Association between non-traditional lipid-inflammatory parameters and incident diabetes: a national prospective cohort study

Non-traditional lipid indices are diabetes risk factors, but their combined effects with inflammatory markers remain unclear. The present study systematically investigated and compared the associations between eight non-traditional lipid-inflammatory parameters and new-onset diabetes. Data were obtained from the 2011–2020 China Health and Retirement Longitudinal Study. The lipid-inflammatory parameters were created by integrating non-traditional lipid indices and high-sensitivity C-reactive protein (hsCRP). Cox regression and restricted cubic spline models examined the associations of baseline and cumulative lipid-inflammatory parameters with diabetes risk. Time-dependent receiver operating characteristic analyses evaluated the predictive performance of these parameters. Mediation analyses explored the reciprocal links between non-traditional lipid indices, hsCRP, and diabetes risk. The study enrolled 7,356 participants, with 1,173 (15.95%) developing diabetes over a median follow-up period of 9 years. In the multivariable-adjusted model, individuals with higher baseline and cumulative non-traditional lipid-inflammatory parameter levels had an elevated risk of developing diabetes, especially for lipoprotein combined index (LCI)-hsCRP (hazard ratio HR = 2.03, 95% confidence interval CI: 1.70–2.41). All lipid-inflammatory parameters were nonlinearly associated with diabetes risk. The area under the curve (AUC) values for the eight lipid-inflammatory parameters ranged from 0.595 to 0.619, with LCI-hsCRP exhibiting the highest predictive value (AUC = 0.619, 95% CI: 0.597–0.640). The results were consistent across sensitivity and subgroup analyses. Mediation analyses showed significant bidirectional mediation between non-traditional lipid indices and hsCRP for diabetes. Elevated baseline and cumulative non-traditional lipid-inflammatory parameter levels are linked to a higher risk of incident diabetes, with LCI-hsCRP showing the highest predictive value. Not applicable.