Insulin Responses to the Oral Glucose Tolerance Test in Women of Different Ethnicity With Polycystic Ovary Syndrome

Objective: To evaluate insulin responses to the oral glucose tolerance test (OGTT) in women of different ethnic origins diagnosed with polycystic ovary syndrome (PCOS). Methods: We evaluated 92 women diagnosed with PCOS. Their ethnic origins were Western European (n = 41), Middle Eastern (n = 18), African American (n = 15), East Indian (n = 9), and South American (n = 9). The clinical diagnosis of PCOS included at least 3 of the following symptoms: menstrual disturbances (amenorrhea or oligomenorrhea); ovulatory infertility, hirsutism, and elevated serum testosterone (>= 2.0 nmol/L); or a luteinizing hormonel follicle-stimulating hormone ratio of >= 3. The diagnosis was also supported by ultrasonographic changes revealing the presence of multiple small antral follicles distributed peripherally. All investigations were performed after an overnight fast on days 2 through 5 of a spontaneous menstrual cycle or progesterone-induced withdrawal bleeding. The women underwent an OGTT with a glucose loading of 75 g. The responses of glucose and insulin to the OGTT were analyzed as the area under the curve (AUC) and were calculated with the trapezoidal method. Results: There were no significant differences in age or body mass index (BMI) among the different ethnic groups. All groups showed endocrine changes consistent with PCOS, but there were no differences in the hormonal levels among them. Middle Eastern women had higher AUC, glucose (P < 0.02; 95% confidence interval [CI], 0.5-3.5), and insulin (P < 0.04; 95% CI, 13.3-593.4) levels than did women with Western European origin. Conclusions: Middle Eastern women with PCOS expressed different insulin responses to OGTT than did Western European women, suggesting that Middle Eastern women with PCOS had poor carbohydrate metabolism.