Background: The associations of endogenous estrogen with lipid profiles and insulin resistance were conflicting in both men and women. We determined the associations of serum estradiol level and free estradiol index (FEI) with lipid profiles and insulin resistance in aged Japanese men and women.
Methods: One hundred seventy-four men and 208 postmenopausal women aged from 50 to 85 y were included in this study. Lipid profiles, fasting glucose and insulin as well as estradiol, testosterone, dehydroepiandrosterone-sulfate (DHEA-S) and sex hormone-binding globulin (SHBG) in serum were measured.
Results: Serum estradiol concentration in men showed a significant and negative correlation with high density lipoprotein-cholesterol (HDL-C) concentration and a significant and positive correlation with triglyceride (TG) after adjustment for age and body mass index (BMI). In addition, estradiol level was positively correlated with insulin and HOMA index. In women, serum levels of estradiol and testosterone were not correlated with lipid profiles and insulin resistance. SHBG concentration was negatively correlated with TG after adjustment for age and BMI in women.
Conclusion: Endogenous estradiol level is associated with unfavorable lipid profiles and insulin resistance in aged men. In aged women, SHBG level is associated with favorable lipid profiles.