By Dr. Ingrid Kruse, DPM
Foot problems are a common issue for many people living with diabetes, but they’re not inevitable. In order to take an active role in preventing them, it’s important to understand why they occur so frequently in people with diabetes. The main reason is nerve damage (neuropathy), but blood flow problems (vascular disease) and diabetes that’s poorly controlled also contribute to the problem. Luckily, all of these are treatable and, more importantly, preventable.
What Is Neuropathy?
The ability to feel pain is one of our body’s main warning systems. It informs the brain that something is wrong somewhere. Ignoring pain is never a good idea. Anyone who has forced himself or herself to ignore a toothache knows that things typically get worse when you do that sort of thing. When you lose the ability to feel pain, an alarm bell will not go off, and you will become prone to injury that may go undetected.
High blood glucose levels over long periods of time (we’re talking years and years) are highly correlated with the development and progression of neuropathy, and tight blood glucose control has been shown to reduce its incidence. Neuropathy typically starts in the toes with some tingling and numbness, but can progress up the leg to where people are numb all the way up to their knees. It may also affect fingers and hands, but this is less common.
The nerves that are typically affected in diabetic neuropathy are the ones transmitting the sensations of pain, temperature, fine-touch, and pressure. It is not uncommon for people to burn themselves and not realize it. Something as simple as sitting too close to an open fireplace with your feet propped up or walking barefoot outside on hot pavement can have serious consequences.
When your feet are numb, you can also fracture a bone without knowing it. Your foot, ankle, and leg will become very swollen and warm; this is called a Charcot’s joint. It may take a long time for your doctor to figure out what is going on since there are many reasons for swelling in the feet and legs. The big distinction here is that we’re talking about just one foot and leg being swollen, not both. It is important to see your primary care provider (PCP) or podiatrist immediately if this should happen and make sure you get an x-ray or CT to check for fractures.
How Do You Know If You Have Neuropathy?
How can you tell if you have neuropathy? A simple and painless way to find out is to have your physician check your feet with the 5.07 Semmes Weinstein monofilament, which exerts 10 grams of pressure on several parts on your foot. This simple test will let you and your PCP know if you have so-called “protective sensation”; that is, enough feeling in your feet for you to know when some injury occurs. Your doctor may also do vibration testing with a tuning fork, and check reflexes, temperature sense, and pinprick sensation. Other causes of neuropathy should also be excluded before making the diagnosis of diabetic peripheral neuropathy.
Painful Diabetic Neuropathy
In some people with neuropathy, the predominant symptom is not numbness but pain. This is called painful diabetic neuropathy (PDN). The nerves are not damaged to the point where they are unable to feel anything but rather they are “irritated” and hyperactive, firing all the time and giving your brain pain messages. This type of pain is typically worse at night and the most common symptoms include burning pains, sharp shooting pains, stabbing pain, electric shock pain, tingling sensation, cramping pain, hot or cold sensations, feeling tightness in the toe joints or ankles, and hypersensitivity to even light touch, such as bed sheets or socks.
Treatment and Prevention
This neuropathic pain is difficult to treat and patients rarely have complete resolution of their pain. It is usually considered successful if a medication can decrease the pain by 50%. The typical medications used to treat neuropathy take 4 to 6 weeks before they have any effect since the doses need to be increased very slowly in order to prevent side effects. Always consult your doctor before taking any type of medication.
The majority of medications used to treat PDN fall into two categories: antidepressants and antiseizure medications. In Europe, alpha lipoic acid (an antioxidant) has been used quite successfully by giving it as an intravenous infusion, which showed not only improvement of symptoms but also nerve function. The antioxidant is also available in pill form as a nutritional supplement in the United States but there are no studies done on whether this is as effective as the intravenous therapy.
There are also topical agents to treat PDN, and also non-medication treatment options such as acupuncture, electro-acupuncture, the TENS unit (transcutaneous nerve stimulation) and more recently, axon therapy
Our best strategy for combating neuropathy is still strict glycemic control. As mentioned before, not only does this prevent the onset of neuropathy, but it has also been shown to slow down the progression of neuropathy by almost 60%! If you only have a little bit of numbness in your toes and you really optimize your blood glucose readings, you can stop neuropathy at this very early stage and prevent any of the problems that accompany nerve damage. Taking control of your diabetes will indeed prevent complications!
Blood flow problems, or vascular disease, is the second most important reason why people with diabetes can develop foot ulcers that fail to heal and result in serious problems.
Arteries are the blood vessels that carry blood from the heart to various parts of the body (including the feet) and they are usually soft and pliable structures. In people with diabetes they can become rigid due to excess calcium deposits, which makes it difficult for them to push the blood along. Furthermore, blockages can develop in the artery itself. Once you have a situation where the flow of blood is impaired, this also means that oxygen, nutrients, and even medications (such as antibiotics) do not get delivered where they should go. In a foot in which an ulcer and perhaps an infection is present, it will be almost impossible for the wound to heal.
Fortunately, we have made great progress in restoring circulation to the feet in people with vascular disease. Bypass surgery can be performed from an area above the blockage all the way down to the foot with great success. More recently, surgeons have started placing stents in the arteries to bypass them, which is a much less invasive surgery and is more easily tolerated by the patient.
