Daily Profile of Serum Leptin in Prader-Willi Syndrome Complicated by Diabetes Mellitus - A Case Report

Abstract

High leptin levels in Prader-Willi (P-W) syndrome may occur as a result of the existence of leptin resistance, because a hypothalamic disturbance may underlay this disorder. In order to study whether there is a defective action of leptin on the hypothalamus in P-W syndrome, we have measured leptin and insulin twice during the daily profile of blood glucose, comparing the results with the recent reports. The patient was a 22-year-old female, who showed the typical feature of P-W syndrome complicated overt diabetes. This case of P-W syndrome was only made to maintain a diet of 1840 kcal/day of examination under hospitalization and was not made to maintain a calorie diet on any other day of examination in clinic. There was no reduction of leptin observed during the day, especially around noon and mid-afternoon, both under hospitalization and in clinic. Our experience suggests that an absence of the normal fall in leptin during the day was not related to eating pattern in this case, but to the defective action of leptin on the hypothalamus as well as excessive production by adipose tissue.

Plasma leptin concentrations in lean and obese human subjects and Prader-Willi syndrome: Comparison of RIA and ELISA methods

“…Thus the severe hyperphagia and hypometabolism characteristic of PWS do not appear to be caused primarily by either leptin deficiency or severe leptin resistance. However, Isotani et al 25 recently reported that the normal diurnal variation in circulating leptin was absent in a PWS patient, suggesting that the regulation of leptin secretion may be abnormal in PWS. Hence additional studies will be necessary to better define the determinants of plasma leptin concentrations in individuals with PWS.…”