Other types of diabetes

In addition from type 1 and type 2 diabetes, there are other types of diabetes that are less common.

Diabetes as side effect of certain diseases

Diabetes can occur in people suffering from certain diseases or health conditions, such as:

  • Pancreatic diseases (cystic fibrosis, cancer, pancreatitis, pancreatectomy, etc.);
  • Endocrine diseases (Cushing’s syndrome, acromegaly, hyperthyroidism, etc.);
  • Genetic syndromes (Down syndrome, Friedreich’s ataxia, Turner’s syndrome, etc.);
  • Viral infections (congenital rubella, cytomegalovirus, etc.).

Diabetes as a side effect of medication

Some medications can increase the risk of diabetes, either temporarily or permanently, such as:

  • Glucocorticoids;
  • Drugs prescribed to prevent the rejection of an organ transplant;
  • Drugs to treat certain cancers;
  • Certain drugs to treat high blood pressure (thiazides);
  • Drugs to treat hypothyroidism;
  • Certain drugs to treat high cholesterol (statins);
  • Anti-epileptic medication;
  • Drugs to treat certain mental health problems.

People who develop diabetes as a result of taking medication are usually considered to have type 2 diabetes and are treated as such.

MODY and LADA diabetes

Some people have a form of diabetes that cannot be classified as either type 1 or type 2. These are rare cases where it’s difficult to make a diagnosis or the diagnosis is eventually questioned due to an unexpected or atypical course of the disease.

MODY (Maturity Onset Diabetes of the Young)

MODY diabetes is a rare form of diabetes that usually presents before the age of 25 in individuals of normal weight. Although these characteristics usually correspond to those of type 1 diabetes, MODY diabetes is closer to type 2 diabetes: the symptoms at the time of diagnosis are less pronounced than in type 1 diabetes and there is no acidosis present.

This diabetes is characterized by an abnormality in insulin secretion caused by a genetic mutation. This condition is highly hereditary. The risk of transmitting it to your child is 50% if you are a carrier.

MODY diabetes is often diagnosed at first as type 1 diabetes. However, it requires surprisingly low amounts of insulin and this obtains over an extended period of time. An atypical progression can also be an indicator of MODY diabetes rather than type 1. If this type of diabetes is suspected, genetic testing can be done to identify the mutated gene.

MODY diabetes can sometimes be treated without insulin injections because the pancreas still secretes insulin, unlike in individuals with type 1 diabetes who depend on insulin injections to survive.

LADA (Latent Autoimmune Diabetes in Adults)

LADA diabetes, sometimes called type 1.5 diabetes, usually presents in people between the ages of 30 and 50 who are of normal weight. Like type 1 diabetes, it has an autoimmune component, characterized by the presence of autoantibodies in the blood. These antibodies cause a slow and progressive destruction of the beta cells of the pancreas responsible for producing insulin.

LADA diabetes, however, differs from type 1 diabetes by a slower progression of the complete destruction of the beta cells. It does not necessarily require insulin at diagnosis and can therefore be considered type 2 diabetes. It can take between six months and six years for insulin to become necessary as a treatment.

Resources for you

Other resources

Research and writing : Diabetes Québec’s team of health professionals

April 2020

© Diabetes Québec

References : 

Expert Committee. Diabetes Canada 2018 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada: Appendix 2 Etiologic Classification of Diabetes Mellitus. Can J Diabetes 2018; 42 (Suppl 1): S308.

American Diabetes Association. (2005). Latent Autoimmune Diabetes in Adults [En ligne]. Repéré à http://diabetes.diabetesjournals.org/content/54/suppl_2/S68.full  (page consultée le 15 mai 2018)

Leslie D. et Valeri C. (2003) Le LADA (Latent Autoimmune Diabetes in Adults). Diabetes voice Vol 48 p.14-16, Fédération Internationale du Diabète

Geoffroy L. et Gonthier M. (2012). Le diabète sous toute ses formes. Dans Le diabète chez l’enfant et l’adolescent, 2e édition. Montréal :Éditions du CHU Ste-Justine