Physical Activity Impacts Diabetes Prevention

Physical activity may help prevent or delay type 2 diabetes mellitus (T2DM) for those who are at high risk, whether or not if they lose weight, according to new study.

The results derive from follow-up data from the landmark Diabetes Prevention Program (DPP) study.  This study, published in 2002, found that lifestyle changes, including moderate weight loss and increased physical activity, reduced the chance of developing T2DM by 58% over 3 years in overweight people with prediabetes.

“Until now, the importance of physical activity in preventing diabetes development in the DPP was thought to be due to its role in achieving weight loss and weight maintenance; however, it was not considered a strong key factor alone,” said lead author Andrea M. Kriska, PhD, MS, Professor, Department of Epidemiology, University of Pittsburgh Graduate School of Public Health. “It is important for health care professionals to look beyond their high-risk patients’ weight, and also consider their physical activity levels, when discussing strategies to prevent progression to type 2 DM.”

The DPP study participants were randomized to one of three groups: lifestyle intervention, metformin, or placebo. Both lifestyle and metformin substantially reduced the risk of developing T2DM; the lifestyle intervention was more effective than metformin. Participants in the lifestyle arm received an intensive behavioral intervention composed of nutrition and physical activity. The goals of the study were physical activity for a minimum of 150 minutes per week and achievement of a weight loss of 7%.

With the success of the lifestyle intervention, all participants were provided a modified version of the intervention and asked to participate in the DPP Outcomes Study. That study demonstrated that the lifestyle arm maintained a significantly lower cumulative diabetes incidence than the other two groups, which could not be explained by differences in weight loss.

At the American Diabetes Association's 76th Scientific Sessions in New Orleans, Kriska reported the results of a 12-year follow-up of a subgroup of 1,793 participants who were asked to wear an activity monitor for one week. A questionnaire was used to track physical activity yearly, and diabetes status was determined by annual oral glucose tolerance and semi-annual fasting plasma glucose tests.

The researchers found that in all three treatment groups -- 589 in the lifestyle group, 599 in the metformin group, 605 in the placebo group -- diabetes incidence was lower for participants who were more physically active, regardless of changes in weight. Specifically, there was a 2% decrease in diabetes incidence.

“These current results show that physical activity, over an average of 12 years, decreased the chances of developing diabetes even after considering any changes in weight. This protective effect was greater in those who were less active at baseline. They also suggest that the lower development of diabetes across the entire study in those that took part in the lifestyle arm of the study may be partially explained by improvement in physical activity levels as well as weight loss," said Krista.

Reference: Physical Activity and Diabetes Development: The Diabetes Prevention Program (DPP) Outcomes Study. Presented at ADA Scientific Sessions, New Orleans, LA. June 14, 2016.