Focus on Diabetes Health: Diabetes and the feetBy: Michael K. Laidlaw, MD
Case: HJ is a 62-year-old woman who has had type 2 diabetes for 12 years. Her average blood glucose is 220. She has had three toe amputations and now has an infection on her right big toe. How did this happen and how can it be prevented?
You've probably heard that diabetics can have infections of the feet. They may even have toes, feet or legs amputated. In fact, a diabetic is 10 times more likely to have an amputation than a non-diabetic. Why does diabetes cause this to happen? Let's have a look at the background. Recall that diabetes is a state of high blood sugar. Over time, this can cause a number of abnormalities in the body. Three types of abnormalities can lead to diabetic foot problems: nerve damage, poor blood supply and an impaired immune system. A diabetic may have one or more of these problems.
Let's look at each problem in more detail. High blood glucose over time can cause damage to nerves of the feet and legs (a condition known as neuropathy). This can lead to numbness of the skin. Because of this, a diabetic may cut or puncture their skin and not realize it. Bacteria can enter the wound, leading to an infection.
Poor blood supply is another problem predisposing to infection. Tissues require a good blood flow to deliver oxygen, nutrients and infection-fighting cells. If the blood supply is poor, not enough of these commodities are supplied to tissues. This can lead to infection and poor wound healing.
The third problem of high glucose is its effect on the immune system. A blood glucose over 180 can actually block the white blood cells (the infection-fighting cells) from working properly. Therefore, even if those cells are present (say in this patient's big toe) to fight bacteria, they haven't got the gusto to actually put up a fight.
Many times an infection is not immediately noticed by the diabetic. This allows it to fester and work its way deeper into the body. For example, it may begin at the tip of a toe and then enter the toe's bones. It may then spread deeper into the foot and up the leg. If not recognized and treated in time, a person may need their leg amputated at the knee. This is why it is essential that the diabetic check their feet (or have someone else check them) every single day! Things to look for include cuts and scrapes, redness, other discoloration, calluses, dry skin, cracks and abnormal toenails.
The doctor should examine the diabetic's foot at each diabetic checkup. Many patients also benefit from a podiatrist (a doctor who specializes in the care of the foot). Remember that infections of the feet and amputations are possible, but also quite preventable! A diabetic must be diligent in controlling their blood sugar and checking their feet every day. Proper foot care is a must.
Michael K. Laidlaw, MD, is a Rocklin physician specializing in endocrinology, diabetes and metabolism.