Weekly green space visit duration is positively associated with favorable health outcomes in people with hypertension: Evidence from Shenzhen, China.

BACKGROUND: Studies from high income 'western' countries indicate that green space visit duration is associated with better health. However, scant comparable research has been done in developing countries with rapid urbanization and on the potential health impacts of specific green infrastructure. OBJECTIVE: Associations between green space visit duration, green infrastructure and various health outcomes were assessed in hypertensive patients. METHODS: A stratified multi-stage cluster random sampling method was applied to select 1116 patients with hypertension aged 35 years or older in Shenzhen, China. Face-to-face survey, physical examination and laboratory biochemical tests were applied to obtain information. Binary logistic regressions with restricted cubic splines were used to explore the degree of linearity in associations between green space visit duration and the following health outcomes: central obesity; diabetes; blood pressure; dyslipidemia; poor physical health; poor mental health. Models were adjusted for age, sex, education, marital status, occupation, and socioeconomic status. Further analysis was made for presence of the following health promoting green infrastructure: health knowledge promotion areas; walking trails; fitness areas; group exercise venues. RESULTS: Each additional 30 min green space visitation was linearly associated with lower odds of self-reported poor mental health [OR (95%CI): 0.937 (0.891-0.985)], self-reported poor physical health [OR (95%CI): 0.918 (0.872-0.966)], and central obesity [OR (95%CI): 0.951 (0.907-0.997)]. Odds of poor mental health [OR (95%CI): 0.886 (0.788-0.997)], poor physical health [OR (95%CI): 0.882 (0.782-0.996)] and central obesity [OR (95%CI): 0.855 (0.765-0.955)] were founded to decrease with a greater number of health promoting green infrastructure. CONCLUSION: More time spent in green space and with more types of green infrastructure were favourably associated with central obesity, and physical and mental health in people with hypertension.