Hilly environment and physical activity among community-dwelling older adults in Japan: a cross-sectional study

OBJECTIVES: We investigated whether a moderate-to-vigorous physical activity (MVPA) level and walking time were associated with a hilly environment in rural Japanese older adults. DESIGN: Cross-sectional study. SETTING: Unnan city, Ohnan and Okinoshima towns in Shimane, Japan. PARTICIPANTS: Data were collected from 1115 adults from the Shimane CoHRE study, who were aged 60 years and older and living in rural Japan in 2012. MEASURES: We measured the total time spent on MVPA and walking using a Japanese short version of the International Physical Activity Questionnaire. The land slope in 400 or 800 m network buffers was assessed using the geographic information system. A multivariable Poisson regression model examined the prevalence ratios (PR) and 95% CIs of walking time or MVPA levels meeting the WHO guideline (>150 min/week) in the land slope categories (low, middle and high), adjusted for confounders. RESULTS: Engaging in the recommended level of MVPA was significantly associated with middle land slope (PR=1.07; p=0.03) and high land slope (PR=1.06; p=0.07) compared with low land slope in the 400 m network buffer, as well as with middle land slope (PR=1.02; p=0.48) and high land slope (PR=1.04; p=0.25) compared with the low land slope in the 800 m network buffer. Walking time was significantly associated with middle land slope (PR=1.13; p=0.04) and high land slope (PR=1.17; p=0.01) compared with low land slope in the 400 m network buffer, and with middle land slope (PR=1.09; p=0.16) and high land slope (PR=1.17; p<0.01) compared with low land slope in the 800 m network buffer. The sensitivity analysis found only a positive association between walking time and land slope in the 400 and 800 m network buffers. CONCLUSIONS: This study showed that a hilly environment was positively associated with walking time among older adults living in rural Japan.