Subtype Presentation and Prevalence of Subclinical Thiamine Deficiency in Morbidly Obese Individuals Seeking Bariatric Surgery

Abstract

Introduction: In the past 20 years, the prevalence of obesity has risen to 35% of adults in the US. Preoperative biochemical studies have reported a 6%-29% prevalence of low whole blood thiamine levels in the morbidly obese. In our prior study of individuals seen for GI consultation after gastric bypass surgery, 18% had thiamine deficiency, and 41% of deficient individuals had gastrointestinal manifestations. The hypothesis of this study is that symptoms of subclinical thiamine deficiency are common in morbidly obese individuals seeking bariatric surgery. Methods: This is a retrospective evaluation of morbidly obese individuals with no history of prior bariatric surgery who underwent preoperative GI consultation in a large, urban community teaching hospital from 2013 to 2014. Men with 15 or more drinks (1 drink = 14 g of alcohol) weekly or women with 8 or more drinks weekly were excluded. Patient charts were reviewed to record the symptoms of thiamine deficiencies including gastrointestinal (abdominal pain, nausea/emesis, or constipation), cardiologic (dyspnea on exertion, palpitations, or lower extremity edema), neurologic (blurred vision, nystagmus, ataxia, or paresthesias), or psychiatric (aggressive behavior or psychosis). Patient demographics were also recorded. Thiamine deficiency is defined by consistent clinical symptoms and either: A. a low whole blood thiamine level or B. resolution of an individual's clinical symptoms after receiving oral or intramuscular thiamine. Results: Among the 138 individuals, the mean age was 46 years (range: 18 to 75 years). The mean body mass index was 47.9 kg/m2 (range: 35 to 102); 84% were women and 16% were men. At evaluation, 11% of these individuals were taking a multivitamin supplement. Twenty-three out of 138 individuals (16.7%) fulfilled the dual criteria for thiamine deficiency: 6 patients (26%) had consistent GI symptoms, 17 patients (73%) had cardiac manifestations, 14 patients (61%) had neurological manifestations, and 1 patient (4%) had a psychiatric manifestation. Conclusion: Symptoms of subclinical thiamine deficiency are common in morbidly obese individuals seen for bariatric surgery. The results of this study support prior preoperative biochemical studies of thiamine deficiency in the morbidly obese. Dietary intake may be both an origin for obesity as well as an origin for thiamine deficiency. GI physicians should consider thiamine deficiency when evaluating morbidly obese patients who have consistent gastrointestinal symptoms.