Prevalence of Clinical Thiamine Deficiency in Individuals with Medically Complicated Obesity
By Alan Gaby, MD
Author: Nath A, et al
Reference: Prevalence of clinical thiamine deficiency in individuals with medically complicated obesity. Nutr Res 2017;37:29-36.
Design: Clinical and laboratory evaluation.
Participants: Four hundred consecutive obese patients (mean age, 45 years; mean body mass index, 48.8 kg/m2) who were seen at a bariatric clinic. Patients with heavy alcohol consumption and those who had had bariatric surgery were excluded.
Study Medication and Dosage: Individuals with symptoms suggestive of thiamine deficiency were offered oral (100 mg twice a day) or intramuscular (200 mg; frequency not clear) thiamine. Individuals who reported symptomatic improvement at their follow-up visit 1-2 months later continued oral (100 mg twice a day) or intramuscular (200 mg once a month) thiamine.
Primary Outcome Measure: Prevalence of clinical thiamine deficiency. Clinical thiamine deficiency was defined as the presence both of symptoms consistent with thiamine deficiency (e.g., nausea, vomiting, dysphagia, constipation, emotional lability, impaired memory, confusion, blurred vision, nystagmus, ophthalmoplegia, tachycardia, palpitations, dyspnea on exertion, lower extremity edema, weakness, numbness, or paresthesias) and by either a low whole-blood thiamine concentration or significant improvement or resolution of symptoms after thiamine supplementation.
Key Findings: Sixty-six patients (16.5%) were diagnosed with clinical thiamine deficiency. Of those 66 patients, 14% had gastrointestinal manifestations, 70% had cardiac manifestations, 59% had peripheral neurologic manifestations, and 5% had neuropsychiatric symptoms. The most commonly improved symptoms were lower extremity edema, numbness, paresthesias, and dysphagia.
Practice Implications: The results of this study suggest that obesity is a risk factor for clinical thiamine deficiency. However, these findings should be considered preliminary, in that a low whole-blood thiamine concentration does not necessarily indicate clinically important thiamine deficiency, and the improvement attributed to thiamine therapy could have been due to a placebo effect, spontaneous remission, or other concurrent treatments. Nevertheless, thiamine is relatively safe and inexpensive, so a clinical trial of thiamine or B-complex vitamins would be reasonable for obese patients experiencing symptoms that could be due to thiamine deficiency.