The contributions of fasting and postprandial blood glucose increments to oxidative stress and inflammation in dyslipidemic type 2 diabetic patients with stable ischemic heart disease

Abstract

Background/objectives: Contributions of fasting and postprandial blood glucose increments on level of inflammation and oxidative stress biomarkers in patients with stable ischemic heart disease (IHD) and diabetes mellitus type 2 (T2DM) was evaluated.

Methodology: Ninety T2DM patients (60 with IHD and 30 without IHD) treated with metformin and/or sulphonylurea were enrolled in cross-sectional nested case-control clinical study. The areas under the six-point daily glucose curve above the fasting glucose concentrations (AUCpp) and over 5.5mmol/L (AUCbg) were calculated to determine postprandial (AUCpp) and fasting (AUCbg-AUCpp) glucose increments. Malondialdehyde (MDA), protein carbonyl group (PCO), fibrinogen, C-reactive protein (hsCRP), leukocyte count and adhesion molecules ICAM-1 and VCAM-1 were determined.

Results: AUCbg-AUCpp 58.2 (95%CI 40.6-75.8) was higher in IHD group compared to non-IHD 36.9 (95%CI 23.5-50.2) mmol*h/L. They had significantly higher ICAM-1 (mean±SD) 72.70±30.6 vs. 60.22±22.6ng/mL and MDA 16.47±4.5 vs. 13.42±4.01μmol/g plasma proteins, but similar PCO, VCAM-1, fibrinogen, hsCRP concentration and leukocyte count. AUCpp positively correlated with MDA (r=0.45) and ICAM-1 (r=0.32) in the presence of IHD, and VCAM-1 (r=0.44) in the absence of IHD. AUCbg-AUCpp positively correlated with PCO (r=0.45) in the absence of IHD. The analysis revealed that AUCpp over turning point of 0mmol*h/L was associated with high MDA and ICAM-1 expression in diabetics with IHD. AUCbg-AUCpp over 30mmol*h/L leads to high oxidative protein modification in diabetics without IHD.

Conclusion: In T2DM patients with stable IHD, AUCpp at any point, significantly contributes to increasing of MDA and ICAM-1 expression. Fasting blood glucose increment showed significant correlation with carbonyl content in diabetics without IHD.

Keywords: Adhesive molecules; Diabetes mellitus; Fasting hyperglycemia; Inflammation; Ischemic heart disease; Oxidative stress; Postprandial hyperglycemia.