Objective olfactory dysfunction linked to mortality in seniors

(HealthDay)—For older adults, objective olfactory dysfunction is associated with increased mortality, according to a study published online Oct. 22 in JAMA Otolaryngology-Head & Neck Surgery.

Janet S. Choi, M.D., M.P.H., from the Keck School of Medicine at the University of Southern California in Los Angeles, and colleagues examined the association between olfactory dysfunction and all-cause five-year mortality in a cohort study involving 3,503 U.S. adults. Olfaction was assessed by self-report and with an objective measure (8-odor Pocket Smell Test).

The researchers found that the prevalence of olfactory dysfunction was 13.5 and 21.6 percent based on results of an objective smell test and based on self-report, respectively. Per 1-point decrease in smell test score, the risk for mortality increased by 18 percent in a multivariate model. The association was not significant among adults aged 40 to 64 years, but was significant among adults aged 65 years or older in association with binary and linear measures of objective olfactory dysfunction (hazard ratios, 1.95 and 1.19, respectively). No association was seen between self-reported olfactory dysfunction and mortality. After further adjustment for the cognitive assessment battery and depression among older adults, the association between objective olfactory dysfunction and mortality remained (hazard ratio, 1.18).

"This work emphasizes the importance of this special sense and shines a spotlight on its importance for the health and longevity of a rapidly growing segment of our population," write the authors of an accompanying editorial.