Vascular effects of estrogen in type II diabetic postmenopausal women

Objectives We assessed the effects of estrogen on vascular dilatory and oth er homeostatic functions potentially affected by nitric oxide (NO)-potentia ting properties in type II diabetic postmenopausal women. Background There is a higher cardiovascular risk in diabetic women than in nondiabetic women. This would suggest that women with diabetes do not have the cardioprotection associated with estrogen. Methods We administered placebo or conjugated equine estrogen, 0.625 mg/day for 8 weeks, to 20 type II diabetic postmenopausal women in a randomized, double-blinded, placebo-controlled, cross-over design. Results Compared with placebo, estrogen tended. to lower low-density lipopr otein (LDL) cholesterol levels by 15 +/- 23% (p=0.007) and increase high-de nsity lipoprotein (HDL) cholesterol levels by 8 +/- 16% (p=0.034). Thus, th e ratio of LDL to HDL cholesterol levels significantly decreased with estro gen, by 20 +/- 24%, as compared with placebo (p=0.001). Compared with place bo, estrogen tended to increase triglyceride levels by 16 +/- 48% and tower glycosylated hemoglobin levels by 3 +/- 13% (p=0.295 and p=0.199, respecti vely). However, estrogen did not significantly improve the percent flow-med iated dilatory response to hyperemia (17 +/- 75% vs. placebo; p=0.501). The statistical power to accept our observation was 81.5%. Compared with place bo, estrogen did not significantly change E-selectin, intercellular adhesio n molecule-1, vascular cell adhesion molecule-1, monocyte chemoattractant p rotein-1 or matrix metalloproteinase-9 levels. Compared with placebo, estro gen tended to decrease tissue factor antigen and increase tissue factor act ivity levels by 7 +/- 46% and 5 +/- 34%, respectively (p=0.321 and p=0.117, respectively) and lower plasminogen activator inhibitor-1 levels by 16 +/- 31% (p=0.043). Conclusions The effects of estrogen on endothelial, vascular dilatory and o ther homeostatic functions were less apparent in type II diabetic postmenop ausal women, despite the beneficial effects of estrogen on lipoprotein leve ls. (J Am Coll Cardiol 2001;38:1409-15) (C) 2001 by the American College of Cardiology.