Context Evidence suggests that physical activity may be related to the clinical
expression of dementia. Whether the association includes low-intensity activity
such as walking is not known.
Objective To examine the association between walking and future risk of dementia
in older men.
Design Prospective cohort study.
Setting and Participants Distance walked per day was assessed from 1991 to 1993 in 2257 physically
capable men aged 71 to 93 years in the Honolulu-Asia Aging Study. Follow-up
for incident dementia was based on neurological assessment at 2 repeat examinations
(1994-1996 and 1997-1999).
Main Outcome Measures Overall dementia, Alzheimer disease, and vascular dementia.
Results During the course of follow-up, 158 cases of dementia were identified
(15.6/1000 person-years). After adjusting for age, men who walked the least
(<0.25 mile/d) experienced a 1.8-fold excess risk of dementia compared
with those who walked more than 2 mile/d (17.8 vs 10.3/1000 person-years;
relative hazard [RH], 1.77; 95% confidence interval [CI], 1.04-3.01). Compared
with men who walked the most (>2 mile/d), an excess risk of dementia was also
observed in those who walked 0.25 to 1 mile/d (17.6 vs 10.3/1000 person-years;
RH, 1.71; 95% CI, 1.02-2.86). These associations persisted after accounting
for other factors, including the possibility that limited amounts of walking
could be the result of a decline in physical function due to preclinical dementia.
Conclusions Findings suggest that walking is associated with a reduced risk of dementia.
Promoting active lifestyles in physically capable men could help late-life