Insulin Resistance and Its Associated Risk Factors in Nigerian Women with Polycystic Ovary Syndrome

Abstract

Background: The etiology of polycystic ovary syndrome (PCOS) is not completely understood; however one condition that correlates closely with the pathogenesis of PCOS is insulin resistance (IR). The objective of this study was to determine the prevalence of insulin resistance (IR) and the association of such abnormality with potential risk factors in women with PCOS. Method: 116 women with confirmed PCOS attending a reproductive clinic at the University of Benin Teaching Hospital in Benin City were studied. IR was determined by homeostatic model assessment (HOMA) ≥ 2 and pre-diabetes by fasting plasma glucose between 110 and 125 mg/dl and/or plasma glucose value between 140 and 200 mg/dl at 2 hours during an oral glucose tolerance test (OGTT) after ingestion of 75 g oral glucose load. Results: Forty-two women were insulin resistant among the 116 women with PCOS. The prevalence of IR was 36.2% (95% CI 26.6 - 46.2). The prevalence of impaired fasting glucose (IFG) showed 1.7% (95% CI 0.97 - 2.03), impaired glucose tolerance (IGT) was 2.6% (95% CI 1.97 - 3.03) and diabetes mellitus (DM) was 1.7% (95% CI 0.97 - 2.03) in the 116 PCOS women. Of these 42 insulin resistant PCOS women, 23.8% (n = 10) were obese and 40.5% (n = 17) were overweight. Multivariate analysis revealed that total cholesterol (OR, 1.07; 95% CI, 1.04 - 1.10), triglycerides (OR, 1.08; 95% CI, 1.04 - 1.13) and LDL-cholesterol (OR, 1.08; 95% CI, 1.04 - 1.12) were statistically significant independent risk factors for IR. Conclusion: The prevalence of IR was high in women with PCOS, and there was a significant association between IR, obesity, and dyslipidemia. However, the prevalence rates of impaired glucose tolerance and DM were low in women with PCOS compared to other studies. Since women with PCOS are at risk of IR and dyslipidemia, early screening, detection, intervention, and lifestyle modification would ameliorate the financial burden of DM and cardiovascular disease (CVD).