Are diabetes guidelines truly evidence based?

The global epidemic of obesity and diabetes underscores the urgency to develop strategies to prevent cardiovascular (CV) disease in this vulnerable population. Clinical guidelines are intended to help the clinician manage these patients, but guidelines are often discordant among professional organizations and not always evidence based. Clinicians must rely upon the best available evidence, and therefore we critically reviewed the evidence behind the American Diabetes Association (ADA) 2016 guidelines on the prevention of CV disease in diabetes. We believe the most robust evidence comes from randomized controlled trials specifically designed for diabetes with hard clinical endpoints such as mortality and CV events. Our analysis supports the ADA recommendations regarding a Mediterranean diet, glycemic control, and BP control, but we believe the evidence to support aspirin and statin therapy in diabetes is inconclusive. This discordance may be multi-factorial including the exclusion of some relevant studies and an over-reliance upon subgroup and meta-analysis. Given the lack of mortality benefit and inconsistent clinical benefits of aspirin and statins, it is essential that clinicians individualize treatment decisions while carefully weighing the risks and harms of any intervention.