Cognitive impairment and low physical function among older Mexican Americans: findings from a 20-year follow-up^☆

Purpose: The aim of the study was to examine the association between cognitive impairment and low physical function over a 20-year follow-up period among older Mexican Americans. Methods: The final sample included 1545 community-dwelling Mexican Americans age ≥ 65 years from the Hispanic Established Population for the Epidemiological Study of the Elderly, who scored moderate-high on Short Physical Performance Battery (SPPB) and were non-disabled at baseline (1993/94). Cognitive impairment was defined at each observation wave as less than equal to 21 points on the Mini Mental State Examination. General Estimating Equation was used to estimate the odds ratio of having low physical function (SPPB <7 points) over time as a function of cognitive impairment, adjusting for socio-demographics, self-reported medical conditions, body mass index, and depressive symptoms. All variables were time-varying, except sex and education. Results: Participants with cognitive impairment had increased odds ratio of low physical function over time compared to those without cognitive impairment (Odds Ratio = 1.89; 95% Confidence Interval = 1.59–2.26, P <.0001), after controlling for all covariates. Conclusion: Despite having moderate to high physical function and being non-disabled at baseline, participants with cognitive impairment were more likely to decline in physical function over 20-years of follow-up.