Age-Varying Relationships Between Physical Function and Cognition in Older Adulthood.
OBJECTIVES
There are positive relationships between physical and cognitive function in older adulthood; however, the strength of these relationships are inconsistent across studies. Although novel statistical tools provide flexibility to explore age-related differences in relationship magnitude, such methods have not been implemented in gerontological research. This study applied such methods to examine variations in relationship magnitude between physical function and cognition in healthy older adults (N = 2,783).


METHOD
Time-varying effects modeling (TVEM) is an extension of regression that models changes in relationships as a function of time-varying metrics like age. TVEM was used to examine if physical function (Turn 360, grip strength) predicted cognitive performance (memory, processing speed/attention, and reasoning) similarly across adults aged 65-90.


RESULTS
All associations between Turn 360 and all cognitive domains were significant and positive; however, speed of processing had significant magnitude variation across age such that the young-old and the old-old demonstrated the strongest relationships. Associations between grip strength and all cognitive domains significantly strengthened with increased age.


DISCUSSION
Results suggest that depending on the sample age, there may be inconsistencies in the relationships between physical and cognitive performance. Future research should explore these relationships longitudinally to better elucidate discrepant findings.
['Sprague|Briana N|BN|', 'Phillips|Christine B|CB|', 'Ross|Lesley A|LA|']
D000367:Age Factors D000368:Aged D000369:Aged, 80 and over D003071:Cognition D003430:Cross-Sectional Studies D005260:Female D018737:Hand Strength D006801:Humans D008297:Male D009068:Movement
Strength Time-varying effects modeling Balance Cognitive aging