Does 8-foot walk time predict cognitive decline in older Mexicans Americans?

OBJECTIVES: To examine the association between 8-foot time walk and change in cognitive function over time in older Mexican Americans. DESIGN: Data used are from the Hispanic Established Population for the Epidemiological Study of the Elderly (1993-2001). SETTING: Five southwestern states: Texas, New Mexico, Colorado, Arizona, and California. PARTICIPANTS: Two thousand seventy noninstitutionalized Mexican-American men and women aged 65 and older who had a Mini-Mental State Examination (MMSE) score of 21 or greater at baseline. MEASUREMENTS: Sociodemographic factors (age, sex, education, marital status), MMSE score, 8-foot walk time, body mass index, medical conditions (stroke, heart attack, diabetes mellitus, depression, and hypertension), and near and distant visual impairment. RESULTS: Using general linear mixed models, it was found that subjects with the slowest 8-foot walk time had a significantly greater rate of cognitive decline over 7 years than subjects with the fastest 8-foot walk time. There was a significant 8-foot walk time-by-time interaction with MMSE scores. Subjects in the lowest 8-foot walk time quartile had a greater cognitive decline over 7 years (estimate=-0.32, SE=0.08; P<.001) than those in the highest quartile. This association remained statistically significant after controlling for potential confounding factors. CONCLUSION: Slow 8-foot walk time in older Mexican-American adults without cognitive impairment at baseline was an independent predictor of MMSE score decline over a 7-year period. Slow 8-foot walk time may be an early marker for older adults in a predementia state who may benefit from early-intervention programs to prevent or slow cognitive decline.