Associations of coronary artery calcification and carotid intima-media thickness with plasma concentrations of vascular calcification inhibitors in type 2 diabetic patients

Vascular calcification is frequently accompanied by intima-media thickening, but the associations among these atherosclerotic features and bone-related peptides in diabetic patients are unclear. We enrolled 168 type 2 diabetic patients and 40 non-diabetic subjects consecutively admitted to our hospital. Mean intima-media thickness (mean-IMT) in common carotid arteries was measured by B-mode ultrasonography. Agatston coronary artery calcium score (CACS) was obtained using multidetector-row computed tomography (MDCT). Plasma bone-related peptides osteopontin and osteoprotegerin levels were measured. Diabetic patients had higher mean-IMT (p = 0.0002) and log(CACS + 1) (p < 0.0001) and similar bone-related peptides compared to non-diabetic subjects. In diabetic patients classified into tertiles according to their CACS levels, those with the highest scores showed the highest mean-IMT (p = 0.0004) and bone-related peptides (p < 0.05) among the groups. log(CACS + 1) and mean-IMT were associated (p < 0.0001) and were positively correlated with osteopontin (p < 0.01) and osteoprotegerin (p < 0.01) in diabetic patients. Multivariate analyses revealed that the significant independent determinants of log(CACS + 1) were age, duration of diabetes and osteopontin (p < 0.0001) and those of mean-IMT were age, hypertension, osteopontin and osteoprotegerin (p < 0.0001), respectively. We have demonstrated that vascular calcification in type 2 diabetic patients is frequently accompanied by intima-media thickening, and osteopontin may act as a vascular calcification inhibitor by increasing intima-media thickness.