Abstract
BACKGROUND: Hearing loss (HL) and visual loss (VL) are recently identified as promising dementia risk factors, but long-term studies with adequate control of other modifiable dementia risk factors are lacking. This 25-year follow-up study investigated the association between objectively measured HL and VL with cognitive decline and incident dementia. METHODS: 1823 participants (age 24-82 years) of the Maastricht Aging Study were assessed at baseline, 6, 12 and 25 years. Baseline HL was defined as pure-tone hearing loss ≥20 dB at frequencies of 1, 2 and 4 kHz and VL as binocular, corrected visual acuity <0.5. Associations with cognitive decline (verbal memory, information processing speed, executive function) and incident dementia were tested using linear mixed models and Cox proportional hazard models, respectively. Analyses were adjusted for demographics and 11 modifiable dementia risk factors (LIfestyle for BRAin health index). RESULTS: Participants with HL (n = 520, 28.7%) showed faster decline in all cognitive domains than participants without HL. No consistent association was found for VL (n = 58, 3.2%), but below-average visual acuity (<1) showed significant associations with information processing speed and executive function. No significant associations with dementia risk were found. Findings were independent of demographics and modifiable dementia risk factors. CONCLUSIONS: HL predicts faster cognitive decline but not dementia risk in adults aged 24-82 years. VL shows no consistent associations, though below-average visual acuity is linked to faster cognitive decline. This study supports HL as an independent risk factor for cognitive decline. Future studies should further evaluate the roles of HL and VL in dementia risk reduction.