Type 1 Diabetes (T1D)

Background

Type 1 diabetes (T1D) is a chronic autoimmune disease due to the destruction of insulin-producing beta-cells in the pancreas. Insulin deficiency leads to a rise in sugar levels in the blood and, along with the onset of ketoacidosis, precipitates severe, lifelong sequela. 
T1D typically begins in childhood but may occur at any age. It is believed that a person’s genetic predisposition, along with some environmental trigger, initiates this autoimmune condition.

Clinical

The buildup of sugar and ketones in the bloodstream can lead to many of the symptoms seen in T1D. Early signs include an increase in urination which, in turn, can lead to dehydration. This dehydration can lead to an increase in thirst, hunger, fatigue, weight loss, blurry vision, and slowed healing of cuts/sores. Over time, hyperglycemia can injure the capillaries and other blood vessels. This can lead to neuropathy (causing tingling, numbness, burning, or pain), retinopathy (leading to cataracts, glaucoma, and blindness), nephropathy (leading to kidney failure or end-stage kidney disease), heart/vessel damage (causing coronary artery disease, heart attack, or stroke), as well as damage to other body systems.

Testing

The goal of T1D screening is to identify people before the onset of symptoms who may benefit from therapies to delay or prevent the development of insulin dependance and to lower the clinical issues associated with ketoacidosis. Current recommendations to identify children and young adults with, or at risk of, T1D center around screening for autoantibodies, namely: anti-glutamic acid decarboxylase; anti-insulin; anti-IA2 tyrosine phosphatase; and anti-zinc transporter-8. 

Treatment

Unfortunately, there is no way to prevent or cure T1D. Treatment is mainly to control the amount of sugar in the blood using insulin, exercise, diet, and a healthy lifestyle. Multiple medications and therapies to delay or prevent the progression of T1D are currently under investigation, including the targeting of specific immune cell, cytokines, or antigens, as well as using immunomodulant and/or immunosuppressive agents. Only Teplizumab, a monoclonal antibody, has been granted US Food and Drug Administration (FDA) approval as a treatment to delay the onset of T1D.

Inheritance

There is a genetic component to T1D, with over 70 genetic regions showing an association with development of this condition. As a result, people with a family history are at an increased risk for developing T1D themselves. Although over 90% of children who develop T1D have no family history, the prevalence of T1D among people with a first-degree relative is 15 times greater than among the general population. Despite the genetic component, it is believed that it is an environmental exposure which somehow interacts with these genes to ultimately lead the development of T1D.