The Association between Triglycerides to High-density Lipoprotein Cholesterol (TG/HDL-C) Ratio and 10-year Prospective Risk of Type 2 Diabetes Mellitus: Yazd Healthy Heart Project

Background: Although the link between dyslipidemia and type 2 diabetes mellitus (T2DM) is well-established, the predictive value of the triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio remains unclear. Most existing evidence comes from East Asian populations, highlighting the need for data from more diverse groups. This study investigates the association between TG/HDL-C ratio and T2DM risk in a broader population and aims to identify a practical cut-off point for predicting T2DM incidence. Materials and Methods: Cohort study using data from the Yazd Healthy Heart Project (YHHP). Two thousand people aged 20 to 74 were followed for an average of 9.9 years. After excluding individuals with diabetes and missing data, 1,107 participants remained. Multivariate Cox proportional hazard models were applied to examine the relationship between TG/HDL-C ratio and T2DM incidence. Results: In the crude analysis, individuals in the highest quartile of TG/HDL-C ratio had a higher risk of T2DM compared to the lowest quartile, with hazard ratios (HR) of 2.52 (95% CI: 1.33–4.70) in males and 4.05 (95% CI: 2.17–7.57) in females. Adjusted HRs for the highest quartile versus lowest were 1.28 (95% CI: 0.45–3.57) in males and 6.74 (95% CI: 1.43–31.8) in females, with a significant trend in females ( P = 0.018) but not in males ( P = 0.080). A TG/HDL-C ratio ≥2.46 showed good sensitivity and specificity for predicting T2DM. Conclusions: Increased TG/HDL-C ratio was associated with higher risk of new-onset T2DM, especially in females, supporting its potential role as a biomarker for T2DM risk.