Relationship between frailty and cognitive decline in older Mexican Americans.

OBJECTIVES: To examine the association between frailty status and change in cognitive function over time in older Mexican Americans.

DESIGN: Data used were from the Hispanic Established Population for the Epidemiological Study of the Elderly.

SETTING: Five southwestern states: Texas, New Mexico, Colorado, Arizona, and California.

PARTICIPANTS: One thousand three hundred seventy noninstitutionalized Mexican-American men and women aged 65 and older with a Mini-Mental State Examination (MMSE) score of 21 or higher at baseline (1995/96).

MEASUREMENTS: Frailty, defined as three or more of the following components: unintentional weight loss of more than 10 pounds, weakness (lowest 20% in grip strength), self-reported exhaustion, slow walking speed (lowest 20% in 16-foot walk time in seconds), and low physical activity level (lowest 20% on Physical Activity Scale for the Elderly score). Information about sociodemographic factors, MMSE score, medical conditions (stroke, heart attack, diabetes mellitus, arthritis, cancer, and hypertension), depressive symptoms, and visual impairment was obtained.

RESULTS: Of the 1,370 subjects, 684 (49.9%) were not frail, 626 (45.7%) were prefrail (1-2 components), and 60 (4.4%) were frail (>/=3 components) in 1995/96. Using general linear mixed models, it was found that frail subjects had greater cognitive decline over 10 years than not frail subjects (estimate=-0.67, standard error=0.13; P<.001). This association remained statistically significant after controlling for potential confounding factors.

CONCLUSION: Frail status in older Mexican Americans with MMSE scores of 21 or higher at baseline is an independent predictor of MMSE score decline over a 10-year period. Future research is needed to establish pathophysiological components that can clarify the relationship between frailty and cognitive decline.