Can Type 2 Diabetes Turn Into Type 1?

Type 1 diabetes and type 2 diabetes are separate conditions with unique causes. One condition cannot turn into the other.

Type 1 diabetes is a disease of insulin deficiency caused by an autoimmune reaction (when the body attacks healthy cells by mistake). Type 2 diabetes is a disease of insulin resistance, in which the body cannot respond to or use insulin efficiently. Type 2 diabetes primarily develops due to lifestyle factors, like obesity and lack of exercise.

This article will distinguish between type 1 and type 2 diabetes. The role of insulin in disease manifestation and treatment will also be explored.

Type 1 vs. Type 2 Diabetes

Type 1 diabetes occurs when a person's immune system attacks and destroys insulin-producing beta cells in the pancreas. Beta cell loss occurs over weeks, months, or years, resulting in a total deficiency of insulin.

Type 1 diabetes is believed to be caused by a complex interaction between various genetic and environmental factors, including viral infections, toxin exposure, or early childhood diet.

Type 2 diabetes is not an autoimmune disease. It develops slowly over time as a person's body stops responding to insulin. Insulin production may decline as the condition progresses and the beta cells stop functioning.

While genetic factors contribute to type 2 diabetes, lifestyle factors, including poor diet, physical inactivity, and being overweight or having obesity, tend to play a more substantial role in disease manifestation.

Other differences between type 1 and type 2 diabetes include:

• Prevalence: Type 1 diabetes is less common than type 2 diabetes. According to a 2018 study, 5.6% of American adults with diabetes have type 1 diabetes, while 91.2% have type 2 diabetes.
• Age of onset: Type 1 diabetes classically develops in childhood or young adulthood, between the ages of 4 and 6 or 10 and 14. Type 2 diabetes is rarely diagnosed before puberty.
  
• Disease onset: The symptoms of type 1 diabetes tend to come on suddenly and intensely. Type 2 diabetes symptoms appear gradually and may involve symptoms of insulin resistance (e.g., dark skin patches called acanthosis nigricans).
• Body type: Most people with type 2 diabetes are overweight or have obesity. People with type 1 diabetes tend to be lean.
• Insulin therapy: Individuals with type 1 diabetes will always require insulin injections, whereas people with type 2 diabetes may not.
• Prevention: Type 1 diabetes cannot be prevented, but type 2 can be delayed or prevented by engaging in healthy lifestyle habits.

Latent Autoimmune Diabetes in Adults (LADA)

LADA is a form of diabetes, sometimes called type 1.5 diabetes, as it shares type 1 and 2 diabetes features. LADA manifests after the age of 30 and accounts for 2% to 12% of all cases of diabetes in adults.

While its exact definition is under debate, experts know that, like type 1 diabetes, LADA is caused by an autoimmune reaction against the insulin-producing beta cells in the pancreas. Unlike type 1 diabetes, LADA is a slowly progressing disease, so people don't usually require insulin for months or years after being diagnosed.

As seen in type 2 diabetes, insulin resistance may also be present in LADA. However, unlike type 2 diabetes, LADA is not associated with excess body weight or obesity.

Misdiagnosis of Type 1 or 2 Diabetes

No single blood test or formal criteria can differentiate between type 1 and type 2 diabetes. Instead, healthcare providers diagnose based on symptoms, medical history, and blood or urine test results.

A misdiagnosis is most likely to occur when the person's age doesn't match the disease's typical age of onset, as in the case of LADA or adult-onset type 1 diabetes. It's believed that as many as 50% of adults with type 1 diabetes might be initially misdiagnosed as having type 2 diabetes.

Conversely, type 2 diabetes in children can be mistaken for type 1 diabetes. Unfortunately, type 2 diabetes is becoming more prevalent in early life, as many children are overweight or have obesity.

Besides clinical features, various blood and urine tests can help distinguish between type 1 and type 2 diabetes. These tests include:

• Blood antibody tests: Antibodies are proteins the immune system produces to defend the body from invaders. In autoimmune diseases, they are mistakenly produced to attack healthy cells in the body (beta cells in type 1 diabetes). Antibodies are present in type 1 diabetes and absent in type 2.
• Urine C-peptide level: C-peptide is a substance made when the pancreas produces insulin. Individuals with type 1 diabetes will have low or undetectable C-peptide in their urine because their pancreas is not producing much insulin. The C-peptide level can also be checked in the blood.

Insulin Dependency

People have abnormally high blood glucose levels with both type 1 and 2 diabetes. However, the treatment for their high blood sugar levels (hyperglycemia) is different.

People with type 1 diabetes are dependent on insulin because they have no (or only a tiny amount of) beta cells to make insulin. Their body has destroyed them. As such, people with type 1 diabetes must be treated with insulin shots immediately after diagnosis.

Conversely, people with type 2 diabetes are insulin resistant. Treatment is focused on helping the body better utilize the insulin being made by the pancreas.

The treatment of type 2 diabetes focuses on lifestyle changes, notably weight loss. In some instances, medication to increase insulin release from the pancreas or lower insulin resistance may also be prescribed.

Insulin injections are generally advised in type 2 diabetes if blood sugars continue to be elevated despite lifestyle interventions and medication.

Summary

Type 2 diabetes cannot turn into type 1 diabetes. They are separate conditions that differ in biology, onset, presentation, and management.

Type 1 diabetes is an autoimmune disease of insulin deficiency typically diagnosed in early life. It requires immediate insulin replacement upon diagnosis.

Type 2 diabetes is a disease primarily of insulin resistance that develops over many years. Treatment involves weight loss and other healthy lifestyle changes. Medication followed by insulin may be required, especially if high blood sugar levels persist.

Unfortunately, no single test or formal criteria exists to distinguish between type 1 and type 2 diabetes. Instead, healthcare providers utilize clinical features and various blood or urine tests to confirm the diagnosis.

A Word From Verywell

If you are diagnosed with type 1 or type 2 diabetes, it's critical to follow through with your treatment plan. Both forms of diabetes can cause permanent damage to various organs in your body, including your kidneys and heart, if not appropriately managed.

It's also essential to receive the correct diabetes diagnosis. In particular, a misdiagnosis of type 1 diabetes may have serious consequences, including developing a potentially life-threatening condition called diabetic ketoacidosis. This condition occurs when the body produces toxic acids called ketones due to insulin deficiency and high blood sugar.