Objective: Testosterone is either neutral or has a harmful effect on the male cardiovascular system. But the role of imbalance of testosterone (T) and estrogen (E2) (T/E2 ratio) in male CHD has been less studied. This study was carried out with the purpose of evaluating the relationship between T/E2 ratio and CHD.
Methods: Fifty-five male CHD patients (aged 61.25 ± 3.44) and 60 age-matched controls (aged 59.54 ± 1.44) were selected in this research.
Results: Compared with control group, levels of both serum T and E2 decreased, but only E2 had statistical significance (P=0.001). The normal testosterone (T)/estradiol (E2) ratio is 1.7 ± 0.12, but the ratio of T/E2 (3.28 ± 0.58) changed significantly in men with CHD group (P<0.05). With the imbalance of T/E2 ratio in CHD group, we further used a linear and multiple regression methods to analyze the correlation between sex hormones and CHD risk factors. The results showed serum T was positively associated with TG (r=0.439, P<0.01) and D-dimer (r=0.258, P<0.05), but negatively associated with HDL-C (r=-0.267, P<0.05) and Hs-CRP (r=-0.214, P<0.05). However, E2 was highly positive associated with TG (r=0.783, P<0.01) and HDL-C (r=0.515, P<0.01), but was negative related with LDL-C (r=-0.219, P<0.05), TC/LDL (r=-0.236, P<0.05) and D-dimer. Multiple linear regression method also showed the same results between E2 and HDL-C (P=0.020), LDL-C (P=0.000), which showed E2's protective role in cases. However, T/E2's effect is more significative than E2's, and the values between T/E2 and index are HDL-C (r=-0.624, P<0.01), LDL-C (r=0.348, P<0.01), TC/HDL (r=0.237, P<0.05), Hs-CRP (r=0.248, P<0.05) and D-dimer (r=0.249, P<0.05). Multiple linear regression method also showed the positive relationship between T/E2 and HDL-C (P=0.000), D-dimer (P=0.000), and negative relationships between T/E2 and TC (P=0.000), TG (P=0.000) or HDL/LDL (P=0.000).
Conclusion: The balance of T/E2 ratio, rather than the absolute levels of androgens, is crucial in modulating the effect of androgens on CHD in males.