title: Proteomic analysis allows for early detection of potential markers of metabolic impairment in very young obese children.
abstract: BACKGROUND
  Early diagnosis of initial metabolic derangements in young obese children could influence their management; however, this impairment is frequently not overt, but subtle and undetectable by routinely used clinical assays. Our aim was to evaluate the ability of serum proteomic analysis to detect these incipient metabolic alterations in comparison to standard clinical methods and to identify new candidate biomarkers.
  
  
  METHODS
  A cross-sectional study of fasting serum samples from twenty-two prepubertal, Caucasian obese (OB; 9.22 ± 1.93 years; 3.43 ± 1.08 BMI-SDS) and twenty-one lean controls (C; 8.50 ± 1.98 years; -0.48 ± 0.81 BMI-SDS) and a prospective study of fasting serum samples from twenty prepubertal, Caucasian obese children (11 insulin resistant [IR]) before (4.77 ± 1.30 BMI-SDS) and after weight reduction (2.57 ± 1.29 BMI-SDS) by conservative treatment in a reference hospital (Pros-OB) was performed. Proteomic analysis (two-dimension-eletrophoresis + mass spectrometry analysis) of serum and comparative evaluation of the sensitivity of routinely used assays in the clinics to detect the observed differences in protein expression level, as well as their relationship with anthropometric features, insulin resistance indexes, lipid profile and adipokine levels were carried out.
  
  
  RESULTS
  Study of the intensity data from proteomic analysis showed a decrease of several isoforms of apolipoprotein-A1, apo-J/clusterin, vitamin D binding protein, transthyretin in OB vs. C, with some changes in these proteins being enhanced by IR and partially reversed after weight loss. Expression of low molecular weight isoforms of haptoglobin was increased in OB, enhanced in IR and again decreased after weight loss, being positively correlated with serum interleukin-6 and NAMPT/visfatin levels. After statistical correction for multiple comparisons, significance remained for a single isoform of low MW haptoglobin (OB vs. C and IR vs. non-IR) and Apo A1 (IR vs. non-IR). Assays routinely used in the clinical setting (ELISA/kinetic nephelometry), only partially confirmed the changes observed by proteomic analysis (ApoA1 and haptoglobin).
  
  
  CONCLUSIONS
  Proteomic analysis can allow for the identification of potential new candidate biomarkers as a complement to routinely used assays to detect initial changes in serum markers of inflammation and lipid metabolism impairment in young obese children.
authors.affiliation: Edison Biotechnology Institute, Ohio University, Konneker Research Laboratories, 1 Water Tower Drive, The Ridges, 45701 Athens, Ohio, USA ; Hospital Infantil Universitario Niño Jesús, Department of Endocrinology, Instituto de Investigación la Princesa, Universidad Autónoma de Madrid, Department of Pediatrics, Av. Menéndez Pelayo, 65, E-28009 Madrid, Spain ; CIBER Fisiopatología Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Gabriel Á
authors.initials: GÁ
authors.lastname: Martos-Moreno
authors.affiliation: Edison Biotechnology Institute, Ohio University, Konneker Research Laboratories, 1 Water Tower Drive, The Ridges, 45701 Athens, Ohio, USA ; Department of Biological Sciences, College of Arts and Sciences, Ohio University, Athens, Ohio, USA ; Molecular and Cellular Biology Program, Ohio University, Athens, Ohio, USA.
authors.forename: Lucila
authors.initials: L
authors.lastname: Sackmann-Sala
authors.affiliation: Hospital Infantil Universitario Niño Jesús, Department of Endocrinology, Instituto de Investigación la Princesa, Universidad Autónoma de Madrid, Department of Pediatrics, Av. Menéndez Pelayo, 65, E-28009 Madrid, Spain ; CIBER Fisiopatología Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Vicente
authors.initials: V
authors.lastname: Barrios
authors.affiliation: Edison Biotechnology Institute, Ohio University, Konneker Research Laboratories, 1 Water Tower Drive, The Ridges, 45701 Athens, Ohio, USA.
authors.forename: Darlene E
authors.initials: DE
authors.lastname: Berrymann
authors.affiliation: Edison Biotechnology Institute, Ohio University, Konneker Research Laboratories, 1 Water Tower Drive, The Ridges, 45701 Athens, Ohio, USA ; Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens, Ohio, USA.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Okada
authors.affiliation: Hospital Infantil Universitario Niño Jesús, Department of Endocrinology, Instituto de Investigación la Princesa, Universidad Autónoma de Madrid, Department of Pediatrics, Av. Menéndez Pelayo, 65, E-28009 Madrid, Spain ; CIBER Fisiopatología Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Argente
authors.affiliation: Edison Biotechnology Institute, Ohio University, Konneker Research Laboratories, 1 Water Tower Drive, The Ridges, 45701 Athens, Ohio, USA ; Molecular and Cellular Biology Program, Ohio University, Athens, Ohio, USA ; Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens, Ohio, USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Kopchick
keywords: Childhood obesity; Insulin resistance; Proteomic; Two dimension electrophoresis