- November 2008 > Wellness Wise
There are three main types of diabetes: type 1, type 2, and gestational diabetes. You may have a health risk factor for type 2 diabetes if you are overweight, are over 45 years of age, or habitually inactive, if you have metabolic syndrome (insulin resistance), high blood pressure, abnormal cholesterol levels, a history of gestational diabetes, polycystic ovary disease, habitually inactive, or have a history of vascular disease (such as stroke or have a family history of diabetes).
Almost everyone knows someone who has diabetes. An estimated 18.2 million people in the United States--6.3 percent of the population--have diabetes, a serious, lifelong condition. Of those, 13 million have been diagnosed, and about 5.2 million people have not yet been diagnosed. Each year, about 1.3 million people aged 20 or older are diagnosed with diabetes.
Diabetes is a group of diseases marked by high levels of blood glucose, also called blood sugar, resulting from defects in insulin production, insulin action, or both. Diabetes can lead to serious complications and premature death, but people with diabetes can take steps to control the disease and lower the risk of complications.
After digestion, glucose passes into the bloodstream where it is used by cells for growth and energy. For glucose to get into cells, insulin must be present. Insulin is a hormone produced by the pancreas, a large gland behind the stomach.
When we eat, the pancreas automatically produces the right amount of insulin to move glucose from blood into our cells. In people with diabetes, however, the pancreas either produces little or no insulin, or the cells do not respond appropriately to the insulin that is produced. Glucose builds up in the blood, overflows into the urine, and passes out of the body. Thus, the body loses its main source of fuel even though the blood contains large amounts of glucose.
The three main types of diabetes are
Type 1 Diabetes
Type 1 diabetes is an autoimmune disease. An autoimmune disease results when the body's system for fighting infection (the immune system) turns against a part of the body. In diabetes, the immune system attacks the insulin-producing beta cells in the pancreas and destroys them. The pancreas then produces little or no insulin. A person who has type 1 diabetes must take insulin daily to live.
At present, scientists do not know exactly what causes the body's immune system to attack the beta cells, but they believe that autoimmune, genetic, and environmental factors, possibly viruses, are involved. Type 1 diabetes accounts for about 5 to 10 percent of diagnosed diabetes in the United States. It develops most often in children and young adults, but can appear at any age.
Symptoms of type 1 diabetes usually develop over a short period, although beta cell destruction can begin years earlier. Symptoms include increased thirst and urination, constant hunger, weight loss, blurred vision, and extreme fatigue. If not diagnosed and treated with insulin, a person with type 1 diabetes can lapse into a life-threatening diabetic coma, also known as diabetic ketoacidosis.
Type 2 Diabetes
The most common form of diabetes is type 2 diabetes. About 90 to 95 percent of people with diabetes have type 2. This form of diabetes is associated with older age, obesity, family history of diabetes, previous history of gestational diabetes, physical inactivity, and ethnicity. About 80 percent of people with type 2 diabetes are overweight.
Type 2 diabetes is increasingly being diagnosed in children and adolescents. However, nationally representative data on prevalence of type 2 diabetes in youth are not available.
When type 2 diabetes is diagnosed, the pancreas is usually producing enough insulin, but for unknown reasons, the body cannot use the insulin effectively, a condition called insulin resistance. After several years, insulin production decreases. The result is the same as for type 1 diabetes--glucose builds up in the blood and the body cannot make efficient use of its main source of fuel.
The symptoms of type 2 diabetes develop gradually. Their onset is not as sudden as in type 1 diabetes. Symptoms may include fatigue or nausea, frequent urination, unusual thirst, weight loss, blurred vision, frequent infections, and slow healing of wounds or sores. Some people have no symptoms.
Gestational diabetes develops only during pregnancy. Like type 2 diabetes, it occurs more often in African Americans, American Indians, Hispanic Americans, and among women with a family history of diabetes. Women who have had gestational diabetes have a 20 to 50 percent chance of developing type 2 diabetes within 5 to 10 years.
Other types of diabetes result from specific genetic conditions, such as maturity-onset diabetes of youth; surgery; medications; infections; pancreatic disease; and other illnesses. Such types of diabetes account for 1 to 5 percent of all diagnosed cases.
Diabetes can lead to serious complications, such as blindness, kidney damage, cardiovascular disease, and lower-limb amputations, but people with diabetes can lower the occurrence of these and other diabetes complications by controlling blood glucose, blood pressure, and blood lipids.
Many people with type 2 diabetes can control their blood glucose by following a healthy meal plan and exercise program, losing excess weight, and taking oral medication. Some people with type 2 diabetes may also need insulin to control their blood glucose.
