Progression of coronary artery calcification in type 1 diabetes: the importance of glycemic control.

Abstract

Coronary artery disease (CAD) occurs earlier in life and is more often fatal in people with type 1 diabetes. This excess risk seems to be higher than in those with type 2 diabetes and is poorly explained by conventional risk factors. The role of glycemic control is controversial and has not been previously addressed in a prospective manner using a reliable marker for subclinical CAD, such as coronary artery calcification (CAC), measured by electron beam computed tomography (EBCT). We measured CAC twice during an interval of 2.7 years in 109 men and women with type 1 diabetes (aged 22-50 years). Progression of CAC was found in 21 patients, based on change in the square root-transformed volume score. In multiple logistic regression, CAC progression was associated with baseline hyperglycemia (odds ratio [OR] 7.11, 95% CI 1.38-36.6, P = 0.02), adjusted for the presence of CAC at baseline (P = 0.01), duration of diabetes (P = 0.02), sex (P = 0.09), and age (P = 0.27). There was also a significant interactive effect of higher insulin dose and higher BMI (P = 0.03). In conclusion, in this young cohort with type 1 diabetes, suboptimal glycemic control (HbA(1c) >7.5%) was a strong risk factor for progression of CAC. Insulin resistance may also play a role.