Smell Loss Predicts Mortality Irrespective of Dementia
Researchers say olfactory loss might mark deteriorating health, irrespective of dementia
FRIDAY, March 24, 2017 (HealthDay News) -- Poor odor identification and poor self-reported olfactory function are associated with greater likelihood of earlier mortality, according to a study published online March 22 in the Journal of the American Geriatrics Society.
In a population-based cohort of 1,774 dementia-free adults aged 40 to 90 years, Ingrid Ekström, from Stockholm University, and colleagues assessed olfactory performance using the Scandinavian Odor-Identification Test (SOIT) and self-reported olfactory function. Additionally, several social, cognitive, and medical risk factors were evaluated at baseline, while incident dementia was calculated over a decade of follow-up.
Over the 10-year study period, 411 of 1,774 participants died. The researchers observed a significant association between higher SOIT score and lower mortality (hazard ratio, 0.74 per point interval). After controlling for age, sex, education, and health-related and cognitive variables, the effect was lessened but remained significant (hazard ratio, 0.92). Furthermore, the association between SOIT score and mortality was retained after controlling for dementia conversion before death (hazard ratio, 0.92). Similar results were seen for self-reported olfactory dysfunction.
"Dementia does not attenuate the association between olfactory loss and mortality, suggesting that olfactory loss might mark deteriorating health, irrespective of dementia," the authors write.