Sensory Impairments and Risk of Mortality in Older Adults

Background: Sensory impairments increase with age and the majority of older people will experience a sensory impairment if they live long enough. However, the relationships of hearing, visual, and olfactory impairments with mortality are not well understood.

Methods: Epidemiology of Hearing Loss Study participants (n = 2,418) aged 53-97 years (mean = 69 years) were examined in 1998-2000 and hearing, visual acuity, and olfaction were measured. Participants were followed for mortality for up to 17 years (mean = 12.8 years). Cox proportional hazards models were used to assess the association between prevalent sensory impairments and the 15-year cumulative incidence of death.

Results: A total of 1,099 (45.4%) of participants died during the follow-up period. In age- and sex-adjusted Cox models, the risk of mortality was higher among participants with one (hazard ratio [HR] = 1.40, 95% confidence interval [CI] = 1.19, 1.64) or two or more (HR = 2.12, 95% CI = 1.74, 2.58) sensory impairments than among participants with no sensory impairments. Olfactory impairment at baseline was significantly associated with mortality (HR = 1.28, 95% CI = 1.07, 1.52) after adjusting for age, sex, sensory comorbidities, cardiovascular risk factors and disease, cognitive impairment, frailty, subclinical atherosclerosis, and inflammatory marker levels (n = 1,745). Hearing and visual impairment were not associated with mortality after adjusting for subclinical atherosclerosis and inflammation.

Conclusion: Olfactory impairment, but not hearing or visual impairment, was associated with an increased risk of mortality. These results suggest that olfactory impairment may be a marker of underlying physiologic processes or pathology that is associated with aging and reduced survival in older adults.