CAUSES OF DIABETES

I have recently been given steroid treatment (prednisolone) for severe arthritis. My joints are better but my doctor has now found sugar in my urine and tells me I have diabetes. Is this likely to be permanent?

Steroids are effective treatment for a number of conditions but they may cause side effects. One of these is to cause diabetes, which can sometimes be controlled with tablets (e.g. gliclazide). If large doses of steroids are being used, people often need insulin to keep the blood glucose under control. When you stop steroid therapy, there is a good chance that the diabetes will disappear.

However, you may have had diabetes without knowing it before you started on steroids, in which case you will still have diabetes after stopping steroids and will need to continue some form of treatment indefinitely.

I am told that other hormones that the body produces may cause diabetes. Is this true?

Diabetes occurs when there is not enough insulin for the body’s needs.

Sometimes excessive amounts of other hormones will tend to push up the blood sugar levels. If the body cannot respond with enough extra insulin, diabetes may result. Thus someone who produces too much thyroid hormone (‘thyrotoxicosis’ or ‘hyperthyroidism’) may develop diabetes, which goes away when their thyroid is restored to normal. Thyrotoxicosis and diabetes tend to run together in families, and people with one of these conditions are more likely to develop the other.

Sometimes a person will produce excessive quantities of steroid hormones (Cushing’s disease or Cushing’s syndrome), and this may lead to diabetes (see the previous two questions for the connection between steroids and diabetes). Acromegaly is a condition where excess quantities of growth hormone are produced and this too may lead to diabetes.

I have had to go to hospital for repeated attacks of pancreatitis and now have diabetes. I am told that these two conditions are related – is this true?

Pancreatitis can be a very painful and unpleasant illness: it means that your pancreas has become inflamed. The pancreas is the gland that produces insulin as well as other hormones and digestive juices. If it is severely inflamed or damaged, it may not be able to produce enough insulin. Sometimes diabetes develops during or after an attack of pancreatitis and tablets or insulin are needed to keep control of the blood glucose. This form of diabetes is usually, but not always, permanent.

What other diseases would increase the chances of getting diabetes?

There are three groups of such diseases:

  • Glandular disorders, in particular thyrotoxicosis (overactive thyroid), acromegaly (excess growth hormone) and Cushing’s disease (excess steroid hormone, see above); polycystic ovary syndrome and fatty liver disease are both linked with insulin resistance and therefore carry an increased risk of Type 2 diabetes;
  • Diseases of the pancreas, including pancreatitis, cancer of the pancreas, iron overload (haemochromatosis) and cystic fibrosis (a serious inherited childhood disorder); surgical removal of the pancreas (for either pancreatitis or cancer) also causes diabetes;
  • Medical problems, such as heart attacks, pneumonia and major surgical operations which put stress on the body: the diabetes usually clears up when the stress is removed but these individuals may be more at risk of diabetes in the future.