Association between lipid profile and circulating concentrations of estrogens in young men

Objectives: Men show higher rates of cardiovascular morbidity and mortality than pre-menopausal women and this sexual dimorphism may be related to sex-specific effects of sex steroids on cardiovascular risk factors. Unlike androgens, estrogens were not extensively investigated in relation to cardiovascular phenotypes in men. Methods: We examined associations of estradiol and estrone and their precursors (total testosterone and androstenedione) with traditional cardiovascular risk factors (lipids, blood pressure, body mass) in 933 young (median age: 19 years), apparently healthy Polish men. Results: Total estradiol was associated with total cholesterol (p = 0.006) and high-density lipoprotein cholesterol (HDL-C) (p < 0.001) and estrone showed the strongest associations with both total cholesterol (p < 0.001) and low-density lipoprotein cholesterol (LDL-C) (p < 0.001) in the unadjusted ANOVA analysis. In the multivariable adjusted models in which other independent variables were held as constant one standard deviation increase in estradiol level was associated with 6%-standard deviation increase in total cholesterol (standardized β = 0.06, p = 0.038) and 6%-standard deviation decrease in HDL-cholesterol (standardized β = −0.06, p = 0.036). An increase in estrone levels by one standard deviation was associated with respective 12%- and 13%-standard deviation increases in total cholesterol (standardized β = 0.12, p < 0.001) and LDL-cholesterol levels (standardized β = 0.12, p < 0.001) after controlling for other predictors of lipids. Estrone correlated linearly with androstenedione (r = 0.28, p < 0.001) but there was no correlation between estradiol and testosterone. Estrogens retained their independent associations with lipids after adjustment for their biochemical precursors in the multivariable analysis. Conclusions: Increased levels of estrogens are associated with unfavourable lipid profile in men and this association is present early in life, before apparent manifestations of cardiovascular disease.