title: Predicting refeeding hypophosphataemia: insulin growth factor 1 (IGF-1) as a diagnostic biochemical marker for clinical practice.
abstract: BACKGROUND
  Refeeding syndrome (RS) is a potentially fatal condition that can occur following the re-introduction of nutrition after a period of starvation. Hypophosphataemia following the reintroduction of nutrition is often the only reliable biochemical marker of RS. Refeeding index (RI) generated from baseline insulin-like growth factor-1 (IGF-1) and leptin has been proposed as a useful biochemical marker for the identification of patients at risk of developing refeeding hypophosphataemia (RH).
  
  
  METHODS
  A prospective study included 52 patients referred for parenteral nutrition (PN). The sensitivity and specificity of IGF-1 measured using a sensitive assay was compared to the RI in predicting the development of RH (a ≥ 30% drop in PO4 during the first 36-h of PN administration). Leptin and IGF-1 were analysed on baseline samples using a quantitative enzyme-linked immunoassay. Daily blood samples were collected from all patients for routine biochemistry for the full duration of PN administration.
  
  
  RESULTS
  High sensitivity IGF-1 measurement alone was comparable with the RI, using receiver-operating characteristic (ROC) curve analysis, with areas under the curve being 0.79 and 0.80, respectively, and superior to leptin alone (0.72) for predicting ≥ 30% drop in PO4. The cut-off value for IGF-1 that gave best sensitivity (91% [95% CI 75-98%]) and specificity (65% [95% CI 41-85%]) was 63.7 µg/L, with a likelihood ratio of 2.59.
  
  
  CONCLUSIONS
  Baseline IGF-1 is an objective, sensitive and specific biochemical marker in identifying patients who are at high risk of developing RH prior to PN administration and therefore may have a role in clinical practice.
authors.affiliation: Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, Denmark Hill, London, UK atul.goyale@nhs.net.
authors.forename: Atul
authors.initials: A
authors.lastname: Goyale
authors.affiliation: Department of Nutrition and Dietetics, King's College Hospital NHS Foundation Trust, Denmark Hill, London, UK.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Ashley
authors.affiliation: Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, Denmark Hill, London, UK.
authors.forename: David R
authors.initials: DR
authors.lastname: Taylor
authors.affiliation: Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, Denmark Hill, London, UK.
authors.forename: Manal O
authors.initials: MO
authors.lastname: Elnenaei
authors.affiliation: Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, Denmark Hill, London, UK.
authors.forename: Jamshid
authors.initials: J
authors.lastname: Alaghband-Zadeh
authors.affiliation: Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, Denmark Hill, London, UK.
authors.forename: Roy A
authors.initials: RA
authors.lastname: Sherwood
authors.affiliation: Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, Denmark Hill, London, UK Experimental Pathology, UCD Conway Institute, School of Medicine and Medical Science, University College Dublin, Ireland.
authors.forename: Carel W
authors.initials: CW
authors.lastname: le Roux
authors.affiliation: Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, Denmark Hill, London, UK.
authors.forename: Royce P
authors.initials: RP
authors.lastname: Vincent
mesh_terms: D000328:Adult; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D017674:Hypophosphatemia / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D020738:Leptin / Q000097:blood*; D008297:Male; D044342:Malnutrition / Q000503:physiopathology / Q000628:therapy*; D008875:Middle Aged; D010288:Parenteral Nutrition; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D055677:Refeeding Syndrome / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology
chemical_list: D015415:Biomarkers; C583557:IGF1 protein, human; D020738:Leptin; D007334:Insulin-Like Growth Factor I
keywords: Refeeding syndrome; insulin-like growth factor-1; leptin; refeeding hypophosphataemia