Black women at less risk of fractures

May 3 2005

A recent report from the U.S. surgeon general on bone health and osteoporosis has found that black women have a lower risk of fracture than white women at every level of bone mineral density.

The report published in the Journal of the American Medical Association says that one in two individuals older than 50 years will be at risk for fractures from osteoporosis, and despite lower fracture rates among black women, osteoporosis is a risk for any aging man or woman, with low Bone Mineral Density (BMD) and is an important predictor for fracture risk.

In the study Jane A. Cauley, Dr.P.H., from the University of Pittsburgh, and colleagues examined nonspinal fractures in older women as part of the Study of Osteoporotic Fractures. Data was collected for 1986-1990 from 7,334 white women aged 67-99 years, and for 1996-1998 from 636 black women aged 65-94 years, with an average 6.1 years of follow-up. Bone mineral content and bone mineral density of the hip and the femoral neck were measured.

Researchers found that black women in the study had a lower risk of fracture than white women at every level of BMD. Fifty-eight black women had a total of 61 fractures, while 1,606 white women had a total of 1,712 fractures. At the beginning of the study, black women had a nine percent higher total hip BMD and a 15 percent higher femoral neck BMD than white women.

The association between BMD and fracture was weakened when adjusted for body weight and other risk factors, especially among black women. The absolute incidence of fracture across the pooled BMD distribution was 30 percent to 40 percent lower among black women at every BMD tertile. However, it is unknown how BMD is associated with fracture in older black women.

The researchers say they have demonstrated that reduced BMD of the hip and femoral neck is associated with an increased risk of all nonspinal fractures in older black women in age-adjusted models, a relationship largely mitigated by other risk factors and that results suggest that low BMD is useful to identify blacks at risk of experiencing an osteoporotic fracture and those who may benefit from therapy and other preventive measures.