title: The relationship between plasma and red cell concentrations of vitamins thiamine diphosphate, flavin adenine dinucleotide and pyridoxal 5-phosphate following elective knee arthroplasty.
abstract: OBJECTIVE
  Water soluble vitamins B1, B2 and B6 are essential precursors for a wide variety of coenzymes involved in intermediary metabolism and their status is usually assessed from blood samples. The aim of the study was to examine the relationship between plasma and intra-cellular B-vitamins following the systemic inflammatory response of surgery.
  
  
  METHODS
  Patients (n = 10) who underwent an elective knee arthroplasty, had venous blood samples withdrawn pre-operatively and at 12, 24, 48, 72 and 168 h after the start of surgery for the analysis of circulating concentrations of C-reactive protein and albumin and also plasma and/ or red cell thiamine diphosphate (TDP), flavin adenine dinucleotide (FAD), pyridoxal 5-phosphate (PLP) as indicators of vitamins B1, B2, and B6 status respectively.
  
  
  RESULTS
  Pre-operative, baseline vitamin assessments were all within population reference ranges. Over the study period of 0-168 h there was a significant increase in circulating C-reactive protein concentrations (peak 48 h, P < 0.001) and a significant fall in albumin concentrations (trough 48 h, P < 0.001). Plasma FAD and PLP concentrations fell transiently (P < 0.001) by approximately 40% reaching their nadir at approximately 48 h.
  
  
  CONCLUSIONS
  The results of the present study indicate that plasma concentrations of FAD and PLP are transiently reduced following an inflammatory insult and therefore unlikely to be a reliable measure of status in the presence of a systemic inflammatory response. It may be that during such a response red cell concentrations provide a more reliable measure.
authors.affiliation: Department of Orthopaedics, Royal Infirmary, Glasgow G31 2ER, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Gray
authors.forename: Donald C
authors.initials: DC
authors.lastname: McMillan
authors.forename: Chris
authors.initials: C
authors.lastname: Wilson
authors.forename: Cathy
authors.initials: C
authors.lastname: Williamson
authors.forename: Denis St J
authors.initials: DS
authors.lastname: O'Reilly
authors.forename: Dinesh
authors.initials: D
authors.lastname: Talwar
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D002097:C-Reactive Protein / Q000032:analysis; D004912:Erythrocytes / Q000737:chemistry*; D005260:Female; D005182:Flavin-Adenine Dinucleotide / Q000097:blood* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D011183:Postoperative Complications / Q000097:blood; D011732:Pyridoxal Phosphate / Q000097:blood* / Q000378:metabolism; D012256:Riboflavin; D012709:Serum Albumin / Q000032:analysis; D018746:Systemic Inflammatory Response Syndrome / Q000097:blood; D013831:Thiamine; D013835:Thiamine Pyrophosphate / Q000097:blood* / Q000378:metabolism; D025101:Vitamin B 6
chemical_list: D015415:Biomarkers; D012709:Serum Albumin; D005182:Flavin-Adenine Dinucleotide; D011732:Pyridoxal Phosphate; D025101:Vitamin B 6; D002097:C-Reactive Protein; D013835:Thiamine Pyrophosphate; D012256:Riboflavin; D013831:Thiamine