title: Plasma levels and adipose tissue messenger ribonucleic acid expression of retinol-binding protein 4 are reduced during calorie restriction in obese subjects but are not related to diet-induced changes in insulin sensitivity.
abstract: BACKGROUND
  Retinol-binding protein 4 (RBP4) may play a role in the development of insulin resistance.
  
  
  OBJECTIVE
  We investigated whether RBP4 adipose tissue mRNA expression and plasma level are related to insulin sensitivity during a diet-induced weight loss.
  
  
  METHODS
  Obese women followed a dietary intervention composed of a 4-wk very low-calorie diet (VLCD), a 2-month low-calorie diet, and 3-4 months of a weight maintenance (WM) phase.
  
  
  METHODS
  Clinical investigation was performed before and at the end of each phase. Insulin sensitivity was assessed with the euglycemic hyperinsulinemic clamp. Adipose tissue mRNA and plasma levels of RBP4 were determined using reverse transcription-quantitative PCR and ELISA, respectively.
  
  
  RESULTS
  Weight and fat mass decreased during VLCD and were stabilized during WM. Glucose disposal rate increased during VLCD and remained elevated thereafter. Plasma levels of RBP4 decreased after VLCD and, although increasing at subsequent phases, remained lower than prediet values. Adipose tissue mRNA levels were diminished after VLCD, and increased during low-calorie diet and WM to reach basal values. Basal RBP4 levels or diet-induced variations of RBP4 were not different in lean women and two groups of obese women with high- and low-insulin sensitivity.
  
  
  CONCLUSIONS
  Severe calorie restriction promotes a reduction in adipose tissue and plasma levels of RBP4. The study does not bring evidence for a role for RBP4 in the regulation of diet-induced changes in insulin sensitivity.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale Université Paul Sabatier U858, IFR31, BP 84225, 31432 Toulouse Cedex 4, France.
authors.forename: Michaela
authors.initials: M
authors.lastname: Vitkova
authors.forename: Eva
authors.initials: E
authors.lastname: Klimcakova
authors.forename: Michaela
authors.initials: M
authors.lastname: Kovacikova
authors.forename: Carine
authors.initials: C
authors.lastname: Valle
authors.forename: Cédric
authors.initials: C
authors.lastname: Moro
authors.forename: Jan
authors.initials: J
authors.lastname: Polak
authors.forename: Jiri
authors.initials: J
authors.lastname: Hanacek
authors.forename: Frédéric
authors.initials: F
authors.lastname: Capel
authors.forename: Nathalie
authors.initials: N
authors.lastname: Viguerie
authors.forename: Blanka
authors.initials: B
authors.lastname: Richterova
authors.forename: Magda
authors.initials: M
authors.lastname: Bajzova
authors.forename: Jindra
authors.initials: J
authors.lastname: Hejnova
authors.forename: Vladimir
authors.initials: V
authors.lastname: Stich
authors.forename: Dominique
authors.initials: D
authors.lastname: Langin
mesh_terms: D000273:Adipose Tissue / Q000502:physiology*; D000328:Adult; D031204:Caloric Restriction; D004038:Diet, Reducing; D005260:Female; D015870:Gene Expression / Q000502:physiology; D015309:Glucose Clamp Technique; D051275:Glucose Transporter Type 4 / Q000235:genetics; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy* / Q000503:physiopathology*; D012333:RNA, Messenger / Q000378:metabolism; D012177:Retinol-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D054839:Retinol-Binding Proteins, Plasma; D015431:Weight Loss / Q000502:physiology
chemical_list: D051275:Glucose Transporter Type 4; D007328:Insulin; C101326:RBP4 protein, human; D012333:RNA, Messenger; D012177:Retinol-Binding Proteins; D054839:Retinol-Binding Proteins, Plasma; C495692:SLC2A4 protein, human