Diabetes is a chronic disease caused when the pancreas, a gland nestled behind the stomach and liver, fails to produce sufficient insulin. Insulin is the vital hormone that allows the body's cells and tissues to absorb glucose (sugar) as a source of energy. The insulin serves as a key, opening a pathway into the cells so that glucose may enter, flooding the cells with energy. In people with diabetes, the lack of insulin prohibits cells from absorbing glucose and consequently, glucose levels build up in the blood and urine, causing excessive urination, thirst, hunger, and problems with fat and protein metabolism. Diabetes has been called "starvation amidst plenty". Cells are starved for energy in spite of the fact that there is plenty of glucose available. Diabetes mellitus differs from the less common diabetes insipidus, which is caused by lack of the hormone vasopressin that controls the amount of urine secreted.

Diabetes has been around a long time. Ancient civilizations in Greece, Rome, India and Egypt recognized diabetes as a condition and recommended changes in diet. Aretaeus (100 BC), a Greek physician, named the condition "diabetes" after the word dia-bainein, or "to siphon", noting the symptoms of weight loss and constant urination. In 1650 Thomas Willis, a London physician, described sugared urine in people with diabetes, which led to the word "mellitus" (Greek for honey-like) to be added to the term diabetes. Prior to the discovery of insulin, diabetes was generally treated by using a low carbohydrate, energy restricted diet.

Today diabetes is most common in adults over 45 years of age; in individuals who have an immediate family member with diabetes; in people who are overweight or physically inactive; and in minority populations including African Americans, Hispanics, and Native Americans. The highest rate of diabetes in the world occurs in Native Americans. More women than men have been diagnosed with the disease.

When food is consumed, a majority of the calories (usually 50% or more) come from carbohydrates (as opposed to fats and proteins--see the nutrition glossary.) Carbohydrates are digested to their simplest form and absorbed, creating an increase in the level of blood glucose. This is also called "blood sugar." Once glucose levels rise, the hormone insulin is called upon to help get the glucose into the cells where it can be burned as a fuel, or, in the case of fat cells, converted to and stored as fat. In diabetes mellitus, glucose builds up in the blood because it cannot enter the cells without an appropriate level of insulin to help absorption. When the blood passes through the kidneys, organs that remove blood impurities, the kidneys cannot absorb all of the excess glucose. This surplus glucose spills into the urine, accompanied by water and electrolytes-ions required by cells to regulate the electric charge and flow of water molecules across the cell membrane. This causes frequent urination to get rid of the additional water drawn into the urine; excessive thirst to trigger replacement of lost water; and hunger to replace the glucose lost in urination. Additional symptoms may include nausea and vomiting, blurred vision, dramatic weight loss, weakness and fatigue, and irritability.

Diabetes is classified into two types. Type 1, also known as insulin dependant diabetes mellitus, or IDDM, causes an individual to produce little or no insulin and therefore become dependent upon insulin from an outside source to survive. Type 1 accounts for 5%-10% of all diagnosed cases of diabetes. Although it may occur at any age, most cases of this type are diagnosed in people under 30, and nearly all diagnosed under age 20 have this type of diabetes. IDDM is classified as an autoimmune disease, caused by exposure to an unknown virus, toxic chemical agents, or other diseases that trigger a reaction from the body where the insulin producing cells of the pancreas are destroyed by the body's own disease fighting cells. It is believed that there is a genetic predisposition to this form of diabetes. People who develop this form of diabetes are usually lean, and have an abrupt onset of symptoms. In Type 2, or non-insulin-dependent diabetes mellitus (NIDDM), formerly called adult-onset diabetes, the body either makes insufficient amounts of insulin or is unable to use it. Symptoms characteristic of Type 2 diabetes include repeated infections or skin sores that heal slowly or not at all, generalized tiredness, tingling or numbness in the hands or feet, and itching.

