The association between reduced bone mineral density and hearing impairment in postmenopausal women.

OBJECTIVES: To assess the association between bone mineral density (BMD) and auditory function in postmenopausal women and to assess the degree of hearing impairment across normal BMD, osteopenia, and osteoporosis. METHODS: In this analytical cross-sectional study, 220 postmenopausal women aged 50-75 years were enrolled. All participants underwent dual-energy X-ray absorptiometry (DXA) of the lumbar spine and hip, followed by pure-tone audiometry and tympanometric assessment. Women using bone-modifying medications, those with metal implants or musculoskeletal conditions interfering with DXA, and those unable to maintain required positioning were excluded. Additional audiological exclusions covered otologic, neurologic, oncologic, inflammatory, and hereditary causes of secondary hearing loss. Hearing loss severity was graded from the better-ear air conduction pure-tone average. Thresholds and tympanometric parameters were compared across BMD groups with non-parametric tests, the severity distribution with exact categorical methods, and the BMD-hearing associations with multivariate logistic regression adjusted for age, body mass index (BMI) and duration of menopause. RESULTS: Decreasing BMD was associated with a stepwise worsening of auditory function. Women with osteoporosis demonstrated significantly higher pure-tone average and bone conduction thresholds, more negative tympanometric peak pressures, lower static admittance, and higher resonance frequencies compared with those with osteopenia and normal BMD (all p < 0.001). Moderate-or-worse hearing loss was most prevalent in the osteoporosis group (72.2%), compared with 41.2% in osteopenia and 22.4% in normal BMD. All pairwise differences were statistically significant. After adjustment for age, BMI and duration of menopause, the odds of moderate-or-worse hearing loss were about nine-fold higher in osteoporosis (adjusted OR = 8.97, 95%CI 3.81-21.1) and about 2.6 -fold higher in osteopenia (adjusted OR = 2.55, 95%CI 1.31-4.98) compared with normal BMD. None of these covariates was independently associated with the outcome. CONCLUSION: Reduced bone mineral density is significantly associated with impaired auditory function in postmenopausal women, with hearing thresholds worsening progressively from normal BMD to osteopenia and reaching its greatest severity in osteoporosis, independently of age, BMI and duration of menopause. Although causal inference cannot be drawn from this cross-sectional study, these findings are consistent with the systemic nature of osteoporosis and a possible involvement of the otic capsule and inner ear structures. Prospective, longitudinal studies are warranted to further clarify this association.