Introduction: A positive association between physical activity and cognition has been reported. However, very few pertinent studies have evaluated physical activity by objective measures.
Hypothesis: In a community-based sample of non-demented men, objectively measured step count was positively associated with higher cognitive function.
Methods: The Shiga Epidemiological Study of Subclinical Atherosclerosis (SESSA) randomly recruited community-dwelling apparently healthy men aged 40-79 years from Shiga, Japan, and measured their step counts over 7 consecutive days using a pedometer (DIGI-Walker, DW-200) at baseline (2006-08). Among 853 mem who returned for follow-up (2010-12), we assessed their cognition using Cognitive Abilities Screening Instrument (CASI) score. The score can range from 0 to 100, and higher score indicates better cognition. We restricted our analyses to those with a valid 7-day average step count at baseline and who remained free of stroke (N=678). We calculated crude and adjusted mean CASI score according to quartile of average step count using linear regression models. All adjusting covariates used in models were asssessed at baseline including age, educational attainment, smoking, and drinking.
Results: The mean [standard deviation] of age and unadjusted score were 63.8 [9.1] years and 90.8 [5.8]. Mean CASI score was higher in higher quartile of average step: 90.2, 90.4, 90.6, and 91.8 from the lowest to the highest quartile of average step (P for trend =0.004) in a model adjusted for age and education. Further adjustment for smoking, drinking and other cardiovascular risk factors resulted in similar pattern of association (Table 1).
Conclusions: Apparently healthy Japanese men with greater 7-day average step count at baseline measured with pedometer was associated with a small but significantly higher CASI score than those with fewer step count. The finding is consistent with the hypothesis that physical activity is protective for cognition in non-demented individuals.