Type 1 diabetes mellitus (T1DM) is a chronic disease of insulin deficiency and hyperglycemia. In the vast majority of cases, insulin deficiency follows immune-mediated destruction of pancreatic beta cells. It most commonly presents in childhood or adolescence, but a significant number of cases are diagnosed in adults. Diabetes manifests only after the destruction of a majority of pancreatic beta cells.
Patients may present with symptoms of hyperglycemia such as weight loss, polyuria, polydipsia, fatigue, nocturnal enuresis, and blurry vision. T1DM patients may present with diabetic ketoacidosis (DKA), a state of severe dehydration and acidemia due to insulin deficiency. Symptoms include abdominal pain, nausea, emesis, inattention, confusion, and even coma in the setting of hyperglycemia and elevated anion gap. DKA is often associated with compensatory hyperventilation (Kussmaul respiration) in the setting of primary metabolic acidosis and a fruity breath odor.
The pathogenesis appears to be rooted in a genetic component that interacts with an environmental insult in most cases. The incidence of T1DM has been increasing in the United States over the last several decades, with 2-3 new cases per 10 000 person years. There have been several reports about increased incidence of T1DM following acute COVID-19 infections.
Genetic risks (HLA haplotype and other identified genes) for T1DM account for almost 40%-50% of cases. The anti-CD3 monoclonal antibody teplizumab-mzwv is approved by the US Food and Drug Administration (FDA) to delay the onset of clinical T1DM for genetic high-risk patients aged 8 years and older.
Type 1 diabetes, or diabetes mellitus, is a condition of too little or no insulin production by the pancreas, and excessive sugar buildup (hyperglycemia) in the bloodstream. Insulin is needed for the body to use food nutrients and sugar as fuel. Without enough insulin, sugar accumulates in the blood.
Type 1 diabetes is a lifelong condition.
Who’s At Risk
Type1 diabetes runs in the family. If you have a close relative with type 1 diabetes, you may have a greater chance of developing type 1 diabetes.
The farther from the equator, the more patients with type 1 diabetes there are. Finland and Scandinavia have the highest incidences of type 1 diabetes.
The most common ages of onset are 4-7 years old, and again 10-14 years old, but it can be diagnosed at any age.
Signs & Symptoms
Common symptoms of type 1 diabetes are:
A fruity breath odor
Unplanned weight loss
Other symptoms include tiredness, blurry vision, excessive hunger, moodiness, dehydration, recurrent yeast infections, and, in children, new onset bed-wetting.
Individuals with type 1 diabetes always need to be on insulin, and skipping doses can result in life-threatening illness. Follow the self-care instructions of your medical team to keep sugar and insulin in balance and to avoid complications of type 1 diabetes (such as blindness, amputation of toes or fingers, heart, kidney or nerve damage). Daily care involves monitoring blood sugar a few times a day, regulating food intake, and taking insulin (shots or insulin pump) as directed.
When to Seek Medical Care
If you notice signs of type 1 diabetes in yourself or your child, contact your health care provider.
If you have been diagnosed with type 1 diabetes and become pregnant, be sure to see your doctor.
An infant with type 1 diabetes will require careful watch that blood sugar doesn't get too low, which can present with poor feeding, poor responsiveness, poor muscle tone, and irritability. Dangerously low blood sugar can cause seizures and coma, and is an emergency. Toddlers, preschool and school aged children must also be watched for signs of dangerously low blood sugar levels, which cause anxiety, jitteriness, and confusion, and can cause a person to pass out or have a seizure. Continue to monitor sugar levels and provide treatment as instructed, but get medical help immediately if signs of dangerously low blood sugar appear.