Associations between dual sensory impairments and the new-onset cardiometabolic multimorbidity among middle-aged and older adults: the mediating role of frailty

PURPOSE: To explore the impact of dual sensory impairments (DSI) on new-onset cardiometabolic multimorbidity (CMM) among middle-aged and older adults, further analyze the mediating role of frailty. METHODS: The data was drawn from the University of Michigan Health and Retirement Study (HRS, 2018-2022), which is a longitudinal survey for Americans. Participants included adults aged 50 years who were free of cardiometabolic disease (CMD) at baseline. DSI encompasses vision impairment (VI) and hearing impairment (HI). CMM is defined as the coexistence of two or more CMDs, including diabetes, heart disease, and stroke. DSI and CMM were assessed through self-reporting, frailty was assessed using the frailty index (FI). The group-based trajectory model (GBTM) was employed to fit the DSI trajectories. Cox proportional hazards models were applied to evaluate potential risk and mediating role. RESULTS: A total of 5933 participants were included, the incidence density of CMM is 3.034/1000 person-years during the 4-year follow-up. This study identified three DSI trajectories: persistently low DSI (n = 1798, 30.305%), persistently moderate DSI (n = 2975, 50.143%), and persistently high DSI (n = 1160, 19.551%). Compared with the persistently low DSI, persistently high DSI has a higher risk of CMM (HR: 2.014, 95%CI: 1.087, 3.732), specifically, CMD (HR: 1.515, 95%CI: 1.289, 1.780), diabetes (HR: 1.483, 95%CI: 1.179, 1.864), heart disease (HR: 1.459, 95%CI: 1.153, 1.846), stroke (HR: 2.136, 95%CI: 1.301, 3.506). Notably, frailty mediated 26.93% of the association between persistently high DSI and new-onset CMD. Mediation effects for diabetes, heart disease, and stroke were 21.52%, 34.31%, and 38.81%, respectively. CONCLUSION: DSI was associated with an increased risk of CMM, and this association is partially mediated by frailty.