What is diabetes?
Diabetes mellitus is a group of diseases characterized by high levels of blood glucose resulting from defects in insulin secretion, insulin action, or both. Diabetes can be associated with serious complications and premature death, but people with diabetes can take measures to reduce the likelihood of such occurrences.
Prevalence of diabetes*
Total: 15.7 million people--5.9 percent of the population--have diabetes.
Diagnosed: 10.3 million people
Undiagnosed: 5.4 million people* For further information on prevalence, see the Appendix.
Incidence of diabetes
New cases diagnosed per year: 798,000.
Deaths among people with diabetes
- Studies
have found death rates to be twice as high among middle-aged people
with diabetes as among middle-aged people without diabetes.
- Based
on death certificate data, diabetes contributed to 193,140 deaths in
1996.
- Diabetes
was the seventh leading cause of death listed on U.S. death certificates
in 1996.
- Diabetes
is believed to be underreported on death certificates, both as a condition
and as a cause of death.
Prevalence of diabetes by age
Age 65 years or older: 6.3 million. 18.4 percent of all people in this age group have diabetes.
Age 20 years or older: 15.6 million. 8.2 percent of all people in this age group have diabetes.
Under age 20: 123,000. 0.16 percent of all people in this age group have diabetes.
Prevalence of diabetes by sex in people 20 years or older*
Men: 7.5 million. 8.2 percent of all men have diabetes.
Women: 8.1 million. 8.2 percent of all women have diabetes.
*These figures do not include the approximately 123,000 cases of diabetes in children and teenagers in the United States.
Prevalence of diabetes by race/ethnicity in people 20 years or older
Non-Hispanic whites: 11.3 million. 7.8 percent of all non-Hispanic whites have diabetes.
Non-Hispanic blacks: 2.3 million. 10.8 percent of all non-Hispanic blacks have diabetes. On average, non-Hispanic blacks are 1.7 times as likely to have diabetes as non-Hispanic whites of similar age.
Mexican Americans: 1.2 million. 10.6 percent of all Mexican Americans have diabetes. On average, Mexican Americans are 1.9 times as likely to have diabetes as non-Hispanic whites of similar age.
Other Hispanic/Latino Americans: On average, Hispanic/Latino Americans are almost twice as likely to have diabetes as non-Hispanic whites of similar age. (Sufficient data are not currently available to derive more specific estimates.)
American Indians and Alaska Natives: 9 percent of American Indians and Alaska Natives have diagnosed diabetes. On average, American Indians and Alaska Natives are 2.8 times as likely to have diagnosed diabetes as non-Hispanic whites of similar age.
Asian Americans and Pacific Islanders: Prevalence data for diabetes among Asian Americans and Pacific Islanders are limited. Some groups within this population are at increased risk for diabetes. For example, data collected from 1988 to 1995 suggest that Native Hawaiians are twice as likely to have diagnosed diabetes as white residents of Hawaii.
The four types of diabetes
Type 1 diabetes was previously called insulin-dependent diabetes mellitus (IDDM) or juvenile-onset diabetes. Type 1 diabetes may account for 5 to 10 percent of all diagnosed cases of diabetes. Risk factors are less well defined for type 1 diabetes than for type 2 diabetes, but autoimmune, genetic, and environmental factors are involved in the development of this type of diabetes.
Type 2 diabetes was previously called non-insulin-dependent diabetes mellitus (NIDDM) or adult-onset diabetes. Type 2 diabetes may account for about 90 to 95 percent of all diagnosed cases of diabetes. Risk factors for type 2 diabetes include older age, obesity, family history of diabetes, prior history of gestational diabetes, impaired glucose tolerance, physical inactivity, and race/ethnicity. African Americans, Hispanic/Latino Americans, American Indians, and some Asian Americans and Pacific Islanders are at particularly high risk for type 2 diabetes.
