Diabetes is a major risk factor for cardiovascular disease (CVD), which is the most common cause of death among adults with diabetes. “This relationship underscores the need for aggressive CVD risk factor management among patients with diabetes,” says Richard W. Grant, MD, MPH. In 1999, the American Heart Association (AHA) and the American Diabetes Association (ADA) published a joint statement focusing on CVD prevention in diabetes. In 2007, the AHA and ADA issued a combined set of recommendations that described primary prevention of CVD in diabetes.
Since the last update was issued, several new clinical trials have emerged that have changed the clinical practice of CVD risk management in diabetes, Dr. Grant says. Given the changes in the diabetes landscape over the past several years, the AHA and ADA have developed a new updated scientific statement that summarizes key studies pertaining to lifestyle and the “ABC’s” of diabetes—which include A1C, blood pressure (BP), and cholesterol management—for the primary prevention of CVD. The statement was published jointly in Diabetes Care and Circulation.
The updated scientific statement summarizes information from studies published since 2008 and relevant changes in current CVD prevention guidelines as they pertain to type 2 diabetes. Efforts were made to unify recommendations from AHA and ADA, with the goal being to have the document serve as a “one-stop resource” for clinicians to get the most up-to-date information regarding CVD prevention.
Examining Key Changes
In addition to the ABC components of primary prevention in diabetes and CVD, the AHA/ADA update includes information on diagnostic criteria for diabetes and guidance on lifestyle management, including physical activity and nutrition, weight management, and aspirin use. In addition, screening for renal and CVD complications are described (Table).
Since the last update was released, questions have been raised about whether or not reducing the upper target of A1C of 7% would provide further benefits regarding CVD risk reduction. Data from three major trials in 2008—ACCORD, ADVANCE, and VADT—indicated that reducing A1C levels to below the 7% threshold did not lead to significant reductions in cardiovascular risk. “The A1C goal of 7% is still a target, but glucose levels are not necessarily the primary target when focusing on preventing CVD,” says Dr. Grant.
Guidelines for the management of BP have also changed recently based on data from the ACCORD study. The BP target was loosened from 130/80 mm Hg to 140/90 mm Hg because ACCORD found that the low BP goal did not provide further benefit and was associated with more side effects.
Regarding cholesterol, a key change came in 2013 when the AHA and American College of Cardiology released guidelines recommending clinicians to stop treating patients to specific LDL targets. Instead, they are recommended to base their use of statins on overall CVD risk for each individual patient. The updated position statement recommends that most people with type 2 diabetes be placed on moderate- or high-dose statins.
Lifestyle Still Critical
Lifestyle modification was another component discussed in the update. Data from the Look AHEAD trial, which were released in 2013, indicated that intensive lifestyle intervention did not reduce risks for CVD. However, it was shown to improve functioning and quality of life and reduced the number of medications that patients with diabetes needed to take.
“Appropriate treatment of CVD risk factors has been a major driver for improvements in CVD outcomes,” says Dr. Grant. “That said, vigilance is needed to promote healthy lifestyles among patients with diabetes. Lifestyle management continues to be the cornerstone of clinical care and is the first step in treating patients. Physical activity, nutrition, weight loss, and smoking cessation all play an important role in the treatment of type 2 diabetes and CVD risk prevention. These risk factors need to be proactively addressed in order to improve patient outcomes.”
Areas for Future Research
Although recent studies have shown that CVD risks are improving among patients with type 2 diabetes, the incremental CVD risks associated with the disease persist. “Considerable work still needs to be done to enhance our understanding of how to more effectively prevent CVD in patients with type 2 diabetes,” says Dr. Grant. “We need to find out the best way to tailor treatment strategies in real world settings.”
The updated scientific statement highlights several important key areas of controversy that require further research. For example, the role of antihyperglycemic therapy and bariatric surgery must be further explored in clinical trials. Future studies are necessary to more fully characterize the burden of hypoglycemia and its risks, particularly on the cardiovascular system. “The therapeutic targets for BP and cholesterol lowering among specific subpopulations also require more study,” Dr. Grant says. In addition, trials are needed to determine if screening for subclinical CVD, particularly with newer modalities, can reduce CVD event rates in patients with diabetes
“In the future, research will continue to emerge and educate clinicians on optimal strategies for primary prevention of CVD in all patients with diabetes,” Dr. Grant says. “This is an important investment to truly making an impact on the CVD, diabetes, and obesity epidemics. In the meantime, the AHA/ADA update can serve as a valuable tool for clinicians to reference when striving to prevent CVD in patients with diabetes.”
Fox CS, Golden SH, Anderson C, et al; on behalf of the American Heart Association Diabetes Committee of the Council on Lifestyle and Cardiometabolic Health, Council on Clinical Cardiology, Council on Cardiovascular and Stroke Nursing, Council on Cardiovascular Surgery and Anesthesia, Council on Quality of Care and Outcomes Research, and the American Diabetes Association. Update on prevention of cardiovascular disease in adults with type 2 diabetes mellitus in light of recent evidence: a scientific statement from the American Heart Association and the American Diabetes Association. Circulation. 2015;132:691-718. Available at: http://circ.ahajournals.org/content/132/8/691.full.
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