Treatment

Diabetes Intensive Therapy Lowers Retinopathy, Nephropathy, Heart Complications

David Mendosa Health Guide July 28, 2009
  • The American Medical Association today published the results of a large and long study that is good news for anyone who has diabetes. The study shows that intensive control substantially lowers the risk of some serious complications of diabetes.

    No surprise that intensive control works. But the surprise is how well it works.

    The study followed 1,375 people with type 1 diabetes for 30 years of their diabetes. The complications measured were proliferative retinopathy, nephropathy, and cardiovascular disease. Conventional treatment led half of them to proliferative retinopathy, one-quarter to nephropathy, and 14 percent to cardiovascular disease.


    Those in the intensive therapy group has substantially lower rates of these complications -- 21 percent, 9 percent, and 9 percent respectively. Fewer than 1 percent became blind, required kidney replacement, or had an amputation because of diabetes during those 30 years.

    But it can be even better when we take a closer look. Remember, first, that all the participants in the study had type 1, where really intensive therapy is more difficult because of the greater risks of hypos that all type 1s have, since they must use insulin. But only about one-fourth of type 2s use insulin. So, second, we need to see how the study defines "intensive therapy."

    Intensive therapy is now the standard of care. It means at least three daily insulin injections or use of an insulin pump with the "goal of achieving glycemic control as close to the nondiabetic range as safely possible." Checking blood glucose at least four times a day is the guide to determining the insulin dose.

    The study, "Modern-Day Clinical Course of Type 1 Diabetes Mellitus After 30 Years' Duration," appears in the July 27 issue of the Archives of Internal Medicine, a publication of the American Medical Association. The abstract of the article went online today, but a few days ago the AMA sent me the full-text of the article.

    "The prospects for patients with type 1 diabetes are far better than they were in the past," the study concludes. "Intensive therapy must be implemented universally and as early as practical and safe to ensure the health of persons with type 1 diabetes."

    Dr. David Nathan, M.D., is the lead author of the study. He is affiliated with Massachusetts General Hospital and Harvard Medical School.

    I asked him for the study's definition of "the nondiabetic range." Surprisingly, the research report failed to spell that out.

    "Our recommendation for many years," Dr. Nathan told me, "based on the results of the DCCT during which the intensive treatment group aimed for a normal (less than 6.1 percent) A1C, but achieved an A1C of  about 7 percent, has been to aim for glycemic control as close to normal as safely possible. This translates into achieving an A1C of less than 7 percent, a goal that has been promulgated by the ADA and other organizations."

    Even more surprising is how much difference an average A1C levels of 7 percent can make when contrasted with conventional therapy. We can only imagine at this point how much more we would be able to reduce our risks of complications when we achieve truly normal A1C levels.