Polycystic ovary syndrome: Is obesity a sine qua non? A clinical, hormonal, and metabolic assessment in relation to body mass index

Objective : To determine the proportion of polycystic ovarian syndrome (PCOS) patients who have normal body mass index (BMI) and to compare the clinical, hormonal, and metabolic profile between lean and overweight patients of PCOS. Materials and Methods: One hundred consecutive infertile women with PCOS were studied and divided into lean (BMI between 18.5 and 23) and overweight (BMI ≥ 23). Metabolic and hormonal profile (serum FSH, LH, testosterone, prolactin, TSH on days 2-3 of menstrual cycle; serum progesterone premenstrually; serum insulin-fasting and 2 hours postglucose, glucose tolerance test, and fasting serum lipid profile) was performed along with pelvic sonogropahy; and clinical features, viz. waist hip ratio, hirsutism, acne, acanthosis nigricans, and clitoromegaly were recorded. Results: 42% of the PCOS subjects had normal BMI. Average age, hirsutism (80.9% vs. 89.7%), irregular cycles (92.8% vs. 96.6%), acne (9.5% vs. 15.5%), clitoromegaly (2.3% vs. 3.4%), endometrial thickness >4 mm (9.5% vs. 15.5%), and hormonal profile were similar in the lean and overweight PCOS groups. Family history of diabetes (9.5% vs. 24.1%), abnormal glucose tolerance test (GTT) (4.7% vs. 10.3%), deranged lipid profile (14.2% vs. 31%), and 2-hour postprandial insulin levels were higher in the overweight PCOS (P < 0.05). Insulin resistance was observed in 83.3% of lean PCOS but was still lower than 93.1% seen in overweight PCOS (P < 0.05). Conclusion: 42% of the PCOS had normal BMI, but clinical and hormonal profile was similar to PCOS patients with elevated BMI (overweight/obese). However, insulin resistance is observed in 83.3% of lean PCOS. Family history of diabetes, impaired GTT, deranged lipid profile, and insulin resistance were more prevalent in overweight PCOS