A T-score of -0.7 is Not Considered Osteoporosis
A T-score of -0.7 is classified as normal bone mineral density (BMD), not osteoporosis. According to established World Health Organization (WHO) criteria and clinical guidelines, this value falls within the normal range of bone density 1.
Bone Mineral Density Classification
The WHO classification system for bone mineral density uses T-scores to categorize bone health as follows:
| Category | T-score |
|---|---|
| Normal BMD | ≥ -1.0 |
| Osteopenia/low bone mass | -1.0 to -2.5 |
| Osteoporosis | ≤ -2.5 |
Since the T-score of -0.7 is greater than -1.0, it falls within the normal range of bone density 1. This classification is consistently applied across major clinical guidelines and is the standard for interpreting DXA scan results.
Diagnostic Considerations
When evaluating bone health:
- T-scores are the primary metric used to classify bone density in postmenopausal women and men over 50 years of age 2
- Z-scores (which compare to age-matched peers) are typically used for premenopausal women and men under 50, though the International Osteoporosis Foundation (IOF) has recommended using T-scores in younger adults who are no longer growing 2
- The diagnosis of osteoporosis is confirmed when the BMD T-score values at the lumbar spine, femoral neck, or total hip are at or below -2.5 3
Clinical Context
It's important to understand that:
- While a T-score of -0.7 is not osteoporosis, bone health exists on a continuum
- The T-score alone does not capture fracture risk in its entirety 4
- Other clinical risk factors should be considered when assessing overall fracture risk, even with normal BMD
- Fracture risk assessment tools like FRAX incorporate various clinical risk factors with or without BMD to compute fracture probability 4
Common Pitfalls to Avoid
- Relying solely on BMD measurements without considering other clinical risk factors for fracture 1
- Misinterpreting terminology by using "osteoporosis" as a synonym for any degree of bone loss 1
- Overlooking that fracture risk depends on multiple factors beyond BMD, including age, previous fractures, and other clinical risk factors 1
- Failing to recognize that vertebral fractures are generally taken as diagnostic of osteoporosis, even if spine BMD values are not in the osteoporotic range 3
In summary, a T-score of -0.7 represents normal bone mineral density and is not classified as osteoporosis according to established clinical guidelines.