Bone metabolism in adolescent boys with anorexia nervosa

J Clin Endocrinol Metab. 2008 Aug;93(8):3029-36. doi: 10.1210/jc.2008-0170. Epub 2008 Jun 10.


Background: Anorexia nervosa (AN) is a condition of severe undernutrition associated with low bone mineral density (BMD) in adolescent females with this disorder. Although primarily a disease in females, AN is increasingly being recognized in males. However, there are few or no data regarding BMD, bone turnover markers or their predictors in adolescent AN boys.

Hypotheses: We hypothesized that BMD would be low in adolescent boys with AN compared with controls associated with a decrease in bone turnover markers, and that the gonadal steroids, testosterone and estradiol, and levels of IGF-I and the appetite regulatory hormones leptin, ghrelin, and peptide YY would predict BMD and bone turnover markers.

Methods: We assessed BMD using dual-energy x-ray absorptiometry and measured fasting testosterone, estradiol, IGF-I, leptin, ghrelin, and peptide YY and a bone formation (aminoterminal propeptide of type 1 procollagen) and bone resorption (N-telopeptide of type 1 collagen) marker in 17 AN boys and 17 controls 12-19 yr old.

Results: Boys with AN had lower BMD and corresponding Z-scores at the spine, hip, femoral neck, trochanter, intertrochanteric region, and whole body, compared with controls. Height-adjusted measures (lumbar bone mineral apparent density and whole body bone mineral content/height) were also lower. Bone formation and resorption markers were reduced in AN, indicating decreased bone turnover. Testosterone and lean mass predicted BMD. IGF-I was an important predictor of bone turnover markers.

Conclusion: AN boys have low BMD at multiple sites associated with decreased bone turnover markers at a time when bone mass accrual is critical for attainment of peak bone mass.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Absorptiometry, Photon
  • Adolescent
  • Anorexia Nervosa / metabolism*
  • Body Composition
  • Body Mass Index
  • Bone Density
  • Bone and Bones / metabolism*
  • Humans
  • Insulin-Like Growth Factor I / analysis
  • Male
  • Peptide Fragments / blood
  • Peptide YY / blood
  • Procollagen / blood


  • Peptide Fragments
  • Procollagen
  • procollagen Type I N-terminal peptide
  • Peptide YY
  • Insulin-Like Growth Factor I