title: High-dose thiamine supplementation improves glucose tolerance in hyperglycemic individuals: a randomized, double-blind cross-over trial.
abstract: OBJECTIVE
  To assess the effect of high-dose oral thiamine supplements on glucose tolerance in patients with impaired glucose metabolism.
  
  
  METHODS
  Twelve hyperglycemic subjects (10 cases of impaired glucose tolerance and 2 new cases of type 2 diabetes) completed this randomized, double-blind trial, where all participants received both placebo and thiamine capsules (3 × 100 mg/day) for 6 weeks in a cross-over manner. The main endpoint was changes in 2-h plasma glucose. Fasting plasma glucose and insulin, 2-h plasma insulin, the hemostatic model assessment of insulin resistance (HOMA-IR), renal function measurement and thiamin status were also evaluated at the commencement and completion of each treatment period.
  
  
  RESULTS
  Thiamine supplementation resulted in significant decrease in 2-h plasma glucose relative to baseline (8.78 ± 2.20 vs. 9.89 ± 2.50 mmol/l, p = 0.004), with no significant change in the placebo arm. Fasting plasma glucose and insulin, and HOMA-IR increased significantly from baseline after 6 weeks in the placebo arm (p = 0.003, p = 0.04 and p = 0.02, respectively). These variables did not change with thiamine supplementation. There were no significant changes in 2-h plasma insulin or renal function marker, within or between arms.
  
  
  CONCLUSIONS
  Supplementation with high-dose thiamine may prevent deterioration in fasting glucose and insulin, and improve glucose tolerance in patients with hyperglycemia. High-dose thiamine supplementation may prevent or slow the progression of hyperglycemia toward diabetes mellitus in individuals with impaired glucose regulation.
authors.affiliation: School of Public Health, Curtin University, Kent Street, Bentley, Perth, WA, 6102, Australia, fariba.alaeishahmiri@postgrad.curtin.edu.au.
authors.forename: F
authors.initials: F
authors.lastname: Alaei Shahmiri
authors.forename: M J
authors.initials: MJ
authors.lastname: Soares
authors.forename: Y
authors.initials: Y
authors.lastname: Zhao
authors.forename: J
authors.initials: J
authors.lastname: Sherriff
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005215:Fasting; D005260:Female; D018149:Glucose Intolerance / Q000188:drug therapy*; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D013831:Thiamine / Q000008:administration & dosage*
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007328:Insulin; D013831:Thiamine