Background: It has been suggested that bariatric operations can control diabetes irrespective of weight loss. Change in glucose metabolism is credited to duodenal bypass and consequent variation in digestive hormones levels. This study aims to evaluate the effect of duodenal bypass on glucose levels in lean individuals submitted to gastrectomy for gastric cancer.
Methods: We reviewed 56 patients (36 males, mean age 61 years) submitted to gastrectomy and Roux-en-Y reconstruction for gastric cancer between January, 2000 to July, 2006. Partial gastrectomy was the operative approach in 37 (66%) patients and total gastrectomy in 19 (34%). Patients were excluded if obese (BMI>30), diabetic, submitted to palliative surgery, or with a follow-up lower than 1 month. Six patients with the diagnosis of diabetes mellitus were studied separately (2 treated with insulin, 4 with oral medication). Glucose levels were measured the day before operation in all patients but did not follow specific clinical protocols after the operation.
Results: Glucose levels were not significantly altered after operation, p=0.5 (table 1). There was no correlations between glucose level and time of follow-up for the whole population (r=0.0002), partial gastrectomy (r=0.0001) or total gastrectomy (r=0.0042) (figure 1). Diabetes control was improved in 1 patient with oral medication (decrease in dosage).
Conclusion: Duodenal bypass in lean individuals treated for gastric cancer do not decrease glucose levels.

Time (months)	0	1-6	7-12	13-18	19-24	24-36	37-48	>48
Glucose Level mg/dL(median)	99	94	94	90	93	96	91	102