The impact of sensory impairment on cardiometabolic multimorbidity in middle-aged and older adults: the mediating role of depressive symptoms.

BACKGROUND: Sensory impairment has imposed a great burden on public health, particularly among middle-aged and older adults. Individuals with dual sensory impairment (DSI) often experience multiple chronic conditions. This study aimed to investigate the association between sensory impairment and cardiometabolic multimorbidity (CMM) and to explore the mediating role of depression. METHODS: This study included 8602 individuals from the China Health and Retirement Longitudinal Study (CHARLS) for longitudinal analysis. Cox proportional hazards regression models were used to assess the associations between vision impairment (VI), hearing impairment (HI) and incident CMM. In addition, sensory impairment was categorized into four groups to examine its relationship with CMM. Furthermore, subgroup analyses were conducted to better stratify analyses among certain populations and show the interaction of variables. We performed a mediation analysis to determine the mediating role of depression in the relationship between sensory impairment and CMM. Finally, sensitivity analyses were conducted to suggest the robustness of the main findings. RESULTS: During the 7-year follow-up period, the mean age of the 8602 participants was 58.35 ± (8.79), and 46.57% were male. In the longitudinal analysis, VI and HI were associated with incident CMM. Compared with people without sensory impairment, those with DSI were more likely to have CMM, with an HR of 1.4 (95%CI 1.1-1.78) after adjustment for all covariates. A lower education level was found to be an effect modifier, significantly interacting with sensory impairment in relation to CMM. Depression played a mediating role in the relationships among VI, HI, DSI and CMM that accounted for more than 19% of the total effect. CONCLUSIONS: This study revealed that VI, HI and DSI were associated with incident CMM. In addition, depressive symptoms played a mediating role in the relationships among VI, HI, DSI and CMM. Our results provide new insights into the prevention of CMM through the targeting of sensory impairment and depressive symptoms.