Résumé
In type 2 diabetes the effects of short-term calorie restrictions on glycaemia are usually judged on fasting plasma glucose. As fasting duration rarely exceeds 2-3 h, we determined the effects of calorie restriction over different daytime periods using a continuous glucose monitoring system (CGMS) in noninsulin-using patients with type 2 diabetes.
Fourteen poorly controlled (mean HbA1c = 9.3%) overweight or obese patients (mean body mass index = 30.1 +/- 0.7 kg m(-2)) with type 2 diabetes were investigated twice with a CGMS, at baseline and at the end of a 18-day calorie-restricted diet (1490 kcal day(-1)). Areas under curves (AUCs) of 24-h glucose monitoring were measured and divided into postprandial and interprandial AUCs according to meal times.
Areas under curves of 24-h glucose monitoring were significantly decreased after dieting: -37%, P = 0.0047. Both post and interprandial AUCs were significantly diminished (-26%, P = 0.0186 and -48%, P = 0.0037, respectively), but changes in interprandial AUCs were more marked than changes in postprandial AUCs (P = 0.0060). Nycthemeral peaks of glucose were observed at mid-morning times and were not significantly different before (242 +/- 15 mg dL(-1)) and after dieting (227 +/- 16 mg dL(-1)).
Short-term calorie restriction in overweight or obese patients with type 2 diabetes resulted in dichotomous responses between interprandial and postprandial glycaemic excursions. The resistance of mid-morning glucose peaking to calorie restriction should result in additional dietary or pharmacological measures at breakfast.