DISCORDANCE BETWEEN ULTRASOUND OF THE CALCANEUS AND BONE-MINERAL DENSITY IN BLACK-AND-WHITE WOMEN

Black women have 40% of the incidence rate for hip fracture and have a higher bone mineral density (BMD) than white women. The possibility w as raised that bone quality may be disproportionately greater than the advantage in bone density in protection against osteoporotic fracture s in black versus white women. Ultrasound (US) of the calcaneus is bel ieved to measure properties of bone in addition to its density. We per formed bone density measurements and US of the calcaneus in 108 black and 177 healthy white women, aged 20-70 years. The highest correlation was seen between total body bone density and speed of sound (r = 0.75 ). The interracial differences in BMD were all statistically significa nt and varied from 3.4 to 7.6%. The US measurements had lesser interra cial differences than the bone density measurements, with velocity bar ely different between races. These findings suggest that US of the cal caneus measures properties of bone different from density. Fracture pr ediction data using US from prospective data in white women should not be extrapolated to black women because of the discordance between bon e density and US measurements. Prospective studies are needed comparin g US measurements in black women to the occurrence of osteoporotic fra ctures.