The causes of hyperproinsulinaemia in type 2 diabetic patients with coronary artery disease

Aim: We aimed to evaluate the relation between the basal serum proinsulin concentration and metabolic control parameters, markers of pancreatic β cells secretory dysfunction, indices of insulin resistance in type 2 diabetic patients with concomitant coronary artery disease. Material and methods: We studied 67 type 2 diabetic patients, 80 patients with diabetes type 2 and concomitant coronary artery disease, 88 patients with coronary artery disease and 31 healthy volunteers. Fasting glycaemia, HbA1c, lipid profile incuding lipoprotein (a) concentration, C-peptide, insulin and proinsulin concentrations in serum at fasting conditions were estimated.
Results: There was an increase in proinsulin serum level in patients with diabetes type 2 and concomitant coronary artery disease in comparison to patients with coronary artery disease and to healthy group. Serum proinsulin level was correlated with HDL cholesterol and triglycerides but multivariate regression analysis revealed that proinsulin concentration in serum is mainly determined by insulin resistance index, and less significantly, by markers of β cells dysfunction.

Conclusions: These data show that fasting serum proinsulin concentration in patients with diabetes type 2 and concomitant coronary artery disease is related to dyslipidemia, however is mainly dependent on insulin resistance. It suggests that using antidiabetic agents decreasing insulin resistance proinsulin-dependent risk of atherosclerosis could be diminished.