To survive, people with type 1 diabetes must have insulin delivered by injection or a pump.
Among adults with diagnosed diabetes—type 1 or type 2—14 percent take insulin only, 13 percent take both insulin and oral medication, 57 percent take oral medication only, and 16 percent do not take either insulin or oral medication. Medications for each individual with diabetes will often change over the course of the disease.
Many people with diabetes also need to take medications to control their cholesterol and blood pressure.
Self-management education or training is a key step in improving health outcomes and quality of life. It focuses on self-care behaviors, such as healthy eating, being active, and monitoring blood glucose. It is a collaborative process in which diabetes educators help people with or at risk for diabetes gain the knowledge and problem-solving and coping skills needed to successfully self-manage the disease and its related conditions.
Pre-diabetes is a condition in which individuals have blood glucose levels higher than normal but not high enough to be classified as diabetes. People with pre-diabetes have an increased risk of developing type 2 diabetes, heart disease, and stroke.
People with pre-diabetes have impaired fasting glucose (IFG) or impaired glucose tolerance (IGT). Some people have both IFG and IGT.
IFG is a condition in which the fasting blood glucose level is 100 to 125 milligrams per deciliter (mg/dL) after an overnight fast. This level is higher than normal but not high enough to be classified as diabetes.
IGT is a condition in which the blood glucose level is 140 to 199 mg/dL after a 2-hour oral glucose tolerance test. This level is higher than normal but not high enough to be classified as diabetes.
In 1988 to 1994, among U.S. adults aged 40 to 74 years, 33.8 percent had IFG, 15.4 percent had IGT, and 40.1 percent had pre-diabetes—IGT or IFG or both. More recent data for IFG, but not IGT, are available and are presented below.
In 2003 to 2006, 25.9 percent of U.S. adults aged 20 years or older had IFG—35.4 percent of adults aged 60 years or older. Applying this percentage to the entire U.S. population in 2007 yields an estimated 57 million American adults aged 20 years or older with IFG, suggesting that at least 57 million American adults had pre-diabetes in 2007.
After adjusting for population age and sex differences, IFG prevalence among U.S. adults aged 20 years or older in 2003 to 2006 was 21.1 percent for non-Hispanic blacks, 25.1 percent for non-Hispanic whites, and 26.1 percent for Mexican Americans.
Progression to diabetes among those with pre-diabetes is not inevitable. Studies have shown that people with pre-diabetes who lose weight and increase their physical activity can prevent or delay diabetes and even return their blood glucose levels to normal.
In the Diabetes Prevention Program, a large prevention study of people at high risk for diabetes, lifestyle intervention reduced the development of diabetes by 58 percent over 3 years. The reduction was even greater, 71 percent, among adults aged 60 years or older.
Interventions to prevent or delay type 2 diabetes in individuals with pre-diabetes can be feasible and cost-effective. Research has found that lifestyle interventions are more cost-effective than medications.
The estimates on diabetes in this fact sheet were derived from various data systems of the Centers for Disease Control and Prevention (CDC), the outpatient database of the Indian Health Service (IHS), the U.S. Renal Data System of the National Institutes of Health (NIH), the U.S. Census Bureau, and published studies. Estimates of the total number of persons with diabetes and the prevalence of diabetes in 2007 were derived using 2003–2006 National Health and Nutrition Examination Survey (NHANES), 2004–2006 National Health Interview Survey (NHIS), 2005 IHS data, and 2007 resident population estimates. Many of the estimated numbers and percentages of people with diabetes were derived by applying diabetes prevalence estimates from health surveys of the civilian, noninstitutionalized population to the most recent 2007 resident population estimates. These estimates have some variability due to the limits of the measurements and estimation procedures. The procedures assumed that age-race-sex-specific percentages of adults with diabetes—diagnosed and undiagnosed—in 2007 are the same as they were in earlier time periods—for example, 2003 to 2006—and that the age-race-sex-specific percentages of adults with diabetes in the resident population are identical to those in the civilian, noninstitutionalized population. Deviations from these assumptions may result in over- or under-estimated numbers and percentages. For further information on the methods for deriving total, diagnosed, and undiagnosed prevalence of diabetes from NHANES data, see www.cdc.gov/mmwr/preview/mmwrhtml/mm5235a1.htm.
Total: 23.6 million people—7.8 percent of the population—have diabetes.
Diagnosed: 17.9 million people
Undiagnosed: 5.7 million people
Age 20 years or older: 23.5 million, or 10.7 percent, of all people in this age group have diabetes.
