Association between living environmental quality and risk of gastrointestinal diseases among middle-aged and older adults: evidence from a national study

BACKGROUND: With the rapid progression of population aging in China, gastrointestinal (GI) diseases have become one of the most common chronic conditions among middle-aged and older adults, substantially impairing quality of life and increasing healthcare burdens. However, evidence regarding the combined effects of multiple living environment factors and their potential interactions on GI health remains limited. METHODS: exposure. Logistic regression and Cox proportional hazards models were applied to examine cross-sectional and longitudinal associations between LEQ and GI diseases. RESULTS: The results showed that each one-point increase in LEQ score was associated with a higher risk of GI diseases in both cross-sectional analysis (OR = 1.05, 95% CI: 1.01-1.08, P = 0.013) and longitudinal analysis (HR = 1.06, 95% CI: 1.02-1.10, P < 0.001). Compared with the favorable LEQ group, the unfavorable LEQ group showed significantly higher odds and risks of GI diseases in cross-sectional (OR = 1.18, 95% CI: 1.03-1.35, P = 0.018) and longitudinal analyses (HR = 1.26, 95% CI: 1.10-1.45, P < 0.001), respectively, with a clear dose-response relationship. In longitudinal analyses, non-tap water and dual solid fuel for heating and cooking were significantly associated with an increased risk of GI diseases (all P < 0.05). Kaplan-Meier analysis further showed significant differences in the cumulative incidence of GI diseases across LEQ groups (log-rank P < 0.0001), with poorer LEQ associated with higher cumulative incidence. These associations remained robust in subgroup, interaction, and sensitivity analyses. CONCLUSIONS: Poorer LEQ may be associated with an increased risk of GI diseases among middle-aged and older adults, with non-tap water use and dual solid fuel use found as important environmental factors.