Black Women's Fracture Risk Lower Than Whites'
Among Older Women, Blacks Have Fewer Fractures Than Whites, Researchers Say
May 3, 2005 -- Older black women may have a lower bone-fracture risk than their white peers, even when compared to those who have similar
"Black women have a lower fracture risk at every level of bone mineral density," write Jane Cauley, DrPH, and colleagues in the May 4 issue of The Journal of the American Medical Association.
Bone density and fracture risk are assessed by imaging called a bone mineral density test. The test identifies low bone mineral density, which indicates
Low bone mineral density was associated with increased risk of bone fractures in both black and white women, say the researchers. However, they say bone fracture rates were 30% to 40% lower for black women at every level of bone mineral density.
Race-specific databases may be appropriate for defining osteoporosis, write Cauley and colleagues, calling for more studies. A journal editorial agrees that more work is needed on the topic.
Men are also at risk for osteoporosis as they age. This study did not include any men.
Cauley's study included 7,334 white women aged 67-99 and 636 black women aged 65-94. Their height, weight, and hip bone density were measured.
Every four months for about six years, the women were contacted by letter or phone to ask if they'd had any bone fractures. The study did not include fractures of the spine or those sustained in a major trauma, such as a car crash. Reported fractures were confirmed by X-rays.
Women could report more than one fracture.
A total of 1,712 bone fractures were reported by 1,606 white women. There were 61 bone fractures among 58 black women.
Body weight, height, age, and other factors were also considered. For instance, the researchers noted if the women took calcium supplements,
used hormones, and drank alcohol.
Those factors have been shown to affect bones. For instance, adequate calcium intake is believed to protect bones, while drinking too much alcohol may sap bone strength. Thin women are also at increased risk of osteoporosis, a condition that can run in families.
In Cauley's study, the black women were older and heavier than the white women. They were also less likely than whites to take calcium supplements, walk for exercise, or consume alcohol, say the researchers.
After taking into account a woman's age and low bone mineral density and other factors associated with increased fracture risk, black women were 48% less likely than white women to have bone fractures, says the study.
Groups With Higher Bone Risks
Looking just at the black women in the study, those who had a bone fracture tended to have a couple of things in common:
- Slightly older age
- Less likely to report walking as a form of exercise
- More likely to report osteoarthritis
- More likely to report falling two or more times in the past year
- More likely to say they needed to use their arms to stand up from a chair