Association of increased serum glycated albumin levels with low coronary collateralization in type 2 diabetic patients with stable angina and chronic total occlusion

Background: We investigated whether serum glycated albumin (GA) levels are related to coronary collateralization in type 2 diabetic patients with chronic total occlusion. Methods: Blood levels of GA and glycosylated hemoglobin (HbA1c) were determined in 317 diabetic and 117 non-diabetic patients with stable angina and angiographic total occlusion of at least one major coronary artery. The degree of collaterals supplying the distal aspect of a total occlusion from the contra-lateral vessel was graded as low (Rentrop score of 0 or 1) or high collateralization (Rentrop score of 2 or 3). Results: For diabetic patients, GA (21.2 +/- 6.5% vs. 18.7 +/- 5.6%, P < 0.001) but not HbA1c levels (7.0 +/- 1.1% vs. 6.8 +/- 1.3%, P = 0.27) was significantly elevated in low collateralization than in high collateralization group, and correlated inversely with Rentrop score (Spearmen's r = -0.28, P < 0.001; Spearmen's r = -0.10, P = 0.09, respectively). There was a trend towards a larger area under the curve of GA compared with that of HbA1c for detecting the presence of low collateralization (0.64 vs. 0.58, P = 0.15). In non-diabetic patients, both GA and HbA1c levels did not significantly differ regardless the status of coronary collateralization. In multivariable analysis, female gender, age > 65 years, smoke, non-hypertension, duration of diabetes > 10 years, metabolic syndrome, eGFR < 90 ml/min/1.73 m(2), and GA > 18.3% were independently determinants for low collateralization in diabetic patients. Conclusions: Increased GA levels in serum are associated with impaired collateral growth in type 2 diabetic patients with stable angina and chronic total occlusion.