Read an Excerpt
In Six Easy Steps
By Maggie Greenwood-Robinson
St. Martin's PressCopyright © 2002 Lynn Sonberg
All rights reserved.
Stopping a Silent Killer
If you have diabetes, take comfort in knowing that you're not alone in your challenges. In the United States, there are 16 million people with diabetes, and some 2,200 more are being diagnosed each day.
There are many more people who have diabetes but aren't even aware of it — 5.4 million Americans to be exact, according to the American Diabetes Association. In fact, diabetes has been dubbed a "silent killer" because in the early stages of diabetes there are very few symptoms, or the symptoms are so mild that they don't seem to warrant serious attention. In fact, most people are unaware that they have it until diagnosed with one of its life-threatening complications, such as blindness, kidney disease, nerve disease, or cardiovascular disease. The early warning signs of diabetes are listed in the box on page 4.
Diabetes is on the rise too. Consider: While deaths from heart disease and cancer are falling, deaths from diabetes have been escalating for the past ten years. Though treatable, diabetes is the seventh leading cause of death in the United States. It contributes to nearly two hundred thousand deaths a year.
Even so, there is tremendous hope. Of all life-threatening diseases, diabetes is one of easiest to get under control, because it can be managed mostly with something we all need to do: healthy living.
WHAT IS DIABETES?
For background, diabetes is a disorder of metabolism — your body's food-to-fuel process. More specifically, diabetes is a sugar metabolism disorder in which there's too much sugar (glucose) in the blood. Glucose, your body's chief fuel, is always traveling through the bloodstream. Under normal conditions, it goes from the blood into cells, where it nourishes and energizes those cells. Glucose enters the cells with the help of a hormone called insulin, which is produced by beta cells in the pancreas, a flask-shaped organ situated behind and just below the stomach.
When you eat a meal, beta cells release insulin to help your cells use and store glucose from the digestion and absorption of food. Insulin is thus the main regulator your body uses to reduce levels of glucose in the blood. Normally, blood glucose stays in the range of 70 to 115 milligrams per deciliter (mg/dl). This is the unit of measure used to describe how much glucose is in your blood at any given time.
In diabetes, though, two things can go wrong. Either the body doesn't make any or enough insulin — a condition termed insulin deficiency. Or cells don't respond properly to insulin — a condition called insulin resistance — and they receive no nourishment. In both situations, glucose is unable to enter cells, and it starts building up in the bloodstream — a condition called hyperglycemia or high blood sugar.
When there is too much glucose in circulation, it gums up the blood vessels that feed your organs and limbs. This is a toxic situation that provokes all sorts of metabolic problems. Blood can't travel to where it needs to go, causing problems in circulation. Your body is starved of energy, and eventually its organs deteriorate — unless blood sugar can be brought under control.
Although diabetes is often thought of as being a single disease, it is actually a family of disorders, all involving faulty metabolism of glucose. There are three major types of diabetes: type 1, type 2, and gestational diabetes.
UNDERSTANDING TYPE 1 DIABETES
Also known as insulin-dependent diabetes, type 1 diabetes is a disease in which the body either produces little insulin or no insulin at all. The disease was once called juvenile-onset diabetes, but that name has been dropped because type 1 diabetes strikes young and old alike.
Type 1 diabetes is caused by damage to the pancreas. Within the pancreas are clusters of various types of cells called islets of Langerhans. Beta cells, which make insulin, are located in the islets.
The job of the pancreas is twofold: to secrete powerful digestive enzymes for the breakdown of food and to promote the production of insulin from beta cells in the pancreas. Insulin helps glucose gain entry into cells where it is used to supply energy.
In type 1 diabetes, because the body can no longer produce insulin or make enough of it, cells cannot absorb the glucose they need for fuel. To compensate for this, the body starts breaking down proteins and digesting its own muscle tissue for fuel, resulting in muscle loss and weakness. There is also a flash flood of glucose in the blood — a surge that ultimately leads to diabetic complications. Type 1 diabetic patients, who typically get the disease at a young age, must rely on daily injections of insulin to survive.
In type 1 diabetes, insulin-producing beta cells are killed off by the body's own immune system. Upon invading the pancreas, immune cells called T cells and B cells mistake beta cells for germs and attack them — a physiological blunder referred to as an autoimmune response. This is why type 1 diabetes is referred to as an autoimmune disease. No one knows for sure why the body mounts such an attack, but researchers believe multiple forces may be at work.
RISK FACTORS FOR TYPE 1 DIABETES
Type 1 diabetes accounts for about 5 to 10 percent of those diagnosed with the disease. Major risk factors include:
Family history. At greater risk of type 1 diabetes are children and siblings of people with the disease.
