Should DEXA (Dual-Energy X-ray Absorptiometry) scans be performed in all Crohn's disease patients?

DEXA Scans in Crohn's Disease Patients

DEXA scanning should be performed in all patients with Crohn's disease who have persistently active disease, those repeatedly exposed to corticosteroids, and patients with long disease duration. 1

Risk Factors for Bone Loss in Crohn's Disease

Crohn's disease patients are at significant risk for bone loss due to multiple factors:

• Chronic inflammation contributes directly to bone loss through inflammatory cytokines, with approximately 35-40% of patients suffering from osteopenia and 15% from osteoporosis 2
• Low body mass index (BMI) correlates with lower bone mineral density, indicating a potential risk factor for bone loss 3, 4
• Corticosteroid use is a major risk factor, with bone mineral density correlating negatively with lifetime steroid use 1, 2
• Early disease onset is associated with lower T-scores and increased risk of osteoporosis 3
• Malnutrition and vitamin D deficiency are common and contribute to bone loss 4

Evidence Supporting DEXA Scanning in Crohn's Disease

Studies have consistently shown high prevalence of bone disorders in Crohn's disease:

• Osteoporosis (defined as BMD more than 2 SD below age-matched control mean) is found in 41% of patients with Crohn's disease 1
• Patients with Crohn's disease have a significantly higher fracture risk compared to the general population (4.8% vs 1.1%) 1
• The British Society of Gastroenterology guidelines indicate that osteoporosis is common in Crohn's disease and less so in ulcerative colitis 1

When to Perform DEXA Scans

DEXA scanning should be performed in:

• All patients with persistently active Crohn's disease 1
• Those repeatedly exposed to corticosteroids 1
• Patients with long disease duration 1
• Those with additional risk factors including low BMI, early disease onset, and high cumulative corticosteroid doses 3
• Patients with fractures or known risk factors for osteoporosis 1

Management Recommendations

For patients identified with bone loss:

• Basic preventive measures should be advised to all patients including adequate calcium (500-1000 mg/day) and vitamin D (800-1000 IU/day) intake 1, 2
• Pancreatic enzyme supplementation if indicated for malabsorption 1
• Regular weight-bearing exercise and avoidance of smoking and alcohol 1, 2
• In post-menopausal women with osteoporosis, regular use of bisphosphonates, calcitonin and its derivatives, and raloxifene reduce or prevent further bone loss 1
• In males with osteoporosis, bisphosphonates are probably of value 1

Important Considerations and Pitfalls

• The presence of osteoporosis is one (but not the only) risk factor for fractures; vertebral fractures have been documented in patients with both reduced and normal bone density 1
• The strongest predictor of future fracture is a prior vertebral fracture 1
• Patients with Crohn's disease receiving pancreatic enzyme replacement therapy for fat malabsorption had a lower risk of fractures than other Crohn's patients 1
• Treatment of the underlying inflammation is crucial for bone health, highlighting the need for effective disease management strategies 2, 5

By implementing regular DEXA scanning in all Crohn's disease patients, especially those with risk factors, clinicians can identify bone loss early and implement appropriate interventions to prevent fractures and improve quality of life.