What Is Type 1 Diabetes?

Type 1 diabetes mellitus (type 1 diabetes, insulin-dependent diabetes mellitus), one of the most common chronic diseases in childhood, is caused by insulin deficiency following auto-immune destruction of the pancreatic beta cells. Until the one and only therapeutic option – the life-long supplementation of insulin or its analogues – was established, affected children died within a short time. Although extensive investigations on the pathogenesis of type 1 diabetes have been performed, the underlying causes and mechanisms are still far from being completely understood. The consequence is a lack of prevention strategies or causal therapies.

What Causes Type 1 Diabetes?

Type 1 diabetes is thought to be caused by an autoimmune reaction (the body attacks itself by mistake) that destroys the cells in the pancreas that make insulin, called beta cells. This process can go on for months or years before any symptoms appear.

Some people have certain genes (traits passed on from parent to child) that make them more likely to develop type 1 diabetes, though many won’t go on to have type 1 diabetes even if they have the genes. Being exposed to a trigger in the environment, such as a virus, is also thought to play a part in developing type 1 diabetes. Diet and lifestyle habits don’t cause type 1 diabetes.

Risk factors

Some known risk factors for type 1 diabetes include:

• Family history. Anyone with a parent or sibling with type 1 diabetes has a slightly increased risk of developing the condition.
• Genetics. The presence of certain genes indicates an increased risk of developing type 1 diabetes.
• Geography. The incidence of type 1 diabetes tends to increase as you travel away from the equator.
• Age. Although type 1 diabetes can appear at any age, it appears at two noticeable peaks. The first peak occurs in children between 4 and 7 years old, and the second is in children between 10 and 14 years old.

Symptoms

HIGH BLOOD SUGAR

The following symptoms may be the first signs of type 1 diabetes. Or, they may occur when blood sugar is high.

• Being very thirsty
• Feeling hungry
• Feeling tired all the time
• Having blurry eyesight
• Feeling numbness or tingling in your feet
• Losing weight despite an increased appetite
• Urinating more often (including urinating at night or bedwetting in children who were dry overnight before)

For other people, these serious warning symptoms may be the first signs of type 1 diabetes. Or, they may happen when blood sugar is very high (diabetic ketoacidosis):

• Deep, rapid breathing
• Dry skin and mouth
• Flushed face
• Fruity breath odor
• Nausea and vomiting; inability to keep down fluids
• Stomach pain

LOW BLOOD SUGAR

Low blood sugar (hypoglycemia) can develop quickly in people with diabetes who are taking insulin. Symptoms usually appear when a person’s blood sugar level falls below 70 milligrams per deciliter (mg/dL), or 3.9 mmol/L. Watch for:

• Headache
• Hunger
• Nervousness, irritability
• Rapid heartbeat (palpitations)
• Shaking
• Sweating
• Weakness

After many years, diabetes can lead to serious health problems, and as a result, many other symptoms.

DIAGONSIS AND TREATMENT

Diagnostic tests include:

• Glycated hemoglobin (A1C) test. This blood test indicates your average blood sugar level for the past two to three months. It measures the percentage of blood sugar attached to the oxygen-carrying protein in red blood cells (hemoglobin). The higher your blood sugar levels, the more hemoglobin you’ll have with sugar attached. An A1C level of 6.5 percent or higher on two separate tests indicates diabetes.

If the A1C test isn’t available, or if you have certain conditions that can make the A1C test inaccurate — such as pregnancy or an uncommon form of hemoglobin (hemoglobin variant) — your doctor may use these tests:

• Random blood sugar test. A blood sample will be taken at a random time and may be confirmed by repeat testing. Blood sugar values are expressed in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). Regardless of when you last ate, a random blood sugar level of 200 mg/dL (11.1 mmol/L) or higher suggests diabetes, especially when coupled with any of the signs and symptoms of diabetes, such as frequent urination and extreme thirst.
• Fasting blood sugar test. A blood sample will be taken after an overnight fast. A fasting blood sugar level less than 100 mg/dL (5.6 mmol/L) is normal. A fasting blood sugar level from 100 to 125 mg/dL (5.6 to 6.9 mmol/L) is considered prediabetes. If it’s 126 mg/dL (7 mmol/L) or higher on two separate tests, you have diabetes.

If you’re diagnosed with diabetes, your doctor may also run blood tests to check for autoantibodies that are common in type 1 diabetes. These tests help your doctor distinguish between type 1 and type 2 diabetes when the diagnosis is uncertain. The presence of ketones — byproducts from the breakdown of fat — in your urine also suggests type 1 diabetes, rather than type 2.

After the diagnosis

You’ll regularly visit your doctor to discuss diabetes management. During these visits, the doctor will check your A1C levels. Your target A1C goal may vary depending on your age and various other factors, but the American Diabetes Association generally recommends that A1C levels be below 7 percent, which translates to an estimated average glucose of 154 mg/dL (8.5 mmol/L).

Compared with repeated daily blood sugar tests, A1C testing better indicates how well your diabetes treatment plan is working. An elevated A1C level may signal the need for a change in your insulin regimen, meal plan or both.

In addition to the A1C test, the doctor will also take blood and urine samples periodically to check your cholesterol levels, thyroid function, liver function and kidney function. The doctor will also examine you to assess your blood pressure and will check the sites where you test your blood sugar and deliver insulin.