What is the Difference between Type 1 and Type 2 Diabetes?

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By : dLife Editors

Reviewed by: Qin Yang, M.D., Ph.D.

Are you confused about the various types of diabetes?  In this article, we’ll explore the different types of diabetes and how you can distinguish between them.

Diabetes is a metabolic condition characterized by an accumulation of sugar (glucose) in the body. It is caused by either insufficient insulin production or the body not being able to use insulin in the way it should.

Before we go any further, let’s explain what insulin is and why it’s so important.  Insulin is a hormone produced by the beta cells or β-cells of the pancreas. β-cells are also known as the ‘Islets of Langerhans’ for their tendency to form tiny clusters that are scattered throughout the pancreas.

Insulin acts as a sugar regulator, enabling blood glucose to be transported to the cells where it is converted into energy. In people suffering from type 1 diabetes, the β-cells of the pancreas that produce insulin are destroyed by the body’s own immune cells through an autoimmune mechanism.  Type 2 diabetes is another form of the disease which begins with insulin resistance, a condition in which the cells fail to respond to insulin.

A lack of insulin or getting insufficient amounts causes an accumulation of blood glucose in the body. It leads to the development of classic diabetes symptoms, including the following:

  • Increased thirst
  • Increased hunger
  • Frequent urination
  • Weight loss

When left uncontrolled, high blood sugar can also cause other complications, affecting the eyes, nerves, kidneys, and cardiovascular system.

Difference Between Type 1 and Type 2 Diabetes

The difference between type 1 and type 2 diabetes is that in type 1, the body does not produce insulin at all; this is why it is sometimes called ‘insulin dependent diabetes.’

In type 2 diabetes, the body produces insulin, but the cells are not able to utilize the insulin produced; this is why it is commonly referred to as ‘insulin resistant diabetes.’ Over time, the body’s cells can develop insulin resistance in type 1 diabetes, too.

Diabetes is diagnosed by testing the level of blood sugar or A1C (glycated hemoglobin). An A1C reading measures the three-month average plasma glucose concentration in the blood.

Type 1 diabetes can be distinguished from type 2 by testing for the presence of autoantibodies (a type of protein produced by an individual’s immune system directed against one or more of the individual’s own proteins).  When specific autoantibodies are found, a doctor can make the diagnosis of type 1 diabetes.

The American Diabetes Association has proposed an etiological classification of type 1 diabetes: type 1A (related to immune-mediated diabetes) and type 1B (non-autoimmune related/idiopathic kind).

Due to increasing incidences of type 1 diabetes in adults in recent years, a third category has been introduced—it is known as latent autoimmune diabetes of the adult (LADA).

Adults who develop LADA have the same symptoms as type 2 diabetes patients but produce a unique antigen/protein called Human Leukocyte Antigen (HLA).

Prevalence of Type 1 Diabetes vs Type 2 Diabetes

Type 1 diabetes is a rarer form of diabetes than type 2. Type 1 diabetes accounts for only five to 10 percent of all diabetes cases. Although it can occur at any age, it is more common in children and adolescents less than 15 years of age.

This is why the condition was previously coined ‘juvenile diabetes.’ The occurrence is similar in men and women, although in children it is more common in girls.

Type 1 diabetes most commonly occurs during puberty. Because girls typically enter puberty earlier than boys, the condition is often diagnosed earlier in girls. After puberty, the incidence rate drops in women but continues to occur in men between the ages of 29 and 35.

More than 500,000 children are currently living with this condition globally. The incidence of type 1 diabetes is increasing worldwide with close to 90,000 cases diagnosed in children each year.

The incidence rate of this condition varies between different countries. It is highest in Scandinavian countries followed by Europe, North America, and Australia.

In Asian countries, such as India, China, and Japan, type 1 diabetes is a rare condition. The difference in incidence rate between these countries is likely due to differences in genetic susceptibility and environmental or lifestyle factors.

The incidence rate differs even within the same countries. For example, children in Russia who suffered from a history of infections have shown a lower risk of developing type 1 diabetes than children who had the same genetic risk but a history of fewer infections.

Learn more about the causes, symptoms, complications and treatment options for type 1 Diabetes here.  Learn about the causes, symptoms, diagnosis, and treatment of type 2 diabetes here.

Qin Yang, M.D., Ph.D., is an assistant professor of medicine, physiology, and biophysics at the Center for Diabetes Research in the Department of Medicine, Division of Endocrinology, at the UC Irvine School of Medicine.  He specializes in Endocrinology & Metabolism and Internal Medicine.


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