TYPE 2 DIABETES AND AMPUTATION
Nerve disease caused by type 2 diabetes is the leading cause of amputation of feet, toes, legs, hands and arms among diabetes sufferers. Collectively, the disorders which cause these amputations are called Diabetic Neuropathies.
Foot problems are the most frequent reasons for hospitalization of people with type 2 diabetes. But many diabetes-linked hospitalizations and amputations could be prevented by better management of diabetes via increased insulin sensitivity and the reversal of the imbalance of blood glucose and insulin called Insulin Resistance.
The earlier that action is taken to maximize insulin sensitivity, the greater the chance is of avoiding the need for amputation.
Sadly, jazz legend Ella Fitzgerald received a late diagnosis of diabetes and had to have both legs amputated below the knee.
People with diabetes can, over time, develop damage to nerves throughout the body. Neuropathies lead to numbness and sometimes pain and weakness in the hands, arms, feet, and legs. Problems may also occur in other areas, including the digestive tract, heart, and sex organs.
Persons with diabetes can develop nerve problems at any time. But the longer a person has diabetes, the greater the risk. An estimated 50% of persons with diabetes have some form of neuropathy, though not all those with neuropathy have symptoms. The highest rates of neuropathy are among people who have had the disease for at least 25 years.
Diabetic neuropathy also appears to be more common in people who have problems controlling their blood sugar, in people with high levels of blood fat and blood pressure, in overweight people and in those over the age of 40. The most common type of neuropathy is peripheral neuropathy - also called distal symmetric neuropathy - which affects the arms and legs.
Researchers are studying the effect of glucose on nerves to find out exactly how prolonged exposure to high glucose levels causes neuropathy. Nerve damage is likely due to a combination of factors:
- metabolic factors, such as having Metabolic Syndrome (Syndrome X), high blood glucose, long duration of diabetes, low levels of insulin and abnormal blood fat levels (high triglycerides and LDL "bad" cholesterol and low levels of HDL "good" cholesterol)
- neurovascular factors, such as damage to the blood vessels that carry oxygen and nutrients to the nerves
- auto-immune factors that cause inflammation in nerves
- mechanical injury to nerves, such as carpal tunnel syndrome
- inherited traits that increase susceptibility to nerve disease
- lifestyle factors such as smoking or alcohol use
Some people experience both pain and numbness. Often, symptoms are minor at first and, since most nerve damage occurs over several years, mild cases may go unnoticed for a long time.
Symptoms may include:
- numbness, tingling or pain in the toes, feet, legs, hands, arms and fingers
- wasting of the muscles of the feet or hands
- indigestion, nausea or vomiting
- diarrhea or constipation
- dizziness or faintness due to a drop in blood pressure when changing positions (i.e. going from sitting to standing)
- problems with urination
- erectile dysfunction (ED) or vaginal dryness
- feeling of weakness
By lowering insulin intake and dependency through more effective management of your diabetes, you are likely to experience better long-term health and a greater sense of well being. You may also reduce your risk as a person with diabetes of developing serious, insulin imbalance-linked complications such as the need for amputation, failing eyesight and kidney disease.
Types of Diabetic Neuropathy:Peripheral Neuropathy
This type of neuropathy damages nerves in the upper and lower extremities. The feet and legs are likely to be affected before the hands and arms. Many people with diabetes have signs of neuropathy upon examination but have no symptoms at all.
Symptoms of peripheral neuropathy may include: numbness or insensitivity to pain or temperature, a tingling, burning or prickling sensation, sharp pains or cramps extreme sensitivity to touch. These symptoms are often worse at night.
Peripheral neuropathy may also cause signs such as muscle weakness and loss of reflexes, especially at the ankle, leading to changes in gait (the way someone walks). Foot deformities, such as hammertoes and the collapse of the mid-foot, may occur.
Peripheral Neuropathy and Foot Care
The nerves to the feet are the longest in the body and are the ones most often affected by neuropathy. Loss of sensation in the feet means that blisters, sores or injuries may not be noticed.
There is an increased risk of ulceration or infection because pressure or injury goes unnoticed. If foot injuries are not treated promptly, the infection can spread to the bone, and the foot may then have to be amputated. Circulation problems can also cause ulcers.