Age 60 years or older: 12.2 million, or 23.1 percent, of all people in this age group have diabetes.
Men: 12.0 million, or 11.2 percent, of all men aged 20 years or older have diabetes.
Women: 11.5 million, or 10.2 percent, of all women aged 20 years or older have diabetes.
Non-Hispanic whites: 14.9 million, or 9.8 percent, of all non-Hispanic whites aged 20 years or older have diabetes.
Non-Hispanic blacks: 3.7 million, or 14.7 percent, of all non-Hispanic blacks aged 20 years or older have diabetes.
Source: 2004–2006 National Health Interview Survey estimates projected to year 2007.
Sufficient data are not available to derive prevalence estimates of both diagnosed and undiagnosed diabetes for all minority populations. For example, national survey data cannot provide reliable estimates for the Native Hawaiian and other Pacific Islander population. However, national estimates of diagnosed diabetes for certain minority groups are available from national survey data and from the IHS user population database, which includes data for approximately 1.4 million American Indians and Alaska Natives in the United States who receive health care from the IHS. Because most minority populations are younger and tend to develop diabetes at earlier ages than the non-Hispanic white population, it is important to control for population age differences when making race and ethnic comparisons.
Data from the 2005 IHS user population database indicate that 14.2 percent of the American Indians and Alaska Natives aged 20 years or older who received care from IHS had diagnosed diabetes. After adjusting for population age differences, 16.5 percent of the total adult population served by IHS had diagnosed diabetes, with rates varying by region from 6.0 percent among Alaska Native adults to 29.3 percent among American Indian adults in southern Arizona.
After adjusting for population age differences, 2004 to 2006 national survey data for people aged 20 years or older indicate that 6.6 percent of non-Hispanic whites, 7.5 percent of Asian Americans, 10.4 percent of Hispanics, and 11.8 percent of non-Hispanic blacks had diagnosed diabetes. Among Hispanics, rates were 8.2 percent for Cubans, 11.9 percent for Mexican Americans, and 12.6 percent for Puerto Ricans.
A total of 1.6 million new cases of diabetes were diagnosed in people aged 20 years or older in 2007.
Source: SEARCH for Diabetes in Youth Study.
NHW=Non-Hispanic whites; AA=African Americans; H=Hispanics;
API=Asians/Pacific Islanders; AI=American Indians
SEARCH for Diabetes in Youth is a multicenter study funded by the CDC and the NIH to examine diabetes—type 1 and type 2—among children and adolescents in the United States. SEARCH findings for the communities studied include:
Based on 2002 to 2003 data, 15,000 youth in the United States were newly diagnosed with type 1 diabetes annually, and about 3,700 youth were newly diagnosed with type 2 diabetes annually.
The rate of new cases among youth was 19.0 per 100,000 each year for type 1 diabetes and 5.3 per 100,000 for type 2 diabetes.
Non-Hispanic white youth had the highest rate of new cases of type 1 diabetes.
Type 2 diabetes was extremely rare among youth aged <10 years. While still infrequent, rates were greater among youth aged 10 to 19 years compared with younger children, with higher rates among U.S. minority populations compared with non-Hispanic whites.
Among non-Hispanic white youth aged 10 to 19 years, the rate of new cases of type 1 diabetes was higher than for type 2 diabetes. For Asian/Pacific Islander and American Indian youth aged 10 to 19 years, the opposite was true—the rate of new cases of type 2 was greater than the rate for type 1 diabetes. Among African American and Hispanic youth aged 10 to 19 years, the rates of new cases of type 1 and type 2 diabetes were similar.
Diabetes was the seventh leading cause of death listed on U.S. death certificates in 2006. This ranking is based on the 72,507 death certificates in 2006 in which diabetes was listed as the underlying cause of death. According to death certificate reports, diabetes contributed to a total of 233,619 deaths in 2005, the latest year for which data on contributing causes of death are available.
Diabetes is likely to be underreported as a cause of death. Studies have found that only about 35 to 40 percent of decedents with diabetes had it listed anywhere on the death certificate and only about 10 to 15 percent had it listed as the underlying cause of death.
Overall, the risk for death among people with diabetes is about twice that of people without diabetes of similar age.
Heart Disease and Stroke
In 2004, heart disease was noted on 68 percent of diabetes-related death certificates among people aged 65 years or older.
In 2004, stroke was noted on 16 percent of diabetes-related death certificates among people aged 65 years or older.
Adults with diabetes have heart disease death rates about two to four times higher than adults without diabetes.
The risk for stroke is two to four times higher among people with diabetes.
