Glossary · Tests

T-score

Definition: A T-score is the bone mineral density measurement on a DEXA scan compared to the mean of healthy young adults of the same sex, expressed in standard deviations. A T-score ≥ -1.0 is normal, -1.0 to -2.5 is osteopenia, and ≤ -2.5 is osteoporosis. T-scores are the primary diagnostic measure used in postmenopausal women.

Detailed definition

The T-score is the number of standard deviations a patient's BMD measurement deviates from the mean BMD of healthy young adults of the same sex (typically aged 20–29). It is the diagnostic measure used in WHO criteria for osteoporosis. The T-score is reported separately for spine, total hip, and femoral neck; the lowest of these is generally used for diagnosis. A T-score of -2.5 corresponds roughly to a 2.5-fold increase in fracture risk relative to a young-adult woman.

Why it matters in menopause

For postmenopausal women, the T-score is the dominant measure on a DEXA report. A spine T-score of -2.0 with a hip T-score of -1.5 is osteopenia at both sites and triggers attention to lifestyle, calcium/vitamin D, and consideration of HRT or other bone-active therapy depending on FRAX-predicted fracture risk.

Sources

External references: Wikipedia.

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