Association Of Cognitive Function With BMI And Physical Function In Older Adults: The CogEx Study

Abstract

Aging negatively impacts cognitive function and physical function in older adults. Physical activity may protect or improve the brain and physical functions that are crucial for multiple health outcomes in older adults, whereas obesity may negatively impact these outcomes. PURPOSE: To examine the association between cognitive function with BMI and physical function in underactive older adults. METHODS: Baseline data were examined from sedentary older adults (N=31; age=70.3±3.7 years; BMI=28.8±4.6 kg/m2) prior to engaging in a 12-month physical activity intervention. Assessments included height, weight, physical function, and cognitive function. Cognitive function was assessed using the Modified Mini-Mental State (3MS) examination and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Physical function performance was assessed using the time to complete the 400-Meter Walk Test (minutes). RESULTS: Average time to complete the 400-meter walk was 6.3±1.0 minutes, which was modestly associated with BMI (r=0.312, p=0.088). The 3MS Total Score (94.7±3.7) was not significantly correlated with BMI (r=-.158; p=.397) or 400-Meter Walk Test performance (r=-.152; p=.415). Similarly, the RBANS Sum of Index Score (209.0±21.1) was not significantly correlated with BMI (r=-.297; p=.105) or 400-Meter Walk Test performance (r=-.164; p=.378). When examining this relationship by cognitive domain, a higher BMI was associated with a poorer RBANS Immediate Memory Index Score (r=-.412; p=.021). We also observed that worse performance on the 400-Meter Walk Test was associated with poorer RBANS Immediate Memory Index Score (r=-.314; p=.08). Neither BMI nor 400-Meter Walk performance were significantly associated with RBANS Visuospatial/Constructional Index, Language Index, Attention Index, or Delayed Memory Index scores. CONCLUSION: Findings reveal that RBANS Immediate Memory Index score was inversely associated with both BMI and physical function in sedentary older adults. This may suggest that both obesity and poor physical function negatively impact immediate memory performance in older adults. Future studies to investigate whether and how physical therapeutics may enhance short-term memory function in older adults are warranted. Supported by UPMC Enterprises