Body Composition, Metabolic Characteristics, and Insulin Resistance in Obese and Nonobese Women with Polycystic Ovary Syndrome.

OBJECTIVES

The objective was to compare body composition, metabolic characteristics, and insulin resistance between obese (body mass index [BMI] ≥25 kg/m) polycystic ovary syndrome (PCOS) and nonobese PCOS (BMI <25 kg/m) women and their age- and BMI-matched controls.

MATERIALS AND METHODS

A total of 81 PCOS women (Rotterdam criteria) (obese - 42; nonobese - 39) and 86 controls (obese - 42; nonobese -44) were recruited in this cross-sectional study. All women underwent a detailed assessment of clinical, anthropometric, and metabolic parameters, insulin resistance indices, and body composition measurements with visceral adipose tissue assessment (VAT) (dual-energy X-ray absorptiometry scan).

RESULTS

Of PCOS women, 27% (80% - obese PCOS; 20% - nonobese PCOS) were diagnosed with metabolic syndrome (International Diabetes Federation criteria), 35% of PCOS women (46% - obese PCOS; 54% - nonobese PCOS) had impaired glucose tolerance, and 7% of PCOS women (2/3 - obese PCOS; 1/3 - nonobese PCOS) had diabetes mellitus. Insulin resistance was seen in about 80% in obese PCOS women and 20% in nonobese PCOS women based on various insulin resistance indices such as fasting insulin (≥12.2 μU/ml), Homeostasis Model Assessment-Insulin Resistance (≥2.5), and Quantitative Insulin Sensitivity Check Index (<0.33). Total body fat, estimated (Est.) VAT, and corrected Est. VAT (corrected for body weight) were significantly increased ( = 0.0001) in both obese and nonobese PCOS women when compared to those of their age- and BMI-matched controls. However, corrected Est. VAT (corrected for body weight) was not significantly different between obese and nonobese PCOS women.

CONCLUSION

Both obese and nonobese PCOS women when compared with their age- and BMI-matched controls were metabolically worse and had more visceral adiposity. Nonobese PCOS poses similar risk as that of obese PCOS in having similar amount of VAT (corrected for body weight).