Recognizing Other Types of Diabetes

By Alan L. Rubin

Cases of diabetes other than type 1 and type 2 are rare and usually don’t cause severe diabetes in the people who have them. But occasionally one of these other types is responsible for a more severe case of diabetes, so you should know that they exist. The following list gives you a brief rundown of the symptoms and causes of other types of diabetes:

  • Diabetes due to loss or disease of pancreatic tissue: If you have a disease, such as cancer, that necessitates the removal of some of your pancreas, you lose your pancreas’s valuable insulin-producing beta cells and your body becomes diabetic. This form of diabetes isn’t always severe, because you lose glucagon, another hormone found in your pancreas, after your pancreatic surgery. Glucagon blocks insulin action in your body, so when your body has less glucagon, it can function with less insulin, leaving you with a milder case of diabetes.

  • Diabetes due to iron overload: Another disease that damages the pancreas, as well as the liver, the heart, the joints, and the nervous system, is hemochromatosis. This condition results from excessive absorption of iron into the blood. When the blood deposits too much iron into these organs, damage can occur. This hereditary condition is present in 1 of every 200 people in the United States; half of those who have it develop a clinical disease, sometimes diabetes.

    Hemochromatosis is less common in younger women, who are protected by the monthly loss of iron that occurs with menstrual bleeding. This finding has led to the current treatment for hemochromatosis, which is removing blood from the patient regularly until the blood iron returns to normal; then repeating the procedure occasionally to keep iron levels normal. If treatment is done early enough (before organs are damaged), complications such as diabetes are avoidable.

  • Diabetes due to other diseases: Your body contains a number of hormones that block insulin action or have actions that are opposed to insulin’s actions. You produce these hormones in glands other than your pancreas. If you get a tumor on one of these hormone-producing glands, the gland sometimes produces excessive levels of the hormones that act in opposition to insulin. Usually, this condition gives you simple glucose intolerance rather than diabetes, because your pancreas makes extra insulin to combat the hormones. But if you have a genetic tendency to develop diabetes, you may develop diabetes in this case.

  • Diabetes due to hormone treatments for other diseases: If you take hormones to treat a disease other than diabetes, those hormones could cause diabetes in your body. The hormone that is most likely to cause diabetes in this situation is hydrocortisone, an anti-inflammatory agent used in diseases of inflammation, such as arthritis. (Similar drugs are prednisone and dexamethasone.) If you take hydrocortisone and you have the symptoms of diabetes, talk to your doctor.

  • Diabetes due to other drugs: If you’re taking other commonly used drugs, be aware that some of them raise your blood glucose as a side effect. Some antihypertensive drugs, especially hydrochlorothiazide, raise your blood glucose level. Niacin, a drug commonly used for lowering cholesterol, also raises your blood glucose. Even the wonder drugs for lowering cholesterol, the statins, have been implicated. If you have a genetic tendency toward diabetes, taking these drugs may be enough to give you the disease.