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Causes of Diabetes

Causes of DiabetesThere exist a big number of factors and conditions that can lead to diabetes mellitus. The most reasonable way of distinguishing them is grouping the causes according to each type of diabetes.

Causes of Type 1 Diabetes Mellitus

The reason why people have type 1 diabetes mellitus, which is characterized by the deficiency of insulin produces by the pancreas, is the destruction of pancreas ?-cells. These cells are destroyed by the body, which is called an autoimmune reaction. The reasons of this type of autoimmune reaction leading to type 1 diabetes are yet not clear. Existing explanations of type 1 diabetes causes include:

  • Specific viral or bacterial infection
  • Action of chemical toxins consumed with food
  • Action of a yet unidentified component of cow’s milk that triggers an autoimmune reaction in young infants

These hypotheses have not been proven yet.

Causes of Type 2 Diabetes Mellitus

The reasons of type 2 diabetes mellitus are the lack of response from insulin receptors to the action of insulin (insulin resistance), insulin defects that prevent this hormone from acting properly, or simply the lack of insulin available. The following factors are the most common causes of type 2 diabetes:

  • Increasing age
  • Obesity
  • Physical inactivity

More rarely, type 2 diabetes mellitus can be caused by the following:

  • Specific medications
  • Pregnancy (for more details, please read the “Gestational Diabetes” Section)
  • Disease of the pancreas that prevents it from producing insulin at a normal range

Myths About Diabetes Causes

Though the years, there appeared many myths about the causes of diabetes. It is important to distinguish them from the real diabetes causes. The following does not cause diabetes:

  • Consuming sweets. It temporarily raises the glucose levels but is not dangerous, as a healthy body starts automatically producing more insulin. Still, be aware that unhealthy diet and lifestyle may lead to obesity, which is a common cause of type 2 diabetes mellitus.
  • Stress. It doesn’t cause diabetes but may trigger the disease symptoms in those patients having prediabetes.
  • People with diabetes. Diabetes mellitus is not contagious and cannot be passed from a diabetic patient to a healthy person.

Full List of Diabetes Mellitus Causes

It should be said that the research on the cause of diabetes continues, as some of conditions are only supposed to be the reason of diabetes, and not all of the hypotheses are proven. At the moment, the list of diabetes mellitus causes includes the following:

I. Genetic defects of pancreas ?-cells function:

  • Maturity onset diabetes of the young (MODY) – monogenic diabetes caused by mutations in a gene inherited from either of the parents.
  • Mitochondrial DNA mutations

II. Genetic defects of insulin action/insulin processing:

  • Proinsulin conversion defects – disorder of proinsulin conversion into insulin
  • Insulin gene mutations – mutations in the gene responsible for the action and quality of insulin
  • Insulin receptor mutations – mutations in the gene responsible for activity of transmembrane receptors that are activated by insulin and help the body cells absorb glucose

III. Exocrine pancreatic defects:

  • Chronic pancreatitis – long-standing inflammation of the pancreas
  • Pancreatectomy – surgical removal of pancreas or its part
  • Pancreatic neoplasia – cancer of the pancreas
  • Cystic fibrosis – recessive genetic disease that affects excretory glands, functions of breathing organs and gastrointestinal tracts, and especially fibrosis and cyst formation in the pancreas
  • Haemochromatosis – accumulation of iron in the body
  • Fibrocalculous pancreatopathy – disorder of the pancreas exocrine function

IV. Endocrinopathies (diseases of the endocrine system):

  • Acromegaly – growth hormone excess syndrome
  • Cushing’s syndrome – hormone disorder characterized by high levels of cortisol in blood
  • Hyperthyroidism – increased activity of thyroid gland tissue producing thyroid hormones
  • Phaeochromocytoma – tumor of the medulla of adrenal glands or extra-adrenal chromaffin tissue that causes excessive secretion of catecholamines
  • Glucagonoma – tumor of the pancreas ?-cells that causes the overproduction of glucagon in up to 1000 times higher than normal

V. Infections:

  • Cytomegalovirus infection – infectious disease triggered by cytomegalovirus, which leads to a number of different pathologies
  • Coxsachie B4 virus – a virus that triggers an autoimmune reaction that makes the human body ruin its own pancreas ?-cells responsible for the production of insulin.

VI. Medications:

  • Glucocorticoids
  • Thyroid hormone
  • ?-adrenergic agonists

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