摘要：Objective. We examined whether older persons who live in areas that are conducive to walking are more active or less obese than those living in areas where walking is more difficult. Methods. We used data from the Adult Changes in Thought cohort study for a cross-sectional analysis of 936 participants aged 65 to 97 years. The Walkable and Bikable Communities Project previously formulated a walkability score to predict the probability of walking in King County, Washington. Data from the cohort study were linked to the walkability score at the participant level using a geographic information system. Analyses tested for associations between walkability score and activity and body mass index. Results. Higher walkability scores were associated with significantly more walking for exercise across buffers (circular zones around each respondent’s home) of varying radii (for men, odds ratio [OR]=5.86; 95% confidence interval [CI]=1.01, 34.17 to OR=9.14; CI=1.23, 68.11; for women, OR=1.63; CI=0.94, 2.83 to OR=1.77; CI=1.03, 3.04). A trend toward lower body mass index in men living in more walkable neighborhoods did not reach statistical significance. Conclusions. Findings suggest that neighborhood characteristics are associated with the frequency of walking for physical activity in older people. Whether frequency of walking reduces obesity prevalence is less clear. In the United States, obesity has been called an epidemic: an increasing proportion of Americans are overweight or obese. 1 , 2 Numerous studies have highlighted the large proportion of overweight and obese adults, and the number of older adults who are overweight or obese continues to rise. 3 , 4 Obesity has been associated with many health problems, including cardiovascular disease, diabetes, some cancers, depression, and arthritis. 2 , 5 – 10 Physical activity is believed to be an important determinant of health and body weight. Most Americans do not regularly engage in physical activity, 11 and efforts are being made nationally to increase the activity level of the population to prevent comorbid disease. Older people are at increased risk of decline in functional independence as they age. Of community-dwelling adults aged 75 years or older, 10% lose independence each year, as measured by activities of daily living. 12 A decline in independence is associated with higher rates of hospitalization and mortality. 13 In addition to its inverse association with obesity, exercise is associated with a slowing in functional decline 14 and dementia 15 and may help some older persons maintain functional independence. Older adults may choose walking as a form of physical activity, both for recreation and as a means of transport for completing tasks of daily living. An older person’s activity level may be influenced by the built environment, which is defined by the Centers for Disease Control and Prevention as human-formed, developed, or structured areas. 16 Neighborhood aesthetics, convenience to destinations, availability of paths and sidewalks, and other environmental attributes are believed to influence the walkability of a neighborhood. 17 As people age they may spend a greater amount of time around their homes and have the opportunity to walk for exercise or for transportation; thus the study of the built environment in relation to activity and obesity is important. Some have called for gender-specific analysis of physical activity, citing differences in the perception of environment, convenience to destinations, and automobile use. 18 , 19 Indeed, older women appear to take fewer trips per day than do older men, indicating that the tendency to travel by any means, including walking, varies by gender. 20 Little is known about the association between the built environment and activity and obesity in older men and women. Recently, new measurement tools have made study of the relation between obesity, physical activity, and the built environment possible. 17 , 21 , 22 Our study explored whether more walkable neighborhoods are associated with more activity and less obesity in older men and women.
