Association between the triglyceride-glucose index-to-waist-to-height ratio and cardiovascular disease risk in Chinese adults: A prospective cohort study.
Cardiovascular disease (CVD) is one of the major chronic non-communicable diseases worldwide, with high incidence and mortality. This study aims to investigate the association of the triglyceride-glucose index-to-waist-to-height ratio (TyGI-WHtR) with CVD and its subtypes [myocardial infarction (MI) and stroke] in middle-aged and older Chinese adults.
This prospective cohort study was based on 3 follow-up surveys of the China Health and Nutrition Survey (CHNS) from 2009 to 2015. A total of 5 395 participants aged 40 to 80 years who were free of CVD at baseline and had participated in at least 2 survey waves were included. Cox proportional hazards models were used to evaluate the associations of TyGI-WHtR with CVD and its subtypes. Weighted generalized additive models and smooth curve fitting were applied to explore potential nonlinear relationships. Time-dependent receiver operating characteristic (ROC) curves assessed predictive performance, and Kaplan-Meier analysis was used to calculate cumulative incidence of CVD across different groups.
During a median follow-up of 72 months (interquartile range: 48 to 72 months), 210 incident CVD events were recorded, including 126 strokes and 92 MIs. Among them, 8 patients had both MI and stroke. After adjustment for confounders, each one-standard-deviation (SD) increase in TyGI-WHtR was associated with a significantly higher risk of incident CVD [adjusted hazard ratio (HR)=1.397, 95% confidence interval (CI) 1.111 to 1.758] and incident MI (adjusted HR 1.747, 95% CI 1.241 to 2.460), while no statistically significant association was observed with stroke (adjusted HR=1.198, 95% CI 0.890 to 1.613). Compared with lowest quartile, participants in the highest TyGI-WHtR quartile had significantly increased risks of CVD and MI (both P for trend <0.005), whereas no such trend was observed for stroke (P for trend=0.103). Further analyses revealed a nonlinear association between TyGI-WHtR and CVD. When TyGI-WHtR was <4.804, HR was 2.121 (95% CI 1.350 to 3.333); when it was ≥4.804, HR was 1.066 (95% CI 0.754 to 1.507). The nonlinear inflection point for stroke was 4.477, while the association with MI remained linear [ln(likelihood ratio)=0.212]. Time-dependent ROC analysis showed that the area under the curve of TyGI-WHtR for predicting CVD was 0.629, with a sensitivity of 77.3%, and specificity of 43.2%.
In middle-aged and older Chinese adults, TyGI-WHtR is an independent risk factor for incident CVD, particularly MI, but is not independently associated with stroke. Moreover, its predictive ability for CVD demonstrates a nonlinear saturation-threshold effect, with risk significantly increased only when TyGI-WHtR is below 4.804.
This prospective cohort study was based on 3 follow-up surveys of the China Health and Nutrition Survey (CHNS) from 2009 to 2015. A total of 5 395 participants aged 40 to 80 years who were free of CVD at baseline and had participated in at least 2 survey waves were included. Cox proportional hazards models were used to evaluate the associations of TyGI-WHtR with CVD and its subtypes. Weighted generalized additive models and smooth curve fitting were applied to explore potential nonlinear relationships. Time-dependent receiver operating characteristic (ROC) curves assessed predictive performance, and Kaplan-Meier analysis was used to calculate cumulative incidence of CVD across different groups.
During a median follow-up of 72 months (interquartile range: 48 to 72 months), 210 incident CVD events were recorded, including 126 strokes and 92 MIs. Among them, 8 patients had both MI and stroke. After adjustment for confounders, each one-standard-deviation (SD) increase in TyGI-WHtR was associated with a significantly higher risk of incident CVD [adjusted hazard ratio (HR)=1.397, 95% confidence interval (CI) 1.111 to 1.758] and incident MI (adjusted HR 1.747, 95% CI 1.241 to 2.460), while no statistically significant association was observed with stroke (adjusted HR=1.198, 95% CI 0.890 to 1.613). Compared with lowest quartile, participants in the highest TyGI-WHtR quartile had significantly increased risks of CVD and MI (both P for trend <0.005), whereas no such trend was observed for stroke (P for trend=0.103). Further analyses revealed a nonlinear association between TyGI-WHtR and CVD. When TyGI-WHtR was <4.804, HR was 2.121 (95% CI 1.350 to 3.333); when it was ≥4.804, HR was 1.066 (95% CI 0.754 to 1.507). The nonlinear inflection point for stroke was 4.477, while the association with MI remained linear [ln(likelihood ratio)=0.212]. Time-dependent ROC analysis showed that the area under the curve of TyGI-WHtR for predicting CVD was 0.629, with a sensitivity of 77.3%, and specificity of 43.2%.
In middle-aged and older Chinese adults, TyGI-WHtR is an independent risk factor for incident CVD, particularly MI, but is not independently associated with stroke. Moreover, its predictive ability for CVD demonstrates a nonlinear saturation-threshold effect, with risk significantly increased only when TyGI-WHtR is below 4.804.