Associates of bone mineral density in older African Americans.
OBJECTIVE
To assess correlates of bone mineral density (BMD) in older African Americans.


METHODS
189 women and 115 men over age 64.


METHODS
Variables investigated: BMD by dual X-ray absorptiometry (DXA), medications, cardiovascular disease risk factors, demographic, lifestyle factors and functional status. Variables showing univariate correlation with BMD (p < or = 0.1) were entered into sex-stratified linear regression models.


RESULTS
Age range 67-96 (mean 75). The mean BMD (gm/ cm2 +/- standard deviation) is reported for three sites. Total body: 1.03 (+/- 0.12) in women, 1.21 (+/- 0.11) in men. Spine: 1.05 (+/- 0.24) in women, 1.22 (+/- 0.26) in men. Total hip: 0.85 (+/- 0.15) in women, 1.04 (+/- 0.17) in men. Gender was significantly associated with BMD (t-test, p < 0.001). The R2 for tested variables were highly significant only for weight. Age was only significant for total hip in women (p < 0.05). Each kilogram of weight change was associated with a 5.3-6.8 mg/cm2 change in BMD.


CONCLUSIONS
In a population-based cohort of older African Americans, average BMD was significantly greater in men than women. Weight accounted for most of the explained variability (R2) in BMD; age added little to the overall R2. Lower-weight, older African-American men and women are at significantly increased risk for low BMD and, thus, likely to be at greater risk for osteoporotic fracture.
Robbins
John
J
Department of Internal Medicine, University of California, Davis, Sacramento, CA, USA. jarobbins@ucdavis.edu
Hirsch
Calvin
C
Cauley
Jane
J
D000368:Aged; D001835:Body Weight; D015519:Bone Density; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D010024:Osteoporosis / Q000208:ethnology; D012307:Risk Factors