Obese women with PCOS had decreased microvascular, metabolic insulin sensitivity

Polycystic ovary syndrome appeared to further impair metabolic insulin sensitivity in obese women with the condition, compared with normal-weight women who had PCOS in a recently published study.

Researchers from the Netherlands investigated the effects of insulin sensitivity in 35 women with PCOS (19 normal weight; 16 obese) and 27 age- and BMI-matched controls (14 normal weight; 13 obese) at baseline and during hyperinsulinemia.

Both microvascular and metabolic insulin sensitivity were decreased in obese women compared with normal-weight women (P<.001). This decrease was independent of PCOS, according to the researchers.

Obese women with PCOS had a greater decrease in metabolic insulin sensitivity compared with obese controls (P=.02). Normal-weight women with PCOS had similar insulin sensitivity as their normal-weight healthy peers.

The researchers also evaluated responses to acetylcholine and reported no major differences among the four groups. However, acetylcholine responses were significantly greater in normal-weight women with and without PCOS during insulin infusion compared with obese women with and without PCOS. – by Katie Kalvaitis

J Clin Endocrinol Metab. 2008;9:3365-3372.

The important point to remember is that many women with PCOS are obese, and obese women frequently also have PCOS, but the two populations of women are not the same. This study’s results remind us of that fact and suggest that obesity may be a greater risk factor for diabetes and cardiovascular disease than just PCOS alone. The question is: Just how much greater are the risks for women who are both obese and have PCOS?

– Robert W. Rebar, MD

Endocrine Today Editorial Board member