Association of the Triglyceride Glucose Index with All-cause and Cardiovascular Mortality in a General Population of Iranian Adults

Background: The triglyceride glucose (TyG) index is a new and low-cost marker to determine insulin resistant which may be a predictor of cardiovascular disease (CVD). Although available evidence showed that its association with CVD mortality (CVM) and all-cause mortality (ACM) may differ in different populations, scarce data are available in this regard specially in low and middle-income countries.

Purpose: To examine the association between TyG index and risk of CVM and ACM in Iranians.

Methods: This prospective cohort study included 5432 adults (age ≥ 35 years) with no history of CVD events. Fasting glucose and triglyceride were measured at baseline in all participants and TyG index was calculated. Cox frailty model was used to calculate hazard ratios (HRs) for CVM and ACM across the tertiles of TyG index.

Results: After a median follow-up of 11.25 years, a total number of 191 cardiovascular deaths, and 487 all-cause mortality was recorded. The risk of both CVM and ACM increased across the tertiles of TyG index. In the adjusted model for lifestyle and metabolic variables, the risks of ACM and CVM increased by 41% (95% CI 1.11, 1.81; P for trend = 0.005) and 64% (95% CI 1.07, 2.50; P for trend = 0.024), respectively. However, adjustment for diabetes mellitus disappeared the significance for both ACM and CVM. These associations may vary by sex. TyG was not related to the risk of non-CVD mortality.

Conclusion: The predicting value of TyG index for ACM and CVM might be mediated by diabetes status. Further studies are required to confirm these findings.