Association of olfactory impairment with indexes of sarcopenia and frailty in community-dwelling older adults.

AIM: Individuals with olfactory or gustatory impairment often have associated difficulties with food-related activities. As both functions decline in older adults, we investigated the association of these impairments with sarcopenia/frailty indexes in community-dwelling older adults. METHODS: A total of 141 participants (69 men and 72 women, mean age 73.0 years) were enrolled. Odor identification was examined using the Open Essence test. Salty and sweet tastes were assessed using a whole-mouth gustatory test. Participants underwent evaluation of the appendicular skeletal muscle mass index (ASMI) by InBody720 and grip strength, and determination of the Study of Osteoporotic Fractures frailty index. RESULTS: Participants with olfactory impairment (Open Essence ≤7), but not with gustatory impairment, showed a significantly higher prevalence of ASMI and grip strength less than the cut-off values recommended by the Asian Working Group for Sarcopenia, and Study of Osteoporotic Fractures frailty and/or pre-frailty status, compared with those without impairment. Multivariate logistic regression analysis showed a significant association of olfactory impairment with ASMI less than the cut-off value, grip strength less than the cut-off value, Asian Working Group for Sarcopenia sarcopenia and pre-frailty/frailty in the Study of Osteoporotic Fractures index in the whole population, and with ASMI less than the cut-off value and Asian Working Group for Sarcopenia sarcopenia in women, after adjustment. Three (Japanese cypress, wood and roasted garlic) and four (Japanese orange, India ink, menthol and curry) Open Essence odorants were elucidated as the "sarcopenia subset" and "frailty subset," respectively, and showed higher ability to identify sarcopenia and frailty status, compared with the remaining five odorants. CONCLUSIONS: These findings suggest that olfactory impairment is closely associated with sarcopenia and/or frailty in community-dwelling older adults. Geriatr Gerontol Int 2019; 19: 384-391.