INTRODUCTION: Dual-energy X-ray absorptiometry (DEXA) provides the ability to measure total body bone mineral density (BMD) in humans. Previous studies suggest that BMD varies between racial and ethnic populations but the extent to which differences exist remains unknown.

PURPOSE: The purpose of this study is to compare BMD and Z-Scores (number of standard deviations away from average BMD value for age and sex) among adults in four different racial and ethnic categories.

METHODS: This retrospective study used an existing database of DEXA tests conducted at Wichita State University. Files were randomly selected until 25 males and 25 females, aged 18-45 years, were identified in each of four categories: Asian, Black, Hispanic and White. Age, BMD and Z-score data for these 200 individuals were retrieved and compared using one-way ANOVA and post hoc Bonferroni correction.

RESULTS: Overall mean age was 27.2 ± 7.8 (mean ± SD) years with no differences (p>0.05) between groups. BMD was lower (P<0.001) in Asians (1.105 ± 0.11 g/cm3) compared to Blacks (1.255 ± 0.13 g/cm3), Hispanics (1.199 ± 0.12 g/cm3) and Whites (1.207 ± 0.12 g/cm3). Z-scores were also lower (P<0.001) in Asians (-0.522 ± 1.19 g/cm3) compared to Blacks (0.294 ± 1.08 g/cm3), Hispanics (0.760 ± 1.00 g/cm3) and Whites (0.538 ± 1.06 g/cm3). BMD and Z-scores were not different between Blacks, Hispanics and Whites.

CONCLUSION: Asians exhibited lower BMD and Z-scores compared to other racial and ethnic groups. Further investigations may provide insight into the underlying factors contributing to these differences in bone health.