The most common form of diabetes, Type 2 accounts for 90 to 95 percent of all cases of diagnosed diabetes in the United States. Approximately 80% of type 2 diabetics are obese or have a history of obesity at the time of diagnosis.¹ NIDDM can occur at any age, but most frequently occur in the elderly. The onset of Type 2 diabetes usually occurs after the age of 40, and often after the age of 55. Because symptoms develop slowly, individuals with the disease may not immediately recognize that they are sick. Scientists believe that in some persons weight gain or obesity triggers diabetes.²

Insulin resistance is defined as a condition in which a normal amount of insulin does not produce the expected effects. Blood glucose levels are not maintained within the normal range. The cells in the human body that require insulin to take in glucose from blood are liver cells, muscle cells, and fat cells. The outer membranes of these cells have sites that attract insulin molecules (called insulin receptors.) Biochemical processes both on the cell membrane and in the cell result in letting glucose into the cell where it is used for fuel. This process is called glucose disposal. In insulin resistance, glucose disposal is impaired.

A high percentage of body fat and insufficient exercise create insulin resistance. For years prior to developing hyperglycemia, the individual with insulin resistance is producing abnormally high levels of insulin. The ability to compensate for insulin resistance is variable among individuals. As long as large amounts of insulin can be secreted, blood glucose levels may be normal or only slightly elevated. It is only when the ability to secrete this large amount of insulin declines that Type 2 diabetes develops.

There is mounting evidence that the hyperinsulinemia that precedes Type 2 diabetes has serious detrimental effects on health. It is believed that it contributes to the development of high blood pressure, cholesterol abnormalities and vascular damage. This may explain why a large number of people have cardiovascular disease by the time their diabetes is diagnosed.

Gestational diabetes develops in 2-5% of all pregnancies but disappears when the pregnancy is over. Gestational diabetes occurs more frequently in African Americans, Hispanic/Latino Americans, and persons with a family history of diabetes. This condition usually occurs during the second or third trimester when hormones that interfere with the function of insulin increase to a point that insulin resistance occurs. Early control of hyperglycemia decreases the risk for the fetus and neonate. The use of insulin during this period may be necessary. Within 5 to 15 years, 40-60% of women who have had gestational diabetes develop non-insulin dependant diabetes.

Diabetes is the 7th leading cause of death in the US. Sixteen million Americans, have diabetes (6% of the population.). About 52% of are women and 48% are men. Large percent of Americans (34%) of diabetic remain undiagnosed. Trends show that minority and elderly populations are heavily affected by diabetes.

Carbohydrate: 55-65% calories should come from carbohydrates. Grains, starches, vegetables, fruits, and dairy products are sources of carbohydrates. Simple sugars, (refined sugar, honey, high fructose corn sweetener, etc.) are also sources of carbohydrate, and can be worked into a diabetic diet. Simple sugars are found in sweets such as pies, cakes, cookies, ice cream, sodas, etc. The belief that simple sugar aggravates hyperglycemia has not been found to be true and the first priority in a diabetic diet is the total amount of carbohydrate consumed rather than the source of carbohydrate.

It has been recommended that for all healthy diets (not just diabetic), that not more than 10% of total daily caloric intake come from simple sugars. Often sweets are high in total carbohydrate, high in saturated fats, and low important nutrients such as vitamins and minerals and fiber.

Protein: 15-20% of calories should come from protein. Good protein sources are dairy products, meat, fish, poultry, beans, peas and lentils. Choose low fat dairy products and lean meats. Remove the skin and all visible fat prior to cooking. Food should be prepared so that they have the lowest fat content possible: Bake, roast broil, grill, poach, steam or boil these foods. Avoid fried foods.

Fat: No more than 30% of total calories should come from fat. Fat is in many foods, including meats and dairy products, and in obvious fat sources such as butter, margarine, cream, oil, nuts, salad dressings, seeds, bacon, shortening and lard.

Fat comes in three forms that have different effects on human health. Saturated fats, found in cream, lard, butter, and mostly red meats, and vegetable products such as coconut oil, palm oil and palm kernel oil, contribute greatly to the elevation of serum cholesterol and increase the risk of heart disease. Because individuals with diabetes have and increased risk for heart disease, it has been recommended that no more than 7% of the total calories should come from saturated fat.

Monounsaturated fats are fats that are found to be the healthiest. Intake of monounsaturated fats is associated with a lowering of the bad type of cholesterol (LDL cholesterol) while not lowering the good type of cholesterol (HDL cholesterol.) Intake of this type of fat should be 10-15% of total calories. Good sources of monounsaturated fats include olive oil, canola oil, (canola oil margarine), peanut oil, olives, nuts, peanuts, and sesame seeds.

