title: Decreased circulating 25-(OH) Vitamin D concentrations in obese female children and adolescents: positive associations with Retinol Binding Protein-4 and Neutrophil Gelatinase-associated Lipocalin.
abstract: OBJECTIVE
  Hypovitaminosis D has been associated with adult as well as childhood obesity. Retinol-binding-protein-4 (RBP-4) and Neutrophil Gelatinase-associated Lipocalin (NGAL) are altered in obese individuals. The aim of this study was to examine circulating 25-(OH) Vitamin D (25-(OH) D) concentrations according to BMI and its associations with RBP-4 and NGAL in female children and adolescents.
  
  
  METHODS
  Seventy-nine (79) children, aged 8-16 years, were studied and divided into four groups: 19 control (BMI z-score range -2.15 - 1.24), 20 overweight (1.34 - 2.49), 20 obese (2.50 - 2.87) and 20 ultra-obese (3 - 4.37). Patients were derived from a Pediatric Obesity Clinic. Plasma 25-(OH) D, RBP-4 and NGAL concentrations were measured with specific assays.
  
  
  RESULTS
  Plasma 25-(OH) D concentrations were decreased significantly in the ultra-obese (p=0.005) and marginally in the obese group (p=0.05) compared to the control group. In the entire BMI range, Spearman correlations revealed strong positive associations between 25-(OH) D and RBP-4 (r=0.349, p=0.002) and between 25-(OH) D and NGAL (r=0.338, p=0.003).
  
  
  CONCLUSIONS
  25-(OH) D is deficient in a clinical population of obese female children and adolescents, whereas in the entire BMI range 25-(OH) D is associated with RBP4 and NGAL concentrations. Longitudinal studies are needed to reveal the role of these associations in metabolic alterations related to childhood and adolescent obesity and associated metabolic morbidities.
authors.affiliation: Childhood Obesity Clinic, First Department of Pediatrics, University of Athens Medical School, Athens, Greece.
authors.forename: Dimitra
authors.initials: D
authors.lastname: Metheniti
authors.forename: Sophia
authors.initials: S
authors.lastname: Sakka
authors.forename: Maria
authors.initials: M
authors.lastname: Dracopoulou
authors.forename: Alexandra
authors.initials: A
authors.lastname: Margeli
authors.forename: Ioannis
authors.initials: I
authors.lastname: Papassotiriou
authors.forename: Christina
authors.initials: C
authors.lastname: Kanaka-Gantenbein
authors.forename: George P
authors.initials: GP
authors.lastname: Chrousos
authors.forename: Panagiota
authors.initials: P
authors.lastname: Pervanidou
mesh_terms: D000209:Acute-Phase Proteins; D000293:Adolescent; D002112:Calcifediol / Q000097:blood*; D002648:Child; D005260:Female; D006801:Humans; D000071068:Lipocalin-2; D054834:Lipocalins / Q000097:blood*; D009765:Obesity / Q000097:blood*; D050177:Overweight / Q000097:blood; D011518:Proto-Oncogene Proteins / Q000097:blood*; D054839:Retinol-Binding Proteins, Plasma / Q000378:metabolism*
chemical_list: D000209:Acute-Phase Proteins; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; C101326:RBP4 protein, human; D054839:Retinol-Binding Proteins, Plasma; D002112:Calcifediol