Relationship Between Cognitive Function And Lower Extremity Performance In Older Adults With Mobility Limitations

BACKGROUND: Falls are a leading cause of injury, disability, and mortality in older adults. Physical and cognitive function are related risk factors for falls in older adults. However, the relationship between cognitive and physical function domains in older adults is less clear. PURPOSE: To determine the relationship between cognition and lower extremity physical function domains as it relates to fall risk in older adults METHODS: 83 older adults with limited mobility from the community or senior living facilities (age = 78.8 + 7.9; BMI = 27.8 + 6.4; females = 60%) completed neuropsychological assessments of global cognition (Montreal Cognitive Assessment), executive function (Trail Making Test B minus A), total recall (Rey Auditory Verbal Learning Test (RAVLT) trials 1 through 5), learning (RAVLT trial 5 minus 1), and forgetting (RVLT trial 5 minus delayed recall). Participants also completed the Short Physical Performance Battery (SPPB), which consists of three, 10-second standing tasks, a 4-meter walk test, and a 5-times sit-to-stand. Scores range from 0 to 12, with higher scores indicating greater physical function. Pearson’s correlations determined the relationship between cognitive domains and SPPB scores. A linear regression with SPPB as the independent variable and cognitive domains as the dependent variables controlling for age, sex, race, BMI, and education was performed. RESULTS: There was a positive, significant relationship between total SPPB scores and global cognition (r = 0.54; p < .001), executive function (r = 0.58; p = 0.02), total recall (r = 0.63; p < .001), learning (r = 0.33; p = 0.02), and forgetting (r = 0.04; p = 0.25). When controlling for age, race, sex, BMI, and education, SPPB was significantly associated with global cognition (R2 = 0.24; β = 0.42; p < .001), executive function (R2 = 0.29; β = -0.27; p = 0.02), total recall (R2 = 0.36; β = 0.43; p < .001), and learning (R2 = 0.05; β = 0.31; p = 0.02), but not forgetting (R2 = 0.02; β = -0.15; p = 0.25). CONCLUSIONS: Worse lower extremity function is associated with declines in global cognition, executive function, total recall, and learning in older adults with limited mobility. Interventions improving lower extremity function may also improve areas of executive function, recall, and learning to reduce fall risk in older adults with limited mobility. Supported by: Georgia State University/Augusta University Seed Award