How often is a Dual-Energy X-ray Absorptiometry (DEXA) scan needed?

From the Guidelines

The frequency of DEXA scans should be individualized based on a person's baseline bone density and risk factors, with follow-up scans generally recommended every 2-3 years for those with normal results, but more frequently (every 1-2 years) for those with osteopenia or osteoporosis, as supported by the most recent study 1.

Key Considerations

• The timing between scans allows for meaningful changes in bone density to be detected, as bone remodeling occurs slowly.
• Individuals with risk factors such as early menopause, low body weight, family history of osteoporosis, or use of certain medications (like corticosteroids) should start testing earlier, typically around age 50.
• For premenopausal women and men under 50 with risk factors, follow-up scans are recommended every 1-2 years if there is a high risk for accelerated bone loss, but otherwise every 2 years 1.
• Patients receiving treatment who demonstrate decreasing BMD on follow-up scans may require an adjustment in their pharmacotherapy regimen 1.
• Scan intervals <1 year are discouraged, unless there is a high risk for rapid bone loss, such as in patients receiving glucocorticoid therapy 1.

Special Populations

• In people with type 2 diabetes, DXA scan should be performed at least 5 years after the diagnosis of diabetes, and reassessment is recommended every 2-3 years depending on the screening evaluation and the presence of additional risk factors 1.
• For patients with chronic liver disease, repeat DEXA after 2-3 years in patients within normal BMD, and within 1 year when rapid bone loss is expected 1.

Monitoring and Treatment

• The measurement of hip BMD continues to be the most reliable way of evaluating hip fracture risk, whereas imaging of the spine is optimal for monitoring treatment response 1.
• BMD measurements do not need to be repeated routinely in patients with osteopenia unless the baseline T-score is < 2.0 or risk factors develop 1.
• Patients receiving treatment who demonstrate decreasing BMD on follow-up scans may require an adjustment in their pharmacotherapy regimen 1.

From the Research

Frequency of DEXA Scans

• The frequency of DEXA scans is not explicitly stated in the provided studies, but it can be inferred that the scans are typically performed as part of routine care for patients with osteoporosis or other conditions that affect bone mineral density 2, 3, 4, 5, 6.
• The study by 2 collected DEXA scan results from a cohort of 25 individuals with Fabry disease over a period of 15 years, suggesting that scans may be performed at irregular intervals depending on the patient's condition and treatment plan.
• Another study by 5 mentions that DEXA body composition analysis can be used to monitor changes in body composition over time, implying that scans may be performed at regular intervals to track changes in bone mineral density and other parameters.

Indications for DEXA Scans

• DEXA scans are commonly used to diagnose and monitor osteoporosis, as well as to assess bone mineral density in patients with other conditions that affect bone health 3, 4, 5, 6.
• The study by 5 highlights the use of DEXA body composition analysis in patients with secondary osteoporosis, as well as other conditions such as HIV, obesity, and sarcopenia.
• The International Society for Clinical Densitometry (ISCD) has developed official positions on the use of DEXA for body composition analysis, including indications for patients with HIV, obesity, and sarcopenia 5.

Limitations of DEXA Scans

• The study by 6 found that lumbar DEXA scans do not accurately represent bone structure in patients with osteoporosis, highlighting the limitations of this diagnostic tool.
• Another study by 3 discusses the potential pitfalls of DEXA acquisitions and BMD measurements, including technical, patient, and interpretive factors that can affect the accuracy of scan results.
• The study by 2 found that Z-scores and T-scores from DEXA scans correlated with certain parameters such as Lyso-GL3 levels and calcium levels, but not with others such as renal function and vitamin D levels, highlighting the complexity of interpreting DEXA scan results.