Changes in triglyceride-glucose index and progression of coronary artery calcification in asymptomatic adults: a longitudinal cohort study

Introduction The triglyceride-glucose (TyG) index is a readily available surrogate marker of insulin resistance; however, the association between changes in TyG index and coronary artery calcification (CAC) progression remains unclear. Methods This retrospective cohort study included 14,407 Korean adults without cardiovascular disease who underwent two baseline examinations during 2012–2018 and at least three examinations overall. At each baseline examination, TyG index status was classified as low or high using a predefined cutoff, yielding low-to-low (L-L), low-to-high (L-H), high-to-low (H-L), and high-to-high (H-H) groups. CAC progression was defined as a difference of ≥2.5 between the square root-transformed coronary artery calcium score (CACS) of the follow-up and index examination. Cox proportional hazards and linear mixed-effects models were used to estimate hazard ratios (HRs) and 5-year fold changes, respectively. Results During a median follow-up of 5.34 years, 4,139 participants experienced CAC progression. Compared with the L-L group, the risk of CAC progression increased across the L-H, H-L, and H-H groups, with adjusted HRs (95% confidence intervals) of 1.07 (0.96–1.19), 1.14 (1.02–1.27), and 1.30 (1.20–1.41), respectively. Associations differed between CAC subgroups ( p for interaction <0.001), with more pronounced associations observed among participants with CACS of zero at both the first and index examinations. The 5-year fold change was 11% higher in the L-H group than in the L-L group and 9% lower in the H-L group than in the H-H group. Conclusion Changes in TyG index status were associated with CAC progression, particularly among individuals without detectable CAC. Serial TyG index assessment may aid in cardiovascular risk stratification.