Heart Disease Guidelines Are Unclear for People With Diabetes

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If you've watched the news on TV or read a newspaper yesterday or today, you are aware that there are new guidelines from the American Heart Association (AHA) and the American College of Cardiology (ACC) about the treatment of cholesterol and the lowering of the risk of atherosclerotic cardiovascular disease (ASCVD). These guidelines emphasize treating people who have risk factors for heart disease rather than treating to prespecified target cholesterol values.

There's been lots of media attention speculating that implementation of these guidelines will result in a lot more people being placed on statins. Oh, and there's mention that the guidelines apply to people with diabetes - though the guidelines are (to my thinking) inadequate to assist diabetes docs in caring for people with diabetes, particularly those under age 40.

One of the four major statin benefit groups that were identified "where the ASCVD risk reduction clearly outweighs the risk of adverse events" were individuals with diabetes aged 40 to 75 years with LDL-C between 70 to 189 mg/dL without clinical ASCVD. People with "Clinical ASCVD" were categorized into a different group, and was defined as "acute coronary syndromes, or a history of MI, stable or unstable angina, coronary or other arterial revascularization, stroke, TIA, or peripheral arterial disease presumed to be of atherosclerotic origin."

As I understand the guidelines, if you have both diabetes and heart disease (such as a prior myocardial infarction or other clinical ASCVD), you fit into the "Clinical ASCVD" group (and hence are excluded from the diabetes-without-ASCVD group). There's a reason for that distinction: people with ASCVD (whether or not they have diabetes) are recommended to have "high-intensity" therapy with statins; those with diabetes without ASCVD may only require "moderate-intensity" statin therapy - unless they are considered to have an "estimated 10-y ASCVD risk greater than 7.5 percent."

I have the general feeling that the cardiologists who wrote these guidelines have little or no idea of what the varying types of diabetes are all about, nor were they attuned to the problems of accelerated atherosclerosis in folks with type 1 diabetes, let alone treating cholesterol in children and young adults with type 2 diabetes. I suspect the authors will beg off responding, declaring that there were no studies worthy of inclusion in their guidelines to address these problems. But they don't list management of cholesterol in younger people with diabetes in their wish-list for future research: I think they should have done so.

The guidelines frequently discuss "diabetes" without any reference to what type of diabetes, thereby lumping all diabetes into the same bucket. There's occasional mention in some of the guidelines specifically about being type 2, and sometimes there's mention about a guidance for being either type 1 or type 2. But there's no mention whatsoever of what to recommend for other forms of diabetes (such as LADA, or more importantly, type 2 diabetes in children and young adults).

For instance, there's a nearly-incomprehensible statement lumping type 1 and type 2 diabetes when discussing how hard to push statin therapy: "For the primary prevention of ASCVD in individuals with diabetes (diabetes mellitus type-1 and type-2), estimated 10-year ASCVD risk can also be used to guide the intensity of statin therapy." That statement does not mention age - although a subsequent flow chart clearly indicates that the authors are only concerned with "Diabetes Type 1 or 2 Age 40-75 y". What should be advised for people with diabetes under age 40? Would it be the same for someone under 40 with type 1 diabetes as for someone with type 2 diabetes?

Taken all together, these guidelines contain interesting new recommendations, but for the average physician who wants to decide how to implement them for their diabetes patients, these guidelines are inadequate and confusing. I think the American Diabetes Association and/or the American Association of Clinical Endocrinologists will need to review them, and issue expanded versions of these guidelines for people with diabetes.

The guidelines themselves have been placed on-line on the websites of both the ACC and the AHA, and will be published in a future print issue of the Journal of the American College of Cardiology. And the ACC has issued a press release about the guidelines, which is also on-line.