An important study was published in November 14th’s edition of the Lancet medical journal, which proves that diabetes can be prevented with lifestyle changes, and that this benefit can persist over the long term.

This study is called the Diabetes Prevention Program Outcome Study (DPPOS), and is a follow up to the landmark Diabetes Prevention Program initial study (DPP) that was published in 2002 in the New England Journal of Medicine.

The DPP was a study of over 3,000 prediabetics who were randomized to received either intensive lifestyle counseling, a diabetes medication called metformin, or placebo treatment, to see how effective these strategies were in preventing progression to full blown diabetes. The DPP trial was stopped prematurely, because the evidence for the superiority of the lifestyle intervention was already clear. After an average of 2.8 years, the lifestyle group had a 58% lower rate of development of diabetes than the placebo group, which was even better than the metformin treated group, who had a 31% lower rate of development of diabetes than placebo. Weight loss was also superior in the lifestyle group at 5.6kg, compared to 2.1kg in the metformin group, and 0.1kg in the placebo group.

In the DPPOS follow up study, all patients were offered lifestyle therapy, similar to the initial lifestyle group of the DPP, but in a less intense format. Placebo was stopped, and the metformin group continued their metformin.

During the 10 year follow up in the DPPOS, the original lifestyle group regained most of their weight, which may be related to the less intense nature of the DPPOS lifestyle program. Both the metformin and the original placebo groups lost a bit of weight (with the onset of the lifestyle program), but gained it back. As such, there was no significant difference in weight between the 3 groups at the end of the DPPOS.

However, despite there being no difference in weight, there continued to be an overall lower rate of onset of diabetes in the original lifestyle and metformin groups: they still had a 34% and 18% lower incidence of diabetes than the original placebo group, respectively. In other words, the original intensive lifestyle undertaken in the first 2.8 years of this study delayed diabetes onset by 4 years, and metformin delayed diabetes onset by 2 years.

Furthermore, although the overall diabetes incidence was highest in the placebo group, the rate of onset of diabetes in both the placebo and metformin groups fell to equal the rate of onset in the original lifestyle group, due to the institution of lifestyle therapy at the start of DPPOS. This points again towards the benefits of lifestyle in prevention of diabetes.

The bottom lines:

  • Effectively changing your lifestyle in favor of healthy eating and increasing exercise is beneficial to prevent diabetes.
  • The more intensive the support and counseling in making these changes, the more effective that program is to prevent diabetes.
  • Even if an intensive support program is not feasible for the very long term, the benefits of diabetes prevention during the time of the intense program are still maintained over the long term!

Dr. Sue © 2009