Race/ethnic Differences in Bone Mineral Densities in Older Men

Summary: BMD was compared across race/ethnic groups. There were substantial race/ethnic differences in BMD even within African or Asian origin. Additional adjustment for body size greatly attenuated or reversed the differences between US Caucasian men vs Asian men. It illustrates the role of body size on the difference between these groups.

Introduction: There is insufficient epidemiologic information about men's bone mineral density (BMD) levels across race/ethnic groups and geographic locations.

Methods: In a cross-sectional design, we compared BMD in older men across seven race/ethnic groups in four countries. Femoral neck, total hip, and lumbar spine BMD were measured in men (age 65 to 78 years) from the Osteoporotic Fractures in Men (MrOS) Study (4,074 Caucasian, 208 African-American, 157 Asian, and 116 Hispanic men in USA), Tobago Bone Health Study (422 Afro-Caribbean men), MrOS Hong Kong Study (1,747 Hong Kong Chinese men), and the Namwon Study (1,079 South Korean men). BMD was corrected according to the cross-site calibration results for all scanners.

Results: When compared with US Caucasian men, Afro-Caribbean and African-American men had, respectively, 8-20% and 6-11% higher age-adjusted mean BMD at all three bone sites. Hip BMD was similar in US Caucasian and Hispanic men, US Asian, Hong Kong Chinese, and Korean men had 3-14% lower BMD at all bone sites except femoral neck in Korean men. Additional adjustment for weight and height greatly attenuated or reversed the differences between US Caucasian men vs Asian men including US Asian, Hong Kong Chinese, and South Korean men. Among Asian groups, Korean men had higher femoral neck BMD and lower total hip BMD.

Conclusion: These findings show substantial race/ethnic differences in BMD even within African or Asian origin and illustrate the important role of body size on the difference between Asian men and others.