Polyunsaturated fats are thought to lower both the bad (LDL) cholesterol, and the good (HDL) cholesterol. For that reason it is recommended that 10% or less of fats come from polyunsaturated sources. Common sources of polyunsaturated fats include: margarine from safflower, soy, sunflower, corn sources, mayonnaise, salad dressings made from these oils, pumpkin seeds, and sunflowers seeds.

Fiber: Although soluble fiber (from legumes, oats, fruits and some vegetables) is capable of inhibiting glucose absorption from the small intestine, it is felt that this is not clinically significant. But, it has been found that diets containing a significant amount of soluble fiber will lower total and LDL cholesterol levels. The recommendations for fiber intake for persons with diabetes are therefore similar to those for the general public: approximately 20-35 grams per day of dietary fiber. Daily inclusion of fiber containing breakfast cereal, whole grain products, fruits, vegetables, and legumes is recommended.

Alcohol: The effect of alcohol on blood glucose levels depends not only on the amount of alcohol ingested, but also its relationship to food intake. For most individuals, blood glucose levels are not affected by moderate use of alcohol when diabetes is well controlled. Persons whose blood glucose is out of control, those with elevated triglycerides, and pregnant women should avoid alcohol.

The following nutrients may contribute greatly to managing or preventing risk factors associated with diabetes:

*See Nutrition Glossary for a list of excellent LifeSource sources for each nutrient.

Complications of diabetes:
Heart Disease

Heart disease is the leading cause of diabetes-related deaths. Adults with diabetes have heart disease death rates about two to four times as high as that of adults without diabetes. Persons with Type 2 diabetes have a two to fourfold increase in the prevalence of elevated triglycerides, and decreased HDL cholesterol. It is believed that low density liproproteins (LDL cholesterol-the "bad" type of cholesterol) becomes glycosolated (or glucose molecules attach to them.) This causes a problem with clearing them, creating an accumulation that fosters the generation of atherosclerosis or blocked arteries or veins.

Studies suggest that hyperinsulinemia may exaggerate the risk for atherosclerosis in diabetes. Most Type 2 diabetic individuals have hyperinsulinemia due to insulin resistance or excessive insulin use. Many Type 1 individuals also have high insulin concentrations due to the timing or route of insulin administration. Insulin may promote metabolic changes that foster the generation of atherosclerosis. Hyperinsulinemia may also contribute to hypertention by inducing the kidneys to retain sodium.

The risk of stroke is 2-4 times higher in people with diabetes. Again, glycosolation of LDL cholesterol generates atherosclerosis. Stroke is caused by a blocked blood vessel in the brain.

An estimated 60-65% of people with diabetes have high blood pressure. Hypertension is the major risk factor for heart disease for Type 1 diabetic individuals. It is believed that hypertension induced physical stress on the blood vessels along with other abnormalities of the walls of the arteries, plus abnormalities in the components of the blood (lipoproteins and platelets) accelerate atherosclerosis.

Diabetes is the leading cause of new cases of blindness in adults 20 to 74 years old and diabetic retinopathy causes from 12,000 to 24,000 new cases of blindness each year. In both types of diabetes, the development and progression of retinopathy is associated with degree and duration of elevated blood sugar levels. Visual loss is attributable to the changes that occur in the blood vessels of the eye. The exact mechanisms leading to these changes are not completely understood, but it is known that excess entry of glucose into tissues and the linkage of glucose to these tissue proteins (glycosylation) causes destruction of the tissues.

Diabetes is the leading cause of end-stage renal disease, accounting for about 40% of new cases, and 27,851 people with diabetes developed end-stage renal disease in 1995. In fact, in 1995, a total of 98,872 people with diabetes underwent dialysis or kidney transplantation. It is believed that hyperglycemia causes diabetic nephropathy (kidney disease) by several different abnormal mechanisms in the kidney. Albumin, a protein circulating in blood, may become attached to the excess glucose and deposited in the kidney, causing damage to kidney tissue. Hypertension frequently occurs during the course of diabetic nephropathy and may accelerate the progression of the disease.

About 60% to 70% of people with diabetes have mild to severe forms of nervous system damage (which often includes impaired sensation or pain in the feet or hands, slowed digestion of food in the stomach, carpal tunnel syndrome, and other nerve problems.) Severe forms of diabetic nerve disease are a major contributing cause of lower extremity amputations.

