Objectives: To investigate the relationship between global cognition, three specific domains of cognition, and lower extremity function in community-dwelling elderly African Americans (AAs) from two community settings.
Design: Cross-sectional study.
Setting: Community.
Participants: Ninety-six AA men and women aged 60 and older from two community settings, enrolled in the Boosting Minority Involvement (BMI) study, a community-based cohort study designed to increase research participation of older low-income AAs.
Measurements: Physical performance was assessed using Short Physical Performance Battery score, which is composed of three timed tests: a 4-m walking task, static balance assessment, and a chair stand test. The Bushke Memory Impairment Screen (MIS) and Mini-Mental State Examination were used to assess global memory and global cognition, respectively. For domain-specific performance, three z-score composite scores (attention, verbal memory, and executive function) were developed using the Computer-based Assessment of Mild Cognitive Impairment.
Results: All domains of cognition were significant predictors of lower extremity function except for verbal memory. Executive function and MIS were the best predictors of lower extremity function in adjusted models. Participants with poor executive function were more than four times as likely to have poorer lower extremity function (odds ratio=4.96, 95% confidence interval=1.07-23.0).
Conclusion: Global memory and executive function were the best predictors of lower extremity function in a sample of community-dwelling AA adults. Deficits in lower extremity function may depend on multifaceted higher executive function control processes.