Diabetes mellitus is a chronic disease caused by the inability of the pancreas to produce insulin or to use the insulin produced in the proper way. Diabetes is the 7th leading cause of death among Americans; over 15 million Americans suffer from one form or another of this disease.
After a meal, a portion of the food a person eats is broken down into sugar (glucose). The sugar then passes into the bloodstream and to the body's cells via a hormone (called insulin) that is produced by the pancreas.
Normally, the pancreas produces the right amount of insulin to accommodate the quantity of sugar. However, if the person has diabetes, either the pancreas produces little or no insulin or the cells do not respond normally to the insulin. Sugar builds up in the blood, overflows into the urine and then passes from the body unused. Over time, high blood sugar levels can damage:
- eyes - leading to diabetic retinopathy and possible blindness
- blood vessels - increasing risk of heart attack, stroke and peripheral artery obstruction
- nerves - leading to diabetic neuropathy, foot sores and possible amputation, possible paralysis of the stomach, chronic diarrhea
- kidneys - leading to kidney failure
Diabetes has also been linked to impotence and digestive problems. It is important to note that controlling blood pressure and blood glucose levels, plus regular screenings and check-ups, can help reduce risks of these complications.
There are two main types of diabetes, Type I and Type II:
Type I diabetes or insulin-dependent diabetes (formerly called juvenile-onset diabetes, because it tends to affect persons before the age of 20) affects about 10 percent of people with diabetes. With this type of diabetes, the pancreas makes almost no insulin.
Type II diabetes or non-insulin-dependent diabetes. This was previously called "adult-onset diabetes" because in the past it was usually discovered after age 40. However, with increasing levels of obesity and sedentary lifestyle, this disease is now being found more and more in adolescents - and sometimes even in children under 10 - and the term "adult onset" is no longer used.
Type II diabetes comprises about 90 percent of all cases of diabetes. With this type of diabetes, either the pancreas produces a reduced amount of insulin, the cells do not respond to the insulin, or both.
There are three less common types of diabetes called gestational diabetes, secondary diabetes and impaired glucose tolerance (IGT):
Secondary diabetes is caused by damage to the pancreas from chemicals, certain medications, diseases of the pancreas (such as cancer) or other glands.
Impaired glucose tolerance (IGT) is a condition in which the person's glucose levels are higher than normal.
The cause of Type I diabetes is genetically based, coupled with an abnormal immune response.
The cause of Type II diabetes is unknown. Medical experts believe that Type II diabetes has a genetic component, but that other factors also put people at risk for the disease. These factors include:
- sedentary lifestyle
- obesity (weighing 20 percent above a healthy body weight)
- advanced age
- unhealthy diet
- family history of diabetes
- improper functioning of the pancreas
- minority race (higher risk in Black, Hispanic, American Indian, westernized Asian and native Hawaiian populations)
- medication (cortisone and some high blood pressure drugs)
- women having given birth to a baby weighing more than 9 lbs.
- previously diagnosed gestational diabetes
- previously diagnosed IGT
Usually, the symptoms of Type I diabetes are obvious. That is not true for Type II. Many people with Type II do not discover they have diabetes until they are treated for a complication such as heart disease, blood vessel disease (atherosclerosis), stroke, blindness, skin ulcers, kidney problems, nerve trouble or impotence.
The warning signs and symptoms for both types are:
Type II: Any Type I symptom, plus: unexplained weight gain, pain, cramping, tingling or numbness in your feet, unusual drowsiness, frequent vaginal or skin infections, dry, itchy skin and slow healing sores.
Note: If a person is experiencing these symptoms, they should see a doctor immediately.
Besides a complete history and physical examination, the doctors will perform a battery of laboratory tests. There are numerous tests available to diagnose diabetes, such as a urine test, blood test, glucose-tolerance test, fasting blood sugar and the glycohemoglobin (HbA1c) test.
A urine sample will be tested for glucose and ketones (acids that collect in the blood and urine when the body uses fat instead of glucose for energy).
