If the Shoe Doesn't Fit...

Nov. 20, 2007 — -- More than 80,000 foot amputations are performed every year on people with diabetes. Most of these are preventable, and one of the culprits for amputation is right below your nose: your shoes.

According to a new study, 63 percent of diabetic patients wear the wrong size shoes, putting them at higher risk of developing foot ulcers, which can lead to amputations.

"We were seeing so many patients in the clinic, with foot ulcers, we decided to investigate this problem," said Dr. Graham Leese of the diabetic clinic at Ninewells Hospital and Medical School at the University of Dundee, in the United Kingdom. Leese authored the study.

In the study, published this week in the International Journal of Clinical Practice, the researchers measured the foot length of 100 diabetic patients, and took measurements, and noted the various deformities that patients had with their feet. They found that 63 of these patients were wearing shoes of the wrong size, usually too tight or too narrow.

"One person in four or five with diabetes will develop a diabetic ulcer," said Leese, adding that shoes that don't fit are a big part of this problem.

The Gift of Pain

For most people, wearing shoes a little too small or narrow is not a big deal.

"The percentage of nondiabetic people wearing the wrong size shoes is probably the same, not much worse," said Leese. "But if you have good feeling in your feet, you will know when your shoes aren't comfortable."

The problem stems from the inability to feel pain — called diabetic neuropathy, or numb feet.

"When you can't feel your feet, you can't feel the shoe rubbing," said Leese. And 80 percent of eventual amputations start with an ulcer, which can be caused by rubbing.

If this ulcer becomes infected, it can lead to big problems, especially when combined with poor circulation.

"The combination of numb feet, infection, and poor circulation can really be the start of trouble," said Leese.

Previous studies into shoe size yielded results similar to Leese. In 2006, Dr. David Armstrong evaluated the shoe sizes of 440 patients at a Veterans Affairs Medical Center in southern Arizona, and found that nearly 75 percent of the veterans were wearing improperly sized shoes.

"Pain is a gift," said Armstrong, associate dean of the William M. Scholl College of Podiatric Medicine at Rosalind Franklin University of Medicine and Science, and a spokesperson for the American Diabetes Association. "It's a gift that no one wants, but a gift, nonetheless. Patients with diabetes lose that gift."

It's often hard for patients to pinpoint when neuropathy sets in, but a doctor can test the sensitivity on both feet. Once the pain sensation is lost, "they can't feel when they're in discomfort. They'll wear a hole in their foot, the same way you or I will wear a hole in our sock," said Armstrong.

Putting the Best Foot Forward

According to Armstrong, the need for better foot awareness is clear. "The end result is amputation, and the five-year mortality rate for amputation is actually worse than it is for cancer. And that is so extraordinary to us."

He recommends that patients with diabetes get their feet checked at least once a year — more often, if they have problems. And he offers a simple recommendation for daily comfort.

"Change your shoes two or three times a day," Armstrong said. "In the time it takes you to take off the shoes and put on another pair, you can rest the skin and pressure points. And you can also look at your feet to see if any ulcers are occurring."

Armstrong's group studies the use of a new skin thermometer, which could help patients detect early when their feet are rubbing against their shoes.

Study author Leese agrees that there are steps people can take.

"Look at your footwear when it's on your feet," he said. "Look for bulging around the toes, which means that the shoe is too narrow." He recommends examining the feet every day, looking for signs of rubbing or redness, to catch any problems in the earliest stage.

"Fortunately, foot ulcers and amputations can be prevented at least half the time, if not more," said Dr. Aaron Vinik, research director of the Strelitz Diabetes Center at Eastern Virginia Medical School, in ABCNEWS.com's special Diabetes Resource Site.

The most important details, according to Vinik, include "excellent glycemic control, prevention of neuropathy, prevention of deterioration of blood supply to the foot, as well as inspecting the foot on a regular basis."

Treating diabetes becomes a struggle for physicians to recognize and respond to the absence of symptoms, rather than the symptoms themselves, according to Armstrong. And for patients, he recommends, "Use the gift of pain; let comfort guide you."