Triglyceride glucose index and smoking are linked to new coronary artery calcification after normal baseline scan

This study evaluated the incidence and severity of the new onset of coronary artery calcification (CAC) related to clinical factors assessed at follow-up CAC scan among 6993 asymptomatic Korean adults (48.4 ± 7.2 years; 79.8% men) without underlying baseline CAC. During a median follow-up of 3.3 years, the risk of (a) the new onset of CAC (defined as coronary artery calcium score [CACS] > 0 at follow-up), (b) difference of ≥ 2.5 between baseline and follow-up square root (√) transformed CACS (Δ√transformed CACS), and (c) CACS > 100 at follow-up was evaluated. The incidence of the new onset of CAC, Δ√transformed CACS ≥ 2.5, and CACS > 100 was 19.3%, 13.0%, and 1.0%, respectively. After adjusting for traditional risk factors identified at initial CT scan and interscan period, the levels of systolic blood pressure, triglyceride glucose (TyG) index, hemoglobin A1C (HbA1C), and low-density lipoprotein cholesterol and current smoking were positively associated with the risk of the new onset of CAC and Δ√transformed CACS ≥ 2.5, respectively. TyG index, HbA1C, and current smoking were associated with the risk of CACS > 100 (all P < 0.05). An age-based subgroup analysis revealed that TyG index and current smoking were significantly associated with the new onset of CAC, Δ√transformed CACS ≥ 2.5, and CACS > 100 among participants aged < 55 years. In conclusion, both TyG index and smoking were independently associated with the new onset of CAC and its severity, especially in adults aged < 55 years without baseline CAC.