title: Leptin levels among prepubertal children with Down syndrome compared with their siblings.
abstract: OBJECTIVE
  To compare levels of leptin and other obesity-related hormones in prepubertal children with Down syndrome (DS), a population at high obesity risk, and those in unaffected siblings to better understand the pathophysiology of obesity in children with DS.
  
  
  METHODS
  This was a cross-sectional study of 35 children with DS and 33 control siblings, ages 4 to 10 years, with a fasting blood sample and anthropometric measurements to estimate body composition. Generalized estimating equations were used to account for the lack of independence between siblings.
  
  
  RESULTS
  In addition to having higher body mass index and percent body fat, children with DS had higher leptin levels than unaffected siblings, even after adjustment for age, sex, race, and ethnicity (difference, 5.8 ng/mL; 95% CI, 2.4-9.3; P = .001) and further adjustment for percent body fat (difference, 2.7 ng/mL; 95% CI, 0.08-5.40, P = .04). Leptin and percent body fat were positively associated in both groups (P < .0001), but with a significantly greater positive association in the DS group, suggesting a significant effect modification (P < .0001).
  
  
  CONCLUSIONS
  This group of children with DS had increased leptin levels for percent body fat than their unaffected siblings. This difference may contribute to the increased risk for obesity in children with DS.
authors.affiliation: Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.
authors.forename: Sheela N
authors.initials: SN
authors.lastname: Magge
authors.forename: Kristen L
authors.initials: KL
authors.lastname: O'Neill
authors.forename: Justine
authors.initials: J
authors.lastname: Shults
authors.forename: Virginia A
authors.initials: VA
authors.lastname: Stallings
authors.forename: Nicolas
authors.initials: N
authors.lastname: Stettler
mesh_terms: D015415:Biomarkers / Q000097:blood; D050218:Body Fat Distribution; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D020738:Leptin / Q000097:blood* / Q000378:metabolism; D008297:Male; D009765:Obesity / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D011336:Probability; D011446:Prospective Studies; D012016:Reference Values; D018570:Risk Assessment; D035781:Siblings
chemical_list: D015415:Biomarkers; D020738:Leptin