Bariatric Surgery Reduces Oxidative Stress by Blunting 24-h Acute Glucose Fluctuations in Type 2 Diabetic Obese Patients

OBJECTIVE: We evaluated the efficacy of malabsorptive bariatric surgery on daily blood glucose fluctuations and oxidative stress in type 2 diabetic obese patients. RESEARCH DESIGN AND METHODS: The 48-h continuous subcutaneous glucose monitoring was assessed in type 2 diabetic patients before and 1 month after biliopancreatic diversion (BPD) (n = 36), or after diet-induced equivalent weight loss (n = 20). The mean amplitude of glycemic excursions and oxidative stress (nitrotyrosine) were evaluated during continuous subcutaneous glucose monitoring. During a standardized meal, glucagon-like peptide (GLP)-1, glucagon, and insulin were measured. RESULTS: Fasting and postprandial glucose decreased equally in surgical and diet groups. A marked increase in GLP-1 occurred during the interprandial period in surgical patients toward the diet group (P < 0.01). Glucagon was more suppressed during the interprandial period in surgical patients compared with the diet group (P < 0.01). Mean amplitude of glycemic excursions and nitrotyrosine levels decreased more after BPD than after diet (P < 0.01). CONCLUSIONS: Oxidative stress reduction after biliopancreatic diversion seems to be related to the regulation of glucose fluctuations resulting from intestinal bypass.