Prevalence and neurodegenerative or other associations with olfactory impairment in an older community

Objective: To determine the prevalence of olfactory impairment and its associations with neurodegenerative and other conditions in older adults. Method: 1,636 participants (≥60 years) enrolled in the Blue Mountains Eye Study (2002-2004) were analyzed. Olfaction was assessed by the San Diego Odor Identification Test and used to classify mild impairment (4 or 5), moderate impairment (≤3), or any impairment (<6). Results: Prevalent olfactory impairment was 27.0%. After multivariate adjustment, the likelihood increased twofold with each decade of life after 60 years and was higher in men than women. Olfactory impairment and body mass index (BMI) were inversely associated. Persons with Parkinson’s disease and cognitive impairment had an increased likelihood of mild and moderate olfactory impairment. Discussion: Over one in four older persons had olfactory impairment. The prevalence was higher in men, increased with age and decreasing BMI, and was higher among persons with Parkinson’s disease and cognitive impairment.