Mikyung Ryu
Background/Objectives: Tinnitus becomes more common with age, and age-related hearing loss accounts for an increasing share of cases in later life, whereas modifiable behavioural factors may contribute relatively more in midlife. Population-based evidence linking sitting time-a construct distinct from physical inactivity-to tinnitus is limited and has not accounted for psychological and sleep-related correlates. Methods: We analysed Korean women aged 40-64 years in the Korea National Health and Nutrition Examination Survey (KNHANES) 2014-2018, a nationwide complex-sample survey (N = 7239; current tinnitus prevalence 21.9%). Self-reported daily sedentary time was categorised into survey-weighted quartiles (cut-points 5, 7, and 10 h/day). Survey-weighted modified-Poisson regression estimated adjusted prevalence ratios (aPRs), adjusting for demographic, socioeconomic, behavioural, aerobic-activity, and auditory factors; further models added perceived stress, depressive symptoms, physician-diagnosed depression, sleep duration, menopausal status, and non-occupational noise. Results: Tinnitus prevalence rose across quartiles (weighted 19.7%, 21.6%, 23.2%, and 24.9%; model-standardised 19.4%, 21.9%, 23.5%, and 24.9%). Relative to the lowest quartile, aPRs were 1.13 (95% confidence interval 0.98-1.31), 1.21 (1.07-1.36), and 1.29 (1.11-1.49; p = 0.0007), with a trend of 1.09 per quartile (p = 0.0001). The estimate was 1.26 (1.09-1.46) after mental-health and sleep adjustment, and 1.27 (1.10-1.47) when fully adjusted. A similar association was seen in men (1.22, 1.03-1.45; sedentary-by-sex interaction p = 0.93); in women aged 65 years and over it was absent (0.86, 0.74-1.01). Conclusions: Longer sedentary time was associated with a modestly higher prevalence of current tinnitus, not accounted for by the measured covariates. The design is cross-sectional, the absolute difference was small (5.6 percentage points), and reverse causation cannot be excluded; prospective confirmation is required.