Risk factors for cognitive decline associated with gait speed in community-dwelling elderly Koreans with MMSE scores of 30.

Abstract

We aimed to investigate the association between lower gait speed and cognitive decline over a 3-year period in community-dwelling older people with mini-mental state examination (MMSE) scores of 30 at baseline. The study was based on data from 10,003 Koreans aged 60years or older who completed the National Elderly Survey in both 2008 and 2011. Among them 620 subjects achieved MMSE scores of 30 in 2008. Over a 3-year period, preservation of MMSE score 28 or more was defined as preserved cognition and decrease of three or more points as cognitive decline. A 4-m gait speed was measured at baseline. Data on sociodemographic factors (age, number of schooling years, and household composition), alcohol drinking, current smokers, Korean version of Short form Geriatric Depression Scale score, and self-reported comorbid conditions, were collected. Of 620 (weighted 884) respondents included in the analysis, 208 (52.3%) of 398 males (weighted 567) and 152 (68.5%) of 222 females (weighted 317) suffered cognitive decline over the 3-year period. After adjustment, lower gait speed was associated with cognitive decline in males (OR 2.29; 95% CI 1.07-4.89, P=0.032). Educational level was a significant risk factor for both men and women (OR 0.86; 95% CI 0.79-0.93 in males, OR 0.75; 95% CI 0.65-0.87 in females). Males diagnosed with hypertension (OR 0.44; 95% CI 0.22-0.88) or male smokers (OR 0.38; 95% CI 0.19-0.75) were significantly less likely to have cognitive decline. There was no significant association between cognitive decline and gait speed in females. Higher 4-m gait speed is associated with preservation of cognitive function over time in men, but not in women.