Associations of cumulative exposure and longitudinal change patterns of the triglyceride glucose–Chinese visceral adiposity index with incident cardiovascular disease in middle-aged and older adults: evidence from CHARLS

The triglyceride glucose–Chinese visceral adiposity index (TyG-CVAI), an integrated marker of insulin resistance and visceral adiposity, has been associated with cardiovascular outcomes. However, the longitudinal cardiovascular implications of cumulative TyG-CVAI exposure and directional changes in TyG-CVAI remain insufficiently characterized. This study aimed to examine the associations of cumulative TyG-CVAI exposure and longitudinal TyG-CVAI change patterns with incident cardiovascular disease (CVD) among middle-aged and older Chinese adults. This prospective study included 4,338 participants from the China Health and Retirement Longitudinal Study (CHARLS) who were free of CVD during the exposure assessment period from 2011 to 2015 and had complete TyG-CVAI data in 2011 and 2015. Participants were categorized into four TyG-CVAI change patterns (low–low, low–high, high–low, and high–high). Cumulative TyG-CVAI was calculated using repeated measurements from 2011 to 2015 and analyzed as both a standardized continuous variable and quartiles. Incident CVD was defined as new-onset heart disease or stroke during follow-up. Kaplan–Meier analysis, multivariable Cox proportional hazards models, and restricted cubic spline (RCS) analysis were performed. During a mean follow-up of 5 years, 845 incident CVD events occurred among 4,338 participants. Compared with the low–low group, the fully adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for incident CVD were 1.50 (1.21–1.88) for the low–high group, 1.64 (1.20–2.25) for the high–low group, and 1.77 (1.49–2.09) for the high–high group. When cumulative TyG-CVAI was analyzed as a standardized continuous variable, each 1-SD increase was associated with a higher risk of incident CVD after full adjustment (HR 1.10, 95% CI 1.06–1.14). When categorized into quartiles, participants in the highest quartile had a higher CVD risk than those in the lowest quartile (HR 1.91, 95% CI 1.56–2.33; P for trend < 0.001). RCS analysis revealed a significant nonlinear association between cumulative TyG-CVAI and incident CVD. Higher cumulative TyG-CVAI burden and unfavorable longitudinal change patterns were associated with an increased risk of incident CVD among middle-aged and older Chinese adults. These findings suggest that repeated TyG-CVAI assessment may help identify individuals with sustained or worsening metabolic-visceral burden and support longitudinal cardiovascular risk stratification.