The term diabetes type 3 summarizes various rare types of diabetes that arise in other ways than type 1 and type 2 diabetes. LADA also holds a special position. Read all about diabetes type 3 and LADA diabetes here!
What is a type 3 diabetes?
The term diabetes type 3 (or “other specific types of diabetes”) includes several special forms of diabetes mellitus. They are all much rarer than the two main types of diabetes type 1 and type 2 diabetes. Type 3 diabetes includes the following subgroups:
- Type 3a diabetes: caused by gene defects in the insulin-producing beta cells; also called MODY
- Type 3b diabetes: caused by gene defects in insulin action
- Type 3c diabetes: caused by diseases of the pancreas (pancreopriver diabetes)
- Diabetes type 3d: caused by diseases / disorders of the endocrine system
- Type 3e diabetes: caused by chemicals or medications
- Type 3f diabetes: caused by viruses
- Type 3g diabetes: caused by autoimmune diseases
- Type 3h diabetes: caused by genetic syndromes
By the way: Gestational diabetes (gestational diabetes) is sometimes referred to as type 4 diabetes.
Diabetes Type 3a (MODY)
Diabetes type 3a (also known as MODY) is estimated to affect one to two percent of all diabetics. The abbreviation MODY stands for “Maturity Onset Diabetes of the Young”. These are so far 13 different forms of adult diabetes (MODY1 to 13), which already occur in children and adolescents. They are different genetic defects of the insulin-producing beta cells in the pancreas. The mutations cause an abnormal development of the pancreas or islet cells (to which the beta cells belong) or a disorder of insulin secretion. All of them, like any type of diabetes, lead to abnormally high blood sugar levels (hyperglycaemia).
MODY is inheritable, Therefore, several members of a family are usually affected. The disease usually breaks before the age of 25 out. The patients are mostly normal weight as well as type 1 diabetics. Unlike these, however, MODY patients have no diabetes-specific autoantibodies.
The different MODY variants show slightly different clinical pictures with different degrees of hyperglycemia. This is how it goes, for example MODY2 mild and stable for years. As a treatment usually a diet and regular physical activity are sufficient because the body still produces enough insulin. Diabetic sequelae (such as retinal damage, kidney disease, diabetic foot, etc.) are rare here.
It looks completely different MODY1 out: This type of diabetes type 3 is increasingly difficult and often causes sequelae. Patients must reduce their elevated blood sugar levels with oral antidiabetics (sulfonylureas). Some people also need insulin when they are older.
at MODY3 the course is initially quite mild. The disease progresses on and on. Most sufferers need oral hypoglycemic agents, and sometimes insulin. Often there are diabetes-related sequelae.
The other MODY variants are extremely rare.
By the way: MODY patients are often initially classified as Type 1 diabetics. If you are severely overweight (which is less the case), you may be misdiagnosed to have type 2 diabetes.
Diabetes type 3b
This type of diabetes type 3 is due to genetic defects of insulin action. There are different variants:
Of the Insulin resistance type A is associated with a pronounced insulin resistance: the body cells of patients so hardly respond to insulin. Other symptoms include the so-called Acanthosis nigricans. These are gray-brown-black skin changes with a velvety appearance. They form mainly in the flexion folds (armpits, neck, etc.). Acanthosis nigricans is not specific to this type of type 3 diabetes. Rather, it is seen in many other diseases, for example, gastric cancer.
At the Lipatrophic diabetes (Lawrence syndrome), insulin resistance is very pronounced. In addition, the body fat is gradually reduced. This is indicated by the term lipatrophy (= loss of subcutaneous fatty tissue). So far no effective therapy for lipatrophic diabetes is known.
Diabetes type 3c
This representative of type 3 diabetes will too pancreopriver diabetes called. It is caused by diseases or injuries of the pancreas which, among other things, impair insulin secretion. Examples:
- chronic inflammation of the pancreas (Chronic pancreatitis): It affects both the secretion of digestive enzymes (exocrine pancreatic function) as well as the release of insulin, glucagon and other pancreatic hormones (endocrine function). The main cause is chronic alcohol consumption.
