Threshold BMI to predict Non-Insulin-resistance in PCOS

To suggest a threshold BMI at which IR becomes significant

This is a cross sectional study conducted at Gandhi Hospital, a tertiary care centre, teaching hospital at Hyderabad, India. The study includes 167patients diagnosed as PCOS by revised Rotterdam criteria in the age-group of 18–30 years attending the gynaecology O.P between January 2013 to August2013. All were subjected to a uniform questionnaire, medical examination, investigations, inclusion and exclusion criteria.

40% of 167 PCOS patients studied had IR. 87.88% of 66 IR PCOS patients had a BMI >25 kg/m&sup2; (Sensitivity-87.88%). 60.39% of 101 non-IR PCOS patients had BMI <25kg/m&sup2; (Specificity-60.39%). Among the 98 PCOS patients with BMI >25 kg/m&sup2;, 58 (59.18%) had IR. Hence the predictive value of positive test is 59.18%. Among 69 PCOS patients with BMI <25, 61(88.4%) had no IR. Hence the predictive value of negative test is 88.4%. Correlation coefficient (r-value) between the two data sets of BMI and IR was 0.842. This shows that increasing BMI and IR are strongly correlated.

IR strongly correlates with BMI. Hence BMI is a simple and easy tool to predict Non-IR among PCOS patients. BMI<25kg/m&sup2; is highly predictive of Non-IR and may be used as a threshold to demarcate between IR and non-IR patients.