I recently came across this article. It's not new, but the search function doesn't turn up previous discussions about it on ExcelMale.
It's some food for thought for guys with high testosterone who might use AIs to push estradiol down to "normal".
Imbalance of testosterone/estradiol promotes male CHD development
Abstract
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.
It's some food for thought for guys with high testosterone who might use AIs to push estradiol down to "normal".