Objective: Several groups have reported the important role of the estradiol/testosterone (E-2/T) ratio in benign prostatic hyperplasia and cerebral vessels. However, there has been no study on the role of the E-2/T ratio in women with coronary heart disease (CHD). This study aimed to evaluate the association among the ratio of sex hormones and known risk factors of atherosclerosis in postmenopausal women with CHD. Methods: 114 controls and 124 postmenopausal women with CHD were selected for this study. Serum levels of estradiol, testosterone, aromatase, sex hormone-binding globulin (SHBG), lipid-lipoprotein profile and high-sensitivity C-reactive protein were determined. Results: Compared with the control, the E-2/T ratio decreased from 5.35 +/- 2.78 to 3.88 +/- 2.51 (p < 0.0001). Multiple linear regression analysis showed that the E-2/T ratio was negatively associated with total cholesterol, low-density lipoprotein cholesterol (LDL-c) and the atherogenic index of plasma, but positively associated with high-density lipoprotein cholesterol (HDL-c) and HDL-c/LDL-c (for all, p < 0.0001). We found that there was a negative correlation between the E-2/T ratio and aromatase (r = -0.192, p = 0.032) and a positive correlation between aromatase and SHBG (r = 0.938). Conclusion:The balance of the serum E-2/T ratio was broken in the women with CHD, and an imbalanced E-2/T ratio showed a strong association with cardiovascular risk factors in postmenopausal women with CH D. Copyright (C) 2012 S. Karger AG, Basel