Test may help diabetics save their feet

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Test may help diabetics save their feet
By Stephanie Innes
Arizona Daily Star
Tucson, Arizona | Published: 01.26.2009


A common blood test to assess heart disease could help prevent people with diabetes from having limbs amputated, a Tucson podiatrist and researcher says.
That's especially important in Southern Arizona, "the epicenter of diabetes," says Dr. David G. Armstrong.
He published the results of his peer-reviewed study on using the C-reactive protein test for diabetics in this month's issue of the Journal of Foot and Ankle Surgery.
Diabetes results in the amputation of about 96,000 limbs in the U.S. every year, and most of those are preventable, says Armstrong, who directs the University of Arizona's new Southern Arizona Limb Salvage Alliance.
The alliance works, through clinical care and research, to improve foot care among diabetics and to prevent amputations in North America and worldwide.
Armstrong, who is also a professor of surgery at the UA, came to Tucson last year to direct the alliance, located at University Medical Center.
He created a similar, internationally recognized program at the Scholl College of Podiatric Medicine at Rosalind Franklin University of Medicine and Science in Chicago. He also helped to create amputation-prevention programs on six continents and to develop classifications of risks and wounds that are used as standards worldwide.
One of the reasons Armstrong came to Southern Arizona is its high rate of diabetes, which is due in part to a "triple whammy" of three high-risk populations — seniors, Hispanics and American Indians.
The latest study, which he co-authored, says the C-reactive protein test, when combined with a clinical assessment of wounds in diabetics, may be more accurate in detecting limb-threatening bone infection than either test alone.
In an interview, Armstrong talked about what that means for diabetics and their doctors:
Q: Why would a test for inflammation in the arteries of the heart have anything to do with the risk of limb loss in diabetics?
A: "The test is a marker to detect high-grade inflammation. For so many problems in the body, so much is caused by unwanted or uncontrolled inflammation. The whole concept of inflammation seems to be consistent with the source and progression of so many diseases now.
"If you add on the method of looking for inflammation to the clinical techniques we use for diabetes patients, then it increases the accuracy in pinpointing a problem. . . .
"The bottom line is that every 30 seconds, someone in the world loses a limb to diabetes. The reason is that people get wounds on their feet, called ulcers. They wear a hole in the foot like a hole in a stocking. People with diabetes may ultimately lose the gift of pain, so they are often unaware there's a problem."
Q: What does this study mean in terms of what doctors could be doing differently?
A: "This is one test that could improve the batting average. But it is not a substitute for the good quality care of a team approach to preventing amputation.
"Sometimes the C-reactive protein test is already part of the battery of tests a doctor may order for their patient. But this may alert them to look at that result more closely. It is not an exotic test. The results of the study are an additional arrow in our quiver."
Q: Does a lot of potentially limb-threatening bone infection — osteomyelitis — go undetected?
A: "A lot of foot infections in general go undetected, delayed or ignored. We say, 'If you ignore your feet, they'll go away.'
"The sinister thing about diabetes is that the symptoms are muted or erased. These kinds of problems are silent, and the damage affects millions of people and costs more than the entire U.S. cell phone industry."
Q: What is the Southern Arizona Limb Salvage Alliance (known as SALSA), and what do you mean by limb salvage?
A: "Work from our unit and others suggests that 85 to 90 percent (of amputations) are preventable. The key ingredient is the team. We boil the team down to what we call the 'toe and the flow.'
"SALSA is a service of the surgery department, part of vascular surgery. We have one of the best vascular surgery programs in the country in terms of peripheral vascular surgery here. When the vascular part — the flow — is sorted out, it becomes a structural problem. I take care of wound healing, targeted surgical intervention, prevention.
"We've seen thousands of patient visits, and we're getting busier."
Q: How can patients use the results of your study to improve their outcomes?
A: "They can bring up the issue of the (C-reactive protein) test, but much more importantly, they should see a foot specialist. . . . All of these big problems — the infections, gangrene, amputations — all start out as minor problems. The key is to intervene at that time.
"The next time someone with diabetes goes to their doctor, I would say, 'Knock your socks off.' If they take their shoes and socks off in the doctor's office, it may prompt the doctor to evaluate a problem that neither knew was there."

Contact medical reporter Stephanie Innes at 573-4134 or at sinnes@azstarnet.com