BACKGROUND AND AIMS We aimed to investigate the association between metabolic syndrome (MetS) and coronary artery calcium (CAC) progression in statin-naïve young adults.

METHODS From the KOrea Initiatives on Coronary Artery calcification registry, we included asymptomatic young adults aged 20-45 years who underwent serial CAC scans for routine health check-ups. The primary endpoint was CAC progression. We estimated the risk of CAC progression based on the presence and burden of MetS. Among participants with MetS, the temporal relationship between changes in metabolic burden and CAC progression was evaluated.

RESULTS Of 2151 young adults (mean age 41.3 ± 3.8 years; male 85.4%), 488 (22.7%) had MetS. The mean CAC score was 10.8 and 81.3% of them had a CAC score of zero at baseline. During follow-up (median, 2.1 years), CAC progression was observed in 325 (15.1%) adults. MetS was associated with an approximately 1.8-fold increased risk of CAC progression (adjusted hazard ratio [aHR] 1.83, p < 0.001). The risk of CAC progression was directly proportional to the metabolic burden. Elevated blood pressure and elevated triglyceride levels were independent components related to CAC progression, with the strongest contribution being made by elevated blood pressure (aHR 2.00, p < 0.001). A reduction in at least two metabolic burdens was associated with a halved risk of CAC progression in young adults having MetS (odds ratio 0.41, p = 0.018).

CONCLUSIONS In statin-naïve young adults, the metabolic burden was associated with a risk of CAC progression in a dose-dependent manner. Improvement in metabolic imbalance may have a preventive effect on CAC progression.