Endogenous oestradiol but not testosterone is related to coronary artery disease in men

Objectives Men die of coronary artery disease (CAD) more often than women. There is evidence that testosterone either is neutral or has a beneficial effect on male cardiovascular disease. The role of oestrogens in male CAD has been less studied. This study was carried out with the purpose of evaluating the relationship between sex hormone levels and CAD. Design Case-control study. Participants Men (aged 40-70) submitted to coronary angiography. A 70% occlusion of at least one major coronary artery defined the cases; subjects with <= 50% occlusion constituted the control group. Measurements Blood samples were collected for total testosterone (TT), oestradiol, luteinizing hormone, follicle-stimulating hormone, sex hormone-binding globulin, lipid profile and albumin measurements. Bioavailable and free testosterone, free androgen index (FAI) and free oestrogen index (FEI) were calculated. Oestradiol and TT levels were examined as terciles, based on the whole study population. Results Of the 140 patients included, 72 were cases and 68 were controls. The baseline characteristics of the two groups were similar, except for the older age and lower LDL-C in the cases. Oestradiol and FEI but not total, bioavailable and free testosterone and FAI correlated positively with CAD. After adjustments for potential confounders, oestradiol remained statistically significant. The prevalence of CAD was significantly higher in the 3rd than in the 1st tercile of oestradiol. Conclusion In this study, men with CAD had higher oestradiol and FEI levels. Additional studies are needed to clarify the direction of causality and possible underlying mechanisms.