Diabetes is not a single disease, but rather a complex of diseases in which the body either does not make enough insulin or cannot use insulin properly. Insulin is a hormone that moves glucose (a simple sugar) from the bloodstream into the cells for energy and storage. Without enough insulin, the blood sugar rises. Having high blood sugar for an extended period of time can damage blood vessels, nerves, and organs such as the kidneys, eyes, and heart.
About 9.4 percent of Americans have diabetes, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Most of them have type 2 diabetes. Because symptoms often do not appear until the disease is advanced, more than one in four people with this condition do not know they have it.
Diabetes is diagnosed at different rates based on race or ethnicity. At the top of the list by far are American Indians and Alaskan Natives at 14.5%. Blacks, Hispanics, Asians and white are diagnosed at 12.1%, 11.8%, 9.5%, and 7.4 % respectively. Diversity in diagnosis is seen among Hispanics from different origins. 8.3% of Central and South American Hispanics are diabetic, along with 6.5% of Cubans. 14.4% of Mexican Americans, and 12.4% of Puerto Ricans.
TYPES OF DIABETES
Type 1 diabetes is an autoimmune disease. The immune system attacks and damages insulin-producing cells in the pancreas. Without insulin, glucose cannot move from the bloodstream into the cells.
In type 2 diabetes, the pancreas makes insulin. However, the body’s cells become resistant to the effects of this hormone. Increasingly larger amounts of insulin are needed to move glucose into the cells. Eventually, the pancreas can become damaged from trying to produce enough insulin to meet the body’s needs. The stage at which blood sugar levels are high, but not yet high enough for a diagnosis of diabetes is called prediabetes. The CDC estimates that about 96 million adults in the U.S have prediabetes, and many are unaware that they have it.
Gestational diabetes is high blood sugar during pregnancy. Usually gestational diabetes will go away once the baby is born. However, it can increase the mother’s risk of developing type 2 diabetes later in life.
CAUSES
The exact cause of type 1 diabetes is not fully understood. A combination of genes and environmental factors are likely involved. Researchers think a virus may trigger the condition in susceptible people. Type 1 diabetes used to be called juvenile diabetes because it usually affected children, whereas type 2 was found mainly in adults. Due to rising obesity rates, type 2 diabetes is sometimes identified during childhood.
Obesity and inactivity are significant risks for type 2 diabetes. Fat tissue is more resistant to the effects of insulin than other types of tissue. However, not everyone with type 2 diabetes is overweight. Genes, increasing age, and other factors are also involved. Metabolic syndrome is the name for a group of conditions that increase the risk for developing heart disease and diabetes. A person with metabolic syndrome generally is overweight or obese, is inactive, and might have insulin resistance. Elevated blood pressure and levels of cholesterol in the blood are also characteristic of metabolic syndrome. This is a condition in which the body does not use insulin as efficiently as it should to feed muscles and organs. Having metabolic syndrome can increase risk of Type 2 diabetes and lead to a state of prediabetes.
Gestational diabetes is caused by hormones the placenta produces, which make the mother’s cells more resistant to insulin. Obesity in the mother and a family history of diabetes are other contributing factors.
SYMPTOMS
Symptoms of type 1 diabetes typically come on quickly. Type 2 diabetes can take many years to progress to the point where symptoms are noticeable.
The following are symptoms of both type 1 and type 2 diabetes:
- increased thirst and hunger
- fatigue
- frequent urination
- unexplained weight loss
- blurred vision
- numbness or tingling in the hands or feet
- sores that are slow to heal
- repeated urinary tract infections or other types of infections
DIAGNOSIS
Testing is done for type 1 diabetes in people with symptoms, or in those who have a family history of the condition. Doctors recommend testing for type 2 diabetes in people ages 45 and older, and in those ages 19 to 44 who are overweight or obese. Testing is also recommended for women who have had gestational diabetes.
A fasting blood glucose test diagnoses both type 1 and type 2 diabetes. A fasting blood sugar level of 100 to 125 milligrams per deciliter (mg/dL) is considered prediabetes. A level of 126 mg/dL or higher on two separate tests is diabetes.
An oral glucose tolerance test (OGTT) measures your blood sugar level after you fast overnight, and then drink a sweet liquid. A reading of 200 mg/dL or higher indicates diabetes.
