AimTo study alterations in particle components of high density lipoprotein subspecies and activities of the key lipid transfer proteins for its metabolism in type 2 diabetic patients, the correlation between these alterations and related blood glucose indicators were also explored. Methods26 new-onset type 2 diabetic patients (T2DM group) and 25 healthy subjects (control group) were recruited. Plasma was both fasting and postprandial sampled for all subjects, then blood glucose, insulin and lipid spectrum were determined. High density lipoprotein 3 was separated by modified one-step precipitation method and the compositions were measured, then the major compositions of high density lipoprotein 2 were calculated. Activities of cholesterol ester transfer protein and phospholipid transfer protein was determined by enzyme fluorescence assay kits. Results (1)There were no differences in plasma high density lipoprotein cholesterol (HDLC) between T2DM group and control group (p＝0.579). (2)There were no significant differences in either cholesterol ester transfer protein or phospholipid transfer protein activity between T2DM group and control group (p>0.5). (3)The following particle components of high density lipoprotein 3 (HDL₃) in T2DM group were decreased significantly than those in control group (p<0.01): HDL₃C (0.60±0.17 mmol/L vs 0.75±0.22 mmol/L), phospholipids (PL, 1.14±0.19 mmol/L vs 1.29±0.22 mmol/L), free cholesterol (FC, 0.021±0.012 mmol/L vs 0.033±0.012 mmol/L), cholesterol ester (CE, 0.97±0.28 mmol/L vs 1.19±0.36 mmol/L).All the subjects’ FC and CE from H- DL₃ were significantly and negatively correlated with the following indicators (p<0.05): postprandial blood glucose (PBG), glycosylated hemoglobin (HbA1c), home-ostasis model assessment of insulin resistance (HOMA-IR). (4)The apolipoprotein AI (Apo AI) of HDL₂ in T2DM group was significantly decreased than those in control group (604.8±233.3 mg/L vs 755.4±198.0 mg/L, p<0.05), and the Apo AI of HDL₂ in all subjects was significantly and negatively correlated with PBG, HOMA-IR and plasma triglycerides (TG) (p<0.05). ConclusionsThe major components of HDL₃ and HDL₂ were decreased significantly in T2DM group than that in control group. We speculate that the size of HDL₃ and HDL₂ particle shrinks and might relate to hyperglycemia and insulin resistance.