[Increased physical and intellectual activity and changes in cognitive function in elderly dwellers: lessons from a community-based dementia prevention trial in Suginami Ward, Tokyo].

Purpose: This study was conducted to examine the effect of increased physical and/or intellectual activities on changes in cognitive function in elderly dwellers.

Methods: The subjects comprised 61 residents aged 65 or over living in Suginami Ward, Tokyo, who took part in a community-based dementia prevention class aimed at increasing both physical and intellectual activities. Physical activity was evaluated by the number of daily steps using a pedometer. Intellectual activity was evaluated by the number of pictures taken by a cellular phone and/or submitted through an internet "Dress" system by cellular phone. These activities were classified into two groups (higher and lower activity groups) according to whether above or below the respective median value. For assessment, the subjects underwent tests of physical and cognitive functions before and after the 7-weeks intervention.

Results: Subjects with a greater increment in physical activity during the intervention period showed a greater improvement in usual and maximal walking speed than did those with a lesser increment in physical activity. Analysis using the general linear model demonstrated that increase in physical activity independently correlated with improvement in physical function, but did not correlate with cognitive function. Subjects with a greater increment in intellectual activity showed a greater improvement in weight, BMI and trail making test-task B. This association was independent of potential confounders. Further, those who used the "Dress" system more often showed a greater improvement in stress coping tests. Analysis using a general linear model indicated that increased intellectual activity was independently associated with changes in cognitive and mental function.

Conclusion: The present findings suggest that community-based dementia prevention classes should be stressed not only for increasing physical activity but also in order to stimulate intellectual activity.