Endocrine Abstracts

Background: Osteoprotegerin (OPG) is a bone-related glycopeptide produced by vascular smooth muscle cells due to arterial damage. OPG is considered as an independent predictor of cardiovascular disease in diabetic populations.

The aim of this study was to evaluate the interrelation between circulating OPG and coronary vasculature damage in type 2 diabetes mellitus patients.

Methods: One hundred and twenty six subjects with stable diabetes mellitus 2 type with previously angiographic documented asymptomatic CAD were enrolled to the study. Vessel-wall and plaque geometrical and compositional parameters were measured on contrast-enhanced CT angiography. The volume of intramural calcium of >320 HU in major coronary vessels was measured in 428 coronary segments with a highly standardized method. Coronary artery calcification was quantified by calculating the Agatston’ score index and calcification mass measurement. OPG plasma levels were measured with ELISA.

Results: Circulating OPG level was increase in 105 patients (5201 pg/ml (95% CI=3605–6280 pg/ml) and was normal in 21 subjects (880 pg/ml; 95% CI =745–1140 pg/ml; P<0.0001). The relationship between coronary artery calcium by Agatston’ score index and percent atheroma volume (PAV) was determined by linear regression. PAV and remodeling index were significantly higher in patients with elevation of OPG plasma level when compared with those who have normal OPG (adjusted odds ratio (OR)=4.60 (95% CI =2.23–14.50); P=0.006). There was significant correlation between Agatston’ score index and PAV (r²=0.46, P=0.008). Results did not change after adjustment for age, BMI, hypercholesterolemia, arterial hypertension, and exposure of antidiabetic drugs (β=0.490, 95% CI=0.31–1.02, P=0.282). Comparable results were found for calcification mass. However, minimal luminal diameter and minimal luminal area were higher in patients with normal OPG plasma level (P=0.002).

In conclusion, we demonstrated that OPG plasma level can associate with vessel-wall thickening, percent atheroma volume, and Agatston’ score index value in type 2 diabetes mellitus patients with previously angiographic documented CAD. Results from this study underline the importance of this biomarker use for screening procedure in diabetic populations aimed to specify of coronary vasculature damage severity and probably to recalculate cardiovascular risk.