Increase in thiobarbituric acid-reactive substances and vascular complications in type 2 diabetes mellitus

Lipid peroxidation was assessed by measuring the concentrations of thiobarbituric acid-reactive substances in plasma from 204 Type 2 diabetic patients, relative to 107 controls. The concentrations obtained in diabetic patients (3.08 +/- 0.37 mumol/l) were significantly higher than in controls (2.80 +/- 0.34 mumol/l) (p < 0.0001). Values were also significantly increased in patients with macroangiopathy and/or microangiopathy (3.17 +/- 0.41 mumol/l), relative to patients void of vascular complications (2.92 +/- 0.34 mumol/l) (p < 0.001). Elevated concentrations were independent of the type of vascular complication and their possible associations. In patients without vascular affection, thiobarbituric acid-reactive substances were in significantly higher concentrations in hypertensive (3.07 +/- 0.36 mumol/l) than in normotensive (2.87 +/- 0.29 mumol/l) (p < 0.01) patients. There was a correlation between these values and those of total cholesterol (r = 0.46, p < 0.0001) and triglyceride (r = 0.45, p < 0.0001). Statistical analysis by multivariate logistical regression revealed that among the independent factors (TBARS, APO A1, hypertension, age), thiobarbituric acid-reactive substances constituted the parameter most strongly linked to the existence of vascular complications. This study has evidenced a lipid peroxidation disorder in non insulin- dependent diabetes mellitus, more marked in patients with vascular affection. Thiobarbituric acid-reactive substances appear to be an independent marker of vascular complications in Type 2 diabetes.