Surgical amputation of toes, feet or legs is a dreaded outcome of diabetes that can be prevented with good medical care. That can be hard to get if you live in the wrong zip code. People with diabetes in the lowest income neighborhoods of California were 10 times more likely to lose lower extremities to amputation than people with diabetes in the highest income neighborhoods, according to a new paper published in Health Affairs.

Many news outlets covered the story, but none that I read provided much context beyond repeating what the Health Affairs paper had to say, which is a shame because there’s a lot to report. Most didn’t even bother to mention the racial divide and relentless impact of segregation on diabetes outcomes.

The study authors mapped hot spots of diabetic amputation in Los Angeles and across California, where rates varied from less than 1 to more than 10 amputations per 1,000 people age 45 and older with diabetes in 2009.

Many earlier studies have documented brutal racial inequalities in diabetes care. Blacks in the United States are two to four times more likely than whites to have diabetes-related amputations. Rates in some Native American populations remain three to four times higher than in non-Hispanic whites.

The root causes have been pretty well established. People in disadvantaged or racially segregated neighborhoods lack access to high-quality primary care and easily navigable chronic disease management support. And this unequal access probably explains much of the difference in diabetes outcomes.

“These shockingly higher rates for areas with large minority populations underscore the limits of improvements in medical care when access to care differs,” asserted Joe Feinglass of Northwestern University and co-authors of a study of racial differences in diabetic amputations in northern Illinois. The magnitude of the disparities “can only be explained by differences in social determinants of health, and reflect the disease burden frequently associated with the effects of low socioeconomic status, segregation, and concentrated neighborhood poverty,” the Chicago-based authors concluded.

Some authorities continue to argue that innate genetic differences could partly explain the drastically worse outcomes among blacks and Native Americans. Others like to emphasize individual behavior and lack of self-care as causes. Neither claim is persuasive. People of African descent in the United Kingdom who have diabetes face no greater risk of amputation. In fact, their risk may even be lower than that of people of European descent in the U.K., a nation that decades ago established universal health coverage and access to primary care for everyone.

When marginalized people in the U.S. develop limb-threatening complications of diabetes requiring specialty care, they’re more likely to go to hospitals with less experience doing procedures that can save limbs and where doctors more often resort to amputation.

One study found that blacks are less likely than whites to undergo attempts to save limbs with revascularization procedures – even after adjusting for differences in socioeconomic status, severity of diabetes, presence of other health problems, and characteristics of the hospital or providers from whom black and white patients receive care.

And when blacks undergo revascularization procedures, they are more likely to have them done by nonspecialists in low-volume hospitals with high amputation rates, another study uncovered.

[The figures are from Geographic Clustering Of Diabetic Lower-Extremity Amputations In Low-Income Regions Of California, by Carl D. Stevens, David L. Schriger, Brian Raffetto, Anna C. Davis, David Zingmond and Dylan H. Roby, Health Affairs (2014)]

[I posted an earlier version of this rant over at Covering Health, the blog of the Association of Health Care Journalists.]