THE DIABETES CONTROL AND COMPLICATIONS TRIAL:
What Did It Really Tell Us?
By Deb Butterfield
This article is available in Italian
The Diabetes Control and Complications Trial (DCCT) was a $280 million study conducted by the National Institutes of Health (NIH). The purpose of the project was to compare how the incidence and degree of secondary diabetic complications are affected when 4-6 insulin injections and blood tests are performed daily (intensive therapy) as opposed to only one or two insulin injections and blood tests daily (conventional therapy). The study concluded that the lower blood sugar levels achieved with intensive therapy can delay and even prevent the onset of secondary diabetic complications. Yet when all is said and done, the fact remains that the rate and incidence of blindness, amputation, heart attacks, and kidney failure caused by diabetes--as reported by the NIH--continue to rise. Insurance companies and health care providers ponder this failure and, with few exceptions, conclude that "educating diabetics" to adhere to an intensive regimen of injections and diets will solve the problem. This philosophy has been the cornerstone of diabetes management and consequently the "blame" for secondary complications has shifted from the disease itself to the person who has it. The detail of the DCCT provides clues as to why intensive therapy has not translated into practice.
The DCCT is generally believed to have tracked 1,441 randomly selected diabetic participants for a period of 10 years. The truth is that the study began in 1983 with only 278 participants, the first two years were devoted to planning and feasibility studies and the DCCT's full cohort of 1,441 participants was not achieved until 1989, only four years before the study ended. Of the original 278 participants, 8 dropped out and 11 died. These sad statistics were caused in large part by severe hypoglycemia. Changes were made in the eligibility criteria for the full-scale trial to exclude anyone with this very common short-term complication of diabetes. This exclusion raises questions about the randomness of this selection process. Indeed, the DCCT Research Group reported that intensive therapy is not recommended for children under age 13, people with heart disease or advanced complications, older adults, and people with a history of frequent severe hypoglycemia. The DCCT Research Group itself reported that only 17% of the insulin-dependent diabetes population in the US would qualify for intensive therapy. Nevertheless, intensive therapy is the basis of today's treatment methodology for all diabetics.
Intensive therapy is a lofty theory that fails abysmally in practice. The two most significant points of failure in these programs are (1) human behavior, and (2) severe hypoglycemia. To succeed with intensive therapy a person must take three or more daily injections of insulin (or insulin pump therapy), four or more daily blood glucose tests, and follow dietary instructions. The principle underlying the belief that more diabetes education will improve a person's ability and/or desire to practice intensive insulin therapy is grounded in the assumption that it is reasonable to expect a person to perform these acts every day for the rest of his or her life. At the beginning of 1998, the NIH published their final recommendations for the strategy that will guide their diabetes initiative.
One of their recommendations to "achieve desirable outcomes" is to "apply behavioral theories and strategies to maximize diabetes self-management". Their recommendations are to "develop and evaluate strategies that address social and cultural barriers to adherence," and "to study interventions to decrease psychiatric and social co-morbidities in individuals with diabetes (for example, depression, eating disorders, and family dysfunction)."
Perhaps the best test of these "behavioral theories and strategies" would be to follow 1,441 non-diabetic people over a period of 10 years as they try to comply with the regimen of injections, restrictions and uncertainty that is expected of the diabetic population. The conclusion would, I'm sure, be that the regimen itself is unreasonable and that the co-morbidities of depression, eating disorders and family dysfunction are, after all, only human. The disparity between the findings of the DCCT and the continued escalation of secondary complications points to one undeniable truth--only a cure for diabetes can have any significant impact on the human toll the disease extacts.