What are the guidelines for bone density scans and treatment of osteoporosis?

Guidelines for Bone Density Scans and Treatment of Osteoporosis

Dual-energy X-ray absorptiometry (DXA) is recommended for screening women aged 65 years and older and men aged 70 years and older for osteoporosis, with earlier screening indicated for individuals with specific risk factors. 1

Screening Recommendations by Population

Women

• Age 65 and older: Universal screening with DXA 1
• Age 60-64: Screening if at increased risk for osteoporotic fractures 1
• Postmenopausal women <65: Screening if they have risk factors 1

Men

• Age 70 and older: Universal screening with DXA 1
• Age 50-69: Screening if they have risk factors 1

Special Populations Requiring Screening

• Individuals on medications that affect bone health:
  • Aromatase inhibitor therapy for breast cancer 1
  • Androgen deprivation therapy for prostate cancer 1
  • Glucocorticoid therapy (≥5 mg prednisone or equivalent daily for ≥3 months) 1
• Individuals with medical conditions affecting bone health:
  • Chronic renal failure 1
  • Rheumatoid arthritis and inflammatory arthritides 1
  • Eating disorders 1
  • Organ transplantation 1
  • Prolonged immobilization 1
  • Gastrointestinal disorders (celiac disease, IBD, postgastrectomy) 1
  • Endocrine disorders (hyperparathyroidism, hyperthyroidism, Cushing syndrome) 1

Risk Factors for Osteoporosis

• Low body weight (<70 kg) - strongest predictor 1
• Prior fracture, especially low-trauma fracture
• Family history of hip fracture
• Smoking
• Excessive alcohol intake
• Inadequate physical activity
• Low calcium and vitamin D intake
• Hypogonadism 1

DXA Testing Protocol

• Preferred measurement sites: Femoral neck and lumbar spine 1
• Femoral neck measurements by DXA are the best predictor of hip fracture 1
• T-score interpretation:
  • Normal: T-score ≥ -1.0
  • Osteopenia: T-score between -1.0 and -2.5
  • Osteoporosis: T-score ≤ -2.5 1

Follow-up Testing Intervals

• Same DXA scanner should be used for follow-up scans 1
• Standard follow-up intervals:
  • For untreated patients: Every 2 years 1
  • For patients initiating therapy or at high risk for rapid bone loss (e.g., glucocorticoid therapy): Annual follow-up 1
  • For women with normal BMD or mild osteopenia: Approximately 15 years 2
  • For women with moderate osteopenia: Approximately 5 years 2
  • For women with advanced osteopenia: Approximately 1 year 2

Additional Diagnostic Tools

• Vertebral Fracture Assessment (VFA): Indicated for patients with T-scores < -1.0 and one or more of:
  • Women ≥70 years or men ≥80 years
  • Historical height loss >4 cm
  • Self-reported but undocumented prior vertebral fracture
  • Glucocorticoid therapy 1
• Quantitative CT (QCT): Useful for patients with advanced degenerative changes in the spine 1
• Trabecular Bone Score (TBS): Emerging tool for qualitative bone assessment 1

Treatment Recommendations

• Lifestyle modifications for all patients:

  • Regular weight-bearing exercise
  • Smoking cessation
  • Limiting alcohol intake
  • Adequate calcium and vitamin D intake 1

• Pharmacologic therapy indicated for:

  • T-score ≤ -2.5 (osteoporosis)
  • History of fragility fracture
  • High fracture risk based on clinical risk factors
  • Patients on long-term glucocorticoids 1

• First-line medications:

  • Bisphosphonates for prevention and treatment of osteoporosis 1
  • Denosumab for treatment of postmenopausal women and men with osteoporosis at high risk for fracture 3

Common Pitfalls to Avoid

1. Failure to screen appropriate populations: Only 4.6% of individuals with fractures receive appropriate treatment after the fracture, with particularly low rates in men (2.8%) 4
2. Inconsistent follow-up: Ensure appropriate monitoring intervals based on baseline BMD and risk factors
3. Scanner variability: Use the same DXA machine for serial measurements 1
4. Ignoring vertebral fractures: VFA can identify patients who need treatment despite BMD above osteoporotic threshold 1
5. Overlooking secondary causes: Screen for underlying conditions in patients with osteoporosis or low-trauma fractures 1

Osteoporosis screening and treatment are critical for reducing fracture risk, which affects 50% of women and 20% of men over age 50, with mortality rates of 20% within the first year after fracture 1. Early identification through appropriate screening allows for timely intervention to reduce morbidity, mortality, and healthcare costs.