An Updated Reference for Calculating Bone Mineral Density T-Scores.

Context: Bone mineral density (BMD) T-score references may be updated when the peak BMD of the population is unclear and warrants reevaluation.

Objective: To update BMD T-score references using the peak BMD from the most recent National Health and Nutrition Examination Survey (NHANES) data.

Methods: This cross-sectional study used NHANES data from 2005 to 2014. Non-Hispanic White females between the ages of 10 and 40 years (N = 1549) were our target population to estimate peak BMD (SD). Individuals aged ≥ 50 years (N = 5523) were used to compare the percentages of osteoporosis and low bone mass based on existing and updated BMD T-score references. BMD data within the age at attainment of peak BMD ± 5 years were used to calculate updated BMD T-score references.

Results: The updated average of BMD (SD) for diagnosing osteoporosis at the femoral neck and lumbar spine were 0.888 g/cm2 (0.121 g/cm2) and 1.065 g/cm2 (0.122 g/cm2), respectively. The percentages of individuals with osteoporosis at the femoral neck and low bone mass at the femoral neck and lumbar spine based on the updated BMD T-score references were higher than the percentages of people designated with these outcomes under the existing guidelines (P < 0.001). However, we observed the opposite pattern for lumbar spine osteoporosis (P < 0.001).

Conclusions: We calculated new BMD T-score references at the femoral neck and lumbar spine. We found significant differences in the percentages of individuals classified as having osteoporosis and low bone mass between the updated and existing BMD T-score references.