Introduction

In the past year there have been dramatic new findings from clinical research in Diabetes, which will change the way clinical care will be delivered in the next five years. While basic understanding of the disease - that is, what causes diabetes, including genetic, metabolic and environmental causes, is rapidly expanding, there does not appear to be any cure for the disease available or on the horizon.

This is of some concern for Canadians are really not aware of how serious and pervasive this disease is. It affects about 1.5 million Canadians, and an additional 750,000 Canadians have the disease and don't know they have it. Once you get the disease, you cannot "cure" it. You can treat it, simply with diet and exercise or eventually with pills, but it does not go away! You have it for the rest of your life. You are living with the constant concern that you may develop loss of eyesight, loss of sensation in your extremities, kidney disease and of course a 2 to 5-fold risk of heart disease and stroke. Because this is not a simple health care problem in Canada, but a serious one that is increasing in incidence every year, the new research on treating the disease is very hopeful and stimulating.

What are some of these new findings?

The American Diabetes Association as well as the World Health Organization and the Canadian Diabetes Association have studied the disease and come out with new criteria for its diagnosis and new recommendations as to whom should be tested and when. These new Canadian Guidelines were published in October 1998. What are some of the more important new recommendations?

First, everyone over the age of 45 should have a single blood test for the presence of diabetes. Those with one of the following high risk factors should be tested even before age 45. These risk factors include high blood pressure or other cardiovascular disease, a family history of diabetes, a history of diabetes during pregnancy, abnormal cholesterol and other lipids in the blood, and obesity.

Secondly, the level at which diabetes will be diagnosed will be lower. Whereas the normal fasting blood glucose does not exceed 6.1 mmols/L, we formerly diagnosed diabetes only when the level was higher than 7.8 mmols/L. We now realize that level was too high and too many with diabetes were not being diagnosed. The critical level was therefore reduced to less than 7.0 mmols/L. Even so, up to 56% of people with mild diabetes will be missed by this new standard. Many, however, will now be recognized earlier, and treatment provided. This is of great importance when we realize that 50% of those diagnosed with diabetes already have at least one complication of the disease. So earlier diagnosis will, we hope, prevent these problems.

Thirdly, the new guidelines emphasize that the treatment of diabetes must be much more aggressive than most physicians realize. It will be necessary in the future to bring the blood sugar down much nearer to normal than currently emphasized. The goal level of fasting blood glucose is to be less than 7.5 mmols/L. Only by achieving this can we avoid complications from developing in the person with diabetes.

At almost the same time as these new guidelines were published, the largest single study on the treatment of type 2 diabetes - the diabetes that usually begins after the age of 30 - was published [1, 2]. Called the United Kingdom Prospective Diabetes Study, this study enrolled about 5000 people and followed them with various treatment regimens over 15 years. This study proved some things that were well known, and taught us some things completely new. In the well known group, it was shown that type II diabetes is a very hard disease to treat, and that it is very hard to get people to change their lifestyle, eating habits, exercise habits, and medications on a long-term basis. It is not hard to make such changes over the short term, but it is nearly impossible under conventional treatment schemes to change behaviour permanently.

How was this shown?

The best treatment when provided by family physicians who are specifically advised how and what to do, is only able to slow the downward spiral and is not able to prevent heart attacks and major complications to a great degree. Thus, optimal treatment only reduced overall major complications by 12% compared to those treated in a casual fashion. While some microvascular complications such as progression of eye disease were reduced (25%), the known high incidence of major complications was not significantly reduced in those treated in the "intense" manner. The findings are much more encouraging if one looks at all those patients who successfully lowered their glucose levels. When viewed this way, from the point of view of an epidemiologist, it was seen that for every 1% reduction in the Hemoglobin A1c level (the standard test indicating blood glucose control) there was a 21% reduction in diabetes complications. With that information, it becomes clear that we must find a way to lower the blood glucose levels in all people with diabetes, and to maintain that low level over the long term.