Prediction of clinical non-spine fractures in older black and white men and women with volumetric BMD of the spine and areal BMD of the hip: the Health, Aging, and Body Composition Study*.
In a prospective study of 1446 black and white adults 70-79 yr of age (average follow-up, 6.4 yr), vertebral TrvBMD from QCT predicted non-spine fracture in black and white women and black men, but it was not a stronger predictor than total hip aBMD from DXA. Hip aBMD predicted non-spine fracture in black men.


BACKGROUND
Areal BMD (aBMD) at multiple skeletal sites predicts clinical non-spine fractures in white and black women and white men. The predictive ability of vertebral trabecular volumetric BMD (TrvBMD) for all types of clinical non-spine fractures has never been tested or compared with hip aBMD. Also, the predictive accuracy of hip aBMD has never been tested prospectively for black men.


METHODS
We measured vertebral TrvBMD with QCT and hip aBMD with DXA in 1446 elderly black and white adults (70-79 yr) in the Health, Aging, and Body Composition Study. One hundred fifty-two clinical non-spine fractures were confirmed during an average of 6.4 yr of >95% complete follow-up. We used Cox proportional hazards regression to determine the hazard ratio (HR) and 95% CIs of non-spine fracture per SD reduction in hip aBMD and vertebral TrvBMD.


RESULTS
Vertebral TrvBMD and hip aBMD were both associated with risk of non-spine fracture in black and white women and black men. The age-adjusted HR of fracture per SD decrease in BMD was highest in black men (hip aBMD: HR = 2.04, 95% CI = 1.03, 4.04; vertebral TrvBMD: HR = 3.00, 95% CI = 1.29, 7.00) and lowest in white men (hip aBMD: HR = 1.23, 95% CI = 0.85, 1.78; vertebral TrvBMD: HR = 1.06, 95% CI = 0.73, 1.54). Adjusted for age, sex, and race, each SD decrease in hip aBMD was associated with a 1.67-fold (95% CI = 1.36, 2.07) greater risk of fracture, and each SD decrease in vertebral TrvBMD was associated with a 1.47-fold (95% CI = 1.18, 1.82) greater risk. Combining measurements of hip aBMD and vertebral TrvBMD did not improve fracture prediction.


CONCLUSIONS
Low BMD measured by either spine QCT or hip DXA predicts non-spine fracture in older black and white women and black men. Vertebral TrvBMD is not a stronger predictor than hip aBMD of non-spine fracture.
Mackey
Dawn C
DC
San Francisco Coordinating Center, California Pacific Medical Center Research Institute, San Francisco, CA 94107, USA. dmackey@sfcc-cpmc.net
Eby
Jean Gaare
JG
Harris
Fran
F
Taaffe
Dennis R
DR
Cauley
Jane A
JA
Tylavsky
Frances A
FA
Harris
Tamara B
TB
Lang
Thomas F
TF
Cummings
Steven R
SR
D001741:Black or African American; D000368:Aged; D001823:Body Composition; D015519:Bone Density; D005260:Female; D005500:Follow-Up Studies; D050723:Fractures, Bone / Q000453:epidemiology* / Q000208:ethnology; D006615:Hip; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012737:Sex Factors; D013131:Spine; D014481:United States; D044465:White People