More than half of all lower limb amputations in the United States occur in people with diabetes – 86,000 amputations per year at the last count. Doctors estimate that nearly half of the amputations caused by neuropathy and poor circulation could have been prevented by careful foot care. Here are general steps for persons with diabetes to follow; please consult your healthcare practitioner for specific guidelines:
- Clean your feet daily, using warm – not hot – water and a mild soap. Avoid soaking your feet. Dry them with a soft towel and dry carefully between your toes.
- Inspect your feet and toes every day for cuts, blisters, redness, swelling, calluses, or other problems. Use a mirror (laying a mirror on the floor works well) or get help from someone else if you cannot see the bottoms of your feet. Notify your health care provider of any problems.
- Moisturize your feet with lotion but avoid getting it between your toes.
- After a bath or shower, file corns and calluses gently with a pumice stone.
- Each week or when needed, cut your toenails to the shape of your toes and file the edges with an emery board.
- Always wear shoes or slippers to protect your feet from injuries. Prevent skin irritation by wearing thick, soft, seamless socks.
- Wear shoes that fit well and allow your toes to move. Break in new shoes gradually by wearing them for only an hour at a time at first.
- Before putting your shoes on, look them over carefully and feel the insides with your hand to make sure they have no tears, sharp edges, or objects in them that might injure your feet.
- If you need help taking care of your feet, make an appointment to see a foot doctor, also called a podiatrist.
- quitting smoking
- checking your blood sugar levels carefully to make sure they are controlled
- eating a healthy, balanced diet
- being physically active to maintain strength, flexibility and blood flow to damaged areas and to control pain - good exercises include cycling, swimming and aqua aerobics
- seeing your doctor regularly
- reducing your weight to a healthy level
- checking with a doctor before using heating pads or electric blankets to avoid burning your skin, since feelings in your limbs could be lost
Autonomic neuropathy affects the nerves that control the heart, regulate blood pressure and control blood glucose levels. It also affects other internal organs, causing problems with digestion, respiratory function, urination, sexual response and vision.
In addition, the system that restores blood glucose levels to normal after a hypoglycemic (low blood sugar) episode may be affected, resulting in loss of the warning signs of hypoglycemia such as sweating and palpitations.
This loss is called "hypoglycemia unawareness." Normally, symptoms such as shakiness occur as blood glucose levels drop below 70 milligrams per deciliter (mg/dL) In people with autonomic neuropathy, symptoms may not occur, making hypoglycemia difficult to recognize.
However, other problems can also cause hypoglycemia unawareness (see the separate article Diabetes and Hypoglycemia on this web site), so this condition does not always indicate nerve damage.
Heart and Circulatory System
The heart and circulatory system are part of the cardiovascular system, which controls blood circulation. Damage to nerves in the cardiovascular system interferes with the body's ability to adjust blood pressure and heart rate. As a result, blood pressure may drop sharply after sitting or standing, causing a person to feel light-headed – or even to faint.
Damage to the nerves that control heart rate can mean that it stays high, instead of rising and falling in response to normal body functions and exercise.
Nerve damage to the digestive system most commonly causes constipation. Damage can also cause the stomach to empty too slowly, a condition called gastroparesis.
Severe gastroparesis can lead to persistent nausea and vomiting, bloating and loss of appetite. Gastroparesis can make blood glucose levels fluctuate widely as well, due to abnormal food digestion.
Nerve damage to the esophagus may make swallowing difficult, while nerve damage to the bowels can cause constipation alternating with frequent, uncontrolled diarrhea, especially at night. Problems with the digestive system may lead to weight loss.
Urinary Tract and Sex Organs
Autonomic neuropathy most often affects the organs that control urination and sexual function. Nerve damage can prevent the bladder from emptying completely, allowing bacteria to grow in the bladder and kidneys and causing urinary tract infections. When the nerves of the bladder are damaged, urinary incontinence may result because a person may not be able to sense when the bladder is full or control the muscles that release urine.
Neuropathy can also gradually decrease sexual response in men and women, although the sex drive is unchanged. A man may be unable to have erections (erectile dysfunction or ED) or may reach sexual climax without ejaculating normally. A woman may have difficulty with lubrication of the vagina or achieving arousal and orgasm.
Autonomic neuropathy can affect the nerves that control sweating. When nerve damage prevents the sweat glands from working properly, the body cannot regulate its temperature properly. Nerve damage can also cause profuse sweating at night or while eating.
