What does a T score greater than -2.5 indicate in terms of bone density and osteoporosis risk?

T-Score Greater Than -2.5: Bone Density Classification

A T-score greater than -2.5 means the patient does NOT have osteoporosis by World Health Organization (WHO) criteria and falls into either the normal bone density range (T-score > -1.0) or osteopenia/low bone mass range (T-score between -1.0 and -2.5). 1, 2

WHO Diagnostic Classification System

The T-score represents the number of standard deviations a patient's bone mineral density (BMD) is above or below the mean of a young, healthy reference population. 1 The WHO established the following diagnostic thresholds:

• Normal BMD: T-score > -1.0 1, 2
• Osteopenia (Low Bone Mass): T-score between -1.0 and -2.5 1, 2
• Osteoporosis: T-score ≤ -2.5 1, 2

The diagnostic classification is based on the lowest T-score from any of the recommended DXA measurement sites (lumbar spine, femoral neck, total hip, or one-third radius). 2

Clinical Implications by T-Score Range

T-Score > -1.0 (Normal Range)

• Indicates normal bone mineral density with minimal increased fracture risk compared to young healthy adults 2
• Routine monitoring rather than immediate intervention is appropriate 3
• Focus on maintaining bone health through weight-bearing exercise, adequate calcium (1,000-1,200 mg/day), and vitamin D (800-1,000 IU/day) 1, 3

T-Score Between -1.0 and -2.5 (Osteopenia)

• Represents low bone mass but not osteoporosis 1, 3
• Approximately 40-50% of patients with inflammatory bowel disease fall into this category 1
• Critically, 50% of fragility fractures occur in postmenopausal women with T-scores greater than -2.5 (in the osteopenic range), making risk assessment beyond BMD alone essential 1

Risk Assessment for Patients with T-Scores > -2.5

For patients with osteopenia (T-scores between -1.0 and -2.5), the FRAX tool should be used to calculate 10-year fracture probability. 1 The FRAX algorithm incorporates:

• Hip BMD measurement 1
• Age, gender, height, and weight 1
• Family history of hip fracture 1
• Current smoking status 1
• Glucocorticoid use >3 months 1
• Rheumatoid arthritis 1
• Alcohol consumption 1

The National Osteoporosis Foundation recommends pharmacologic treatment for patients with osteopenia when FRAX calculations show either a 10-year hip fracture probability ≥3% OR a 10-year major osteoporotic fracture probability ≥20%. 1

Treatment Considerations

Non-Pharmacologic Interventions (All Patients with T-Score > -2.5)

• Weight-bearing exercise regimen to maintain and potentially improve bone density 1, 3
• Calcium intake of at least 1,200 mg/day through diet or supplements 1, 3
• Vitamin D supplementation of 800-1,000 IU/day 1, 3
• Smoking cessation and limiting alcohol consumption 1, 3

Pharmacologic Therapy Indications

Pharmacologic treatment is NOT automatically indicated for T-scores > -2.5 unless:

• FRAX criteria are met (as described above) 1
• Personal history of fragility fracture after age 50 is present 3
• Calcium and vitamin D supplementation should be considered if T-score is less than -1.5, particularly with history of pre-existing fracture 1

Special Populations

For premenopausal women and men under age 50, Z-scores (comparison to age-matched peers) are preferred over T-scores for assessment. 2 In these populations, a Z-score ≤ -2.0 suggests bone density below expected range for age and warrants evaluation for secondary causes of bone loss. 2

Monitoring Recommendations

For patients with T-scores > -2.5 not on treatment:

• Normal BMD (T-score > -1.0): Repeat BMD testing interval of approximately 15 years 4
• Mild osteopenia (T-score -1.0 to -1.5): Repeat BMD testing interval of approximately 15 years 4
• Moderate osteopenia (T-score -1.5 to -2.0): Repeat BMD testing interval of approximately 5 years 4
• Advanced osteopenia (T-score -2.0 to -2.5): Repeat BMD testing interval of approximately 1 year 4

When repeating BMD measurements, ensure testing is performed on the same DXA scanner using identical protocols, as vendor differences prohibit direct comparison unless cross-calibration has been performed. 1, 3

Common Pitfalls to Avoid

• Do not rely solely on T-scores for treatment decisions without considering overall fracture risk assessment using FRAX or similar tools 3
• Recognize that fracture risk exists on a continuum, with many fractures occurring in the osteopenic range rather than only in patients with osteoporosis 1, 3
• Failure to address calcium and vitamin D deficiency before considering pharmacologic therapy is a common error 5
• Do not use T-scores for diagnosis in premenopausal women or men under 50; use Z-scores instead 2
• Be aware that degenerative changes in the lumbar spine may artificially elevate BMD measurements, potentially masking true bone loss 5