Pioglitazone versus glimepiride on coronary artery calcium progression in patients with type 2 diabetes mellitus: a secondary end point of the CHICAGO study.

OBJECTIVE To compare coronary artery calcium (CAC) progression between 2 treatment groups, pioglitazone versus glimepiride. METHODS AND RESULTS The CHICAGO (Carotid Intima-Media Thickness in Atherosclerosis Using Pioglitazone) study demonstrated that pioglitazone significantly decreased carotid intima-media thickness progression compared with glimepiride in patients with type 2 diabetes mellitus. The CAC level was determined at baseline and at the end of 72 weeks of treatment in the pioglitazone (n=146) and glimepiride (n=153) treatment groups using electron beam computed tomography. There was no difference in CAC progression between the treatment groups. By using backward and forward selection models, age, race/ethnicity, and baseline apolipoprotein B level predicted CAC progression. There was no relationship between carotid intima-media thickness and CAC progression during the study. CONCLUSIONS There was no difference in CAC progression in patients with type 2 diabetes mellitus treated with pioglitazone or glimepiride. Age, race/ethnicity, and baseline apolipoprotein B level predicted CAC progression in patients with type 2 diabetes mellitus.