Racial background. There is a higher incidence of type 1 diabetes among whites than is found in other racial groups.
Age. Half of those diagnosed are under age twenty.
What causes type 1 diabetes? Here's a closer look at how type 1 diabetes may develop.
As noted above, type 1 diabetes tends to run in families. Thus, you're at a greater risk of developing type 1 diabetes if your parents or siblings have the disease, or if you're white. Whites — particularly those of European descent — are more prone to type 1 diabetes than are people of other races.
Whether you will develop type 1 diabetes also has to do with your genes, the basic units of heredity that carry instructions for individual characteristics. Although many different types of genes may lead to the development of type 1 diabetes, researchers have pinpointed some specific genes that may predispose you to this form of the disease.
Doctors and scientists have observed that type 1 diabetes often strikes after viral epidemics. The viruses in question include those that cause mumps and German measles. Another is the Coxsackie family of viruses, which is a close relative of the virus that causes polio.
These viruses resemble proteins found in the beta cells of the pancreas. In a bodily sort of "friendly fire," the immune system mistakes beta cells for virus particles and obliterates them, along with their ability to manufacture insulin.
Some researchers suspect that exposure to cow's milk during infancy may trigger an autoimmune response leading to type 1 diabetes. This theory cropped up after studies revealed that children newly diagnosed with type 1 diabetes often had high levels of antibodies to a specific protein found in cow's milk. This protein is called bovine serum albumin (BSA), and it resembles a protein found in beta cells.
The intestines of babies in the first several months of life cannot properly break down or digest certain foods, including proteins. These large, undigested proteins pass through the intestines into the bloodstream. The body considers such proteins, including BSA, as foreign invaders and creates antibodies to attack them. In a case of a biochemical mistaken identity, those same antibodies attack beta cells because they look like BSA.
To date, research has found that infants fed cow's milk during their first three months of life are one and a half times more likely to develop type 1 diabetes. However, some research shows no link between cow's milk and the development of the disease. In response to such contradictory findings, scientists emphasize that more studies are needed to verify a connection and to firmly establish whether there is a true risk associated with feeding cow's milk to infants.
Some diabetes investigators theorize that free-radical damage may contribute to type 1 diabetes. Free radicals are unstable molecules generated by metabolism, respiration, stress, environmental pollutants, and other factors. They injure cell membranes, making it easy for bacteria, viruses, and other disease-causing agents to slip in and inflict harm. Free radicals can destroy cells, tissues, and even organs, weakening the immune system and leaving the body vulnerable to a range of diseases.
Normally, your body has a built-in brigade of natural substances, including enzymes, that prevent free-radical damage. But in type 1 diabetes, cells in the pancreas are naturally low in levels of these protective enzymes. Unchecked, free radicals can run rampant and decimate beta cells.
Fortunately, though, powerful nutrients called antioxidants, found in foods and nutritional supplements, can snuff out free radicals, fortify internal enzyme defenses, and protect the body against needless damage. For more information on antioxidants, see Step 2.
Chemicals and Drugs
Research indicates that exposure to or ingestion of certain chemicals and drugs can trigger type 1 diabetes. One of these is Pyriminil, a rat poison. Others are pentamidine, used to treat pneumonia; and L- asparaginase, an anticancer agent. Other chemicals have been shown to cause diabetes in animals, but researchers aren't yet sure whether they do the same in people.
Because diabetes is so complex, it is unlikely that a single drug or chemical causes the disease by itself. Rather, exposure to drugs or chemicals may activate diabetes if you are already genetically susceptible to the disease.
The cornerstone for treating type 1 diabetes is insulin, which is available in several different strengths and forms. Insulin replaces the insulin your body can no longer produce. Your physician will specify which kind of insulin to take, how much, and when. Information on how to use insulin is provided in Step 4.
Insulin alone won't control your diabetes. Other approaches are necessary too. These include:
Meal planning that focuses on low-fat nutrition, moderate amounts of protein, and designated quantities of high-fiber, complex carbohydrates. Your diet must also be consistent; that is, you must eat roughly the same amount of calories each day, eat meals and snacks at the same time every day, and not miss meals.
Exercise that includes both strength training and aerobics to help your cells take in glucose, to build muscle, and to prevent diabetic complications.
Regular blood sugar checks to keep track of how you're doing.
Stress management to ensure that your body's own immunity and healing power are not hampered by stress and other health-defeating emotions.
Once you start following these strategies on a day-to-day basis, controlling your diabetes will become second nature. The new habits you adopt will improve many other aspects of your health, and you'll be a healthier person for it.
