Diabetes is a serious disease that affects millions of Americans, and that number will grow astronomically as the baby boomer generation ages. The complications associated with diabetes can be devastating and can lead to organ failure and even death. Complications related to the feet in particular are very common in diabetes and unfortunately cause the majority of leg amputations performed by surgeons. Comprehensive care from a podiatrist can identify foot problems before they lead to leg loss and, in many cases, can prevent those problems in the first place. This article will discuss the ways a podiatrist can protect diabetic feet and ultimately save a diabetic’s limb and life.
Diabetes is a disease in which glucose, the body’s main source of “fuel,” is not properly absorbed into the body’s tissues and remains trapped in the bloodstream. Glucose is a type of ‘sugar’ derived from the body’s digestion of carbohydrates (grains, breads, pastas, sugary foods, fruits, starches and dairy products). The body needs a hormone called insulin, which is produced in the pancreas, to coax glucose into body tissue to feed it. Some diabetics are born or develop at a young age an inability to produce insulin, resulting in type 1 diabetes. Most diabetics develop their disease as they age, and the ability of insulin to attract glucose into the tissues decreases due to a kind of resistance or ineffectiveness of insulin action. This is called type 2 diabetes. Diabetes can also develop from the use of high doses of steroids, during pregnancy (where it is temporary), or after disease of the pancreas or certain infections. The high concentration of glucose in the blood that remains outside the body tissue in diabetes can cause damage to parts of the entire body. Organs and tissues that are slowly damaged by high concentrations of trapped glucose in the blood include the heart, kidneys, blood vessels, brain, nerve tissue, skin, and injury repair and immune cells. The higher the concentration of glucose in the blood, and the longer this blood glucose is present in an elevated state, the more damage will occur. Death can occur with severe levels of glucose in the bloodstream, although this is not the case in most diabetics. Most diabetics who do not control their blood glucose well develop tissue damage over a long period of time, eventually leading to serious illness, organ failure, and the possibility of losing a leg, though not right away.
Foot disease in diabetes is common and one of the most devastating and demanding complications associated directly and indirectly with high blood sugar. Foot disease presents as decreased sensation, poor circulation, an increased chance of developing wounds and skin infections, and a decreased ability to heal those wounds and skin infections. The key to this entire spectrum of foot complications is the presence of poor sensation. Most diabetics have less tenderness in their feet than non-diabetics, due to the indirect action of increased glucose on nerve tissue. This decreased sensation may be significant numbness, or it may be just subtle numbness that makes sharp objects seem smooth or erases irritation from a tight shoe. Advanced cases may actually have phantom burning or tingling pains in addition to numbness. With decreased sensation comes a much higher risk of skin injuries, primarily due to the inability to feel pain from thick calluses, sharp objects on the ground, and ill-fitting shoes. When a wound has formed as a result of the skin dying under the tension of a callus or thick callus, a needle or splinter stuck in the foot, or a tight shoe rubbing a friction burn on the skin, the diabetic foot has great difficulty starting and completing the healing process. Untreated skin wounds will break down further, and the wound can spread to deeper tissues, including muscle and bone. Bacteria will enter the body through these wounds and can potentially cause an infection that can spread beyond the foot. A diabetic’s body has a hard time defending itself against bacteria because of the way high glucose affects the same cells that eat bacteria, and diabetics also tend to get infected with multiple species of bacteria. Combine all of this with decreased circulation (and therefore less distribution of nutrients and chemicals to preserve foot tissue and help it thrive), and you have all the components in place for a potential amputation. Amputations are performed when bacteria spread throughout the body and threaten death, when wounds and tissue in the foot fail to heal as a result of gangrene from tissue death and infection, and when poor circulation prevents the tissue thrive ever again. The following statistics on leg amputation are grim: about half of diabetics who undergo an amputation will require amputation of the other foot or leg, and about the same number will die in five years due to cardiac stress when the body has to expend energy to use a prosthesis.
A podiatrist can ensure that all of the above complications are significantly limited and, in some cases, prevented altogether. Podiatrists are medical doctors who specialize solely in the care of diseases of the foot and ankle, through medicine and surgery. After college, they attend a four-year podiatric medical school and then enter a two- or three-year hospital residency program to hone their advanced reconstructive surgical skills and study advanced medicine. Podiatrists are generally considered experts on all things related to the foot and ankle, and their unique understanding, among other medical specialties, of how the foot works in relation to the leg and the ground (biomechanics) allows them to guide therapy to control or change that function in addition to treating tissue disease. The vast majority of problems that lead to diabetic amputations begin as problems related to the structure of the foot and its relationship to the ground and the shoes worn on it. Controlling or repairing these structural problems will often result in injury prevention, which in turn will prevent infection, gangrene, and amputations.
To start, a podiatrist will give a diabetic patient a comprehensive foot exam that takes into account circulation, sensation, bone deformities and skin problems, and pressures generated by walking and standing. From this initial assessment, a course of protection and treatment specific to the diabetic’s individual needs can be created for maintenance, protection, and active treatment of developing problems. Maintenance services commonly performed include regular exams several times a year to identify developing problems, toenail care to prevent a diabetic with poor sensitivity from accidentally cutting themselves while trying to cut their nails, regular thinning of calluses to prevent wounds to develop and repetitive education on diabetic foot problems to ensure proper habits are followed. Preventive services include the use of special deep shoes with protective inserts in diabetics at risk of developing wounds from regular shoes, evaluation for possible circulation problems with immediate referral to vascular specialists if necessary, and possible surgery to reduce the chance of wounds to develop in areas of bony prominences. Active treatment of foot problems by a podiatrist involves wound care and healing, treatment of diabetic infections, and surgery to treat serious foot injuries, deep infections, gangrene, and other urgent problems. Due to a podiatrist’s unique understanding of how the structure of the foot affects disease and injury, all treatment will focus on the principles of how the foot works in conjunction with the leg and the ground. This becomes invaluable in the fight to prevent diabetic wounds and infections, while allowing one to remain mobile and active at the same time.
The essential goal of a podiatrist in caring for a diabetic patient is to prevent injuries, infections, and the resulting amputations. This philosophy is called limb salvage and is achieved through the methods mentioned above. Due to the seriousness of foot disease as a complication of diabetes, a podiatrist is an integral part of a diabetic’s care, and sometimes may even be the doctor who first diagnoses diabetes if foot disease feet appears as an early symptom of undiagnosed diabetes. For these reasons, all diabetics should be evaluated by a podiatrist for potential problems, and those at risk for foot injuries and infections should receive regular foot exams and preventative treatment. As a final note, online resources from podiatrists discussing diabetic foot issues abound, including a regular blog by this author (thediabeticfoot.blogspot.com). While these resources are not a substitute for a diabetic foot exam, they do help educate diabetics on how best to care for their feet and what to do if problems develop. This can lead to a better knowledge and understanding of foot problems when diabetics start seeing a podiatrist regularly, and can help prevent the development of early foot complications.