African-Americans More Likely to Lose Limbs Due to Vascular Disease than Other Groups

Researchers at the Johns Hopkins physical medicine and rehabilitation department report that African Americans with vascular disease are up to four times more likely to have lower limb amputations than those of other groups with the same medical conditions.

The findings, reported in the September issue of the Archives of Physical Medicine and Rehabilitation, reveal that African Americans accounted for approximately 40 percent of the state's lower limb dysvascular amputations, or amputations required because of blood vessel disease. African-Americans also were more likely to have amputations at higher levels than whites, for example, while 34 percent of African-Americans underwent above knee amputations, only 27 percent of whites had the same procedure.

"Rising rates of lower limb amputations in the general population combined with disproportionately higher rates among African Americans are concerning and warrant further investigation into their underlying causes and consequences," says Timothy R. Dillingham, M.D., lead author of the study and associate professor in the Johns Hopkins' physical medicine and rehabilitation department. "We need to better understand the causes of racial differences in amputation rates and policy makers need to identify and promote public health initiatives that alleviate the excess risk of limb loss the among minority populations."

Dillingham and his team analyzed information on 27,149 Maryland hospital patients from 1986 to 1997 who required lower limb amputations due to vascular disease. Patients excluded from the study sample included those who had a lower limb amputation due to trauma, including fractures, crash and burn injuries, bone or soft tissue malignancy, or congenital anomalies.

Rates for dysvascular amputations increased from 41.4 per 100,000 in 1986 to 47.2 per 100,000 in 1997. For all levels of amputation, annual rates of amputation among African Americans were two to four times higher than whites of similar age and gender. According to Dillingham, there are approximately 133,000 amputations performed annually in the United States.

Unlike previous research examining amputation rates among diabetics, the current study looked at amputation rates over time for a broader group of patients with vascular disease. "Regardless of race or ethnicity, persons with diabetes are at a significantly higher risk of limb amputation than those without the condition," added Dillingham. "Nonetheless, even within a diabetic population, African Americans, Hispanics and Native Americans have been shown to have a higher risk of lower limb amputations than their white counterparts, although we don't know why."

The study authors say, management of patients with diabetes and peripheral vascular disease often encompasses treatment using angioplasty and bypass grafting. It is unclear whether angioplasty and bypass grafting reduce amputations for patients with diabetes or peripheral vascular disease, but Dillingham says that additional research is necessary to evaluate whether these procedures can reduce amputations or improve the quality of life for patients with leg pain due to vascular insufficiency.

The study was supported by the National Institutes of Health, National Institute of Child Health and Human Development, and the National Center for Medical Rehabilitation Research. Other authors were Liliana E. Pezzin, Ph.D., and Ellen J. MacKenzie.