How does Diabetes affect the feet?

There are several types of diabetes, yet they all have relatively similar changes occurring in the foot, which is directly related to sugar levels being too high in the blood. When sugar levels run high in the blood, a diabetic individual becomes very susceptible to developing a condition called NEUROPATHY, which basically means nerve damage or nerve dysfunction. Why is this important? Because the nerves in our feet perform many important functions unknown to most people. Most people think of our nerves as providing us with our feeling of sensation, but they also perform many other important functions as listed below.

1. Position Sense (proprioception). Our ability to determine where our body parts (i.e. foot) are in relation to space or our shoe is dependent on us having intact position sense. Unfortunately prolonged high blood sugars cause the nerves in diabetic individuals to fail to alert them to where their feet are in relation to the ground or the inside of the shoe. This causes the person with diabetes to damage their joints and rub their feet on the inside of their shoe without feeling pain.

2. Sensation. Before frank numbness sets in, most diabetic individuals experience sensations of pins and needles or burning in their feet and legs. Typically after approximately a year this is followed by numbness, which starts at the ends of the toes and progresses up into the foot. Because of this numbness, a diabetic cannot feel if their shoe is rubbing a blister on their foot, or perhaps if something has fallen into the shoe and is causing damage to their foot. They also may not be able to appreciate how hot their bath water is or how hot the sand at the beach is. For this reason, going barefoot is strongly discouraged. 

3.  Sebaceous oil gland secretion. Believe it or not, how moist our feet are is controlled by our nerves. If the nerves of the diabetic individual are damaged by high blood sugars, the nerves lose their ability to regulate the amount of moisture in the skin of the foot. This makes the skin of the diabetic more susceptible to cracking and rubbing from the shoe. 

4.  Vasodilation. If the nerves are damaged they lose their ability to regulate the blood flowing into the foot, which causes the mineral content of the bones to be washed away rendering the bones weak and brittle. If you add this to the loss of position sense described above, this is an equation for disaster. 

5.  Intrinsic muscle (muscles in the foot) weakness. When the nerves are damaged, they fail to offer optimal stimulation to muscles in the foot, which causes the toes to become contracted up (hammertoes). This is a very serious problem because now all of the force of body weight is concentrated on the ball of the foot in a person who can't feel that part of their foot. This leads to a breakdown of the skin in this part of the foot, which the individual cannot feel because of the loss of sensation (numbness) now present in their foot. This skin breakdown is called an ulcer. Ulcers are one of the biggest reasons for hospital admission, intravenous antibiotics and ultimately amputation in the diabetic population.

Although the most significant problem facing diabetic feet is neuropathy, it unfortunately is oftentimes joined by immune deficiency, decreased circulation and other problems.

Immune deficiency. Diabetic individuals are particularly susceptible to fungal and yeast infections of the feet and especially the toenails. Couple this with the fact that the white blood cells don't do their job correctly and you have an unusually high rate of infection, many times the signs of which the diabetic individual completely misses due to the numbness.

          Important signs of infection…
*Redness (erythema)
*Heat
*Swelling
*Drainage
*Foul odor
*PAIN IS NOT A RELIABLE INDICATOR IN A DIABETIC 

What Can Be Done?

Control the high sugar (hyperglycemia). This is up to the patient and patients primary caregiver. Many times long term tests such as Hemoglobin A1c or Fructosamine will help to determine how well controlled the sugars have been to allow the diabetic to rate how well their particular protocol is doing. This is THE MOST IMPORTANT factor in decreasing the likelihood of nerve damage (neuropathy).

Look at the feet everyday. If the patient has poor vision, a family member or caregiver should look at the feet, especially the bottoms and between the toes. Any blisters, cracks, redness, swelling, or any signs mentioned above should be considered emergent warranting an immediate visit to the podiatrist or primary care physician. 

No barefoot walking. Even in the house! Because of the numbness, a number of interesting objects have become embedded in the feet of patients, with no recollection about the event. Sewing needles are one of the common offenders. 

Don't soak the feet of a diabetic. Because of the sweat gland damage mentioned above, soaking the feet removes whatever protective moisture is present. If the feet are soaked, or after bathing, put lotion on the feet. A good one is Bag Balm. No lotion between the toes as this increases the likelihood of infection, particularly from fungus (athletes foot infection). In order to increase the moisturizing properties of whatever you choose to use, put saran wrap around the foot after placement of the lotion and wear while sleeping. 

Wear proper shoes. Because of the numbness that so often accompanies the diabetic state, tight fitting shoes are a common offender in causing blisters and ulcers. Medicare individuals with diabetes are entitled to one free pair of shoes per year and 3 free inserts made of a material called plastizote, which protects numb feet. 

Regular examinations are a must. Periodic reduction of long thick toenails greatly reduces the incidence of ingrown toenails and resultant infection.

As part of a regular examination, all diabetic individuals should be tested for something called protective threshold, which is a determiner of how well their nerves are able to alert them to damaging forces. This test is carried out using a monofilament placed at various places on the bottom of the foot.

Proper nutrition and weight loss are also encouraged as part of an overall well-being program.