low bone mineral density in people with anorexia nervosa

Last reviewed 01/2018

Low bone mineral density in people with anorexia nervosa

• bone mineral density results should only be interpreted and explained to people with anorexia nervosa by a professional with the knowledge and competencies to do this
  
  
• before measuring bone density, discuss with the person and their family members or carers why it could be useful
  
  
• explain to people with anorexia nervosa that the main way of preventing and treating low bone mineral density is reaching and maintaining a healthy body weight or BMI for their age
  
  
• consideration for a bone mineral density scan in the following circumstances:
  
  
  • after 1 year of underweight in children and young people, or earlier if they have bone pain or recurrent fractures
    
    
  • after 2 years of underweight in adults, or earlier if they have bone pain or recurrent fractures
    
    
• in children and young people with faltering growth, use measures of bone density that correct for bone size (such as bone mineral apparent density [BMAD])
  
  
• a repeat bone mineral density scan should be considered in people with ongoing persistent underweight, especially when using or deciding whether to use hormonal treatment
  
  
  • however do not repeat bone mineral density scans for people with anorexia nervosa more frequently than once per year, unless they develop bone pain or recurrent fractures
    
    
• oral or transdermal oestrogen therapy should not routinely be offered to treat low bone mineral density in children or young people with anorexia nervosa
  
  
• seek specialist paediatric or endocrinological advice before starting any hormonal treatment for low bone mineral density. Coordinate any treatment with the eating disorders team (1)
  
  
• transdermal 17-beta-estradiol (with cyclic progesterone) should be considered for young women (13-17 years) with anorexia nervosa who have long-term low body weight and low bone mineral density with a bone age over 15
  
  
• incremental physiological doses of oestrogen should be considered in young women (13-17 years) with anorexia nervosa who have delayed puberty, long-term low body weight and low bone mineral density with a bone age under 15
  
  
• bisphosphonates should be considered for women (18 years and over) with anorexia nervosa who have long-term low body weight and low bone mineral density
  • benefits and risks (including risk of teratogenic effects) must be discussed with women before starting treatment
    
    
• people with anorexia nervosa and osteoporosis, or related bone disorders, should be advised to avoid high-impact physical activities and activities that significantly increase the chance of falls or fractures

Reference:

• NICE (May 2017). Eating disorders: recognition and treatment