- Injuries to the pancreas(about accidents)
- surgical removal of the pancreas (in whole or in part), perhaps due to a tumor
- Neoplasms of the pancreas (Neoplasm or neoplasia = increased neoplasm of tissue)
- Cystic Fibrosis: Incurable hereditary disease. About 30 percent of patients also suffer from type 3 diabetes, because viscous secretions form in the pancreas. It clogs the ducts and damages the cells that produce insulin and other pancreatic hormones. Insulin therapy needed.
- hemochromatosis: In the iron storage disease, iron is increasingly stored in the body, which damages the tissue in various organs. In the pancreas, the insulin-producing beta cells are destroyed. This form of type 3 diabetes is also called “bronze diabetes” because the skin takes on a bronze tint due to the iron deposition.
Diabetes type 3d
Type 3 diabetes can also occur as part of other hormonal (endocrine) diseases and disorders. They are then grouped together under the term diabetes type 3d. The triggering hormone diseases include:
- acromegaly: There is excess growth hormone (mostly due to a benign pituitary tumor). As a result, glucose is increasingly being regenerated in the liver (gluconeogenesis). This increases the blood sugar levels. At the same time, the growth hormone promotes insulin resistance of the cells. Overall, this results in a type 3 diabetes.
- Cushing’s disease: Here, the body releases more of the hormone ACTH, which in turn increases the release of endogenous cortisone. This causes elevated blood sugar levels and thus a diabetes type 3. Further consequences of the excess ACTH are about basic obesity, osteoporosis and hypertension.
- glucagonoma: Most malignant tumor of the glucagon-producing cells in the pancreas (A cells). He can produce excess glucagon. Because this hormone is the antagonist of insulin, a surplus can cause the blood sugar to rise abnormally – it causes a type 3 diabetes.
- Somatostatinoma: Malignant tumor of the pancreas or duodenum, which increasingly produces the hormone somatostatin. This inhibits, among other things, insulin production. As a result, the blood sugar can not lower enough, so that type 3 diabetes arises.
- pheochromocytoma: Most benign tumor of the adrenal medulla. He can boost the new formation of glucose (gluconeogenesis) so much that the blood sugar levels rise morbidly – it develops a type 3 diabetes.
- aldosteronoma: Tumor of the adrenal cortex that produces a lot of aldosterone. He may also increase the risk of type 3 diabetes.
- Hyperthyroidism: Hyperthyroidism can also derail blood glucose levels, causing diabetic patients.
Diabetes type 3e
Different chemicals and (rarely) medications can cause type 3e diabetes. These include, for example:
- Pyrinuron: Nagetiergift (rodenticide) and part of the rat poison Vacor (was only in the US on the market and is no longer allowed)
- Pentamidine: Active ingredient against protozoa; used in the treatment of parasitic diseases such as leishmaniasis
- Glucocorticoids (“Cortisone”): They increase blood sugar levels through various mechanisms, for example by inhibiting the release of insulin and increasing the formation of new glucose (especially in the liver).
- Thyroid hormones: for the treatment of hyperthyroidism (hypothyroidism)
- Thiazide diuretics:Diuretic drugs that are prescribed for example in heart failure (heart failure) and high blood pressure
- phenytoin: antispasmodic for the treatment of epilepsy and cardiac arrhythmias
- Beta-agonists: among others for the treatment of COPD, asthma and irritable bladder
- diazoxide: for the treatment of hypoglycemia
- Interferon alpha: among others for the treatment of hepatitis B and hepatitis C
- Nicotinic acid: water-soluble vitamin from the group of B vitamins; can worsen glucose tolerance (ie the normal = healthy body reaction to glucose intake)
Diabetes type 3f
In rare cases, certain viral infections can trigger type 3 diabetes, such as rubella viruses and cytomegaloviruses. The most vulnerable are unborn children: the viruses can be transmitted to them by the expectant mother. Possible viral triggers of type 3 diabetes include:
- Congenital rubella infection: A rubella infection after the first trimester of pregnancy can trigger inflammation of the pancreas (pancreatitis) in the unborn child. This can lead to insulin deficiency and thus to type 3 diabetes.
