Association Between Living Environmental Factors and Stroke in Middle-Aged and Older Chinese Adults: A Nationwide Prospective Cohort Study

Abstract

BACKGROUND: The synergistic effects of multiple environmental factors on stroke remain unknown. The aim of this study was to explore the relationship between multiple living environment factors and stroke in middle-aged and older Chinese adults. METHODS: This study used data of the CHARLS (China Health and Retirement Longitudinal Study). Living environmental factors included ambient fine particulate matter, indoor fuel use, tap water use, room temperature, and residence type. Stroke was ascertained by self-reported physician-diagnosed stroke. Cox proportional hazard regression models were applied to explore the association between living environmental risk factors and stroke events in a cohort analysis. Multiple sensitivity analyses were used to test the robustness of the present finding. RESULTS: A total of 6483 participants from CHARLS (mean age: 58.17 years; female: 54.17%) were included in the 7-year followup. Individuals in the middle-risk (adjusted hazard ratio [HR], 0.73 [95% CI, 0.58-0.90]) and low-risk groups (adjusted HR, 0.56 [95% CI, 0.39-0.80]) demonstrated a 27% and 44% reduction in stroke risk, respectively, compared with the high-risk reference group, when evaluating the synergistic effects of residential environmental exposures. In the fully adjusted continuous model, each 1-unit increment in living environmental quality scores was associated with a 15% lower risk of stroke incidence (adjusted HR, 0.85 [95% CI, 0.78-0.91]). The results of the sensitivity analysis confirmed that our findings are robust. CONCLUSIONS: Living environmental quality is significantly associated with stroke. Poor living quality may increase the risk of stroke. Future studies should focus more on the synergistic effects of exposure to living environmental factors.