Chronic high blood glucose levels are associated with nerve damage (neuropathy). The linkage of glucose to nerve tissue proteins (glycosylation) causes destruction of nerve tissue. Peripheral neuropathy usually affects the nerves controlling sensation in the feet and hands. Autonomic neuropathy affects nerve function controlling various organ systems, including the heart. This can eventually lead to decreased responsiveness to cardiac nerve impulses, leading to "silent" heart disease. Damage to nerves innervating the gastrointestinal tract can cause a variety of problems, including unpredictable stomach emptying, diarrhea or constipation. Gastroparesis or impaired gastric motility affects about 25% of the diabetic population. It leads to various GI symptoms such as feelings of fullness, bloating, nausea, vomiting, diarrhea or constipation, and can cause detrimental effects on blood glucose control.

More than half of lower limb amputations in the United States occur among people with diabetes. From 1993 to 1995, about 67,000 amputations were performed each year among people with diabetes. There are several factors that put diabetics at high risk for lower-extremity amputation. Peripheral neuropathy (see above), ulceration, infection and peripheral vascular disease are the most common components causing limb loss. Ulceration is the most common single event leading to amputation, and has been identified as a component in 85% of lower-extremity amputations. Ulcers may result if blister or calluses reach the skin's inner layers. Blisters or calluses start as red or warm spots. They are often caused by unrelieved skin pressure, and may become infected. Bone infection may occur if infected ulcers spread. Untreated bone infections may lead to loss of foot or lower leg.

Peridontal disease (a type of gum disease that can lead to tooth loss) occurs with greater frequency and severity among people with diabetes. Periodontal disease has been reported to occur among 30% of people aged 19 years or older with Type 1 diabetes. The complications of diabetes such as high blood sugar, vascular disease, and other abnormalities of metabolism result in impaired wound healing, suppression of the immune system, and susceptibility to infection. There is a compromised delivery of nutrients to gum tissue and poor elimination of metabolic waste products. Also saliva contains more sugar, supplying bacteria with an energy source.

The rate of major congenital malformations in babies born to women with preexisting diabetes varies from 0% to 5% among women who receive preconception care to 10% among women who do not receive preconception care. Between 3% to 5% of pregnancies among women with diabetes result in death of the newborn: the rate for women who do not have diabetes is 1.5%. Women with poorly controlled preexisting diabetes are several times more likely to have a baby with as serious birth defect, such as a heart defect or a defect of the brain or spinal cord. They also are at increased risk of miscarriage and stillbirth.

Women with gestational diabetes usually do not have an increased risk of having a baby with birth defects. However, some studies suggest that if a woman's gestational diabetes is severe enough to require treatment with insulin, the risk of having a baby with birth defects is greater. Poorly controlled gestational diabetes also slightly increases the risk of stillbirth. With the improvements in medical care for women with diabetes, stillbirth is rare.

Women with poorly controlled gestational or preexisting diabetes are at increased risk of having a baby who is extremely large, approaching 10 pounds or more. Babies of women with poorly controlled diabetes grow so large because the extra sugar in the mother's blood goes to the fetus. The fetus produces extra insulin that then converts the extra sugar to fat. The fat tends to accumulate around the shoulders and trunk, making delivery difficult and risky for the babies and mother. Women with diabetes who keep their blood sugar levels under control reduce the risk of having large babies.

Babies of women with poorly controlled diabetes are at increased risk of breathing difficulties, low blood sugar levels and jaundice during first weeks of life.

• Diabetes can directly cause acute life-threatening events, such as diabetic ketoacidosis³and hyperosmolar nonketotic coma.⁴
• People with diabetes are more susceptible to many other illnesses. For example, they are more likely to die of pneumonia or influenza than people who do not have diabetes.
• Metabolic abnormalities associated with diabetes result in suppression of the immune system, increasing the chances of infection.

The goal of treatment is to provide individuals with the tools necessary to achieve the best possible glycemic control to prevent, delay or arrest the complications of diabetes while minimizing hypoglycemia and excess weight gain.

• Bloodwork:
• HbA1c (glycosylated hemoglobin-see below) measured every 3-6 months
• Total Cholesterol, HDL, LDL and Triglycerides every year
• Microalbuminuria every year (microalbuminuria signifies the presence of diabetic nephropathy-changes in the kidney that can lead to kidney disease.)
• Annual eye exam
• Annual foot exam
• Annual flu vaccine
• Annual dental visits
• Pneumonia vaccine
• Preconception counseling if considering pregnancy

The health care team (physician, dietitian, nurse, diabetic educator) should work together to implement blood glucose monitoring and establish individual target blood glucose goals. The frequency of monitoring depends on the type of diabetes and overall therapy.

