Olfactory Impairment in Older Adults: Five-Year Incidence and Risk Factors

Objectives/Hypothesis: The objective of this study was to determine the five-year incidence of olfactory impairment and associated risk factors in a general population of older adults. Study Design: Longitudinal population-based study. Methods: Participants (n = 1,556) in the population-based Epidemiology of Hearing Loss Study had olfaction measured at the 5- and 10-year examinations (1998-2000 and 2003-2005, respectively). Olfactory ability was measured by the San Diego Odor Identification Test. Results: The five-year incidence of olfactory impairment was 12.5%. Incidence rates increased with age for men and women. In a multivariate model, age (odds ratio [OR] = 1.79, 95% CI, 1.61-2.00; for every five-year increase), a history of nasal polyps (OR = 2.33, 95% CI, 1.13-4.59), a history of deviated septum (OR = 2.05, 95% CI, 1.14-3.56), and a history of heavy alcohol use (OR = 1.84, 95% CI, 1.13-2.93) were associated with an increased risk of olfactory impairment, whereas use of lipid-lowering agents (OR = 0.68, 95% CI, 0.46-0.99; yes vs. no), exercising at least once a week (OR = 0.69, 95% CI, 0.48-0.98), and oral steroid use (OR = 0.37, 95% CI, 0.11-0.94) were associated with a decreased risk. Conclusions: The five-year incidence of olfactory impairment is high in this population of older adults. Modifiable risk factors associated with impairment suggest some impairment could be amenable to prevention or treatment.