Gestational diabetes develops in 2 to 5 percent of all pregnancies but disappears when a pregnancy is over. Gestational diabetes occurs more frequently in African Americans, Hispanic/Latino Americans, American Indians, and persons with a family history of diabetes. Obesity is also associated with higher risk. Women who have had gestational diabetes are at increased risk for later developing type 2 diabetes. In some studies, nearly 40 percent of women with a history of gestational diabetes developed diabetes in the future.
"Other specific types" of diabetes result from specific genetic syndromes, surgery, drugs, malnutrition, infections, and other illnesses. Such types of diabetes may account for 1 to 2 percent of all diagnosed cases of diabetes.
Complications of diabetes
Heart disease
- Heart disease is the leading cause of diabetes-related deaths. Adults with diabetes have heart disease death rates about 2 to 4 times as high as those of adults without diabetes.
Stroke
- The risk of stroke is 2 to 4 times higher in people with diabetes.
High blood pressure
- An estimated 60 to 65 percent of people with diabetes have high blood pressure.
Blindness
- Diabetes is the leading cause of new cases of blindness in adults 20 to 74 years old.
- Diabetic retinopathy causes from 12,000 to 24,000 new cases of blindness each year.
Kidney disease
- Diabetes is the leading cause of end-stage renal disease, accounting for about 40 percent of new cases.
- 27,851 people with diabetes developed end-stage renal disease in 1995.
- In 1995, a total of 98,872 people with diabetes underwent dialysis or kidney transplantation.
Nervous system disease
- About 60 to 70 percent 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.
Amputations
- 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.
Dental disease
- Periodontal 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 percent of people age 19 years or older with type 1 diabetes.
Complications of pregnancy
- The rate of major congenital malformations in babies born to women with preexisting diabetes varies from 0 to 5 percent among women who receive preconception care to 10 percent among women who do not receive preconception care.
- Between 3 and 5 percent of pregnancies among women with diabetes result in death of the newborn; the rate for women who do not have diabetes is 1.5 percent.
Other complications
- Diabetes can directly cause acute life-threatening events, such as diabetic ketoacidosis* and hyperosmolar nonketotic coma.*
- 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.
*Diabetic ketoacidosis and hyperosmolar nonketotic coma are medical conditions that can result from biochemical imbalance in uncontrolled diabetes.
Cost
Total (direct and indirect): $98 billion (United States, 1997).
Direct medical costs: $44 billion.
Indirect costs: $54 billion (disability, work loss, premature mortality).
This estimate, provided by the American Diabetes Association, is in contrast to higher estimates cited elsewhere that are based on all health care costs incurred by people with diabetes, including costs not resulting from diabetes.
New diagnostic criteria for diabetes*
The new diagnostic criteria for diabetes include the following changes:
- The routine
diagnostic test for diabetes is now a fasting plasma glucose test rather
than the previously recommended oral glucose tolerance test. (However,
in certain clinical circumstances, physicians may still choose to perform
the oral glucose tolerance test.)
- A confirmed**
fasting plasma glucose value of greater than or equal to 126 milligrams/deciliter
(mg/dL) indicates a diagnosis of diabetes. Previously, a value of greater
than or equal to 140 mg/dL had been required for diagnosis.
- In the
presence of symptoms of diabetes, a confirmed** nonfasting plasma glucose
value of greater than or equal to 200 mg/dL indicates a diagnosis of
diabetes.
- When a
doctor chooses to perform an oral glucose tolerance test (by administering
75 grams of anhydrous glucose dissolved in water, in accordance with
World Health Organization standards, and then measuring the plasma glucose
concentration 2 hours later), a confirmed** glucose value of greater
than or equal to 200 mg/dL indicates a diagnosis of diabetes.
*For further
information about the new diagnostic criteria for diabetes, please see
the "Report of the Expert Committee on the Diagnosis and Classification
of Diabetes Mellitus," in the References.
**Except
in certain specified circumstances, abnormal tests must be confirmed by
repeat testing on another day.
Treatment of diabetes
Diabetes knowledge, treatment, and prevention strategies advance daily. Treatment is aimed at keeping blood glucose near normal levels at all times. Training in self-management is integral to the treatment of diabetes. Treatment must be individualized and must address medical, psychosocial, and lifestyle issues.
