At what age should a Dual-Energy X-ray Absorptiometry (DEXA) scan be started?

When to Start DEXA Scan Screening

All women should begin routine DEXA screening at age 65 years, and all men should begin at age 70 years, regardless of risk factors. 1, 2

Standard Screening Ages

Women

• Age 65 and older: Routine DEXA screening is recommended for all women at this age, with no additional risk factors required 3, 1, 2
• Under age 65: Screening is NOT recommended for routine use in women younger than 65 without risk factors 1, 2

Men

• Age 70 and older: Routine DEXA screening is recommended for all men at this age 1, 2
• Under age 70: Screening is NOT recommended for routine use in men younger than 70 without risk factors 1, 2

Earlier Screening for High-Risk Individuals

DEXA screening should be performed earlier than the standard ages in the following situations:

Postmenopausal Women Under 65

• Previous fragility fracture (at any age) 1, 2
• Body weight less than 127 pounds (58 kg) 3
• Parental history of hip fracture 3
• Early menopause or oophorectomy before natural menopause 4
• 10-year major osteoporotic fracture risk ≥9.3% as calculated by FRAX 1, 2

Men Under 70 and Premenopausal Women

• Hypogonadism or surgically/chemotherapeutically induced castration 3
• Androgen deprivation therapy for prostate cancer 1, 2

Medical Conditions (Any Age, Either Sex)

• Glucocorticoid therapy for >3 months or expected to continue >3 months 3, 1
• Chronic alcoholism or established cirrhosis 3, 2
• Chronic renal failure 3
• Rheumatoid arthritis and other inflammatory arthritides 3
• Eating disorders (anorexia nervosa, bulimia) 3
• Organ transplantation 3
• Prolonged immobilization or spinal cord injury (as soon as medically stable) 3, 1
• Gastrointestinal malabsorption, malnutrition, or gastric bypass surgery 3
• Endocrine disorders: hyperparathyroidism, hyperthyroidism, Cushing syndrome, acromegaly 3, 2
• Multiple myeloma 3

High-Risk Medications

• Anticonvulsant drugs 3
• Aromatase inhibitor therapy 3
• Chronic heparin therapy 3

Screening Intervals After Initial DEXA

Normal Bone Density or Mild Osteopenia

• Repeat DEXA in 2-3 years 1, 2
• For women with completely normal BMD at age 65, intervals can extend to 4-8 years without loss of fracture prediction accuracy 1

Osteoporosis or On Treatment

• Repeat DEXA in 1-2 years to monitor treatment effectiveness 1, 2

High Risk for Accelerated Bone Loss

• Repeat DEXA in 1-2 years (e.g., glucocorticoid therapy, spinal cord injury) 3, 1

Critical Pitfalls to Avoid

• Do not screen women under 65 or men under 70 without documented risk factors – this exposes patients to unnecessary radiation and costs without clinical benefit 1, 2
• Do not delay screening in patients with chronic alcoholism, early menopause, or glucocorticoid use – these conditions justify earlier screening regardless of age 2, 4
• Do not repeat DEXA scans more frequently than every 2 years in patients with normal BMD, as testing precision limitations make shorter intervals unreliable 1
• Never repeat DEXA at intervals less than 1 year under any circumstances 1
• Do not assume obesity protects against osteoporosis when other major risk factors are present – obesity is not an indication for screening but does not negate other risk factors 2

Scan Technique and Interpretation

• Scan both lumbar spine (L2-4) and bilateral hips (femoral neck and total hip) 3, 4
• Use T-scores for all postmenopausal women regardless of age 4
• Use Z-scores for premenopausal women and men under 50 3
• Consider Vertebral Fracture Assessment (VFA) during the same session for patients with T-score <-1.0 and additional risk factors (women ≥70 years, men ≥80 years, height loss >4 cm, prior vertebral fracture, or glucocorticoid therapy) 1