What are the NICE (National Institute for Health and Care Excellence) guidelines for using a DEXA (Dual-Energy X-ray Absorptiometry) scan to assess bone mineral density in patients with anorexia nervosa?

From the Guidelines

NICE guidelines recommend DEXA scans for bone mineral density assessment in patients with anorexia nervosa who have specific risk factors, such as being underweight for an extended period, amenorrhea, or a history of low-trauma fractures. The guidelines suggest a targeted approach, focusing on patients with increased risk of bone density issues due to prolonged malnutrition, low body weight, and hormonal disruptions associated with anorexia nervosa 1.

Key Considerations for DEXA Scans in Anorexia Nervosa

• Baseline DEXA scanning is crucial for identifying reduced bone mineral density early, allowing for timely interventions to prevent long-term skeletal complications.
• Repeat scans at 18-24 month intervals are recommended if the initial scan shows reduced bone mineral density or if risk factors persist, as indicated by studies on osteoporosis and bone mineral density management 1.
• The decision to perform DEXA scans should be based on individual patient risk factors, including the duration of being underweight, presence of amenorrhea, and history of fractures, rather than routine scanning for all patients with eating disorders.

Rationale Behind Recommendations

The rationale is rooted in the understanding that anorexia nervosa can significantly impair bone formation and increase bone resorption, leading to osteopenia and osteoporosis at a young age 1. Early detection through DEXA scans enables healthcare providers to implement appropriate interventions, including weight restoration, nutritional rehabilitation, and consideration of hormonal therapies to prevent long-term skeletal complications.

Clinical Application

In clinical practice, the guidelines emphasize the importance of a comprehensive approach to managing anorexia nervosa, incorporating medical, psychiatric, psychological, and nutritional expertise 1. DEXA scans are a valuable tool within this framework, particularly for adolescents and young adults who are at high risk during critical bone development periods. By following the NICE guidelines and considering the latest evidence on osteoporosis and bone mineral density management 1, healthcare providers can optimize the care of patients with anorexia nervosa and reduce the risk of long-term bone health complications.

From the Research

NICE Guidelines for DEXA Scan in Anorexia Nervosa

• The National Institute for Health and Care Excellence (NICE) guidelines for using a DEXA (Dual-Energy X-ray Absorptiometry) scan to assess bone mineral density in patients with anorexia nervosa are not explicitly stated in the provided studies. However, the studies suggest that DEXA scans are an effective tool for assessing bone mineral density in patients with anorexia nervosa 2, 3, 4, 5, 6.

Indications for DEXA Scan

• The studies suggest that a DEXA scan should be considered for patients with anorexia nervosa who have a low body mass index (BMI) 2, 4, a long duration of illness 3, 5, or a history of amenorrhea 5.

Factors Associated with Low Bone Mineral Density

• The studies identified several factors associated with low bone mineral density in patients with anorexia nervosa, including:
  • Low BMI 2, 4
  • Long duration of illness 3, 5
  • History of amenorrhea 5
  • Low percentage of ideal body weight (IBW) 6
  • Use of certain medications, such as proton pump inhibitors (PPI) or selective serotonin reuptake inhibitors (SSRI) 6
  • Tobacco use 6
  • Low 25-hydroxy vitamin D levels 6

Clinical Implications

• The studies highlight the importance of assessing bone mineral density in patients with anorexia nervosa, as low bone mineral density is a common complication of the disease 2, 3, 4, 5, 6.
• The results of the DEXA scan can inform treatment decisions, such as the need for osteoporosis prevention or treatment 2, 3, 4, 5, 6.