A blood test is used to measure the amount of glucose in the bloodstream.
A glucose-tolerance test checks the body's ability to process glucose. During this test, sugar levels in the blood and urine are monitored for three hours after drinking a large dose of sugar solution.
The fasting blood sugar test involves fasting overnight and blood being drawn the next morning.
The glycohemoglobin test reflects an average of all blood sugar levels for the preceding two months.
A landmark study, the 10-year, multi-center Diabetes Control and Complications Trial (DCCT), has now shown that intensifying diabetes management with stricter control of blood sugar levels can reduce long-term complications.
The results of DCCT are extraordinary in that they prove that tight control of glucose levels can in fact dramatically slow the onset and progression of diabetic complications in both Type I and Type II diabetes. Additionally, researchers have found strict attention to diet and exercise also helps in the management of diabetes.
Management of Type I Diabetes
Virtually everyone with Type I diabetes (and more than one in three people with Type II) must inject insulin to make up for their deficiency. Until recently, insulin came only from the pancreases of cows and pigs (with pork insulin more closely duplicating human insulin). While beef, pork and beef/pork combinations are still widely used, there are now two types of "human" insulin available: semisynthetic (made by converting pork insulin to a form identical to human) and recombinant (made by using genetic engineering). All insulin helps glucose levels remain near normal (about 70 to 120 mg/dl).
Different types of insulin work for different periods of time. The numbers shown below are only averages. The onset (how long it takes to reach the bloodstream to begin lowering the blood sugar), peaking (how long it takes to reach maximum strength) and duration (how long it continues to lower the blood sugar) of insulin activity can vary from person to person and even from day to day in the same person.
Rapid or Regular Activity: Onset is within half an hour and activity peaks during a 2 to 5 hour period. It remains in the bloodstream for about 8 to 16 hours. These fast-acting, short-lasting insulins are useful in special cases: accidents, minor surgery or illnesses, which cause the diabetes to go out of control or whenever insulin requirements change rapidly for any reason. These are also being used more and more in combination with a long-acting insulin or alone (prior to meals and at bedtime).
Semilente: A special type of short-acting insulin that takes 1 to 2 hours for onset, peaks 3 to 8 hours after injection and lasts 10 to 16 hours.
Intermediate-Acting: Reaching the bloodstream 90 minutes after injection, intermediate-acting insulin peaks 4 to 12 hours later and lasts in the blood for about 24 hours. There are two varieties of this type of insulin: Lente (called L) and NPH (called N).
Long-Acting: These insulins, which take 4 to 6 hours for onset, are at maximum strength 14 to 24 hours after injection, lasting 36 hours in the bloodstream. Long-acting insulin is referred to as U (for Ultralente).
Please be aware of the following problems that exist with insulin intake:
- Hypoglycemia (low blood sugar) is sometimes called an insulin reaction or insulin shock. It can occur suddenly in people using insulin if too little food is eaten, if a meal is delayed or in the case of extreme exercise. Symptoms include feeling cold, clammy, nervous, shaky, weak or hungry, and some people become pale, have headaches or act strangely.
- Hyperglycemia (high blood sugar) occurs when too much food is eaten or not enough insulin is taken. The warning signs are large amounts of sugar in the urine and blood, frequent urination, great thirst and nausea.
- Ketoacidosis (in its most severe form - diabetic coma) develops when insulin and blood sugar are so out of balance that ketones accumulate in the blood. Symptoms include high blood sugar or ketones in the urine, dry mouth, great thirst, loss of appetite, excessive urination, dry and flushed skin, labored breathing, fruity-smelling breath and possible vomiting, abdominal pain and unconsciousness.
In addition to daily injections of insulin, regular physical activity and a controlled diet are essential. The American Diabetes Association (ADA) recommends the following daily dietary guidelines:
- Up to 70 percent of all calories should be obtained from carbohydrates and unsaturated fats. These carbohydrates should be mainly complex carbohydrates and naturally occurring sugars (simular to those in milk and fruits). Examples of unsaturated fats are vegetable oils and margarine.
