Objective: The aim of this study was to estimate whether coronary artery calcification is associated with serum estradiol (E2) level in postmenopausal women.
Methods: We performed a multidetector CT scan of the heart and measured the coronary artery calcium score (CACS) in 436 postmenopausal women who did not take postmenopausal hormone therapy. Women were divided into two groups according to the CACS (≥100 or <100). Serum E2 level, lipid profile, bone mineral densities of the lumbar vertebrae and femoral neck, current statin treatment status, and other coronary risk factors were analyzed in these two groups.
Results: The proportion of women with a higher serum E2 level (> or =20 pg/mL) was significantly higher in the lower-CACS (<100) group compared with the higher-CACS ((> or =100) group (34.0% vs 12.5%; P < 0.05). The distribution of CACS was significantly different between women with higher and lower (<20 pg/mL) serum E2 levels (P < 0.05), and the CACS was significantly lower in the group with a higher serum E2 level (P = 0.002). After adjusting various risk factors by weighted logistic regression model using inverse probability of treatment weighting, women with a higher serum E2 level had a reduced chance of having a higher CACS (crude odds ratio, 0.28; 95% CI, 0.08-0.95; P = 0.04; adjusted odds ratio, 0.25; 95% CI, 0.07-0.86; P = 0.03).
Conclusions: Postmenopausal women with a higher serum E2 level had a reduced CACS independent of age and other coronary risk factors. These retrospective analyses might suggest that a higher level of E2 possibly lowers the calcified-plaque burden of coronary arteries in postmenopausal women.