Femoral bone mineral density reference values by sex and ethnicity: Findings from the Qatar Biobank study

Objectives

Low bone mineral density (BMD) is a major global health concern due to fracture-related morbidity and mortality. BMD is currently assessed by dual-energy X-ray absorptiometry (DXA) against a US reference population. The aim of the study was to establish an ethnicity- and sex-specific reference for calculating BMD at different femoral sites including femoral trochanter, Ward's triangle and femoral neck in Qatar.

Methods

This cross-sectional study analyzed BMD in 4727 (2277 females and 2450 males) healthy Qatari aged between 20 and 82 years participating in the Qatar Biobank (QBB) study. Standard T-scores provided by the densitometer (T_DXA) were compared with ethnicity- and sex-specific T-scores for the Qatari population (T_QA) calculated using data from the 20-29-year age group for different femoral sites as the reference. The concordance between T_DXA and T_QA was analyzed using kappa statistics.

Results

Males consistently exhibited higher BMD values for the femoral trochanter, Ward's triangle, and the femoral neck across all age groups compared with females. Using T_QA rather than T_DXA as a reference at any site classified fewer individuals as having osteoporosis and osteopenia, especially for females. Agreement between T_DXA and T_QA was higher in males than in females.

Conclusions

These findings underscore the need for local ethnicity- and sex-specific BMD reference values. The use of T_QA significantly reduced overdiagnosis of osteopenia and osteoporosis compared with T_DXA, thereby decreasing overtreatment and impacting participant recruitment decisions into clinical studies.