- Between 10 and 20 percent of calories should be obtained from protein.
- Less than 10 percent of all calories should be obtained from fat. Saturated fats are found in animal products and in some vegetable oils (such as coconut, palm, and palm-kernel oils).
- Eat 30 to 35 grams of fiber.
- Eat no more than 300 mg of cholesterol.
For Type I diabetes, the meal plan should be tailored to the person's individual needs and is likely to include three meals and two or three snacks a day. A person with diabetes must eat these meals and snacks at set times each day to properly balance insulin.
Management of Type II Diabetes
The ADA recommends diet (see ADA guidelines stated above) and regular physical activity as the first line of treatment for Type II diabetes. If normal glycemic levels are not achieved within three (3) months, drug treatment is recommended.
Currently there are four (4) classes of prescription drugs available for the treatment of Type II diabetes:
- Sulfonylureas (Diabinese, Dymelor, PresTab, Orinase, Tolinase, Micronase, DiaBeta, Glynase, Glucotrol, Glucotrol XL and Amaryl), which stimulate the pancreas to release more insulin.
- Biguanides (Glucophage and Metformin), which keep the liver from releasing too much glucose.
- Alpha-glucoside inhibitors (Precose), which slow the digestion of some carbohydrates.
- Thiazolidinediones, which control glucose levels by making muscles more sensitive to insulin and reduce the amount of glucose that the liver produces.
Clinical trials suggest that oral antidiabetic agents - particularly the new noninsulin secretagogues (including Troglitazone and Metformin, which act on the liver and skeletal muscle) - may be useful in delaying or preventing development of Type II diabetes. Both agents, acting primarily by different mechanisms of action, also have demonstrated potential beneficial effects on serum lipid profiles.
Although these oral medications work in different ways, they can be combined to work more effectively to manage Type II diabetes. When these combinations of oral treatments are no longer effective (for about 60 percent of people with Type II diabetes), the doctor will start a regimen of insulin alone or in combination with an oral medication.
How often does the blood sugar need to be checked?
What are the best monitoring techniques for this? How do you measure glucose levels?
What type of insulin or insulins will you be prescribing? Who would help in learning about and giving injections?
Do you have a dietitian you could recommend?
How much can exercise and diet control the diabetes?
Is there information available or assistance on planning a regular exercise program?
What is important for family members to learn also?
How do you recognize a diabetic reaction and when should a doctor be notified?
What are the signs and symptoms of insulin deficit and excess? What measure should be taken for either condition?
Are there any other signs or symptoms that need to be reported to the doctor?
When traveling, is an adjustment in the insulin dose needed?
Can OTC medications be taken? If so, what is the medication and what are the side effects?
(Women) Should there be a concern about taking menopause-based medicine with insulin?
There is no foolproof way to prevent diabetes, but steps can be taken to improve the chances of avoiding it:
- Exercise. Studies of both men and women have shown that vigorous exercise, even if done only once a week, has a protective effect against diabetes. Exercise not only promotes weight loss but lowers blood sugar as well.
- Lose weight. There is evidence that both men and women who gain weight in adulthood increase their risk of diabetes. A study conducted at Harvard showed that adult women who gained 11 to 17 pounds since the age of 18 doubled their risk of diabetes; those who gained between 18 and 24 pounds almost tripled their risk. Fact: 90 percent of diabetics are overweight.
- Diet. The use of a diet low in calories and in saturated fat is an ideal strategy for preventing Type II diabetes. (See the ADA guidelines stated in the TREATMENT section).
- Stop smoking. Smoking is especially dangerous for people with diabetes who are at risk for heart and blood vessel diseases.
- Use alcohol in moderation. Moderation for men means no more than two drinks a day; for women, one drink is the limit. Choose drinks that are low in alcohol and sugar such as dry wines and light beers. If you use mixers, try to select one that is sugar free, such as diet drinks, club soda, seltzer or water. If you take diabetic pills or insulin, alcohol can drop blood glucose levels too far. Have the drink with a meal or snack.