UNDERSTANDING TYPE 2 DIABETES
Also called non-insulin-dependent diabetes, type 2 diabetes is the most common form of the disease, accounting for 90 to 95 percent of all cases. You may have heard that this type of diabetes is not so serious as type 1. That is a myth. Both types of diabetes put you at a higher-than-average risk for heart attack, stroke, kidney disease, and other serious complications.
There are some important differences between type 2 and type 1 diabetes, however. In type 1 diabetes, your body is unable to produce insulin, or there isn't enough insulin to go around. In type 2 diabetes, the body makes insulin, but the cells have trouble using it.
For insulin to work, it has to access cells by first attaching to special proteins on cell membranes called receptors, which have two important functions with regard to glucose. First, receptors operate like door locks. Once insulin gets to the receptor, it acts like a key and unlocks the receptors surrounding the cell. The cell opens up and lets glucose in for use as fuel. Second, insulin receptors signal another type of protein, called a glucose transporter, to carry glucose into the cell.
In type 2 diabetes, things go awry with the entire entrance process. In some cases, the "locks" don't work, and cells ignore — or become resistant to — the insulin. This condition is termed insulin resistance. Because of insulin resistance, insulin can't open the cell. Glucose is locked out, and it clutters up the bloodstream. The pancreas is forced to pump out more insulin to handle the excess glucose in the blood. But eventually, the pancreas can't keep pace with the demand. These events ultimately lead to risky complications.
In other cases, there are too few insulin receptors on cells, or insulin simply doesn't perform the job it is supposed to do. Whatever the problem, glucose can't get into the cell. Also, in some people with type 2 diabetes, beta cells do not manufacture enough insulin.
RISK FACTORS FOR TYPE 2 DIABETES
Risk factors for type 2 diabetes are linked largely to age, diet, and lifestyle, although genetic factors are involved too. Specific risk factors include:
A sedentary lifestyle.
A diagnosis of impaired glucose tolerance (IGT) as a result of a fasting plasma glucose test and an oral glucose tolerance test. IGT is a condition in which your glucose levels are abnormally elevated but are not high enough to indicate full-blown diabetes.
Syndrome X, an abnormal metabolic condition.
Abnormal levels of blood fats in your system.
Ethnic heritage (African Americans, Latinos, Asian and Pacific Islanders, and American Indians are at greater risk).
Having had gestational diabetes, a rare form of diabetes that develops during pregnancy but disappears afterward.
Having given birth to a baby weighing nine pounds or more.
What follows is a closer look at some of the key factors involved in the development of type 2 diabetes.
Your chance of type 2 diabetes catching up with you down the road may depend on your genes. Like type 1 diabetes, type 2 diabetes runs in families. In fact, there may be an even stronger genetic component involved in type 2 diabetes than in type 1 diabetes, an observation that has been substantiated in studies of twins. Researchers have found that if an identical twin develops type 1 diabetes, there is a 25 to 50 percent chance that the other twin will get the disease too. On the other hand, if an identical twin develops type 2 diabetes, there is a 60 to 75 percent chance that the other twin will develop it as well.
Evidence for a genetic component has been observed in studies of ethnic groups. Compared to whites, type 2 diabetes occurs more often in African Americans, Hispanics (with the exception of Cuban Americans), Asian Americans, Pacific Islanders, and American Indians. In fact, American Indians have the highest rates of diabetes in the world.
While it is clear that genes play a significant role in the development of type 2 diabetes, no specific genes have yet been identified. Researchers, however, are finding "errors" in genes that make body cells unresponsive to insulin. They also suspect the existence of an obesity gene, meaning that some people may be genetically inclined to obesity. Obesity is the number-one cause of type 2 diabetes.
One reason diabetes may be on the rise is the escalating rate of obesity in the United States, which has one of the highest rates of obesity in the world. According to a national survey, nearly 74 percent of Americans age twenty-five or older are overweight.
Your odds of developing type 2 diabetes climb as your weight climbs. Weighing at least 20 percent more than what is recommended for your height and build puts you in the obese category. More than 80 percent of people with type 2 diabetes are obese. For reasons that have not yet been fully spelled out by research, excess pudge causes insulin resistance. Body cells, in effect, ignore insulin, and the hormone cannot ease glucose into cells.
Where you carry your weight makes a difference too. If you have an apple shape, or "central obesity," which is characterized by excess abdominal fat, you're at a greater risk of developing type 2 diabetes than those with fat deposited mostly on their hips ("pear shape").
Excerpted from Control Diabetes by Maggie Greenwood-Robinson. Copyright © 2002 Lynn Sonberg. Excerpted by permission of St. Martin's Press.
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