title: Introducing excess body weight in childhood and adolescence and comparison with body mass index and waist-to-height ratio.
abstract: BACKGROUND
  Weight status in children and adolescents is commonly defined using age- and gender-corrected standard deviation scores for body mass index (BMI-SDS, also called z-scores). Values are not reliable for the extremely obese however. Moreover, paediatricians and parents may have difficulties understanding z-scores, and while percentiles are easier to gauge, the very obese have values above the 99th percentile, making distinction difficult. The notion of excess body weight (EBW) is increasingly applied in adult patients, mainly in the context of bariatric surgery. However, a clear definition is not available to date for the paediatric population.
  
  
  METHODS
  A simple definition of EBW for children and adolescents is introduced, with median weight as a function of height, age and gender (characterized by an asterisk): EBW (%) = 100x(weight-median weight*)/median weight*. EBW is compared with BMI-SDS and waist-to-height ratio (WHtR). Using two data sources (APV registry and German Health Interview and Examination Survey for Children and Adolescents (KiGGS)) including more than 14,000 children, the relationships between these anthropometric and various metabolic parameters are analysed for a group of overweight/obese children who have sought obesity therapy (APV), for the general paediatric population and for the subset of overweight/obese children from the general population (KiGGS).
  
  
  RESULTS
  The three anthropometric parameters are strongly correlated, with the linear correlation coefficients exceeding 0.8 in the general population and 0.75 in those seeking obesity therapy. Moreover, their relationship to metabolic parameters is quite similar regarding correlations and area under the curve from receiver operating characteristic analyses.
  
  
  CONCLUSIONS
  EBW has similar predictive value for metabolic or cardiovascular comorbidities compared with BMI and WHtR. As it is reliable at the extreme end of the obesity spectrum, easily communicable and simple to use in daily practice, it would make a very useful addition to existing tools for working with obese children and adolescents. Its usefulness in assessing weight change needs to be studied however.
authors.affiliation: 1] Clinical Trial Centre Leipzig, University of Leipzig, Leipzig, Germany [2] Leipzig University Medical Center, IFB Adiposity Diseases, Leipzig, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Petroff
authors.affiliation: Institute of Human Genetics, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Kromeyer-Hauschild
authors.affiliation: Department of Pediatric Endocrinology and Diabetology, Charité Universitätsmedizin, Berlin, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Wiegand
authors.affiliation: Children's Hospital of Eastern Switzerland, St Gallen, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: l'Allemand-Jander
authors.affiliation: Pediatric Endocrinology and Diabetology, University Children's Hospital, University of Tuebingen, Tuebingen, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Binder
authors.affiliation: Pediatric Endocrinology and Diabetology, Centre for Child and Adolescent Health, University of Freiburg, Freiburg, Germany.
authors.forename: K-O
authors.initials: KO
authors.lastname: Schwab
authors.affiliation: Clinic for Rehabilitation of Children and Adolescents, Sylt, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Stachow
authors.affiliation: Department of Women and Child Health, University Hospital of Leipzig, Leipzig, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Kiess
authors.affiliation: Children's Hospital Wilhelmsstift, Hamburg, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Hammer
authors.affiliation: SANA Hospital Lichtenberg, Berlin, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Sturm
authors.affiliation: Institute of Epidemiology and Medical Biometry, University of Ulm, Ulm, Germany.
authors.forename: R W
authors.initials: RW
authors.lastname: Holl
authors.affiliation: Leipzig University Medical Center, IFB Adiposity Diseases, Leipzig, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Blüher
mesh_terms: D000293:Adolescent; D001827:Body Height; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D005858:Germany; D006305:Health Status Indicators; D006801:Humans; D007223:Infant; D008297:Male; D063766:Pediatric Obesity / Q000175:diagnosis*; D017410:Practice Guidelines as Topic; D012372:ROC Curve; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D049629:Waist-Hip Ratio