Relations of Sex Hormone Levels to Leukocyte Telomere Length in Black, Hispanic, and Asian/Pacific Islander Postmenopausal Women

Abstract

Background Sex hormones may play important roles in sex-specific biological aging. We specifically examined the associations between circulating concentrations of sex hormones and leukocyte telomere length (TL). Methods We conducted a cross-sectional study of 1124 black, 444 Hispanic, and 289 Asian/Pacific Islander women in the Women's Health Initiative Observational Cohort. Concentrations of estradiol and testosterone were measured using electrochemiluminescence immunoassays. TL was measured using quantitative PCR. Results Women included in the study were 50 to 79 years of age. Levels of estradiol were not significantly associated with TL in this sample of women. The associations between total and free testosterone and TL differed by race/ethnicity (P for interaction = 0.03 for total testosterone and 0.05 for free testosterone). Total and free testosterone concentrations were not associated with TL in black and Hispanic women, whereas in Asian/Pacific Islanders, their concentrations were inversely associated with TL (P-trend = 0.003 for both). These associations appeared robust in multiple subgroup analysis and multivariable models adjusted for potential confounding factors. In Asian/Pacific Islanders, doubling of serum free testosterone concentration was associated with 202 bp shorter TL (95% CI, 51 to 353 bp), and doubling of total testosterone concentration was associated with 203 bp shorter TL (95% CI, 50 to 355 bp). Conclusions Serum concentration of estradiol was not associated with leukocyte TL in this large sample of postmenopausal women. Total and free testosterone levels were inversely associated with TL in Asian/Pacific Islander women but not in black and Hispanic women, although future studies to replicate our observations are warranted particularly to address potential ethnicity-specific relations. The significant findings of the study This study elucidates the potential roles of sex hormones in biological aging, and identified that total and free testosterone levels were inversely associated with telomere length in Asian/Pacific Islander women but not in black and Hispanic women. The study adds The findings of this study suggest that Asian/Pacific Islander women may be susceptible to the potential detrimental effects of high testosterone level on biologic aging.