Is a DEXA (Dual-Energy X-ray Absorptiometry) scan appropriate for an 80-year-old female patient with hypertension and potential vitamin D deficiency?

DEXA Scan at Age 80: Highly Appropriate and Recommended

Yes, DEXA scanning is absolutely appropriate and strongly recommended for an 80-year-old female patient, regardless of the presence of additional risk factors like hypertension or vitamin D deficiency. 1, 2

Primary Recommendation

All women aged 65 years and older should undergo routine DEXA screening of the lumbar spine and bilateral hips, with no additional risk factors required to justify the scan. 3, 1, 2 At age 80, this patient is well beyond the threshold age where screening becomes standard of care, making the decision straightforward.

Why This Patient Qualifies

• Age alone is sufficient justification: Women ≥65 years receive routine screening regardless of any other clinical factors, and at 80 years old, this patient has been in the screening-eligible population for 15 years. 1, 2

• Vitamin D deficiency is an additional risk factor: The ACR Appropriateness Criteria specifically lists vitamin D deficiency as a condition that adversely affects bone mineral density and warrants DEXA evaluation. 3

• Hypertension does not contraindicate scanning: While hypertension itself is not a primary osteoporosis risk factor, it does not preclude or interfere with DEXA scanning. 3

Additional Imaging Considerations

Vertebral Fracture Assessment (VFA) should be performed during the same DEXA session if the patient has a T-score <-1.0, given that she meets age criteria (female ≥70 years). 3, 1 This is particularly important because:

• VFA can identify previously unrecognized vertebral fractures that independently increase future fracture risk. 3
• Studies show 60% of patients with vertebral fractures detected on VFA had bone density in the nonosteoporotic range, meaning they would have been missed by BMD measurement alone. 3
• The presence of vertebral fractures can reclassify patients for treatment eligibility even with relatively preserved bone density. 3

Scan Technique Specifications

• Scan both lumbar spine (L1-L4) and bilateral hips as the standard protocol. 3, 2
• Use T-scores for interpretation (not Z-scores) since this is a postmenopausal woman. 3, 2
• Inspect images carefully for degenerative changes that may spuriously elevate lumbar spine BMD values; if more than two vertebral levels show significant degeneration, exclude the entire spine and rely on hip measurements. 3

Follow-Up Interval Planning

The timing of the next DEXA scan depends on the initial results:

• If osteoporosis is diagnosed (T-score ≤-2.5) or treatment is initiated: Repeat DEXA in 1-2 years to monitor treatment effectiveness. 1, 2
• If normal bone density or mild osteopenia: Repeat DEXA in 2-3 years. 1, 2
• Never repeat DEXA at intervals <1 year under any circumstances, as testing precision limitations make shorter intervals unreliable. 1, 2

Critical Pitfalls to Avoid

• Do not delay scanning based on the presence or absence of symptoms: Osteoporosis is asymptomatic until fracture occurs, and age 80 is far beyond when screening should have been initiated. 1, 2

• Do not assume vitamin D supplementation alone is adequate without knowing bone density status: While vitamin D deficiency should be corrected, the patient's actual fracture risk and need for pharmacologic therapy cannot be determined without DEXA. 3

• Do not order plain radiographs instead of DEXA: Standard X-rays are rated as "usually not appropriate" for BMD assessment and cannot reliably detect osteoporosis until 30-40% of bone mass is already lost. 3

• Do not use peripheral screening tools (heel ultrasound, forearm scans) as substitutes: These modalities are rated as "usually not appropriate" for standard screening and cannot be used to diagnose osteoporosis by WHO criteria. 3

Addressing the Vitamin D Deficiency

• Check 25-hydroxyvitamin D levels as part of the comprehensive metabolic workup that should accompany DEXA scanning. 4
• Vitamin D deficiency impairs calcium absorption and directly affects bone metabolism, making it both a risk factor for low BMD and a treatable condition that should be corrected regardless of DEXA results. 3
• Supplementation should be initiated based on measured deficiency, but this does not replace the need for DEXA to assess actual bone density and fracture risk. 4