Associations of Serum Testosterone and 25-Hydroxyvitamin D with Bone Mineral Density in Aging Men

PURPOSE: We aimed to investigate the relationships among testosterone levels, vitamin D levels and bone mineral density (BMD) in elderly men. MATERIALS AND METHODS: A bicentered, cross-sectional study was performed using data from men aged 60 years or older who visited the clinic for general check-ups from January 2020 to December 2024. The T-score of BMD was measured using dual-energy X-ray absorptiometry. Measurements of serum testosterone and 25(OH) vitamin D levels were mandatory. After the exclusion of patients who received cancer-related chemotherapy/radiotherapy, testosterone replacement therapy, androgen deprivation therapy or hyperparathyroidism, correlations among testosterone levels, vitamin D levels and T-scores were tested. RESULTS: In total, 557 men were ultimately analyzed. Among the baseline parameters, the T-score of spine BMD was associated with the body mass index (BMI) and testosterone level, whereas the T-score of hip BMD was related to age, BMI, testosterone level and 25(OH) vitamin D level; age was inversely correlated with the T-score of hip BMD, and the other parameters were positively correlated with hip BMD. After all adjustments were made, testosterone (B=0.058, p=0.015, 95% confidence interval [CI]=0.012-0.105) and 25(OH) vitamin D (B=0.008, p=0.004, 95% CI=0.003-0.014) levels were independently associated with the T-score of hip BMD. With a cutoff value for testosterone deficiency of 3.5 ng/mL and a cutoff value for vitamin D insufficiency of 30 ng/mL, both testosterone deficiency and vitamin D insufficiency were associated with a T-score ≤-1.0 for hip BMD. CONCLUSIONS: Both testosterone deficiency and vitamin D insufficiency should be considered in elderly men with a low hip joint BMD.