PLOS Medicine Senior Editor Richard Turner discusses the fourth and final week of the Special Issue on Preventing Diabetes.
This fourth and ultimate week of PLOS Medicine’s Special Issue on Preventing Diabetes brings together a diverse and important range of topics, ranging from disease genetics to prevention of gestational diabetes. In a Perspective, Jose C. Florez of Massachusetts General Hospital, Boston, Massachusetts, USA discusses the prospects for using genetic information in diabetes prevention efforts. Despite the many genetic variants that are known to be associated with risk of type 2 diabetes, and the technological progress that is speeding acquisition of individual genomic information, the author notes that established clinical predictors already capture implicit genetic information—practical use of genetic variants to assess increased risk of diabetes is therefore likely to be restricted to ethnic groups in which individual variants exert unusually strong effects on disease risk. Suggestions that information on genetic variants may be useful in stratifying patients’ responses to preventive interventions await scrutiny in well-powered clinical studies, Florez notes.
Modification of diet and physical activity are important in prevention of disease in those at risk of type 2 diabetes and, in a systematic review and meta-analysis, Uma Mudaliar of Emory University, Atlanta, Georgia, USA, and colleagues address the benefits of behavioral modification interventions based on the US Diabetes Prevention Program (DPP)—focused on weight loss through at least 150 minutes of moderate physical activity per week and reduction of dietary fat consumption—in practice. Comprising data from 44 studies with nearly 9,000 participants at risk of diabetes, the study indicates that intensive behavioral interventions led to consistent benefits, including reductions in weight, blood pressure, and metabolic markers, across different settings.
Two Research Articles present randomized controlled trials evaluating exercise programs in women at risk of gestational diabetes, which is in turn a risk factor for type 2 diabetes. Trine Moholdt and co-workers, of the Norwegian University of Science and Technology, Trondheim, Norway randomly assigned 91 pregnant women, with a pre-pregnancy BMI greater than or equal to 28 kg/m2, to a program of supervised exercise training or control; although no benefit was observed according to the trial’s primary endpoint of gestational weight gain, there was an apparent benefit in incidence of gestational diabetes according to WHO 2009 criteria in the two groups (2 vs 9 cases, respectively). In the MAGDA study, Sharleen L. O’Reilly of the Institute of Physical Activity and Nutrition, Deakin University, Burwood, Victoria, Australia, and colleagues studied women with prior gestational diabetes in their first postnatal year. Among primary outcomes assessing diabetes risk factors over 1 year, benefits were recorded in terms of weight gain (–0.95kg [95% CI –1.87 to –0.04]) but not in waist circumference or fasting blood glucose. O’Reilly and colleagues also noted a need to increase uptake of such intervention programs. In a Perspective article discussing the studies, Jane E. Norman and Rebecca M. Reynolds, both of the University of Edinburgh, Edinburgh, UK, argue that the short-term endpoints used in such research studies underestimate the benefits for both mothers and offspring, concluding that “Guidelines promoting exercise in pregnancy are likely to do more good than harm, although they are not strongly supported by current evidence.”
In a further Research Article, Sarah H. Wild of the Usher Institute of Population Health Sciences and Informatics, University of Edinburgh, Edinburgh, UK and colleagues report on a randomized controlled trial done in primary care, addressing supported telemonitoring for people with type 2 diabetes. Previous work has shown that self-monitoring does not appear to improve glycemic control in type 2 diabetes not treated with insulin. In Wild and colleagues’ trial, in contrast, twice-weekly self-monitoring of blood glucose, blood pressure, and weight, accompanied by treatment recommendations from health professionals, was beneficial in comparison with usual care as judged by the trial’s primary outcome of mean HbA1c, and in terms of blood pressure, but not weight or other measures.
Lastly, Guest Editors Nicholas J. Wareham and William H. Herman draw together the themes of the Special Issue in an Editorial focused on the clinical and public health challenges of diabetes prevention. The worldwide burden of diabetes is both substantial and growing—no fewer than 642 million people are predicted to have been diagnosed with diabetes by 2040, they note, with the majority in low-income and middle-income countries. The authors reflect that individual-level interventions such as those based on the DPP will need to be complemented by population-level approaches that are not only economically viable, and therefore sustainable, but able to narrow inequalities. Wareham and Herman call for much greater investment in gathering evidence for diabetes prevention in developing countries.
Completion of the Special Issue does not mean that the health and social challenges of diabetes are by any means solved, of course, and PLOS Medicine will continue to welcome high-quality submissions documenting research aimed at preventing diabetes on an ongoing basis.
Richard Turner, PhD is a Senior Editor at PLOS Medicine.
Featured image credit: paul bica, Flickr.