Predictors of bone mineral density reduction in adolescents with anorexia nervosa

J Am Acad Child Adolesc Psychiatry. 2000 Nov;39(11):1365-70. doi: 10.1097/00004583-200011000-00010.

Abstract

Objectives: To determine which variables are associated with a significant reduction in bone mineral density (BMD) in adolescent anorexia nervosa and to establish guidelines for indication of bone densitometry.

Method: One hundred seventy patients (treated from 1997 until 1999), aged 10 to 17 years, with a DSM-IV diagnosis of anorexia nervosa were evaluated by dual-energy-x-ray absorptiometry in the lumbar spine (L2-L4) and the femoral neck. The results were compared with the normative data for BMD values by age and sex in Spanish adolescents.

Results: 44.1% of patients had osteopenia at the lumbar spine and 24.7% at the femoral neck. The following variables were related to osteopenia: more than 12 months since onset of the disorder (p < .001), more than 6 months of amenorrhea (p < .001), body mass index <15 (p < .001), calcium intake <600 mg/day (p < .01), and <3 hours/week of physical activity (p < .001). In a stepwise logistic regression analysis to predict reduced spinal BMD, 3 variables-months elapsed since the onset of weight loss, calcium intake, and body mass index--correctly classified 78.8% of patients.

Conclusions: Adolescent anorexia nervosa patients with the characteristics outlined above are at high risk of reduced BMD, and densitometry is recommended to determine the degree of osteopenia.

MeSH terms

  • Absorptiometry, Photon*
  • Adolescent
  • Age Factors
  • Amenorrhea / etiology
  • Anorexia Nervosa / complications*
  • Anorexia Nervosa / metabolism
  • Anorexia Nervosa / physiopathology
  • Body Mass Index
  • Bone Density*
  • Calcium / metabolism*
  • Child
  • Disease Progression
  • Exercise*
  • Fasting / adverse effects
  • Female
  • Femur Neck / diagnostic imaging
  • Humans
  • Logistic Models
  • Lumbar Vertebrae / diagnostic imaging
  • Osteoporosis / diagnosis*
  • Osteoporosis / etiology
  • Prognosis
  • Sampling Studies

Substances

  • Calcium