Table 1. WHO criteria for the diagnosis of osteoporosis using dual-energy X-ray absorptiometry.

Diagnosis	T-score
Normal	T-score ≥ −1.0 SD
Low bone density	−2.5 SD < T-score < −1.0 SD
Osteoporosis	T-score ≤−2.5 SD
Severe osteoporosis	T-score −2.5 SD with an insufficiency fracture

T-score = (measured bone mineral density - peak bone mineral density of normal Chinese young adult)/Standard deviation of peak bone mineral density of normal Chinese young adult (SD).