Association of insulin, C-peptide and blood lipid patterns in patients with impaired glucose regulation

Background To investigate any associations between blood glucose (BG) and lipid levels in patients with different glucose tolerance statuses, including type 2 diabetes (T2DM) and impaired glucose regulation (IGR) cases as well as normal glucose tolerance (NGT) individuals. Methods A total of 354 participants were recruited to this study including 174 in the T2DM group, 112 in the IGR group and 68 in the NGT group. We compared BG, insulin and C-peptide (CP), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) serum levels during a 3 h oral glucose tolerance test (OGTT) in the 3 groups. Results Basic overall HbA1c serum concentration percentages were 5.52, 6.33 and 9.76% for the NTG, IGR and T2DM cases. During the OGTT, insulin secretion in the IGR group was almost double that of the T2DM group. CP levels were highest in the IGR patients and OGTT related BG concentrations were highest in the T2DM group followed by IGR, but in the IGR group hyperglycemia was less pronounced than in T2DM patients ( P < 0.001). Compared to the NGT group, TC, TG and LDL-C serum concentrations were significantly higher ( P ≤ 0.001) and HDL-C concentrations were significantly lower ( P ≤ 0.001) in IGR and T2DM cases compared to the NTG group. Conclusions IGR led to similar unfavorable blood lipid patterns compared with T2DM patients and an imbalance of insulin and CP serum concentrations during an OGTT.