Finally, autonomic neuropathy can affect the pupils of the eyes, making them less responsive to changes in light. As a result, a person may not be able to see well when the light is turned on in a dark room or may have trouble driving at night.
Proximal neuropathy, sometimes called lumbosacral plexus neuropathy, femoral neuropathy or diabetic amyotrophy, starts with pain in either the thighs, hips, buttocks, or legs, usually on one side of the body.
This type of neuropathy is more common in those with type 2 diabetes and in older people.
Proximal neuropathy causes weakness in the legs, manifested by an inability to go from a sitting to a standing position without help. Treatment for weakness or pain is usually needed. The length of the recovery period varies, depending on the type of nerve damage.
Occasionally, Diabetic Neuropathy suddenly affects specific nerves, most often in the eye, face, torso or leg. Focal neuropathy may cause inability to focus the eye, double vision, aching behind one eye, paralysis on one side of the face (Bell's palsy) and severe pain in the lower back.
There can be pain in the front of a thigh, in the chest, stomach and on the outside of the shin or inside the foot, as well as abdominal pain that is sometimes mistaken for heart disease, heart attack, or appendicitis. However, it tends to improve by itself over weeks or months and does not cause long-term damage.
People with diabetes also tend to develop nerve compressions or entrapment syndromes. One of the most common is carpal tunnel syndrome, which causes numbness and tingling of the hand and sometimes muscle weakness or pain. Other entrapment syndromes may cause pain on the outside of the shin or the inside of the foot.
Diagnosis of Diabetic NeuropathyNeuropathy is diagnosed on the basis of symptoms and a physical examination. During the examination, the doctor may check blood pressure and heart rate, muscle strength, reflexes and sensitivity to pressure, temperature or a light touch.
The doctor may also do other tests to help determine the type and extent of nerve damage.
- A comprehensive foot exam assesses skin, circulation and sensation. The test can be done during a routine office visit. To assess protective sensation or feeling in the foot, a nylon monofilament (similar to a bristle on a hairbrush) attached to a wand is used to touch the foot. Those who cannot sense pressure from the monofilament have lost protective sensation and are at risk for developing foot sores that may not heal properly. Other tests include checking reflexes and assessing vibration perception, which is more sensitive than touch perception.
- Nerve conduction studies check the transmission of electrical current through a nerve. With this test, an image of the nerve conducting an electrical signal is projected onto a screen. Nerve impulses that seem slower or weaker than usual indicate possible damage. This test allows the doctor to assess the condition of the nerves in the arms and legs.
- Electromyography (EMG) shows how effectively muscles respond to electrical signals transmitted by nearby nerves. The electrical activity of the muscle is displayed on a screen. A response that is slower or weaker than usual suggests damage to the nerve or muscle. This test is often done at the same time as nerve conduction studies.
- Quantitative sensory testing (QST) uses the response to stimuli, such as pressure, vibration and temperature, to check for neuropathy. QST is increasingly used to recognize sensation loss and excessive irritability of nerves.
- A check of heart rate variability shows how the heart responds to deep breathing and to changes in blood pressure and posture.
- Ultrasound uses sound waves to produce an image of internal organs. An ultrasound of the bladder and other parts of the urinary tract, for example, can show if these organs maintain a normal structure and whether the bladder empties completely after urination.
- Nerve or skin biopsy involves removing a sample of nerve or skin tissue for examination by microscope. This test is most often used in research settings.
The first step is to bring blood glucose levels within the normal, healthy range to prevent further nerve damage. Although symptoms may get worse when blood glucose is first brought under control, maintaining lower blood glucose levels via improved insulin sensitivity over time helps lessen neuropathic symptoms.
Importantly, good blood glucose control may also help prevent or delay the onset of further problems.
FURTHER READING Abdul-Ghani, M. Increased prevalence of microvascular complications in type 2 diabetics with the metabolic syndrome. Isr Med Assoc J. 2006 Jun;8(6):378-82.
Vinik, AI. Diabetic autonomic neuropathy. Diabetes Care. 2003 May;26(5):1553-79.
Maji, D. Prevention of microvascular and macrovascular complications in diabetes mellitus. J Indian Med Assoc. 2004 Aug;102(8):426, 428, 430 passim.
Hayden, MR. Neural redox stress and remodeling in metabolic syndrome, type 2 diabetes mellitus, and diabetic neuropathy. Med Sci Monit. 2004 Dec; 10(2):RA291-307.