Postprandial adiponectin levels are unlikely to contribute to the pathogenesis of obesity in Prader-Willi syndrome

Aim: To investigate fasting and postprandial adiponectin levels in PWS patients as compared to obese and lean subjects and whether they could contribute to the pathogenesis of obesity in this syndrome. Methods: We studied 7 patients with PWS, 16 obese patients and 42 lean subjects for the fasting study. From this group, we evaluated 7 patients with PWS, 7 age-sex-BMI-matched obese non-PWS patients and 7 age-sex-matched lean subjects before and after the administration of 3,139.5 kJ (750 kcal) of a standard liquid meal (53.2% carbohydrate, 30% fat, 16.7% protein) after an overnight fast. Blood samples were obtained every 15 min for the first hour and every 30 min thereafter until 6 h. Adiponectin, IGF-I, glucose, triglycerides, cholesterol, and insulin were measured. Results: Fasting plasma adiponectin levels were lower in PWS than in lean subjects (5.24 +/- 2.56 vs. 8.28 +/- 4.63 mu g/ml, p = 0.041) but higher than in obese patients (4.01 +/- 1.27 mu g/ml, p = 0.047). After the meal, adiponectin concentrations mildly decreased in PWS at time point 240 min, while in obese and lean subjects no changes were observed. However, 6-hour postprandial AUC for adiponectin was similar in all three groups. Conclusion: Fasting adiponectin levels are low in PWS, but they are so mildly modulated postprandially that these changes do not seem significant for the pathogenesis of obesity in this syndrome.