Racial differences in bone density and fracture risk in the United States

Abstract

Many studies indicate racial differences in areal bone mineral density (aBMD). African-Americans tend to have the greatest aBMD, followed by Caucasian, Hispanic and Native Americans. Asian Americans, on average, have the lowest aBMD. Differences in aBMD are attenuated when adjustments are made for bone size, weight and lifestyle factors. While many studies have focused on racial differences in bone density, it is important to consider fracture risk since it is the clinically meaningful outcome and is determined by many factors other than bone density. African- and Asian-Americans have a relatively low risk of fracture compared to other groups, despite drastically different bone density, as measured by dual X-ray absorptiometry (DXA). Factors that cannot be completely evaluated by DXA, such as bone size, volumetric density, bone microarchitecture and turnover may be important in explaining disparate fracture rates. Newer technologies such as central quantitative computed tomography (CT) and high-resolution peripheral CT promise to contribute important knowledge in this regard. Despite recent advances, more fracture risk data is needed for non-Caucasian groups to assist in the development of relevant screening and treatment guidelines. © 2008 Asia Pacific League of Associations for Rheumatology.