High-density lipoprotein subspecies between patients with type 1 diabetes and type 2 diabetes without/with intensive insulin therapy

The reduced levels of high-density lipoprotein (HDL) 2-cholesterol (C) in diabetes and other metabolic disorders associated with a high risk of cardiovascular disease are well established. Few studies, however, have compared the HDL subspecies in type I diabetes (T1D) with those in type 2 diabetes (T2D) with or without insulin. We examined HDL subspecies in 27 T1D with insulin, 33 T2D with insulin or insulin plus oral-anti-diabetic drugs (OADs), 36 T2D with OADs or diet/exercise, and 25 non-diabetic controls. Insulin was injected four times daily in a basal-bolus manner for both T1D and T2D. Plasma levels of C, apolipoprotcin (apo) AI, and AII were determined in HDL2 and HDL3 by the single precipitation method. HDL-C levels were significantly higher in T1D and lower in T2D, compared with the controls. Insulin-treated T2D had higher HDL-C than non-insulin-treated T2D. T1D had higher HDL2-C and HDL2-apo AI levels than T2D. Insulin-treated T2D had higher HDL2-C and HDL2-apo AI levels than non-insulin-treated T2D. All of these differences were more pronounced for men than for women. HDL3 levels were comparable among controls,T1D and T2D. HDL2-C levels were inversely associated with BMI, HbA1c, triglyceride, small dense LDL-C, and LDL-C. Multiple regression analysis revealed that HDL2-C was independently associated with triglyceride, LDL-C, and intensive insulin therapy but not with HbA1c. In conclusion, these results suggest that intensive insulin therapy is associated with alterations of HDL subspecies, irrespective of the type of diabetes.