title: The relation between acute changes in the systemic inflammatory response and plasma 25-hydroxyvitamin D concentrations after elective knee arthroplasty.
abstract: BACKGROUND
  Studies indicate that low plasma 25-hydroxyvitamin D [25(OH)D] is associated with a range of disease processes, many of which are inflammatory. However, other lipid-soluble vitamins decrease during the systemic inflammatory response, and this response may confound the interpretation of plasma 25(OH)D.
  
  
  OBJECTIVE
  The objective was to examine whether plasma 25(OH)D concentrations change during evolution of the systemic inflammatory response.
  
  
  METHODS
  Patients (n = 33) who underwent primary knee arthroplasty had venous blood samples collected preoperatively and postoperatively (beginning 6-12 h after surgery and on each morning for 5 d) for the measurement of 25(OH) D, vitamin D-binding protein, parathyroid hormone (PTH), calcium, C-reactive protein, and albumin. A final sample was collected at 3 mo.
  
  
  RESULTS
  Preoperatively, most patients were 25(OH)D deficient (<50 nmol/L) and had secondary hyperparathyroidism (PTH > 5 pmol/L). Age, sex, body mass index, season, medical history, and medication use were not associated with significant differences in preoperative plasma 25(OH)D concentrations. By day 2 there was a large increase in C-reactive protein concentrations (P < 0.001) and a significant decrease in 25(OH)D of ≈40% (P < 0.001). C-reactive protein, 25(OH)D, and calculated free 25(OH)D had not returned to preoperative concentrations by 5 d postoperatively (all P < 0.001). At 3 mo, 25(OH)D and free 25(OH)D remained significantly lower (20% and 30%, respectively; P < 0.01).
  
  
  CONCLUSIONS
  Plasma concentrations of 25(OH)D decrease after an inflammatory insult and therefore are unlikely to be a reliable measure of 25(OH)D status in subjects with evidence of a significant systemic inflammatory response.
authors.affiliation: Department of Anaesthesia, Faculty of Medicine, University of Glasgow, Royal Infirmary, Glasgow, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Reid
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Toole
authors.forename: Susan
authors.initials: S
authors.lastname: Knox
authors.forename: Dinesh
authors.initials: D
authors.lastname: Talwar
authors.forename: Johann
authors.initials: J
authors.lastname: Harten
authors.forename: Denis St J
authors.initials: DS
authors.lastname: O'Reilly
authors.forename: Scott
authors.initials: S
authors.lastname: Blackwell
authors.forename: John
authors.initials: J
authors.lastname: Kinsella
authors.forename: Donald C
authors.initials: DC
authors.lastname: McMillan
authors.forename: A Michael
authors.initials: AM
authors.lastname: Wallace
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood*; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D002097:C-Reactive Protein / Q000032:analysis; D002112:Calcifediol / Q000097:blood*; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000150:complications; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D010003:Osteoarthritis / Q000097:blood* / Q000150:complications / Q000276:immunology / Q000628:therapy*; D018709:Statistics, Nonparametric; D018746:Systemic Inflammatory Response Syndrome; D013997:Time Factors; D014808:Vitamin D Deficiency / Q000150:complications; D014809:Vitamin D-Binding Protein / Q000097:blood
chemical_list: D014809:Vitamin D-Binding Protein; D015652:25-Hydroxyvitamin D 2; D002097:C-Reactive Protein; D002112:Calcifediol