Predictors of Endothelial Dysfunction in Young Women With Polycystic Ovary Syndrome

Data from recent studies suggest a possibly increased risk of cardiovascular disease in women with polycystic ovary syndrome (PCOS), but the state of endothelial function in these women remains uncertain. Two recent studies indicate impaired endothelial function and vascular structure in relatively young, nonobese women with PCOS. The present study compared endothelial function in 62 women with PCOS, whose mean age was 22.7 years, and 17 control women matched with the affected women for age and body mass index. Eighteen of the women with PCOS were obese and 21 others were overweight. Endothelium-dependent and endothelium-independent vascular function was evaluated by measuring, respectively, flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) in the brachial artery. The former was estimated by the change in vascular diameter during hyperemia of the hand and the latter by administering sublingual glyceryl trinitrate sublingually. Both FMD and NMD were significantly lower in women with PCOS than in matched control women. The decrements approximated 50% and 25%, respectively. Both differences were statistically significant (P < .0005). Insulin resistance, total testosterone, and total cholesterol were all independent predictors of FMD; they accounted, respectively, for 21%, 10%, and 9% of the variance. FMD tended to deteriorate as body mass index increased, but not to a significant degree. In obese women with PCOS, factors correlating with FMD included body mass index, waist circumference, fasting insulin level, and the level of low-density lipoprotein cholesterol. In these women, total cholesterol and waist circumference accounted for 31% and 22%, respectively, of the variance in FMD. In this study, asymptomatic, relatively young women with PCOS exhibited impaired endothelial function and may be at increased risk of early-onset cardiovascular disease for this reason. Obesity is not a precondition for endothelial dysfunction in this context. It may well be appropriate to assess younger women with PCOS for cardiovascular risk factors and, when indicated, to take cardioprotective measures aimed at improving endothelial function. Possibilities include dietary modification, physical exercise and, possibly, administering an insulin sensitizer or an androgen-lowering drug.