Context: Obesity-related predisposition to polycystic ovary syndrome (PCOS) could reflect overall adiposity and/or regional accumulation of abdominal visceral fat.

Objective: To compare distributions of visceral, abdominal subcutaneous and gluteo-femoral subcutaneous adipose tissue in PCOS cases vs control women.

Design: A cross-sectional study.

Setting and participants: Fat depot measurements from axial MRI images taken at anatomically pre-defined sites, were compared between 22 BMI/fat mass-matched pairs of PCOS cases and controls; whole-group comparisons included 50 PCOS cases vs 28 female controls. All subjects were of UK British/Irish origin.

Main outcome measure(s): Cross-sectional areas of adipose tissue within visceral (mid-L4), abdominal (mid-L4) subcutaneous and gluteo-femoral (greater trochanteric and mid-femoral) subcutaneous fat depots. Other measurements included fat mass, body mass index (BMI), testosterone, SHBG and Homeostasis Model Assessment of Insulin Resistance (HOMA2 IR, a measure of insulin sensitivity). Whole-group analyses were adjusted for fat mass and age.

Results: There were no significant differences in fat-depot measurements between BMI/fat mass-matched pairs of PCOS cases and controls: mid-L4 visceral (P=0.40), abdominal subcutaneous (P=0.22), gluteal subcutaneous (P=0.67) and mid-femoral subcutaneous (P=0.37) depots. Whole-group comparisons gave similar results following adjustments for fat mass and age. Fasting serum insulin concentrations (P=0.03) and HOMA2 IR (P=0.03) were significantly higher in the PCOS group than in BMI/fat mass-matched controls.

Conclusions: PCOS cases and BMI/fat mass-matched control women are indistinguishable with respect to distribution of fat within visceral, abdominal subcutaneous and gluteo-femoral subcutaneous depots, despite significant differences in insulin resistance between these two groups.