ACUTE INSULIN-RESPONSE TO INTRAVENOUS GLUCAGON IN POLYCYSTIC-OVARY-SYNDROME

In order to evaluate the acute insulin response after i.v. injection o f glucagon in polycystic ovary syndrome (PCOS), 35 women affected by P COS and 11 normo-ovulatory controls underwent a 75 g oral glucose tole rance test (OGTT) and, 2 days later, a glucagon test (1 mg i,v,), Pati ents were analysed according to their degree of obesity; the insulin r elease after glucagon injection for lean PCOS subjects and control wom en was not statistically significantly different, Conversely obese PCO S patients had higher insulin secretion after both i,v, glucagon and O GTT when compared to the other groups. Moreover the insulin secretory patterns were heterogeneously represented in lean and obese PCOS women . When the patients were analysed according to their insulinaemic resp onse to OGTT, normoinsulinaemic PCOS women and control subjects had a similar insulin response to i,v, glucagon whereas the hyperinsulinaemi c PCOS group had a higher insulin response (P < 0.0001), Moreover, a h ighly significant relationship was found between the insulin response to OGTT and to glucagon administration in the PCOS population (P < 0.0 001; r = 0.73), which was maintained also after controlling for obesit y. Our results are consistent with the hypothesis that PCOS patients c ould have an insulin hyperresponse to glucagon administration, that is partially independent from obesity and related to their insulinaemic status, Moreover, the glucagon test could represent an effective alter native to OGTT in screening insulin disorders of PCOS patients (at lea st in the absence of other risk factors), due to its reliability, simp licity, and speed of performance.