The A1C blood test provides a snapshot of your blood glucose levels over a three-month period. This test can be used both to diagnose diabetes, and to monitor its treatment. A1C is measured as a percentage. An A1C level of 6.5 percent or above on two separate tests indicates diabetes. An A1C between 5.7% and 6.4% indicates prediabetes.
Another way to diagnose type 1 diabetes is to test the urine for ketones—a substance produced when the body breaks down fat. People who don’t make enough insulin have to use fat for energy. Another test looks for the presence of autoantibodies—antibodies that the body produces against its own tissue in autoimmune diseases.
Pregnant women are routinely screened for gestational diabetes with a glucose challenge test during their second trimester of pregnancy. This test involves drinking a sugary solution, and then getting a blood sugar test an hour later.
TREATMENTS
Treatment for both type 1 and type 2 diabetes involves a combination of lifestyle interventions like diet and exercise, along with medications to control blood sugar levels. For some people with type 2 diabetes, eating a healthy diet and exercising daily may be enough to manage the condition. People with prediabetes who exercise and lose about 7 percent of their body weight may prevent the onset of the disease.
Having diabetes requires checking blood sugar, sometimes several times a day. Some patients have continuous glucose monitoring, which uses a tiny sensor inserted under the skin that measure glucose levels in fluids near cells. The results tell whether to adjust diet, and insulin or medication dose, according to the blood sugar levels.
People with type 1 diabetes will need to take a synthetic form of insulin to make up for what their body no longer produces. Insulin comes in several forms. Rapid-acting insulin goes to work quickly but the effects only last for a few hours. Long-acting forms take several hours to start working, but their effects last for a day or more. Insulin can be delivered manually through a syringe or pen, or continuously via a pump that attaches to the skin. An artificial pancreas is a relatively new device that automatically tests blood sugar levels and delivers insulin through a pump.
People with type 2 diabetes may need to take other medications by mouth or injection to manage their blood sugar levels. Some medicines stimulate the pancreas to produce more insulin. Others help the body use insulin more efficiently, or slow the release of glucose from the liver so the body requires less insulin.
COMPLICATIONS
When diabetes is not well controlled over time, it can lead to serious consequences. The most common complications include
- Heart attack, stroke, narrowing of the arteries (atherosclerosis)
- Kidney failure or end-stage kidney disease
- Diabetic retinopathy, cataracts, glaucoma, blindness
- Nerve pain, numbness, tingling, burning, or loss of sensation, particularly in the arms, legs, hands and feet
- Infections of the feet which may eventually lead to amputations
- Bacterial and fungal skin infections
Gestational diabetes can lead to problems in the baby, such as a larger than normal size at birth, and an increased risk for type 2 diabetes later in life. The mother is also more likely to develop type 2 diabetes in the future.
Resources
Websites
“Diabetes.” Centers for Disease Control and Prevention. October 4, 2023. https://www.cdc.gov/diabetes/index.html (accessed November 6, 2023).
“Diabetes.” Cleveland Clinic. February 17, 2023. https://my.clevelandclinic.org/health/diseases/7104-diabetes (accessed November 6, 2023).
“Diabetes.” Mayo Clinic. September 15, 2023. https://www.mayoclinic.org/diseases-conditions/diabetes/symptoms-causes/syc-20371444 (accessed November 6, 2023).
“Diabetes Overview.” National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/diabetes/overview (accessed November 6, 2023).
Organizations
American Diabetes Association, 2451 Crystal Drive, Suite 900, Arlington, VA, 22202, (800) 342-2383, http://www.diabetes.org .
Joslin Diabetes Center, One Joslin Place, Boston, MA, 02215, (617) 309-2400, https://www.joslin.org .
National Institute of Diabetes and Digestive and Kidney Diseases, 9000 Rockville Pike, Bethesda, MD, 20892, (800) 860-8747, healthinfo@niddk.nih.gov, https://www.niddk.nih.gov .
Watson, Stephanie, and Kimberly Napoli. “Diabetes.” Gale Health and Wellness Online Collection, Gale, 2023. Gale Health and Wellness, link.gale.com/apps/doc/EBQTKX945636309/HWRC?u=slnsw_public&sid=bookmark-HWRC&xid=7afee7b8. Accessed 1 Aug. 2024.