Type 3 diabetes: causes and treatment

The term diabetes type 3 summarizes various forms of diabetes mellitus that can not be clearly assigned to type 1 or 2. Type 3 diabetes is usually due to the destruction of pancreatic tissue by other diseases and consequent insulin deficiency. However, it can also have a variety of other causes. Read all about diabetes type 3 here!

Type 3 diabetes

What is type 3 diabetes?

Type 3 diabetes includes many forms of diabetes mellitus that can not be classified as "classic" type 1 or 2 forms. Causes include:

• damage to the pancreas (pancreopriver diabetes)
• genetic changes
• hormonal causes
• viral infections

Type 3 diabetes: Pancreatic diabetes

Of the various forms of diabetes mellitus type 3, the so-called pancreoprive diabetes is the most common. Pancreopriv means that the pancreas can not produce enough insulin due to damage. However, before the hormone function (endocrine function) is impaired, sufferers usually have complaints with the digestive system, because in the diseased pancreas production of digestive enzymes (exocrine function) first decreases.:

As the disease progresses, the pancreas increasingly loses its ability to produce enough insulin. For the damage of the pancreas different causes can be considered:

Inflammation or surgical removal of the pancreas

Chronic inflammation of the pancreas (chronic pancreatitis) can lead to massive tissue damage, causing type 3 diabetes. By far the most common cause of chronic pancreatitis is chronic alcohol consumption.

Also, the surgical removal of pancreatic tissue in a tumor disease can cause diabetes type 3 with insulin deficiency by tissue loss. Most commonly, a tumor in the pancreas occurs at the so-called pancreatic head. There, however, are mainly cells that produce digestive enzymes. The insulin-producing cells are more localized in the pancreatic and pancreatic tail. If the tumor in the pancreatic head is removed, insulin production does not necessarily have to be impaired.

Removal of parts of the pancreas may also result in the removal of the glucagon-producing A cells of the pancreas. As a result, blood sugar regulation is also disturbed. Glucagon is released with low blood sugar to raise blood sugar levels. If this is not possible, there is a risk of lethal hypoglycemia. Diabetics who inject insulin need to be extra cautious in cases of glucagon deficiency, as their insulin dose can no longer be absorbed by the body's own regulatory mechanism of the glucagon.

Type 3 diabetes in metabolic diseases

The metabolic disease cystic fibrosis (cystic fibrosis) is associated with a viscidity of Körpersekreten. Also, the digestive enzymes produced in the pancreas are particularly thick due to the disease and "stick" the pancreas. The congestion can also lead to chronic pancreatitis, which affects insulin production and can lead to Type 3 diabetes.

In another metabolic disease, hemochromatosis, increased iron is absorbed through the intestine. This leads to an iron overload of many organs of the body. In the pancreas, excessive iron deposition leads to tissue damage, which can cause type 3 diabetes. Those affected often have a very brown skin pigmentation, which is why one speaks in combination with a diabetes type 3 here of a so-called "bronze diabetes".

MODY (Maturity Onset Diabetes of the Young): About one to two percent of diabetics get a MODY. Symptoms typically found in Type 2 diabetes patients appear in younger patients before the age of 25 years. Most of these young patients are also not overweight, as is often the case with type 2 diabetics. In addition, in a MODY usually, no autoantibodies are detectable, which are typical for type 1 diabetes. It is, therefore, a special form of diabetes, which is therefore classified as type 3 diabetes.

There are currently 11 different types of MODY known, which are distinguished according to the causative genetic change. All have in common that the insulin-producing beta cells of the pancreas are compromised and therefore can not produce enough insulin. Because it is a genetic defect, MODY diabetes occurs familial.

It is very important to distinguish MODY from type 1 diabetes. The MODY is gradual and the body cells still react to the secreted residual insulin. Increased sugar intake in the oral glucose tolerance test (oGTT) shows an increase in insulin. In contrast to type 1 diabetes, patients are not prone to hyperacidity of the body (ketoacidosis) because the body still produces residual amounts of insulin.

As a rule, patients do not need insulin injections at the beginning. Due to the gradual course, this diabetes type 3 form can be controlled by a proper diet as well as antidiabetic drugs in tablet form. As you progress, short-acting insulin may become necessary shortly before a meal.

LADA (Late autoimmune diabetes with adult-onset) Diabetes: type-1 diabetes that usually occurs in childhood and adolescence occurs later than usual in this form, namely only in adulthood. Like the typical type 1 diabetes, autoantibodies to the insulin-producing pancreatic beta-cells are found, which destroy the tissue and cause absolute insulin deficiency.

The causes of LADA are not fully understood. However, it seems certain that genes are very important here. As with type 1 diabetes, the HLA (human leukocyte antigen system) system appears to be particularly involved. It refers to a group of genes that are involved in the regulation of the immune system. In addition to genetic causes, however, environmental influences, for example, infections with certain viruses, are also a decisive trigger for LADA.

Type 3 diabetes in trisomy 21

People with trisomy 21 (Down syndrome) are particularly likely to develop type 3 diabetes. The exact causes have not yet been identified.

Genetic disorders with a defect of insulin action

These type 3 diabetes forms include Insulin Resistance Type A Syndrome and Lipatrophic Diabetes (Lawrence Syndrome). These are very rare genetic defects in which the body tissue has very strong insulin resistance and greatly increased blood sugar levels. Insulin resistance means that insulin can not work properly on its target cells.

Insulin resistance type A syndrome: It is characterized by very strong insulin resistance, skin changes (acanthosis migrants), a change in subcutaneous fatty tissue without obesity (lipodystrophy) and in women a surplus of male hormones (hyperandrogenism). There is currently no adequate therapy to cure this type 3 diabetes.

Lipotropic diabetes (Lawrence syndrome): It is an extremely rare disease that affects only about 100 people worldwide. For reasons unknown so far, patients also suffer from severe insulin resistance. In the course of the disease, the subcutaneous fatty tissue decreases markedly in those affected (lipoatrophy). A cure for this type 3 diabetes is not yet possible.

Type 3 diabetes - hormonal causes

Type 3 diabetes can also occur in the context of other hormone disorders in which the regulatory system of the body is disturbed. These include, for example, Cushing's syndrome and acromegaly.

Type 3 diabetes in Cushing's syndrome

In Cushing's syndrome, the patient has an excess of endogenous cortisone. Cortisone is a vital hormone that is released in stressful situations. It raises blood sugar levels and provides energy in the body by stimulating the breakdown of fatty tissue (lipolysis) and proteins (proteolysis). As a result of the increased blood sugar level, the pancreas is continuously stimulated to produce insulin. This leads after some time to a reduced response of the cells to insulin (insulin resistance) and thus to type 3 diabetes.

An elevated blood cortisol level can also be the result of taking medication. The various cortisones are an important therapy for many inflammations and diseases of the immune system. While a low dose and short duration of use usually cause no side effects, long-term, high-dose use is associated with numerous side effects. This includes, among other things, the development of a type 3 diabetes.

Frequently, the diabetic metabolic state disappears when the cortisone is discontinued again. But be careful: Longer-term cortisone should never be discontinued spontaneously, but must be slowly reduced. Otherwise, a life-threatening adrenal cortex failure threatens.