Non-driving older adults living in a rural hilly area are at high risk for poor physical function

Abstract

Abstract Background While some studies have found an association between built environments and physical function, it is unclear whether living in a hilly area is associated with poor physical function among older adults, and whether this association varies by car driving status. This cross-sectional study investigated the association between hilliness and physical function in community-dwelling older adults and whether it varied according to their car driving status. Methods Data were collected from 633 participants aged 60 years and older living in Okinoshima Town, Shimane prefecture, Japan, in 2018. Physical function was objectively assessed; < 1.0 m/s was defined as poor walking speed, and hilliness was measured by mean land slope within a 1000-meter network buffer zone around each participant's home using geographic information system. Logistic regression examined whether hilliness was associated with poor walking speed adjusted for sex, age, body mass index, current smoking, current alcohol consumption, exercise habits, current chronic disease, and living arrangements. A stratified analysis by car driving status was also conducted. Results A total of 159 (25.1%) participants had poor walking speed. After adjusting for all confounders, hilliness was positively associated with poor walking speed (OR = 1.07, 95% CI, 1.02-1.12). The stratified analysis by car driving status showed that living in a hilly area was positively associated with poor walking speed among non-drivers (OR = 1.10, 95% CI, 1.03-1.17), though there were no associations among drivers (OR = 1.00, 95% CI 0.92-1.08). Conclusions Our study found that a hilly environment was associated with poor walking speed in community-dwelling older adults in Japan. Moreover, car driving status potentially modified the relationship between living in a hilly environment and poor walking speed. Key messages Older adults living in a hilly environment were more likely to have poor walking speed, compared to those living in less hilly area. The stratified analysis by car driving status showed that non-driving older adults living in a rural hilly environment may be at high risk for poor physical function.