Long term studies, performed with the goal of capturing more data that will enable more confident conclusions, sometimes become moot when more recent studies eclipse their premise.In the May issue of the Journal Diabetes, researchers at the University of Pittsburgh Graduate School of Public Health reported on the Pittsburgh Epidemiology of Diabetes Complications (EDC) Study’s findings (see press release) that long term complicatons including heart disease and eye disease have not improved over the past 25-30 years for type 1 diabetes juveniles and adolescents treated at Children’s Hospital of Pittsburgh between 1950 and 1980.Now, I certainly respect long term studies, because arguably there are far too few of them and far too many studies that are not only too short term, but also too narrowly focused to reveal all the implications of treatment options. Short term data is awfully compelling, especially if you are a manufacturer seeking marketing approval or just a market edge.
But long term data can lose much of its relevance when it is eclipsed by more recent research that also passes the “long-term” test. Clearly, the EDC study is undercut by the Diabetes Control and Complications Trial conducted from 1983 to 1993, which showed very clear improvement in the risk and severity of complications associated with eye, kidney and nerve disease when Type 1 diabetes had their glucose more tightly controlled:
- Eye disease
76% reduced risk
- Kidney disease
50% reduced risk
- Nerve disease
60% reduced risk
Now, even though patients in the DCCT trial were not expected to have heart-related problems at the beginning of the trial, since they were on average only 27 years old, cardiograms, BP and blood fat were assessed during the trial, revealing at the end of the trial that those with tight glycemic control had significantly lower risk of developing high cholesterol, a significant indicator of risk for developing heart disease.
Therefore, one must seriously question findings of a type 1 study that did not specifically factor the level of glycemic control in a consideration of heart disease or eye disease risk. Almost as significantly, the patients included in this study were type 1 individuals who, at the latest, were patients 13 years before the end of the DCCT trial.
Further, in discussion of the findings, it is noted that “many of the guidelines currently used for managing type 1 diabetes are derived from what we know about people with type 2 diabetes. We need to recognize that they are two different conditions with different processes involved. Therefore, some of the complications we see in type 2 diabetes do not occur in type 1 and vice versa.”
I am struggling to not be harshly critical of statements like this. Type 1 and Type 2 are well known to be starkly different, the only common denominator being a problem of one sort or another with insulin and therefore the need to keep an eye on blood glucose (again, the omission of the level of glycemic control being a glaring omission).
Fast forward to today (read “modern technology”). A type 1 diabetic diagnosed in 2006 faces an order of magnitude difference in treatment than one diagnosed between 1950 and 1980. Research should therefore focus on what we know now, and how we can enhance treatment, rather than what we knew almost 60 years ago.
As a matter of obligation, I must note that my 11 year old daughter has type 1 diabetes, having been diagnosed over four years ago. So yes, maybe I’m biased, but I’m also extremely well informed on this topic. Her most recent HbA1c was 7.4.
Related Tags: diabetes, Medtech, Medical, Medcial-technology