Influence of age, gender, and glucose tolerance on fasting and fed acylated ghrelin in Prader Willi syndrome

Background & aims: Prader Willi syndrome (PWS) is a genetic syndrome characterized by hyperphagia, morbid obesity, relative hypoinsulinemia and normal insulin sensitivity. PWS presents higher total (TG) and acylated ghrelin (AG) levels. The cause of this increase as well as the modulation of ghrelin secretion in fasting and feeding in relation to other metabolic parameters and glucose tolerance in PWS is largely unknown. Methods: We studied TG and AG at fasting in PWS children (14) and adults (18). We also studied TG and AG response to a mixed standardized light breakfast (SLB) in PWS adults without (AD-GT) and with glucose intolerance (AD-GI) at OGTT. Results: TG and AG were higher in children than in adults (p < 0.05). AG was higher in adult males (p < 0.001). Fasting AG and AG/TG ratio were lower in AD-GI than in AD-GT (p < 0.05). TG, but not AG, decreased in AD-GT (p < 0.006), whereas AG, but not TG, increased in AD-GI (p < 0.03) post-SLB. Fasting TG and AG were negatively predicted by fasting insulin (p < 0.05). Post-SLB AG was positively predicted by glucose during OGTT (p < 0.04). Conclusions: Fasting and post-meal AG levels are influenced by glucose tolerance in PWS, suggesting that AG derangement might have a role in the development of glucose intolerance.