High Blood Pressure
Diabetes is the leading cause of new cases of blindness among adults aged 20 to 74 years.
Diabetic retinopathy causes 12,000 to 24,000 new cases of blindness each year.
Diabetes is the leading cause of kidney failure, accounting for 44 percent of new cases in 2005.
In 2005, 46,739 people with diabetes began treatment for end-stage kidney disease in the United States and Puerto Rico.
In 2005, a total of 178,689 people with end-stage kidney disease due to diabetes were living on chronic dialysis or with a kidney transplant in the United States and Puerto Rico.
Nervous System Disease
About 60 to 70 percent of people with diabetes have mild to severe forms of nervous system damage. The results of such damage include impaired sensation or pain in the feet or hands, slowed digestion of food in the stomach, carpal tunnel syndrome, erectile dysfunction, or other nerve problems.
Almost 30 percent of people with diabetes aged 40 years or older have impaired sensation in the feet—for example, at least one area that lacks feeling.
Severe forms of diabetic nerve disease are a major contributing cause of lower-extremity amputations.
More than 60 percent of nontraumatic lower-limb amputations occur in people with diabetes.
In 2004, about 71,000 nontraumatic lower-limb amputations were performed in people with diabetes.
Periodontal, or gum, disease is more common in people with diabetes. Among young adults, those with diabetes have about twice the risk of those without diabetes.
Persons with poorly controlled diabetes (A1C > 9 percent) were nearly three times more likely to have severe periodontitis than those without diabetes.
Almost one-third of people with diabetes have severe periodontal disease with loss of attachment of the gums to the teeth measuring 5 millimeters or more.
Complications of Pregnancy
Poorly controlled diabetes before conception and during the first trimester of pregnancy among women with type 1 diabetes can cause major birth defects in 5 to 10 percent of pregnancies and spontaneous abortions in 15 to 20 percent of pregnancies.
Poorly controlled diabetes during the second and third trimesters of pregnancy can result in excessively large babies, posing a risk to both mother and child.
Uncontrolled diabetes often leads to biochemical imbalances that can cause acute life-threatening events, such as diabetic ketoacidosis and hyperosmolar, or nonketotic, coma.
People with diabetes are more susceptible to many other illnesses and, once they acquire these illnesses, often have worse prognoses. For example, they are more likely to die with pneumonia or influenza than people who do not have diabetes.
Persons with diabetes aged 60 years or older are two to three times more likely to report an inability to walk a quarter of a mile, climb stairs, do housework, or use a mobility aid compared with persons without diabetes in the same age group.
Diabetes can affect many parts of the body and can lead to serious complications such as blindness, kidney damage, and lower-limb amputations. Working together, people with diabetes, their support network, and their health care providers can reduce the occurrence of these and other diabetes complications by controlling the levels of blood glucose, blood pressure, and blood lipids and by receiving other preventive care practices in a timely manner.
Studies in the United States and abroad have found that improved glycemic control benefits people with either type 1 or type 2 diabetes. In general, every percentage point drop in A1C blood test results—for example, from 8.0 to 7.0 percent—can reduce the risk of microvascular complications—eye, kidney, and nerve diseases—by 40 percent.
In patients with type 1 diabetes, intensive insulin therapy has long-term beneficial effects on the risk of cardiovascular disease.
Blood Pressure Control
Blood pressure control reduces the risk of cardiovascular disease—heart disease or stroke—among persons with diabetes by 33 to 50 percent, and the risk of microvascular complications—eye, kidney, and nerve diseases—by approximately 33 percent.
In general, for every 10 mm Hg reduction in systolic blood pressure, the risk for any complication related to diabetes is reduced by 12 percent.
Control of Blood Lipids
Preventive Care Practices for Eyes, Feet, and Kidneys
Detecting and treating diabetic eye disease with laser therapy can reduce the development of severe vision loss by an estimated 50 to 60 percent.
Comprehensive foot care programs can reduce amputation rates by 45 to 85 percent.
Detecting and treating early diabetic kidney disease by lowering blood pressure can reduce the decline in kidney function by 30 to 70 percent. Treatment with angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) are more effective in reducing the decline in kidney function than other blood pressure lowering drugs.
In addition to lowering blood pressure, ARBs reduce proteinuria, a risk factor for developing kidney disease, by 35 percent—similar to the reduction achieved by ACE inhibitors.
Total—direct and indirect: $174 billion
Direct medical costs: $116 billion
Indirect costs: $58 billion—disability, work loss, premature mortality
This information is provided by The University of Texas System, Office of Employee Benefits and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition.
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