Spotlight on diabetes prevention programs
Recent studies offered follow-up data and risk prediction tools from two long-standing programs to prevent progression from prediabetes to diabetes in the U.S. and the U.K.
Several recent studies reported on long-term effects of programs to prevent diabetes.
The first study, published by The Lancet Diabetes & Endocrinology on April 28, used 21 years of follow-up data from the U.S. Diabetes Prevention Program (DPP) trial, which randomized patients with prediabetes to metformin, lifestyle interventions, or placebo. At the end of the three-year trial, placebo was discontinued, metformin was unmasked, and a less intensive lifestyle intervention was offered to all patients. This analysis included 3,195 trial participants with follow-up ranging from 0.2 to 23.2 years (median, 8.0 years).
By the end of follow-up, diabetes incidence was lower in the patients originally treated with lifestyle intervention (hazard ratio [HR], 0.76; 95% CI, 0.68 to 0.85) or metformin (HR, 0.83; 95% CI, 0.74 to 0.93) compared with placebo. Diabetes-free survival was increased by 3.5 years with the lifestyle intervention and 2.5 years with metformin compared to the placebo group. The overall difference appeared to be driven by effects during the active trial, the study authors observed. Effects varied somewhat by baseline variables, but the only significant difference was that metformin was more effective in younger patients than older. “Current evidence for effective and safe means of preventing type 2 diabetes in the long term supports lifestyle intervention, emphasising weight loss and moderate physical activity at any adult age, and metformin in younger adults,” concluded the study authors.
An accompanying editorial noted that the results add to “the body of evidence showing sustained improvements in health from diabetes prevention interventions” but said that clinical inertia remains an obstacle to wider implementation.
A second study, published by Diabetic Medicine on April 18, looked at the effects of the U.K. National Health Service's Diabetes Prevention Programme by age, sex, body mass index (BMI), and socioeconomic deprivation. The program offered patients with prediabetic glycemic levels at least 16 hours of nutrition and exercise education over nine months to a year and found a significant reduction in progression to diabetes compared to control patients. This analysis uncovered no differences in the program's effect on diabetes progression by sex, age, BMI, or quintile on a deprivation index. “Our findings suggest that the intervention of the [Diabetes Prevention Programme] was effective in preventing the development of diabetes in individuals diagnosed with [non-diabetic hyperglycemia], including those in the high-risk groups,” said the study authors.
A third study, published April 23 by the Journal of Clinical Endocrinology & Metabolism, used a cohort of 2,640 patients from the U.S. DPP to develop a risk prediction model for incident diabetes. It was validated in participants with prediabetes from the Multi-Ethnic Study of Atherosclerosis (n=2,104). The model used sex, HbA1c level, fasting plasma glucose level, BMI, triglyceride levels, and intervention (metformin, lifestyle change, or none) to predict individual risk of diabetes development. The model's mean C-statistics were 0.71 (95% CI, 0.68 to 0.74) and 0.86 (95% CI, 0.83 to 0.88) in the development and validation cohorts, respectively. Based on its results, the optimal intervention was lifestyle change for 86% and 97% of the development and validation cohorts, respectively, and metformin for the remaining patients. “Parsimonious and commonly available clinical risk predictors coupled with the development of a free and publicly available online diabetes risk calculator enable high potential clinical utility of this research on individualized diabetes prevention,” the study authors said.
Finally, an article marking the 75th anniversary of the founding of the National Institute of Diabetes and Digestive and Kidney Diseases, published by Diabetes Care on April 24, summarized the history and results of the DPP (initiated in 1996), crediting it with showing the potential of metformin or lifestyle change to reduce diabetes incidence. “Further progress in preventing T2D [type 2 diabetes] will require 1) improvements in screening and individual-directed preventive interventions; 2) addressing determinants of T2D earlier in life (including prenatally), given the increase in youth-onset T2D; and 3) societal measures to modify the diabetogenic environment,” it said.