Which Sex Hormone Markers Best Predict Bone Mineral Density? A NHANES 2013-2014 Analysis

Authors

Katarina Kozakova, University of Texas at AustinFollow
Elina Satlik, University of Texas at AustinFollow
Sarah E. Little-Letsinger, Univeristy of Texas at AustinFollow

Abstract

Osteoporosis is a silent disease that is typically not diagnosed until after a fracture has occurred. Identifying biomarkers routinely collected by physicians can serve as a simple and effective screening approach to detect osteoporosis before debilitating fractures occur. The ratio of total estradiol to total testosterone (E_T x10)/T_T has been proposed as a biomarker associated with bone mineral density (BMD). To further improve predictive power, we propose a ratio of estradiol to free testosterone (E_T/T_F), rather than total, to account for the difference in hormone bioavailability. PURPOSE: The present analysis compares the association between sex hormone predictors and BMD at two primary fracture sites in US adults over age 50. METHODS: NHANES 2013-2014 cycle was analyzed in R Studio, using univariate linear regression to investigate the relationships between free and total sex hormone levels (estradiol, testosterone), as well as their ratios (free androgen index (FAI), free estrogen index (FEI), E_Tx10/T_T, E_T/T_F) with femoral neck and lumbar spine BMD in men, pre-menopausal women, and post-menopausal women. Fully standardized regression coefficients were calculated to allow for direct comparison of effect sizes between the predictor and outcome. RESULTS: In men, free estradiol demonstrated the largest association (β=0.111, p= 0.015) with BMD at the femoral neck. At the lumbar spine, E_Tx10/T_T demonstrated the strongest association (β=0.203, p= 0.014) with BMD. In pre-menopausal women, none of the variables were significantly associated with BMD at the femoral neck. At the lumbar spine, FEI displayed the strongest association with BMD (β= 0.222, p=0.032). E_Tx10/T_T demonstrated a stronger association (β= 0.209, p=0.032) with BMD than E_T/T_F (β= 0.181, p=0.049). In post-menopausal women, none of the variables were significantly associated with BMD at the femoral neck or lumbar spine. CONCLUSION: Standardized effect sizes for E_T/T_F were consistently smaller than E_Tx10/T_T, suggesting a weaker association with BMD at both sites. E_Tx10/T_T predicts BMD as well as estradiol-related measures (total, free, FEI) at the lumbar spine in all groups; interestingly, this relationship was more robust in men. Future research should evaluate the true predictive value of E_Tx10/T_T for lumbar spine BMD in prospective longitudinal and controlled cohorts.

Recommended Citation

Kozakova, Katarina; Satlik, Elina; and Little-Letsinger, Sarah E. (2026) "Which Sex Hormone Markers Best Predict Bone Mineral Density? A NHANES 2013-2014 Analysis," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 18, Article 171.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss18/171