Self-monitoring blood glucose ( SMBG) is done by pricking a finger with a special needle called a lancet that will allow a drop of blood to be obtained. The drop is placed on a test strip, and the strip is put in a meter. The meter then reads the blood sugar level.

There are many meters available. Some meters are made for those with poor eyesight. Others come with memory so test results can be stored. Meters may vary in the precision and accuracy of their measurements. All of the meters must meet certain FDA requirements. A good way to check for accuracy with a meter is to test it in the doctor's office just prior to having blood drawn for lab for analysis. Comparing the results of the meter measurement with the lab analysis should give a good estimate of accuracy. The results should not be off by more than 10 to 15 percent.

The main problem with blood glucose meters is sore fingers. Some strategies to minimize pain include varying test sites, using fine-gauge lancets that are changed regularly, and testing on the sides, not the pads of the fingers. There are several non-invasive or minimally invasive meters on the market today or expected to be available soon. One example of these is Cygnus Glycowatch ®. This device is intended for use at home and in health care facilities to supplement, not replace, information obtained from standard home blood glucose monitoring devices.

Tracking blood sugar can trigger strong feelings. Blood sugar numbers can cause frustration, anger, and depression because of negative self -judgement. It is important to remember that tracking blood sugar is a way to track how well a diabetes care plan is working. The results may show a need for a change in the care plan.

SMBG can be performed up to seven times per day: before each meal, at bedtime, 1-2 hours after meals, during the night (once per week), or to determine causes of hyper or hypoglycemia.

Keeping a log of results is of utmost importance. The log with not only the blood sugar results, but also a record of other events such as exercise, unusual excitement or stress, and special meals will help to interpret what those blood sugar levels mean to an individual.

The term "glycosylated hemoglobin," (HbA1C) also called glycated hemoglobin or glycohemoglobin, refers to a blood test that measures an individual's average blood glucose levels for the preceding 2 or 3 months. It is expressed as a percentage of total hemoglobin that has glucose attached in the "C" fraction of the molecule. As blood sugar levels rise or stay high, HbA1C levels go up. It is a powerful predictor of diabetes complications.

Glucose Goals have been established (these are for nonpregnant adults). Targets are:

• A FASTING (no food eaten 8 hours prior to test) blood glucose of 80-120 mg/dl.
• A bedtime glucose of between 100-140
• 2AM-4AM glucose>80
• 2 hours post-prandial glucose (blood glucose done 1-2 hours after eating)<160.
• HbA1C <7%.

Action should be taken if:

• Fasting blood glucose is<70, >140.
• Bedtime glucose <100 or >160.
• 2-4 am <90 or >160.
• 2 hours post-prandial < 70 or >160.
• HbA1C >8%.

Target Goals for Blood Pressure and Lipids.

• B/P <130/85
• HDL Cholesterol is >45 mg/dl.
• LDL Cholesterol is < 100 mg/dl.
• Triglycerides < 200 mg/dl.

Treatment of Type 1 diabetes: Lack of insulin production by the pancreas makes Type 1 diabetes particularly difficult to control. Treatment requires a strict regimen that typically includes a carefully calculated diet, planned physical activity, home blood glucose testing several times a day, and multiple daily insulin injections.

Treatment of Type 2 diabetes: Treatment typically includes diet control, exercise, home blood glucose testing, and in some cases, oral medication and/or insulin. Approximately 40% of people with Type 2 diabetes require insulin injections.

¹See https://encarta.msn.com. Diabetes Melliuts section contributed by Frank Vinicor, B.A., M.D., M.P.H. Director, Diabetes Translation, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention. Back to article
²See https://encarta.msn.com. Diabetes Melliuts section contributed by Frank Vinicor, B.A., M.D., M.P.H. Director, Diabetes Translation, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention. Back to article
³Center for Disease Control and Prevention. National Diabetes Fact Sheet: National estimates and general information on diabetes in the United States. Revised edition. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, 1998. Back to article
⁴Diabetic ketoacidosis and hyperosmolar nonketotic coma are medical conditions that can result from biochemical imbalance in uncontrolled diabetes. Back to article