Living environmental quality and incident cardiometabolic multimorbidity: a prospective cohort study in China

Abstract Background Cardiometabolic multimorbidity (CMM) is an increasing public health concern in ageing populations. Although individual residential environmental factors have been linked to cardiometabolic health, the association of multidimensional living environmental quality with incident CMM remains unclear. We aimed to construct a Living Environmental Quality (LEQ) index and examine its association with incident CMM among middle-aged and older adults in China. Methods We included 6,330 CHARLS participants aged ≥ 45 years who were free of CMM at baseline. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between baseline LEQ and incident CMM, adjusting for sociodemographic, behavioral, and clinical covariates. Sensitivity and subgroup analyses were performed to assess the robustness and consistency of the results. Results During 7 years of follow-up, 482 participants (7.6%) developed CMM. After multivariable adjustment, compared with the high-risk LEQ group, the HRs for incident CMM were 0.78 (95% CI: 0.64–0.96, P = 0.017) in the middle-risk group and 0.51 (95% CI: 0.37–0.72, P < 0.001) in the low-risk group. Among individual environmental factors, residence in a multi-storey building (HR = 0.56, 95% CI: 0.45–0.70, P < 0.001) and access to tap water (HR = 0.75, 95% CI: 0.62–0.90, P = 0.002) were associated with lower hazards of incident CMM. The overall association remained generally consistent across sensitivity analyses. Conclusion More favorable residential environmental quality at baseline was associated with a lower risk of incident CMM among middle-aged and older Chinese adults. These findings suggest that multidimensional residential environmental conditions may play a role in cardiometabolic health, although residual confounding and limitations of the LEQ construct should be considered. Further studies are needed to confirm these associations.