title: Thiamine Levels During Intensive Insulin Therapy in Critically Ill Patients.
abstract: BACKGROUND
  Thiamine is an essential cofactor in carbohydrate metabolism, and deficiency can therefore cause various organ dysfunctions. Little is known about the prevalence and possible worsening of thiamine deficiency in critically ill patients. In this study, we investigated the prevalence of thiamine deficiency at admission to the intensive care unit (ICU) and hypothesized that intensive insulin therapy, aimed at regulating glucose levels, increases thiamine utilization and therefore might cause or worsen deficiency in patients with limited thiamine stores.
  
  
  METHODS
  An observational prospective cohort study was carried out in a medical-surgical ICU in a general teaching hospital in Apeldoorn, the Netherlands. All adults who were treated during that time with intensive insulin therapy were included. Deficiency was defined as a thiamine level <100 nmol/L. No thiamine supplementation was administered except for normal amounts present in standard enteral feeding.
  
  
  RESULTS
  A total of 58 patients were available for analysis. Median thiamine level at admission was 111 nmol/L. Deficiency was present in 39.7% of patients and was significantly associated with the presence of gastrointestinal pathology and with recent surgery. Thiamine levels increased a median of 14 nmol/L in 48 hours. Only 3.4% of patients showed a predefined relevant decline in thiamine levels.
  
  
  CONCLUSIONS
  Intensive insulin therapy does not appear to cause or worsen thiamine deficiency. However, based on the high prevalence of deficiency at admission, it might be warranted to supplement thiamine in all patients admitted to the ICU, especially when there is an underlying gastrointestinal disease or recent surgery.
authors.affiliation: 1 Department of Intensive Care, Gelre Hospitals, Apeldoorn, the Netherlands.
authors.forename: Wouter
authors.initials: W
authors.lastname: van Snippenburg
authors.affiliation: 2 Department of Dietetics, Gelre Hospitals, Apeldoorn, the Netherlands.
authors.forename: Mariet G J
authors.initials: MGJ
authors.lastname: Reijnders
authors.affiliation: 1 Department of Intensive Care, Gelre Hospitals, Apeldoorn, the Netherlands.
authors.forename: Jose G M
authors.initials: JGM
authors.lastname: Hofhuis
authors.affiliation: 3 Department of Clinical Epidemiology and Biostatistics, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Rien
authors.initials: R
authors.lastname: de Vos
authors.affiliation: 4 Department of Clinical Chemistry and Hematology, Gelre Hospitals, Apeldoorn, the Netherlands.
authors.forename: Stephan
authors.initials: S
authors.lastname: Kamphuis
authors.affiliation: 1 Department of Intensive Care, Gelre Hospitals, Apeldoorn, the Netherlands.
authors.forename: Peter E
authors.initials: PE
authors.lastname: Spronk
mesh_terms: D000368:Aged; D003422:Critical Care / Q000379:methods*; D016638:Critical Illness / Q000628:therapy; D005260:Female; D006760:Hospitalization; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000009:adverse effects*; D007328:Insulin / Q000008:administration & dosage / Q000009:adverse effects*; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D011446:Prospective Studies; D013831:Thiamine / Q000097:blood*; D013832:Thiamine Deficiency / Q000139:chemically induced*
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin; D013831:Thiamine
keywords: ICU; critically ill; intensive insulin therapy; thiamine deficiency