Long‐Term High Level of Insulin Resistance Is Associated With an Increased Prevalence of Coronary Artery Calcification: The CARDIA Study

BACKGROUND: Coronary artery calcification (CAC) is a crucial indicator of subclinical atherosclerotic cardiovascular disease. The relationship between long‐term insulin resistance (IR) trajectory and CAC has been explored in few studies. Therefore, this study aimed to investigate whether the long‐term IR time series of young adults are associated with the incidence of CAC in midlife. METHODS AND RESULTS: In a cohort study comprising 2777 participants from the CARDIA (Coronary Artery Risk Development in Young Adults) study, the homeostasis model assessment for IR was used to measure IR levels, and group‐based trajectory modeling was used to fit three 25‐year homeostasis model assessments for IR trajectories. Logistic regression was used to estimate the association between the 3 homeostasis model assessments for IR trajectories and CAC events at year 25. The results showed that among 2777 participants (mean age, 50.10±3.58 years; 56.2% women; 46.4% Black), there were 780 incident CAC events after a 25‐year follow‐up. After full adjustment, the prevalence of CAC was higher in the moderate‐ (odds ratio [OR], 1.40 [1.10–1.76]) and the high‐level homeostasis model assessments for IR trajectories (OR, 1.84 [1.21–2.78]) than in the low‐level trajectory. This association was observed in obese individuals despite the negative interaction between IR and different types of obesity (all P interactions >0.05). CONCLUSIONS: Our study revealed that young adults with a higher level of IR were more likely to develop CAC in middle age. Furthermore, this association persisted in obese individuals. These findings highlight the importance of identifying subclinical cardiovascular risk factors and implementing primary prevention measures.