- 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 percent of people with type 2 diabetes require insulin injections.
Impaired fasting glucose
Impaired fasting glucose is a new diagnostic category in which persons have fasting plasma glucose values of 110 125 mg/dL. These glucose values are greater than the level considered normal but less than the level that is diagnostic of diabetes. It is estimated that 13.4 million adults, 7.0 percent of this population, have impaired fasting glucose. Scientists are trying to learn how to predict which of these persons will go on to develop diabetes and how to prevent such progression.
Appendix
How were the estimates in this fact sheet derived?
Periodically, the Federal Government conducts surveys to determine the health of Americans. Such surveys involve questionnaires and medical tests. Most of the diabetes prevalence and incidence estimates presented in this fact sheet were developed by analyzing the newest available national survey data and then adjusting for changes in the population based on 1997 census estimates. The prevalence of diagnosed diabetes represents the number who said they had diabetes. The prevalence of undiagnosed diabetes represents the number of people who said they did not have diabetes, but when given a fasting plasma glucose test, they did in fact have abnormally elevated blood glucose levels (defined as fasting plasma glucose levels greater than or equal to 126 mg/dL). Other estimates presented in this fact sheet were based on individual surveys, research projects, and registry data. A listing of references and additional data sources is below. Most of the national diabetes prevalence estimates are based on Harris MI, et al.
Has the number of persons with diabetes changed since the Diabetes Statistics Fact Sheet issued in 1995?
Between the 1995 and 1997 fact sheets, the number of persons with diagnosed diabetes increased from 8 million to 10.3 million, but the number of persons with undiagnosed diabetes decreased. For the 1995 Diabetes Statistics Fact Sheet, the number of persons with undiagnosed diabetes was estimated from research using the oral glucose tolerance test to identify undiagnosed diabetes. In contrast, for the present Diabetes Statistics Fact Sheet, the number of persons with undiagnosed diabetes was estimated from research using the fasting plasma glucose test, according to recently enacted recommendations. These tests are not equivalent, however, and fewer cases of undiagnosed diabetes are identified using the fasting plasma glucose test.
An enhanced national effort to identify previously undiagnosed persons may also have contributed to a decrease in the number of persons with undiagnosed diabetes. Continued efforts to identify persons with undiagnosed diabetes, the implementation of new guidelines for screening, and the use of an easier and less expensive diagnostic test are all likely to lead to even further decreases in the number of persons with undiagnosed diabetes and increases in the number of persons with diagnosed diabetes.
Doctors Corner would like to thank The National Diabetes Information Clearinghouse, which provided most of the content for this publication (NIH Publication No. 99-3892). Modifications in structure have been made by Doctors Corner to enhance viewabilty. Links to this site may be found by selecting Diabetes Resources Directory listed above. This E-text is not copyrighted and may be freely copied and distributed.
The following organizations collaborated in compiling the information for this fact sheet for the NDIC:
American Association of Diabetes Educators
http://www.aadenet.orgAmerican Diabetes Association
http://www.diabetes.orgCenters for Disease Control and Prevention
http://www.cdc.gov/diabetes
http://www.cdc.gov/nchswwwDepartment of Veterans Affairs
http://www.va.gov/health/diabetesHealth Resources and Services Administration
http://www.hrsa.dhhs.govIndian Health Service
http://www.ihs.govJuvenile Diabetes Foundation International
http://www.jdfcure.orgNational Council of La Raza
http://www.nclr.orgNational Diabetes Education Program: A joint program of NIH & CDC
http://ndep.nih.gov
http://www.cdc.gov/diabetesNational Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health
http://www.niddk.nih.govU.S. Department of Health and Human Services Office of Minority Health
http://www.omhrc.gov
National Diabetes Information Clearinghouse
1 Information Way
Bethesda, MD 20892-3560
E-mail: ndic@info.niddk.nih.gov
Doctors Corner INternet Group, Inc. 1997-2004