Serum total carbohydrates, conjugated carbohydrates and total protein glycation index in diabetes mellitus.

Background: Diabetes mellitus is defined according to fasting blood glucose and clinical signs. But, the markers of glycation have been used recently as a criterion to diagnose and monitor the therapy.

Objectives: To measure serum total- and conjugated- saccharides and to define the new marker as serum total protein glycation index (sTPGI ) for diabetes.

Design and methods: The study population consisted of 172 subjects who were divided to control and diabetic cases. Serum total and conjugated saccharides were measured and sTPGI was defined to discriminate serum glycosylated and glycated saccharides.

Results: Patients with diabetes compared with the controls had increased levels of serum (free) glucose, HbA1c, serum total carbohydrates, total conjugated carbohydrates and sTPGI. All three indices of serum carbohydrates showed significant positive correlation with serum glucose, HbA1c and diabetes. The equations: sTPGI = 0.12 Glucose (mg/dL) + 12 and sTPGI = 3.5HbA1c (%) + 5, were deduced for the association of sTPGI with serum free glucose and HbA1c. In ROC analysis, both HbA1c (AUC = 0.965, p ≤ 0.001) and sTPGI (AUC = 0.734, p ≤ 0.001) had strong and significant efficiency to discriminate diabetic cases from control subjects.

Conclusions: The results confirm that sTPGI obtained by indirect assay has high significant efficiency comparable to HbA1c to diagnose diabetes. sTPGI relative to HbA1c indicates the mean level of glycaemia over a shorter period of about one month so it responds more quickly to changes in therapy.