title: Leptin and Leptin-to-Adiponectin Ratio Predict Adiposity Gain in Nonobese Children over a Six-Year Period.
abstract: BACKGROUND
  Previous longitudinal studies have shown inconsistent results regarding the influence of adipokines on changes in weight and body fat. We aimed to determine the predictive value of serum leptin, adiponectin, and their ratio on subsequent changes in obesity measures in children.
  
  
  METHODS
  Two hundred forty-six obese and 532 nonobese children aged 6-11 years were remeasured for BMI and waist circumference after 6.4 ± 0.2 years. Z-score of BMI was used to standardize for age and sex. Obesity was defined using the international BMI cutoffs. Waist-to-height ratio (WHtR) was calculated to define central obesity using a boundary value of 0.5. Fasting serum leptin and adiponectin levels were measured at baseline.
  
  
  RESULTS
  Newly identified obese children had significantly higher levels of leptin and leptin-to-adiponectin ratio than nonobese children. There were lower adiponectin levels in boys with persistent obesity versus those with transient obesity. After adjusting for age, Tanner stage, and corresponding adiposity measures at baseline, leptin levels and leptin-to-adiponectin ratio were positively associated with BMI Z-score gain in girls and WHtR gain in boys. An inverse association between leptin and BMI Z-score gain was detected in boys. Stratified analyses revealed significant associations only in the nonobese and prepubertal group. There were no significant associations between adiponectin and changes in obesity measures.
  
  
  CONCLUSIONS
  High leptin levels and leptin-to-adiponectin ratio are sex-specific predictors of obesity measures gain in nonobese and prepubertal children. Body composition measurement is necessary to assess fat mass growth and distribution during childhood and adolescence.
authors.affiliation: 1 Department of Epidemiology, Capital Institute of Paediatrics , Beijing, P.R. China .
authors.forename: Meixian
authors.initials: M
authors.lastname: Zhang
authors.affiliation: 1 Department of Epidemiology, Capital Institute of Paediatrics , Beijing, P.R. China .
authors.forename: Hong
authors.initials: H
authors.lastname: Cheng
authors.affiliation: 1 Department of Epidemiology, Capital Institute of Paediatrics , Beijing, P.R. China .
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Zhao
authors.affiliation: 1 Department of Epidemiology, Capital Institute of Paediatrics , Beijing, P.R. China .
authors.forename: Dongqing
authors.initials: D
authors.lastname: Hou
authors.affiliation: 1 Department of Epidemiology, Capital Institute of Paediatrics , Beijing, P.R. China .
authors.forename: Yinkun
authors.initials: Y
authors.lastname: Yan
authors.affiliation: 2 Centre de Recherche de l'Institut Universitaire de Cardiologie & Pneumologie de Québec (CRIUCPQ), Université Laval , Québec, Canada .
authors.forename: Katherine
authors.initials: K
authors.lastname: Cianflone
authors.affiliation: 3 Key Laboratory of Endocrinology, Department of Endocrinology, Ministry of Health, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College (CAMS & PUMC) , Beijing, P.R. China .
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: 1 Department of Epidemiology, Capital Institute of Paediatrics , Beijing, P.R. China .
authors.forename: Jie
authors.initials: J
authors.lastname: Mi
mesh_terms: D052242:Adiponectin / Q000097:blood*; D050154:Adiposity / Q000502:physiology*; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D002681:China; D005215:Fasting; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood*; D008297:Male; D063766:Pediatric Obesity / Q000097:blood / Q000175:diagnosis; D011446:Prospective Studies; D012737:Sex Factors; D055105:Waist Circumference; D015430:Weight Gain / Q000502:physiology*
chemical_list: C499918:ADIPOQ protein, human; D052242:Adiponectin; D020738:Leptin
keywords: adiposity gain; childhood; leptin; obesity; prediction; prospective study