Landmarks in Diabetes
Scientific knowledge generally increases through small research steps that build on previous knowledge. But once in a while, there is a pivotal piece of research that is truly groundbreaking in that it challenges previous knowledge, opens up a whole new avenue of thought. The discovery of insulin by Banting and Best stands out as a landmark in diabetes, but would have been impossible without Minkowski's equally notable demonstration of the role of the endocrine secretions of the pancreas in the pathogenesis of diabetes. Likewise, progress in the clinical treatment of diabetes is generally slow, but sometimes a study or a new drug will really alter our way of thinking about diabetes or our treatment. Since understanding diabetes is greatly enhanced by awareness of all these pivotal steps, this section will discuss both landmark scientific achievements, landmark clinical observations and landmark clinical studies.
Rather than a continuous story of progress, history is filled with knowledge gained but lost again and with discoveries whose value was not truly appreciated at the time. For instance, diabetes as a disease hallmarked by sweet urine was identified several thousands of years ago in India and then again in ancient Greece; but a uniform definition only became possible when progress in chemistry allowed us to measure glucose.
Similarly, the beneficial effects of Galega officinalis were known in the Middle Ages, but that this was due to the biguanides it contained became clear only in the 20th century and ultimately resulted in the development of metformin.
A timeline of some major landmarks is presented in figure 1. Inevitably, this timeline is arbitrary and incomplete. Not only because a full listing would be impossible, but also because some major advances such as the diabetes nurse and patient empowerment came along gradually and can not be affixed to a specific point in time.
Figure 1. Some of the highlights in the history of insulin.
Over the centuries, many individuals have contributed to our understanding of the disease and any selection is arbitrary. Notable scientific landmarks include a multitude of discoveries by Claude Bernard, Oskar Minkowski's experiments demonstrating the endocrine role of the pancreas in the pathogenesis of diabetes, and the discovery of insulin by Frederick Bantingand Charles Best.
Changes in clinical practice have often come about by astute clinical observation leading to a novel understanding of the disease. Elliot Joslin and Priscilla White were able to influence diabetes treatment based on their excellent observation, recording and interpretation of patient data accrued in normal clinical practice. These were epidemiologists avant la lettre, working with their own datasets long before large insurance databases became a popular source of information. The introduction of new therapeutic modalities (which usually originated from discoveries in basic science) has also had a major influence on how patients are treated. Among these, the introduction of Insulin, SU derivatives and metformin, as well as the introduction of insulin pens and home blood glucose monitoring systems have shaped diabetes treatment in the last century.
Landmark clinical trials
Improvements in the scientific method have increasingly led to large, randomized trials being a preferred method to test the value of an intervention. Some of the questions answered by the pivotal trials had been the subject of debate for years, for example the question whether glycemic control really mattered to prevent complications. This was settled by the DCCT and DCCT-EDIC for type 1 diabetes, and by the UKPDSand UKPDS- Follow Up for type 2 diabetes. In some cases, however, a trial may also be important for the questions it raises rather than solves, as is the case for the ACCORDtrial.