African Americans have lower TBS than whites among densitometry patients at a Chicago academic center.

Abstract

Trabecular bone score (TBS), an indirect measure of bone structure, has been shown to predict fractures in predominantly white populations. Analysis of NHANES data revealed lower TBS in African Americans than in whites. However, it is not clear if this is true in patients referred for densitometry (where fracture risk stratification is most pertinent) or if ethnic differences in TBS may be related to differences in abdominal soft tissue (tissue thickness), which was not controlled for in the NHANES study. We retrospectively analyzed all BMD scans obtained at a university hospital in Chicago between 2011 and 2016. There were 3187 women (51% African American) and 675 men (32% African American). African American women were older (69.6±10.4 vs. 64.8±1.3) and heavier (BMI 28.3±4.7 vs. 25.4±4.5) than whites were, while men were of similar age and BMI. African American women had higher T-scores at all sites (the lowest of T-scores, termed LowT, -1.5±1.2 vs. -1.9±1.0, p<0.001) but lower TBS than white women even when adjusting for age and tissue thickness (1.231±0.130 versus 1.251±0.130, p<0.001). While LowT was higher in African American men (-1.1±1.2 vs. -1.5±1.4, p<0.001), TBS was lower than in white men even after adjusting for age and tissue thickness (1.232±0.144 vs. 1.275±0.144, p<0.001). African Americans had lower TBS than whites did, even with adjustment for age and tissue thickness. Ethnic differences in TBS should be considered when assessing fracture risk in clinical practice.