Background: It is unknown if TBS predicts incident fractures in men independent of prevalent radiographic vertebral fracture (PVFx)*. Our purpose was to estimate the association of TBS with incident MOF (hip, clinical vertebral, wrist, or proximal humerus) and HF in men after adjustment for; a) PVFx and, respectively, 10 year MOF or HF risk by FRAX with BMD; and b) PVFx and individual clinical risk factors.
Methods: TBS was estimated on AP spine DXA scans obtained at the baseline visit for 5,946 men age ≧65 years enrolled in MrOS. Incident HF and MOF were ascertained by self-report every 4 months and confirmed by review of radiograph reports. The multivariable adjusted hazard ratio (HR) of incident HF and MOF over 10 years follow-up per standard deviation decrease of TBS was estimated with Cox regression.
Results: TBS was associated with a 1.2-fold increased risk of MOF adjusted for PVFx and either 10 year FRAX MOF risk or clinical risk factors. TBS was also associated with similar increase in risk of HF adjusted for PVFx and 10 year FRAX HF risk, but not with HF adjusted for PVFx and individual clinical risk factors.
|Covariates||HR per SD TBS decrease (95% C.I.)|
|PVFxa & FRAX Risk||1.24 (1.14, 1.35)||1.24 (1.08, 1.42)|
|PVFx & Individual Clinical Risk Factorsb||1.27 (1.12, 1.44)||1.09 (0.89, 1.33)|
|bAge, femoral neck BMD, prior fracture, parental history of hip fracture, body mass index, rheumatoid arthritis, glucocorticoid therapy, alcohol use, smoking status|
|aOne or more SQ grade 2 or 3 vertebral fracture(s)|
Conclusion: TBS predicts incident fractures in older men independent of PFVx and FRAX 10 year risks, and these data support development of algorithms to adjust estimated FRAX fracture risks for TBS. TBS does not predict incident hip fracture adjusted for PVFx and individual clinical risk factors.
Disclosure: The authors declared no competing interests. Funded primarily by the National Institute on Aging (NIA) under grant number 1R21AG046571-01, but also by National Institutes of Health under the following grant numbers: U01 AG027810, U01 AG042124, U01 AG042139, U01 AG042140, U01 AG042143, U01 AG042145, U01 AG042168, U01 AR066160, and UL1 TR000128.