Suppression of nocturnal fatty acid concentrations by bedtime carbohydratesupplement in type 2 diabetes: effects on insulin sensitivity, lipids, andglycemic control

Background: Bedtime ingestion of slow-release carbohydrates leads to sustai ned nocturnal fatty acid suppression and improved glucose tolerance in type 2 diabetic patients. Objective: This study assessed the effects of 2 different doses of bedtime carbohydrate supplement (BCS) on morning glycemic control and glycated hemo globin (Hb A(1c)) in type 2 diabetic patients. In addition, the effects of the high-dose BCS on insulin sensitivity and postprandial glucose and triac ylglycerol concentrations were assessed. Design: Two BCS doses were studied separately in 7-wk randomized, placebo-c ontrolled, double-blind studies with either a parallel (low-dose BCS; n = 2 4 patients) or crossover (high-dose BCS; n = 14 patients) design. The effec ts of the low and high doses (0.30 and 0.55 g uncooked cornstarch/kg body w t, respectively) were compared with those of a starch-free placebo. Results: Compared with the starch-free placebo, the high-dose BCS (approxim ate to 45 g) produced enhanced nocturnal glucose (P < 0.01) and insulin (P < 0.01) concentrations as well as a 32% suppression of fatty acid concentra tions (P < 0.01). Moreover, glucose tolerance (P < 0.05) and C-peptide resp onse (P < 0.05) improved after breakfast the next morning. The low-dose BCS (approximate to 25 g) improved fasting blood glucose concentrations (P < 0 .05). However, there were no improvements in insulin sensitivity, post pran dial triacylglycerol concentrations, or Hb A(1c) after 7 wk. Conclusion: Nocturnal fatty acid suppression by BCS improved fasting and po stprandial blood glucose concentrations in type 2 diabetic patients the nex t morning. In contrast, no improvements in insulin sensitivity, postprandia l triacylglycerol concentrations, or long-term glycemic control assessed by Hb A(1c) were seen after BCS supplementation.