Fasting intact proinsulin, insulin, advanced glycation endproducts (AGEs), pentosidine, lipid peroxide and urine 8-isoprostane as well as other metabolic parameters were measured in 64 T2DM subjects.
Using univariate analysis, P/I ratio showed significant positive correlations with plasma glucose (r = 0.465), HbA1c (r = 0.434) and AGEs (r = 0.282), and significant negative correlations with insulin (r = −0.330) and HOMA-β (r = −0.520) even after adjustment for age, sex, duration of diabetes, family history of diabetes, use of sulfonylureas, smoking and body mass index. Additionally, stepwise multiple regression analysis revealed that HOMA-β, HbA1c and AGEs were independently and significantly correlated with P/I ratio.
These findings suggest that not only hyperglycemia per se but also glycation is involved in β-cell dysfunction in T2DM subjects.