title: Sex differences in statural growth impairment in Crohn's disease: role of IGF-1.
abstract: BACKGROUND
  Growth impairment in Crohn's disease (CD) is more common in males than females for unknown reasons. Since insulin-like growth factor-1 (IGF-1) is important for statural growth, we hypothesized that IGF-1 levels are lower in males with CD.
  
  
  METHODS
  Sex differences in hormone Z-scores based on chronological age (CA-Z) and bone age (BA-Z) were examined in a cross-sectional study of 82 CD patients <21 years of age (43% female).
  
  
  RESULTS
  IGF-1 CA-Z and BA-Z-scores were 0.50 units (P = 0.04) and 1.24 units (P = 0.003) lower in males. Mean bone age (12.2 years) was lower than chronological age (13.1 years) (P < 0.0001). Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and albumin did not differ by sex (P ≥ 0.08), but were associated with IGF-1 CA-Z and BA-Z-scores (P ≤ 0.02). Insulin-like growth factor binding protein-3 (IGFBP-3) CA-Z and BA-Z-scores were 0.71 units (P = 0.004) and 1.26 units (P < 0.001) lower in males. Inflammatory markers were correlated with sex hormone CA-Z and BA-Z and pituitary hormone BA-Z-scores in males (P ≤ 0.03), but not females (P ≥ 0.25). IGF-1 BA-Z-scores were positively associated with height BA-Z-scores (P = 0.03). Mean height BA-Z-scores were lower in males (P = 0.03).
  
  
  CONCLUSIONS
  Lower IGF-1 levels in males may explain sex differences in growth impairment in CD. Inflammation appears to more adversely affect hormone levels and statural growth in males. Prospective longitudinal studies are needed to further clarify the role of IGF-1 in sex differences in statural growth impairment in pediatric CD.
authors.affiliation: Department of Pediatrics, University of California, San Francisco, San Francisco, California 94143, USA. ng719@yahoo.com
authors.forename: Neera
authors.initials: N
authors.lastname: Gupta
authors.forename: Robert H
authors.initials: RH
authors.lastname: Lustig
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kohn
authors.forename: Marjorie
authors.initials: M
authors.lastname: McCracken
authors.forename: Eric
authors.initials: E
authors.lastname: Vittinghoff
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003424:Crohn Disease / Q000150:complications* / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005260:Female; D006130:Growth Disorders / Q000209:etiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D011379:Prognosis; D012727:Sex Characteristics; D055815:Young Adult
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I