To investigate the relationship between Cardiovascular-Kidney-Metabolic (CKM) syndrome stages and fall risk among middle-aged and older Chinese adults, providing evidence for early risk identification.

Utilising longitudinal data from the China Health and Retirement Longitudinal Study (2015 and 2018), 7 861 participants aged 45 and older were included after excluding those with missing baseline anthropometric, blood, or key questionnaire data. CKM syndrome was staged according to the American Heart Association scientific statement. The outcome was self-reported falls within the past three years assessed in 2018. Modified Poisson regression models estimated incidence rate ratios (IRR) and 95%confidence intervals (CI), adjusting for demographics, lifestyle, physical and sensory function, cognitive and mental health,other health conditions, and the living environment. Subgroup analyses tested interactions with physical and sensory functions.

During 3 years follow-up, 1 438 (18.3%) participants reported at least one fall. At baseline, CKM Stage 2 was the most prevalent (5 241; 66.7%), followed by Stage 4 (1 746; 22.2%), Stage 3 (472; 6.0%), and Stage 1 (402; 5.1%). Compared with Stage 1, CKM Stage 3 was associated with a 32% increased risk of falls (IRR=1.32, 95% CI: 1.03-1.69). No significant interactions were observed between CKM stages and grip strength, balance, hearing, and visual function (P for interaction >0.05).

CKM syndrome staging is positively associated with fall risk in middle-aged and older adults. CKM Stage 3 may represent a critical window for fall prevention interventions.