- Congenital cytomegalovirus infection: The cytomegalovirus (CMV) belongs to the group of herpesviruses and is very common worldwide. For healthy adults, it is usually harmless. For unborn babies, however, CMV infection can cause serious damage to your health and even mortal danger. Among other things, the child may develop pancreatic inflammation and, subsequently, diabetes.
Diabetes type 3g
In certain cases, certain autoimmune diseases cause type 3 diabetes:
- “Stiff-man” syndrome: autoimmune disease of the central nervous system (brain and spinal cord) and the hormonal system
- Anti-Insulin Receptor Antibodies: They occupy the docking sites for insulin on the surface of body cells. The insulin can then no longer dock itself and ensure that blood sugar is absorbed into the cells.
Diabetes type 3h
These include forms of type 3 diabetes that occur in conjunction with various genetic syndromes. This includes:
- Trisomy 21 (Down syndrome): Affected have three instead of two copies of chromosome 21.
- Klinefelter’s syndrome: Affected boys / men have an excess X chromosome. Therefore one speaks also of XXY syndrome.
- Turner syndrome: Affected girls / women lack one of the two existing X chromosomes or it is structurally defective.
- Wolfram syndromeNeurodegenerative disease characterized by neurological symptoms, optical nerve atrophy (optic atrophy), diabetes mellitus type 1 and diabetes insipidus. The latter is a disturbance of the water balance that does not belong to diabetes mellitus.
- Chorea huntington: Hereditary neurological disease with morbidly increased mobility of the skeletal muscles.
- porphyria: Hereditary or acquired metabolic disease in which the formation of the red blood pigment (heme) is disturbed.
- Friedreich’s ataxia: Hereditary disorder of the central nervous system, which among other causes neurological deficits, skeletal abnormalities and diabetes.
- Dystrophia myotonicaHereditary muscle disease with muscle atrophy and weakness as well as other ailments such as arrhythmia, cataracts and diabetes mellitus.
- Prader-Willi Syndrome (Prader-Willi-Labhart syndrome): Gene defect on chromosome 15, which is associated with physical and mental limitations and disabilities.
Between type 1 and 2: LADA
The abbreviation LADA stands for “Late autoimmune diabetes in adults”. This is a special form of diabetes that is sort of between diabetes type 1 and diabetes type 2:
LADA patients find themselves in the blood diabetes-specific autoantibodies as in type 1 diabetics. However, the latter have at least two different types of such antibodies, for example autoantibodies to insulin (AAI), to islet cells (ICA) or to glutamic acid decarboxylase (GADA). In contrast, LADA patients only have GADA in their blood.
Further differences to the “classic” diabetes type 1 is that people with LADA are already diagnosed older than 35 years are and usually no insulin in the first six months have to inject (their body produces there mostly enough own insulin). Later, sometimes – but not always – insulin therapy may become necessary. In contrast, type 1 diabetes usually causes children or adolescents who all need insulin therapy right from the start.
On the other hand, LADA overlaps type 2 diabetes. Thus, both forms of diabetes generally appear at about the same age. In addition, LADA patients like type 2 diabetics often show Evidence of a metabolic syndrome like lipid metabolism disorders and high blood pressure. However, people with LADA are mostly slimmer as such with type 2 diabetes.
The causes of the LADA are not fully understood. This particular type of diabetes is sometimes referred to as mixed diabetes, a mixture of type 1 and type 2 diabetes. That’s not right. Rather, LADA seems to be two coexisting clinical pictures that develop in parallel. However, the similarities and overlaps with other forms of diabetes do not make it easy for physicians: in everyday practice, LADA is often difficult to get from Type 1 and Type 2 diabetes and also from Type 3 diabetes differ.