title: Menarche in pediatric patients with Crohn's disease.
abstract: OBJECTIVE
  The timing of menarche in Crohn's disease (CD) is poorly described. Our objectives were to study age at menarche onset in CD, and factors associated with this.
  
  
  METHODS
  We compared the age at menarche of 34 CD patients with that for 545 controls, using data in the National Health and Nutrition Examination Survey (NHANES).
  
  
  RESULTS
  Mean chronological age (CA) of CD patients (15.6 years) did not differ from that of the NHANES cohort (15.7 years; P = 0.91). The median CA at menarche (13.9 years) in CD was older than in the NHANES sample (12.0 years) (P < 0.00005). In CD patients, the cumulative incidence of menarche was 10 % at CA 12 years, 51 % at CA 14 years, and 100 % at CA 16 years. Sixty-eight percent reached menarche by bone age (BA) 13.5 years and 100 % by BA greater than 14.0 years. Menarche occurred earliest in South Asians, followed by East Asians, and then Caucasians (P = 0.02).
  
  
  CONCLUSIONS
  CA at menarche is delayed in CD compared with the NHANES cohort. BA at menarche in CD is similar to BA at menarche reported for healthy children. CA at menarche in CD differs by race. If menarche has not occurred by BA greater than 14.0 years, endocrinology referral should be considered.
authors: Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of California, San Francisco, 500 Parnassus Avenue, MU-407 East, Box 0136, San Francisco, CA 94143, USA. ng719@yahoo.com
authors: Neera
authors: N
authors: Gupta
authors: Robert H
authors: RH
authors: Lustig
authors: Michael A
authors: MA
authors: Kohn
authors: Eric
authors: E
authors: Vittinghoff
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D000886:Anthropometry; D016022:Case-Control Studies; D002648:Child; D003424:Crohn Disease / Q000503:physiopathology*; D005260:Female; D006801:Humans; D015994:Incidence; D008572:Menarche; D009749:Nutrition Surveys; D014481:United States