Joint association of high-sensitivity c-reactive protein and Chinese visceral adiposity index with incident stroke in middle-aged and older adults: a prospective cohort study

BACKGROUND: Stroke is a leading cause of mortality and long-term disability worldwide, disproportionately affecting middle-aged and older adults. Visceral adiposity and systemic inflammation are increasingly recognized as independent contributors to cerebrovascular disease; however, their combined association with stroke incidence remains poorly characterized. This study examined the joint association of High-sensitivity C-reactive protein (hs-CRP) and the Chinese Visceral Adiposity Index (CVAI) with incident stroke risk in a nationally representative Chinese cohort. METHODS: Data from 8,370 adults in the China Health and Retirement Longitudinal Study (CHARLS) were analyzed over a 9-year follow-up. Participants were classified into four groups based on median hs-CRP (1.01 mg/L) and CVAI (101.26) values. Cox proportional hazards models were used to examine associations with stroke risk. RESULTS: During the 9-year follow-up, 475 participants (5.7%) developed stroke. In fully adjusted models, elevated CVAI alone (HR = 1.73; 95% CI: 1.27-2.36) and elevated hs-CRP alone (HR = 1.44; 95% CI: 1.04-2.00) were each associated with increased stroke risk compared with low levels of both markers. Concurrent elevation conferred the highest risk (HR = 2.32; 95% CI: 1.75-3.08). No significant interactions were found across most subgroups, except for diabetes status (P = 0.014). Sensitivity analyses confirmed robustness. CONCLUSIONS: Concurrent elevation of hs-CRP and CVAI was associated with substantially higher stroke risk than either biomarker alone. However, the incremental predictive value and clinical utility of this combined approach remain to be formally evaluated in future prediction studies.