Group-based lifestyle interventions have long-term effects on prevention of diabetes beyond the period of active intervention, this clinical trial shows.
Lifestyle interventions, including weight loss, can reduce the risk of long-term cardiovascular consequences of diabetes mellitus (DM), according to the results of a clinical trial. This is the first randomized clinical trial to show that lifestyle intervention in persons with impaired glucose tolerance reduces all-cause and cardiovascular disease mortality.
“Lifestyle intervention delays the onset of diabetes and reduces the incidence of diabetes. We had assessed how mortality was affected by the time free from diabetes, which was defined as the time between randomization and onset of diabetes. We found that the increased delay in the onset of diabetes was associated with significantly lower all-cause and cardiovascular disease mortality,” lead author Professor Guangwei Li of the China-Japan Friendship Hospital, Beijing, China, told ConsultantLive.
“After inclusion of time to onset of diabetes in the multivariable models the intervention variable was no longer statistically significant, suggesting that the reduction in mortality associated with the intervention is mediated by its effect in delaying the onset of diabetes,” he noted.
Many research studies have shown that lifestyle interventions, such as exercise programs or weight loss, in persons with impaired glucose tolerance can prevent progression to overt type 2 DM. However, until now, there has been a lack of high-quality, randomized controlled trial evidence to prove that lifestyle interventions prevent deaths from cardiovascular disease, such as heart attacks and stroke, in these patients.
Dr Li and colleagues enrolled 438 patients assigned to the intervention arm and 138 patients who were assigned to the control arm. The study intervention lasted for 6 years, and patients were then monitored for 23 years.
At the end of the follow-up period, cumulative incidence of death from cardiovascular disease was 11.9% in the lifestyle intervention group versus 19.6% in the control group; death from all causes was 28.1% in the lifestyle group versus 38.4% in the control group. The difference between groups for both outcomes was statistically significant.
“Although the association between duration of diabetes and mortality is well established, serious chronic complications and excess mortality typically only occur after at least 10 years of having diabetes,” Dr Li said. “In the present study, a difference in mortality between the intervention and control group started to emerge 12 years after the study began, slowly increased to a 17% difference by the 20-year follow-up, but became statistically significant only after 23 years.”
Dr Li noted that a key difference between previous other studies and the Da Qing Diabetes Prevention Study is the length of follow-up; in previous studies, the length of follow-up might have been insufficient to detect an effect of intervention on mortality.
Dr Li’s bottom-line message: “Type 2 diabetes can be prevented. Group-based lifestyle interventions over a 6-year period have long-term effects on prevention of diabetes beyond the period of active intervention. The benefits of the intervention extended to a significantly favorable reduction of mortality. These results emphasize the long-term benefits of the intervention and reinforce the overall value and importance of lifestyle interventions as public health strategies to prevent diabetes.”
The researchers published their results online on April 3, 2014 in The Lancet Diabetes & Endocrinology.