Diabetes is a disease characterized by high levels of blood glucose resulting from defects in insulin production, insulin action, or both. Diabetes can be associated with serious complications and premature death, but people with diabetes can take steps to control the disease and lower the risk of complications.
Diabetes is a disease in which the body does not produce or properly use insulin, a hormone that is needed to convert sugar, starches and other food into energy needed for daily life. The cause of diabetes is a mystery, although both genetics and environmental factors such as obesity and lack of exercise appear to play roles. There are two major types of diabetes:
Type 1. An auto-immune disease in which the body does not
produce any insulin, most often occurring in children and young adults. Type
1 diabetes was previously called insulin-dependent diabetes mellitus (IDDM) or
juvenile-onset diabetes. Type 1 diabetes develops when the body's immune system
destroys pancreatic beta cells, the only cells in the body that make the hormone
insulin that regulates blood glucose. This form of diabetes usually strikes
children and young adults, who need several insulin injections a day or an
insulin pump to survive. Type 1 diabetes may account for 5% to 10% of all
diagnosed cases of diabetes. Risk factors for type 1 diabetes include autoimmune,
genetic, and environmental factors.
Who is at greater risk for type 1 diabetes?
- Siblings of people with type 1 diabetes
- Children of parents with type 1 diabetes
Type 2. A metabolic disorder resulting from the body's inability
to make enough, or properly use, insulin. It is the most common form of the disease.
Type 2 diabetes is nearing epidemic proportions, due to an increased number of older
Americans, and a greater prevalence of obesity and sedentary lifestyles. 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% of all diagnosed cases of
diabetes. It usually begins as insulin resistance, a disorder in which the cells do
not use insulin properly. As the need for insulin rises, the pancreas gradually loses
its ability to produce insulin. Type 2 diabetes is associated with 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, Native Americans, and some Asian Americans and Pacific Islanders are at
particularly high risk for type 2 diabetes. Type 2 diabetes is increasingly being
diagnosed in children and adolescents.
Who is at greater risk for type 2 diabetes?
- People over age 45
- People with a family history of diabetes
- People who are overweight
- People who do not exercise regularly
- People with low HDL cholesterol or high triglycerides
- Certain racial and ethnic groups (e.g., African Americans, Latinos, Asian & Pacific Islanders, and Native Americans)
- Women who had gestational diabetes, a form of diabetes occurring in 2-5% of all pregnancies, or who have had a baby weighing 9 pounds or more at birth
Type 2 diabetes is more common among these ethnic groups:
- African Americans. African Americans are 1.7 times as likely to have type 2 diabetes as the general population. An estimated 2.3 million African Americans, or 10.8%, have diabetes.
- Latinos. Latinos are almost twice as likely to have type 2 diabetes. For example, diabetes affects 1.2 million or 10.6% of the Mexican American population.
- Native Americans. Overall prevalence of type 2 diabetes in Native Americans is 12.2% vs. 5.2% of the general population. In some tribes, 50% of the population has diabetes.
- Gestational diabetes develops in 2 -5% of all pregnancies but disappears when a pregnancy is over. Gestational diabetes is a form of glucose intolerance that is diagnosed in some women during pregnancy. Gestational diabetes occurs more frequently among African Americans, Hispanic/Latino Americans, and Native Americans. It is also more common among obese women and women with a family history of diabetes. During pregnancy, gestational diabetes requires treatment to normalize maternal blood glucose levels to avoid complications in the infant. After pregnancy, 5% to 10% of women with gestational diabetes are found to have type 2 diabetes. Women who have had gestational diabetes have a 20% to 50% chance of developing diabetes in the next 5-10 years.
- Other specific types of diabetes result from specific genetic conditions (such as maturity onset diabetes of youth), surgery, drugs, malnutrition, infections, and other illnesses. Such types of diabetes may account for 1% to 5% of all diagnosed cases of diabetes.
Warning Signs of Diabetes
Type 1 Diabetes:
- Frequent urination
- Unusual thirst
- Extreme hunger
- Unusual weight loss
- Extreme fatigue
Type 2 Diabetes:
- Any of the type 1 symptoms
- Frequent infections
- Blurred vision
- Cuts/bruises that are slow to heal
- Tingling/numbness in the hands or feet
- Recurring skin, gum or bladder infections
- Often people with type 2 diabetes have no symptoms.
Treatment of diabetes
- In order to survive, people with type 1 diabetes must have insulin delivered by a pump or injections.
- Many people with type 2 diabetes can control their blood glucose by following a careful diet and exercise program, losing excess weight, and taking oral medication.
- Many people with diabetes also need to take medications to control their cholesterol and blood pressure.
- Among adults with diagnosed diabetes, about 11% take both insulin and oral medications, 22% take insulin only, 49% take oral medications only, and 17% do not take either insulin or oral medications.
Impaired glucose tolerance and impaired fasting glucose
- Impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) are considered to be prediabetic conditions, and studies suggest that they may be reversible.
- IGT is a condition in which the blood sugar level is elevated (between 140 and 199 milligrams per deciliter or mg/dL in a 2-hour oral glucose tolerance test), but not high enough to be classified as diabetes.
- IFG is a condition in which the fasting blood sugar level is elevated (between 110 and 125 mg/dL after an overnight fast) but is not high enough to be classified as diabetes.
- Among U.S. adults 40-74 years of age, 16.0 million (15.6%) have IGT and 10.0 million (9.7%) have IFG.