Having your circulation assessed is an important part of the foot exam. This may simply require checking the pulses, but if they are absent, it may be necessary to do further testing in a vascular lab.
The incidence of vascular disease goes up with the number of years you have had diabetes, just as it does for neuropathy. It also increases with age in general, and unfortunately, we cannot do anything about those factors. Other risk factors, such as smoking, high cholesterol levels, and high blood pressure, can be addressed and treated. This will then contribute to keeping your blood flowing!
The Role of the Immune System
Your immune system plays a crucial role in fighting infection and can be adversely affected by poor blood glucose control. If your blood glucose frequently rises above 250 mg/dL, the immune cells (white blood cells) that travel through your bloodstream to the feet in order to fight infection become sluggish and don’t move well in a forward direction. Therefore, you may need to temporarily take extra insulin or a higher dose of oral medications in order to bring it back down. Testing blood glucose frequently is important whenever you are ill. When you have an infection, make sure you discuss with your HCP how to make adjustments to your medications.
The Daily Foot Inspection
Daily foot inspection is probably the single most important screening tool for preventing serious foot problems in people with diabetes! It is best done just before you go to bed, since most injuries occur not while sleeping but rather during the day:
- Wash feet daily with mild soap and dry carefully, especially between the toes, in order to prevent athlete’s foot infections. Athlete’s foot infection between the toes looks like a crack in the skin or whitish, moist-looking skin. It can also look like little blisters or bumps in the arch area or dry, peeling skin on the bottom of the foot. It may or may not itch. Treat athlete’s foot with creams such as Lamisil, Clotrimazole, or Tinactin, and remember to use the cream both in the morning and at bedtime.
- Inspect for blisters, cuts, scratches, or bruises. Check for cracks in the skin, commonly in the heels. Use moisturizers after bathing.
- If you have trouble reaching your toes, use a long-handled hand mirror or have a family member or friend assist you.
- Check your shoes for foreign objects, torn linings, or things sticking through the bottom before you put your feet in them.
- Always wear socks, but avoid socks with holes or mends.
- Shoes should fit your feet in both length and width, and they should fit perfectly at the time of purchase. Buy them at the end of the day when your feet tend to be more swollen than in the morning. The first time you wear new shoes, wear them only for 1 hour and only around the house. Then inspect your foot for blisters or red areas and slowly increase the wearing time. Medicare will pay for shoes and protective insoles if you are at risk for developing a foot ulcer. See your podiatrist for a prescription.
- Trim your nails straight across with a slightly rounded edge. If you have neuropathy, vision trouble, or difficulty trimming them yourself, see a podiatrist! Please avoid all types of “bathroom surgery,” like trying to fix an ingrown nail yourself.
- Do not walk barefoot, even in the house.
- Make the daily foot inspection a regular part of your daily routine, just like brushing your teeth.
Troubleshooting: What to Do If You Have a Cut, Wound, or Blister
What should you do if you find a blister or cut on your foot during your daily foot inspection? Cleanse the area with an antiseptic; iodine solution or hydrogen peroxide are cheap and effective antiseptics that you can buy in any drugstore. Inspect the wound for foreign objects, which should be removed. Also be sure to check your shoes – the culprit could be inside.
Apply an antibiotic ointment (such as Bacitracin ) and cover with gauze and tape, not just a band-aid. If there is any redness around the wound or if there is an odor or pus coming from the wound, you have an infection and need to be seen by your physician for wound cultures, antibiotic pills, and possibly x-rays. Do not ignore a foot infection; as it will only get worse. If you have neuropathy and experience fever, chills, nausea, vomiting, or your blood glucose is running unusually high, always check your feet—these may be warning signals that an infection is present in your foot.
Neuropathy and vascular disease are common complications of diabetes, but they do not have to lead to amputations. Early diagnosis, halting the progression of neuropathy by strict glucose control, and checking your feet daily for injuries will help you minimize problems and treat them effectively. Addressing factors regarding your circulation, such as high cholesterol, blood pressure, and smoking, will keep you from developing serious vascular disease. This cannot be stressed enough—controlling your diabetes is of the utmost importance, not only for preventing these complications but also for ensuring that your immune system is functioning at its optimum level and is ready to protect you from infection and aid in healing.
A Dose of Dr. E: Avoiding Vascular Complications
Vascular Complications: No Thanks, I’ll Pass!
When Do High and Low Blood Sugars Start to Cause Complications?
Medications and Other Treatment Options to Reduce Complications from Type 2 Diabetes
Wayne has had T1 for 44 years. The last 35 years he has taken 600mg of alpha lipoic acid every day. He has no neuropathy. We had read about the German studies back then and gave it a try. Is it the ALA? good blood sugar control? both? We don’t know but he will keep taking it!
Dr. Kruse, when I saw your name, I immediately thought of the number of Kruse’s that have diabetes in my family! I think it’s eight or 10 and counting. In any event I really liked your article as I believe I am getting neuropathy in my feet and sometimes they are hot and painful. My A1c is 6.3 and I have never been over 6.7 in the last 20 years, my hope is to have better control in the future. I take Lantis and. Januvia
Thanks, Joan Kruse.
I’m glad Wayne is doing so well! There is evidence now that oral ALA is also effective but that it takes longer (several months) compared with the intravenous form.
So, keep taking it.