adult obesity, but few data are reported in childhood obesity. In order to evaluate correlations between metabolic status and kisspeptin, we studied Kisspeptin levels in a population of 27 prepubertal children (13 males) aged 5–12 years, classified as overweight (n=3) or obese (n=24) according to Cole’s criteria. Eight normal weight children, aged 6–12 years, were enrolled as controls. Several metabolic parameters were evaluated: glucose and insulin levels after oral glucose load, total- LDL- and HDL-cholesterol, triglycerides, uric acid, total proteins, C Reactive Protein. Leptin was evaluated using ELISA method (DRG Instruments GmbH, Germany). In order to evaluate kisspeptin levels, morning blood samples were collected; after acidification, peptides were extracted in a C-18 SEP-Column (Phenomenex, Inc., USA). The eluted samples were evaporated and stored at −80  °C until assayed. Kisspeptin (pg/ml) was measured using the RIA kit KISS1 (61-121)-Amide-Metastin (1-54)-NH2 (Phoenix Pharmaceuticals, Burlingame, USA). We did not find significant differences between obese and normal weight children (mean±S.E.M: 20.1±1.96 and 20.7±0.68 pg/ml, respectively) and between males and females obese children (19.05±3.39 and 20.9±2.49 pg/ml). Kisspeptin levels did not correlate with SDS BMI, HOMA index and Insulin peak levels after glucose load. As expected, Leptin levels were higher in obese children than in controls (20.41±2.84 and 4.21±2 ng/ml, respectively), while showed a significant correlation with Kisspeptin levels in normal children (R²=0.12; P value=0.46), but not in obese (R²=0.03; P value=0.6). These preliminary data suggest that Kisspeptin could play a role in metabolic status and could be regarded as metabolic modulator and not only a regulator of pituitary gonadal axis.