Diabetes and progression of coronary calcium under the influence of statin therapy

Abstract

Background: Coronary artery calcium (CAC) is a sensitive marker for the detection of coronary heart disease (CHD). Coronary artery calcification can be accurately quantified using electron beam tomography (EBT). We sought to evaluate the progression of atherosclerosis in asymptomatic persons with type 2 diabetes and measure the influence of statin therapy on CAC progression.

Methods: We evaluated 163 asymptomatic patients with type 2 diabetes (120 men, 43 women). Patients were physician referred and underwent 2 consecutive EBT scans at least 1 year apart. Demographic data, risk factors for CHD, and medication use were collected. Patients with symptoms or known CHD were excluded.

Results: The mean age was 65 +/- 10 years. The mean CAC score at baseline was 651 +/- 414. Only 9 (6%) of 163 of participants had scores of 0 at baseline. The time between scans averaged 27 +/- 15 months. Patients not treated with statins demonstrated a median annual increase in CAC progression of 20% (4%-44%), whereas statin-treated patients demonstrated increase of 10% (4%-25%) (P = .0001). Hemoglobin A 1c was weakly associated with CAC progression.

Conclusions: Asymptomatic diabetic patients show a high prevalence of atherosclerosis based on high frequency of coronary calcification. Statin therapy induced a 50% reduction in the rate of CAC progression. As rapid CAC progression has been associated with coronary events, EBT may serve as a noninvasive method for following atherosclerosis and response to therapy.