Association of exercise with lower long-term risk of olfactory impairment in older adults.

IMPORTANCE: The prevalence of olfactory impairment is high in older adults, and this decline in olfactory ability may pose health and safety risks, affect nutrition, and decrease quality of life. It is important to identify modifiable risk factors to reduce the burden of olfactory impairment in aging populations.
OBJECTIVE: To determine if exercise is associated with the 10-year cumulative incidence of olfactory impairment. DESIGN, SETTING, AND PARTICIPANTS: Observational longitudinal population-based Epidemiology of Hearing Loss Study. Participants without olfactory impairment (n = 1611) were ages 53 to 97 years at baseline and were followed for up to 10 years (1998-2010). MAIN OUTCOMES AND MEASURES: Olfaction was measured with the San Diego Odor Identification Test at 3 examinations (1998-2000, 2003-2005, and 2009-2010) of the Epidemiology of Hearing Loss Study. The main outcome was the incidence of olfactory impairment 5 (2003-2005) or 10 (2009-2010) years later and the association of baseline exercise with the long-term risk of developing olfactory impairment.
RESULTS: The 10-year cumulative incidence of olfactory impairment was 27.6% (95% CI, 25.3%-29.9%) and rates varied by age and sex; those who were older (hazard ratio [HR], 1.88 [95% CI, 1.74-2.03], for every 5 years) or male (HR, 1.27 [95% CI, 1.00-1.61]) had an increased risk of olfactory impairment. Participants who reported exercising at least once a week long enough to work up a sweat had a decreased risk of olfactory impairment (age- and sex-adjusted HR, 0.76 [95% CI, 0.60-0.97]). Increasing frequency of exercise was associated with decreasing risk of developing olfactory impairment (P value for trend = .02). CONCLUSIONS AND RELEVANCE: Regular exercise was associated with lower 10-year cumulative incidence of olfactory impairment. Older adults who exercise may be able to retain olfactory function with age.