Objective: This study investigated the association between obesity and lipid markers CVAI, TyG-WHtR, TyG-WC, TyG-BMI, and C-index with the risk of developing diabetes in high-risk populations for cardiovascular diseases in Hainan Province, providing reference data for the early prevention of diabetes. Methods: Between February 2023 and January 2024, a multistage stratified cluster sampling methodology was employed to conduct an initial screening of 6,148 individuals across eight cities and counties in Hainan Province. This screening involved physical measurements, face-to-face questionnaire surveys, laboratory tests, and other methodologies, ultimately identifying 1,603 individuals at high risk for cardiovascular disease. For these high-risk individuals, various indices were calculated based on their lipid profiles, waist circumference, height, and weight, including the Cardiovascular Adiposity Index (CVAI), the Triglyceride-Glucose Index with Waist-to-Height Ratio (TyG-WHtR), the Triglyceride-Glucose Index with Waist Circumference (TyG-WC), the Triglyceride-Glucose Index with Body Mass Index (TyG-BMI), and the C-index. Logistic regression and restricted cubic spline (RCS) models were used to evaluate the associations and non-linear relationships between these indices and diabetes risk. Additionally, Receiver Operating Characteristic (ROC) curves were generated for these indicators to investigate their predictive capabilities regarding disease risk among high-risk cardiovascular disease populations. Results: This study ultimately included 1,603 individuals at high risk for cardiovascular disease, of whom 330 (20.59%) had diabetes. After adjusting for confounding factors using logistic regression, the risk of developing diabetes was higher in the Q4 group than in the Q1 group for the CVAI, TyG-WHtR, TyG-WC, and TyG-BMI indicators, except for the C-index. The corresponding odds ratios (OR) and 95% confidence intervals (CI) were as follows: CVAI was 2.67 (95% CI: 1.63-4.38), TyG-WHtR was 14.92 (95% CI: 8.75-25.44), TyG-WC was 17.94 (95% CI: 10.17-31.67), and TyG-BMI was 4.86 (95% CI: 3.05-7.73). The RCS results indicated that CVAI, TyG-WHtR, TyG-BMI, and the C-index were positively linearly associated with the risk of diabetes, whereas TyG-WC exhibited a positive nonlinear association with diabetes risk (P < 0.05). ROC curve analysis revealed that the TyG-WC indicator demonstrated the best predictive performance, with an area under the curve (AUC) of 0.735 (95% CI: 0.705-0.766), followed by the TyG-WHtR index, which had an AUC of 0.716 (95% CI: 0.685-0.747). The optimal cutoff values determined based on the maximum Youden index were TyG-WC at 797.89 and TyG-WHtR at 5.08, respectively. Conclusion: Obesity and lipid profile indicators, including CVAI, TyG-WHtR, TyG-WC, TyG-BMI, and C-index, are positively correlated with diabetes in high-risk populations with cardiovascular disease. Among these, CVAI, TyG-WHtR, TyG-WC, and TyG-BMI exhibited predictive value for diabetes, with TyG-WC showing the highest predictive capability.

People at High Risk of Cardiovascular Disease, Obesity Indicators, Lipid Indicators, Diabetes