Imbalance Between Postprandial Ghrelin and Insulin Responses to an Ad Libitum Meal in Obese Women With Polycystic Ovary Syndrome

Obese women with polycystic ovary syndrome (PCOS) may have impairment in the regulation of food intake associated with ghrelin and insulin. In order to compare postprandial ghrelin and insulin responses to an ad libitum meal, we assessed 30 obese women with PCOS and 23 obese women without PCOS (control group). Blood samples were taken under fasting conditions, preprandially, and 15, 45, 75, and 135 minutes after the beginning of an ad libitum meal and ghrelin and insulin concentrations were analyzed. Insulin resistance (IR) was classified using basal insulin, quantitative insulin sensitivity check index, and homeostasis model assessment index. Mean ad libitum food intake was similar between the groups (468 +/- 150 vs 444 +/- 165 g, P = .60). The IR was found in 56.6% in PCOS group compared with 30.4% in the control group (P < .01). The postprandial ghrelin response was similar in both the groups but the insulin area under the curve (AUC) tend to be greater in the PCOS group (12807 +/- 8149.4 vs 8654.4 +/- 7232.3 mu IU/mL/min; P = .057). The ghrelin AUC was negatively correlated with the insulin AUC (r = -.5138; P = .01) only in the control group. The imbalance in the feedback mechanisms between insulin and ghrelin, present in obese women, especially those with IR, may affect food intake throughout the day and that could be a mechanism for the development of obesity in PCOS.