Background: Nutritional deficiencies are a recognized complication of bariatric surgery. Thiamine deficiency has been reported as a possible consequence of both restrictive and malabsorptive bariatric procedures. Most of the reported cases occurred after Roux-en-Y gastric bypass (RYGB) surgery; fewer were described after biliopancreatic diversion, vertical banded gastroplasty, or duodenal switch. Adults who have a high carbohydrate intake derived mainly from refined sugars and milled rice are at greater risk of developing thiamine deficiency, because thiamine is absent from fats, oils, and refined sugars. Currently, no reports have evaluated the preoperative thiamine status of bariatric patients. The aim of this study was to evaluate the degree of thiamine deficiency in obese patients before bariatric surgery at our institution.
Methods: The medical records of consecutive patients who underwent laparoscopic RYGB or laparoscopic adjustable gastric banding at our institution between March 2003 and February 2004 were retrospectively reviewed. Patients were selected for this study on the basis of predetermined criteria. Preoperative thiamine levels were retrospectively recorded. Excluded from this study were patients who had been taking multivitamins or other nutritional supplements before surgical intervention, had a history of frequent alcohol consumption, any malabsorptive diseases, or previous restrictive-malabsorptive surgical interventions, such as RYGB, biliopancreatic diversion, or adjustable gastric banding, according to the initial evaluation and questionnaire.
Results: Of 437 consecutive patients who underwent laparoscopic RYGB or laparoscopic adjustable gastric banding, 303 were included in the study. Forty-seven patients (15.5%) presented with low preoperative thiamine levels. The mean age and body mass index of these patients was 46 years and 60 kg/m(2), respectively. Male patients presented with greater mean preoperative thiamine levels (3.2 microg /dL) than female patients (2.4 microg/dL).
Conclusion: Obese patients undergoing bariatric surgery may have significant thiamine deficiency before surgery.