Levels of serum sialic acid and thiobarbituric acid reactive substances in subjects with impaired glucose tolerance and type 2 diabetes mellitus

Cardiovascular disease is a common cause of death for diabetic patients. High sialic acid levels (SA) and increased oxidative stress are important factors for cardiovascular diseases. We aimed to research whether SA and thiobarbituric acid reactive substances (TBARS) levels are associated with the degree of the diabetic regulation and investigate if SA and TBARS levels can be controlled with the regulation of the blood glucose levels. A total of 179 subjects were included in the study. Three groups, which were comprised of subjects with type 2 diabetes mellitus (DM) (DM group [DMG], n=149), impaired glucose tolerance (IGT) (IGT group [IGTG], n=15), and normal oral glucose tolerance (NGT) (NGTgroup [NGTG], n=15) were constituted. Glucose, cholesterol, high-density lipoprotein (HDL) and glycated hemoglobin (HbA1C), SA, and TBARS were measured in the sera of the patients. SA and TBARS levels were significantly increased in subjects with type 2 DM (P<0.001 for both). SA concentrations showed significant correlation with triglycerides (r=0.229; P<0.05), fasting glucose (r=0.508; P<0.01), 2-hr postprandial glucose (r=0.455; P<0.01), and HbA1C (r=0.467; P<0.01), and there was a positive correlation between TBARS and HbA1C (r=0.251; P<0.01). Diabetic patients were found to have higher risk for inflammation and oxidative stress. The regulation of blood glucose levels may contribute to the decline of both SA and TBARS levels.