Olfaction Is Related to Motor Function in Older Adults.
BACKGROUND
Among older adults, both olfaction and motor function predict future cognitive decline and dementia, suggesting potential shared causal pathways. However, it is not known whether olfactory and motor function are independently related in late life.


METHODS
We assessed cross-sectional associations of olfaction with motor and cognitive function, using concurrent data on olfactory function, mobility, balance, fine motor function, manual dexterity, and cognition in 163 Baltimore Longitudinal Study of Aging participants aged 60 and older without common neurological diseases (n = 114 with available cognitive data). Using multiple linear regression, we adjusted for age, sex, race, smoking history, height, and weight for mobility and balance, and education for cognition. We used multiple linear regression to test whether olfaction-motor associations were independent of cognition and depressive symptoms.


RESULTS
Olfactory scores were significantly associated with mobility (usual gait speed, rapid gait speed, 400-m walk time, and Health ABC Physical Performance Battery score), balance, fine motor function, and manual dexterity (all p < .05). In those with available cognitive data, additional adjustment for depressive symptoms, verbal memory, or visuoperceptual speed demonstrated especially strong independent relationships with challenging motor tasks such as 400-m walk and nondominant hand manual dexterity (p < .005).


CONCLUSIONS
This study demonstrates for the first time that, in older adults, olfactory function is associated with mobility, balance, fine motor function, and manual dexterity, and independent of cognitive function, with challenging upper and lower extremity motor function tasks. Longitudinal studies are needed to determine if olfactory performance predicts future mobility and functional decline.
Longitudinal Studies Section, Translational Gerontology Branch.
Qu
Q
Tian
Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, Maryland.
Susan M
SM
Resnick
Longitudinal Studies Section, Translational Gerontology Branch.
Stephanie A
SA
Studenski
D000368:Aged; D000375:Aging / Q000502:physiology / Q000523:psychology; D003071:Cognition / Q000502:physiology; D060825:Cognitive Dysfunction / Q000175:diagnosis / Q000503:physiopathology; D003430:Cross-Sectional Studies; D056344:Executive Function / Q000502:physiology; D005260:Female; D015577:Geriatric Assessment / Q000379:methods; D006801:Humans; D008297:Male; D051346:Mobility Limitation; D009043:Motor Activity; D055696:Olfactory Perception; D011237:Predictive Value of Tests; D011379:Prognosis; D012678:Sensation Disorders / Q000175:diagnosis / Q000523:psychology; D012903:Smell; D013223:Statistics as Topic
Lower and upper extremity function; Smell; Usual aging