['Prebeta1-HDL is a minor HDL subfraction that is an initial acceptor of cellular free cholesterol. Prebeta1-HDL is elevated in hypertriglyceridemia, which is exaggerated with postprandial hyperglycemia. We investigated whether the prebeta1-HDL concentration changes postprandially in type 2 diabetic patients and blood glucose (BG) control reduces this change.', 'We examined 9 healthy controls and 20 diabetic patients with poor BG control. Seven blood samples (30 min before and 2 h after each meal, and at midnight) were obtained daily in the poor (poor-GC: n=20) and improved (imp-GC: n=11) glycemic control phases of diabetic patients after intensive insulin therapy and a low-calorie diet.', 'The prebeta1-HDL concentration did not change postprandially in the controls. However, the fasting prebeta1-HDL concentration in the poor-GC phase was 28.3% higher than in the controls (25.4+/-6.8 vs 19.8+/-6.9 mg/l ApoAI, p<0.05) and decreased markedly after breakfast (20.9+/-7.7 mg/l ApoAI, p<0.01). In the imp-GC phase, the prebeta1-HDL concentration showed no morning surge, as in the controls.'] Is prebeta1-HDL elevated in the fasting state , but markedly reduced postprandially in poorly controlled type 2 diabetic patients?