What are the treatment options for patients with abnormal Dual-Energy X-ray Absorptiometry (DXA) scan results?

Treatment Options for Abnormal DXA Scan Results

The primary treatment for patients with abnormal DXA scan results should include bisphosphonates as first-line therapy, along with calcium and vitamin D supplementation, lifestyle modifications, and regular follow-up monitoring. 1

Diagnosis and Classification

• DXA (Dual-Energy X-ray Absorptiometry) is the gold standard for diagnosing osteoporosis and is recommended for all women 65 years and older, as well as postmenopausal women younger than 65 with risk factors 1
• Osteoporosis is defined as a T-score of -2.5 or less, while osteopenia (low bone mass) is defined as a T-score between -1.0 and -2.5 1
• Risk factors for osteoporotic fracture include increasing age, female sex, postmenopausal status, low body weight, history of parental hip fracture, previous fracture, rheumatoid arthritis, smoking, alcohol intake, and long-term use of certain medications (especially glucocorticoids) 1

Treatment Recommendations Based on DXA Results

For Patients with Osteoporosis (T-score ≤ -2.5):

• Bisphosphonates are strongly recommended as first-line therapy for adults with high or very high fracture risk 1
• Oral bisphosphonates are preferred due to their proven efficacy in reducing total and vertebral fractures and increasing hip and lumbar spine BMD 1
• For patients at very high fracture risk, parathyroid hormone/parathyroid hormone-related protein (PTH/PTHrP) analogs may be considered over anti-resorptives (bisphosphonates or denosumab) 1
• Denosumab is an option for patients with high fracture risk who cannot tolerate bisphosphonates 1
• Teriparatide should be reserved for patients with severe osteoporosis or those who have had fractures 1

For Patients with Osteopenia (T-score between -1.0 and -2.5):

• Treatment decisions should be based on fracture risk assessment using FRAX (Fracture Risk Assessment Tool) 1
• Pharmacologic treatment should be considered in women with a 10-year risk of major osteoporotic fracture of at least 20% or a risk of hip fracture of at least 3% 1
• Treatment should also be considered in patients who have had a low-trauma fracture, even if DXA does not indicate osteoporosis 1

Calcium and Vitamin D Supplementation

• All patients should receive calcium and vitamin D supplementation based on age 1:
  • Ages 19-50: 1,000 mg calcium, 600 IU vitamin D daily
  • Ages 51-70: 1,200 mg calcium, 600 IU vitamin D daily
  • Ages 71+: 1,200 mg calcium, 800 IU vitamin D daily
• Serum vitamin D levels should be maintained at ≥20 ng/mL (50 nmol/L) for good bone health 1
• For patients on glucocorticoid therapy, vitamin D levels should be maintained at ≥30-50 ng/mL 1

Monitoring Treatment Response

• The American College of Physicians recommends against bone density monitoring during the 5-year pharmacological treatment period for osteoporosis in women due to low-quality evidence 1
• However, more recent guidelines suggest follow-up BMD testing to monitor response to therapy 1
• Follow-up BMD testing should be performed if a fracture has occurred or new risk factors have developed 1
• Shorter intervals between BMD testing may be indicated for patients on medications associated with rapid bone loss (glucocorticoids, aromatase inhibitors, androgen deprivation therapy) 1

Special Considerations

For Patients on Glucocorticoid Therapy:

• Patients on glucocorticoids ≥2.5 mg/day for >3 months should receive osteoporosis therapy if at high or very high fracture risk 1
• Yearly clinical fracture risk assessment is recommended for these patients 1
• BMD testing should be performed every 1-2 years, with more frequent monitoring for very high-risk patients 1

For Patients Receiving Denosumab:

• Serum calcium should be measured before starting denosumab, as hypocalcemia is a common side effect 2
• Vitamin D levels should be evaluated before starting therapy 2
• Regular monitoring of serum calcium is necessary, especially after the first few doses 2
• A baseline dental assessment is mandatory before initiating denosumab to reduce the risk of osteonecrosis of the jaw 2

Lifestyle Modifications

• Weight-bearing and resistance exercises are recommended to optimize bone density 1
• Smoking cessation and limiting alcohol to ≤2 servings per day 1
• Maintaining weight in the recommended range 1
• Fall prevention strategies should be implemented, particularly in elderly patients 1

Common Pitfalls to Avoid in DXA Interpretation

• Artifacts in the lumbar spine (such as osteoarthritis, aortic calcifications) can cause spurious increases in BMD values 1
• Incorrect positioning of the patient can lead to inaccurate measurements 1
• Vertebral fractures may show increased BMD due to trabecular impaction and condensation 1
• Hip prostheses or osteosynthesis hardware make the site unsuitable for diagnostic purposes 1
• Failure to exclude vertebrae affected by significant structural changes or differing by more than a T-score of 1.0 from adjacent vertebrae 1

By following these evidence-based recommendations, clinicians can effectively manage patients with abnormal DXA scan results to reduce fracture risk and improve bone health.