Change in hearing loss and its association with general health in a community-based longitudinal study of middle-aged individuals: The Busselton healthy ageing study

INTRODUCTION: With the ageing of the global population, disabling hearing loss is a major health concern. While age and sex are established determinants, the relation between general and environmental health factors and the progression of hearing loss remains incompletely understood, particularly in middle-aged adults. METHODS: We used data from the Busselton Healthy Ageing Study (BHAS), a population-based cohort in Western Australia. Adults aged 45-70 years at baseline (2010-2015) underwent audiometric testing and health assessments with a six-year follow-up. The better-ear four-frequency Pure Tone Averages for 0.5-4kHZ (4FPTA) and for high frequencies (4 & 8 kHz) (HFPTA) were calculated. Hearing loss was classified according to WHO criteria. Demographic, ear-related, general health, and environmental factors were analysed and their association with change in hearing thresholds using linear mixed models. RESULTS: 3596 participants with reliable audiometry at baseline and follow-up were included (mean baseline age 57.9 years, 55% female). Over 6 years follow-up, the prevalence of mild-or-greater hearing loss increased from 14% to 26% (4FPTA) and from 53% to 71% (HFPTA). Thresholds worsened across all age categories, with greater deterioration in men and at higher frequencies. In univariate models, older age, male sex, higher BMI, smoking, tinnitus, chronic ear infection, noisy workplace exposure (particularly with inconsistent or absent hearing protection), hypertension and pre-diabetes were significantly associated with faster hearing decline after adjustments for age and sex. CONCLUSIONS: In this longitudinal population-based study of middle-aged Western Australians we demonstrated that hearing thresholds significantly declined over a six-year period with greater deterioration in men and at higher frequencies. Findings suggest that hearing loss progression in midlife is shaped not only by age and sex, but also by broader metabolic and environmental health profiles. These outcomes highlight the need for future research to further clarify the complex interplay between metabolic health, environmental exposures, and hearing outcomes.