Dallas, TX and Alexandria, VA - The American Heart Association (AHA) and the American Diabetes Association (ADA) have released a joint "Call to Action" to reduce cardiovascular risk and diabetes [1]. The brief statement, which alludes to "many unresolved scientific issues," appears to be in part an attempt to patch the growing rift between the two organizations over use of the term metabolic syndrome and its clinical significance.

In an interview with heartwire, AHA president and one of the authors on the statement, Dr Robert H Eckel, acknowledged that bickering over semantics wasn't helping the organizations achieve their shared goals.

We're saying, treat the problems, don't worry about what this happens to be called.

"The importance of this paper is just to clarify that 'metabolic syndrome' or 'cardiometabolic risk' are two different terms applied to a clustering of risk factors, but they are not going to divide the AHA and the ADA," Eckel told heartwire. "We felt that it was important to state the case that the AHA and ADA want to prevent heart disease, stroke, and diabetes, and although the metabolic syndrome is a term that has been used divisively, we feel that there is ongoing conversation about it in terms of its relevance and importance, and we're working out these issues scientifically as time evolves. In no way is this term dividing the organizations in terms of their purposes and goals."

Likewise, Dr Robert A Rizza, president of medicine and science for the ADA and another author on the statement, emphasized that the aim of the paper was to ensure that clinicians treated individual risk factors, regardless of whether they appear as part of the "cluster."

"What was happening was that many people were focusing on whether it was or was not a syndrome and whether someone had this syndrome or not, and they weren't just treating the high blood pressure, high glucose, high blood lipids, and so forth," he said. "The ADA and the AHA were trying to refocus the attention back on so-called cardiometabolic risk. We're saying, treat the problems, don't worry about what this happens to be called."

The statement emphasizes the fact that "virtually none" of the approaches for estimating cardiovascular and diabetes risk have been extensively validated, with the possible exception of the Diabetes Personal Health Decisions tool, available on the internet. Yet, say the authors, emerging evidence also hints that simply measuring tobacco use along with blood glucose, blood pressure, and LDL-cholesterol levels might be sufficient "to initiate the appropriate interventions to prevent or identify diabetes and emerging CVD."

But the crux of the matter seems to lie in the "unresolved" science. The statement refers to "a number of intriguing scientific questions [that] remain regarding the relative impact of each risk factor, the hierarchy of risk factors, the inclusion of other risk factors, and the relationships among all of them."

According to Eckel, other issues include disease mechanisms, impact on clinical care, and therapeutic considerations. "All these are things that are reasonable points of discussion that need, I think, more evidence as we go forward. And we continue to do the science, and the AHA and ADA are both in agreement about that."

But where lingering disagreement between the two groups remains palpable, despite the united front presented in the statement, is around the issue of whether multiple risk factors are additive or synergistic.

Eckel hedged. "That's one of the more important considerations before us: in the metabolic syndrome, is the whole is greater than the sum? The AHA's position is unclear at this point in time."

Rizza, for his part, insists this question has been blown out of proportion.

"In certain circumstances, [risk factors] may be additive, and in others, depending on the pathogenesis, they may act together to make things worse," he said carefully. "But now you're getting into this business of, okay, you have a twofold risk of dying tomorrow, and if I treat you, you'll live. And I have a fivefold risk of dying tomorrow, and if you treat me, I'll live. Don't you think both of us should be treated? That's the crux of the matter; whether there is a greater or synergistic risk is really not the issue. Treat the problems, don't spend your time counting your fingers figuring out how many problems you have."

The ADA may be in a position of not wanting to agree with the term, but we both agree with clustering, so let's not let the term take the whole boat down.

But this debate harkens back to the utility of the term metabolic syndrome, a question that appeared to pit the two organizations against one another in the first place, as reported by heartwire. In August 2005, the ADA and European Society of Diabetes (ESD) issued a statement discouraging the diagnosis of "metabolic syndrome"; three weeks later, the AHA and National Heart, Lung, and Blood Institute (NHLBI) released a statement affirming use of the construct in clinical medicine.

Rizza rejected the idea that the two organizations were "squabbling" over this question but repeatedly dodged heartwire's questions about the ADA's position on the use of "metabolic syndrome" in the diagnostic setting.

"It's probably more accurate to say that various groups of individuals, scientists, the ADA, and the ESD have been trying to focus on what causes cardiometabolic risk. And I think it's like most things in life—science and data actually eventually swing toward what are the real issues."

But the AHA, says Eckel, "believes the term works fine."

"We want physicians to be concerned about risks for heart disease, stroke, and diabetes, and certainly the presence of a 'syndrome' may help identify some of the patients who would not be otherwise identified," Eckel insisted. "If you want to call the same thing by a different term, that doesn't really accomplish very much. We're in agreement with the ADA that there is a clustering of risk factors and the metabolic syndrome exists, at least in terms of the [International Diabetes Federation] IDF, the AHA, the NHLBI, the NCEP, and a number of other organizations. The ADA may be in a position of not wanting to agree with the term, but we both agree with clustering, so let's not let the term take the whole boat down."