What are the World Health Organization (WHO) diagnostic thresholds for normal bone mineral density, osteopenia, and osteoporosis?
According to the WHO, it is suggested that the reference data generated from the National Health and Nutrition Examination Survey (NHANES) study be used as a representative sample of the United States population, when using the proximal femur as the measurement site. This normative data was based on Caucasian women aged 20 to 29 years. The T-score is derived when standard deviations (SD) are calculated in relation to the young healthy population.
Based on measurements from DXA:
- • A normal value for BMD is defined as a T-score greater than or equal to −1 SD.
- • An osteopenia T-score is less than −1 and greater than −2.5 SD.
- • An osteoporosis T-score is less than or equal to −2.5 SD.
