The Relationship Between Insulin Resistance and Incidence and Progression of Coronary Artery Calcification: The Multi-Ethnic Study of Atherosclerosis (MESA)

OBJECTIVE: We sought to determine whether insulin resistance predicts the incidence and progression of coronary artery calcification (CAC). RESEARCH DESIGN AND METHODS: We studied 5,464 participants not on hypoglycemic therapy from the Multi-Ethnic Study of Atherosclerosis (MESA). Each had baseline homeostasis model assessment of insulin resistance (HOMA-IR) and baseline and follow-up CAC scores. Incident CAC was defined as newly detectable CAC; progression was defined as advancing CAC volume score at follow-up. RESULTS: Median HOMA-IR was 1.2 (0.8–2.0). Across all ethnicities, there was a graded increase in CAC incidence and progression with increasing HOMA-IR. When compared with those in the 1st quartile, participants in the 2nd–4th quartiles had 1.2, 1.5, and 1.8 times greater risk of developing CAC. Median annualized CAC score progression was 8, 14, and 17 higher, respectively. However, HOMA-IR was not predictive after adjustment for metabolic syndrome components. CONCLUSIONS: HOMA-IR predicts CAC incidence and progression, but not independently of metabolic syndrome.