The study, published in the Journal of Vascular Surgery, found that in the South and West sides of Chicago, African-Americans comprised less than 15 percent of the population, but accounted for 27 percent of all amputation discharges for 33,775 patients at 171 hospitals during the study period of 1987 to 2004.

Lead author Joseph M. Feinglass and co-author William H. Pearce of the Northwestern University Feinberg School of Medicine in Chicago said statistics for the 8 million residents in northern Illinois indicate that major -- above and below knee -- amputation rates declined to 17 per 100,000 residents in the last decade.

Better diabetes management, introduction of statin drugs -- which benefit patients with peripheral arterial disease -- and improved vascular surgery and angioplasty procedures, including increased lower extremity stent replacement, are the most likely reasons for the reduction of overall amputations, the researchers said.

"However, lack of access to educational opportunities or medical care in both the Hispanic and African-American communities creates racial disparities which have remained constant, despite progress in reducing the overall major amputation rate," Pearce said in a statement.