Type 1 Diabetes


What is Type 1 Diabetes

Type 1 diabetes is a life-threatening, life-long disease that is characterized by the lack of insulin, causing excessively elevated glucose in a person's blood (called hyperglycemia).

Type 1 diabetes is the most common form of diabetes in childhood. About 1 in every 350 children in the United States has type 1 diabetes. It can appear in children as young as 6 months of age, although the most common age is around 12. Type 1 diabetes is becoming more frequent than before, particularly among children younger than 5 years of age. Adults can also develop type 1 diabetes.

Individuals of any race or ethnic group can develop this disease but it is more common among non-Hispanic whites. It is slightly more common among males than females.

Causes & Risk Factors

Around 95% of cases of type 1 diabetes are caused by autoimmunity, that is, the body's defense system (called immune system) attacking its own cells, in this case, the insulin-producing cells in the pancreas (beta-cells). The ultimate reason for this attack is unknown. However, we know that there are inherited (genetic) and environmental factors.

Relatives of a patient with type 1 diabetes have increased risk of developing the disease: about 70% for identical twins, 6% of siblings and non-identical twins, 6% for children of a father with type 1 diabetes and 4% for a mother with type 1 diabetes. Certain genes (HLA types) make type 1 diabetes more likely.

We know that the environment also has a role in causing type 1 diabetes but the specific triggers have not been identified.

Today, it is possible to accurately estimate the risk of type 1 diabetes based on the presence of certain markers in blood (named diabetes autoantibodies or islet autoantibodies) in addition to genes and family history. Research studies are ongoing with the ultimate goal of finding safe and effective treatments to prevent to type 1 diabetes in individuals at risk. 

Symptoms & Types

Symptoms of diabetes include increased urination (caused by the kidneys flushing excessive blood glucose), increased thirst (the body's compensatory mechanism of the fluid loss through urine) and weight loss (caused by the loss of glucose through the kidneys, among other factors).

Other symptoms include tiredness and mood changes, bedwetting (consequence of increased urination), blurry vision and infections (skin, urine, vaginal).

If left untreated, increased glucose levels lead to additional complications, such as diabetic ketoacidosis (DKA), which is life-threatening. At this stage, patients have nausea, vomiting, abdominal pain and abnormal breathing followed by loss of consciousness and potentially death. Early diagnosis of type 1 diabetes is critical to prevent development of this fatal complication.

Diagnosis & Tests

Diagnosis of type 1 diabetes requires a test of blood glucose. Patients with clearly elevated glucose in blood will also have glucose in their urine; however, glucose in urine can be normal at certain times of the day and therefore a normal urine test does not rule out diabetes. At the early stages of diabetes, blood glucose can be normal at certain times of the day, and a special test called oral glucose tolerance test (OGTT), which is done by measuring blood glucose 2 hours after drinking a glucose load may be necessary to demonstrate that someone has diabetes.

Once a patient is diagnosed with diabetes, several tests are conducted to diagnose the type of diabetes (for example, diabetes autoantibodies are typical of type 1 diabetes) and the presence of complications (for example, DKA) and other conditions that are present more frequently (for example, thyroid abnormalities).

To diagnose risk of type 1 diabetes, islet autoantibodies are measured in blood. Genetic tests and measurement of the ability to produce insulin help better estimate the risk and establish the stage of the progression.

Treatment & Care

Type 1 diabetes requires treatment with insulin. Today, insulin must be delivered via injection (usually, intravenous in the hospital setting and subcutaneous at home), pump (a device that delivers insulin subcutaneously in a continuous fashion) and, recently, inhaled. To give the right dose of insulin, patients check their blood glucose several times daily. Some patients also wear a continuous glucose monitor that provides additional information.

Children with type 1 diabetes need to have frequent adjustments of the dose and require visits to their diabetes doctor and team (diabetes educator, dietitian and psychologist) every 3 months. It is very important to screen for potential complications (eye, kidney and cardiovascular diseases, depression, eating disorders, obesity, etc.) as well as other autoimmune conditions (thyroid and celiac diseases among others). Screening and early treatment help decrease the risk of complications. Patients with well controlled type 1 diabetes can lead normal lives.

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