The Metabolic Syndrome -- Where Does the IDF Stand?
The Metabolic Syndrome -- Where Does the IDF Stand?
Although the underlying cause of the metabolic syndrome remains controversial, the ultimate importance of the syndrome is that it helps identify individuals at high risk for cardiovascular disease (CVD) and type 2 diabetes. This is clearly a major benefit of its widespread recognition and acceptance. Nevertheless, a recent position paper jointly sponsored by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) has questioned the existence and utility of the metabolic syndrome. Kahn and colleagues, on behalf of these organizations, have suggested that the time has come for a critical appraisal of the metabolic syndrome. They claim that there is confusion about the syndrome. If this is so, then they have further added to this confusion with a long and tortuous exposé of its supposed problems. Their article, we believe, indicates a number of misconceptions and inconsistencies that we would like to address. Many of the issues that they raise have been covered in the recent International Diabetes Federation (IDF) Consensus, which they barely quote.
We recognize the importance of debate; however, the appearance of this initiative on behalf of 2 of the world's leading regional diabetes organizations raises questions of motive and timing. Are the criticisms part of a "turf protection" scenario or do they have a valid scientific basis?
In recent years, there has been increasing interest in the metabolic syndrome by the American Heart Association, the American College of Cardiology, the International Atherosclerosis Society, and other specialist groups in diabetes, insulin resistance, hypertension, and cardiology worldwide, effectively removing it from the province of pure diabetes. Thus, far from the metabolic syndrome being an offshoot of type 2 diabetes, one could consider that type 2 diabetes is but one of several manifestations of the metabolicsyndrome.
The ADA/EASD position paper was released in a burst of publicity, and the issue received considerable media exposure. The authors of the ADA/EASD statement direct their main criticisms at earlier definitions, namely, those of the World Health Organization (WHO) and the National Cholesterol Education Program Adult Treatment Panel III (ATP III). Some investigators in the diabetes field, after embracing the concept wholeheartedly for about 15 years, are having "second thoughts" about the metabolic syndrome, not unreasonable in a rapidly changing field, providing that there are cogent arguments to do so. Several of the authors of the statement have been vigorous proponents of the metabolic syndrome. As recently as 2 years ago, Zachary Bloomgarden, MD, reported on a presentation by Professor Ferrannini, one of the ADA/EASD paper authors, at the Endocrine Society's 85th Annual Meeting:
Glycemic abnormality predicts hypertension and increased blood pressure predicts glycemic abnormality, with hyperinsulinemia an important additional predictive factor, Ferrannini noted, further suggesting the usefulness of the concept of metabolic syndrome. He concluded that 'the syndrome itself is atherogenic,' but suggested that insulin resistance causes atherosclerosis via the 'intermediate phenotypes' of increased blood pressure, dyslipidemia, and abnormal glycemia, suggesting that therapy not be primarily directed at insulin resistance. The metabolic syndrome exists, and he asserted, 'It predicts itself so it's not just an innocent cluster.' Whether it is directly atherogenic is not clearly established, and whether it can be prevented is an important therapeutic question.
Unfortunately, the joint ADA/EASD statement was published before the detailed report of the IDF Consensus report on the metabolic syndrome appeared in print. Nevertheless, the key features of the IDF report were available and summarized on the IDF Web site. It is noteworthy that 2 of the main authors of the ADA/EASD statement were on or represented on the IDF group and signed up to their conclusions. In this commentary, we respond to the ADA/EASD statement in the light of deliberations of the IDF panel.
Setting the Scene: The American Diabetes Association/European Association for the Study of Diabetes Shot Across the Bow of the Metabolic Syndrome
Although the underlying cause of the metabolic syndrome remains controversial, the ultimate importance of the syndrome is that it helps identify individuals at high risk for cardiovascular disease (CVD) and type 2 diabetes. This is clearly a major benefit of its widespread recognition and acceptance. Nevertheless, a recent position paper jointly sponsored by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) has questioned the existence and utility of the metabolic syndrome. Kahn and colleagues, on behalf of these organizations, have suggested that the time has come for a critical appraisal of the metabolic syndrome. They claim that there is confusion about the syndrome. If this is so, then they have further added to this confusion with a long and tortuous exposé of its supposed problems. Their article, we believe, indicates a number of misconceptions and inconsistencies that we would like to address. Many of the issues that they raise have been covered in the recent International Diabetes Federation (IDF) Consensus, which they barely quote.
We recognize the importance of debate; however, the appearance of this initiative on behalf of 2 of the world's leading regional diabetes organizations raises questions of motive and timing. Are the criticisms part of a "turf protection" scenario or do they have a valid scientific basis?
In recent years, there has been increasing interest in the metabolic syndrome by the American Heart Association, the American College of Cardiology, the International Atherosclerosis Society, and other specialist groups in diabetes, insulin resistance, hypertension, and cardiology worldwide, effectively removing it from the province of pure diabetes. Thus, far from the metabolic syndrome being an offshoot of type 2 diabetes, one could consider that type 2 diabetes is but one of several manifestations of the metabolicsyndrome.
The ADA/EASD position paper was released in a burst of publicity, and the issue received considerable media exposure. The authors of the ADA/EASD statement direct their main criticisms at earlier definitions, namely, those of the World Health Organization (WHO) and the National Cholesterol Education Program Adult Treatment Panel III (ATP III). Some investigators in the diabetes field, after embracing the concept wholeheartedly for about 15 years, are having "second thoughts" about the metabolic syndrome, not unreasonable in a rapidly changing field, providing that there are cogent arguments to do so. Several of the authors of the statement have been vigorous proponents of the metabolic syndrome. As recently as 2 years ago, Zachary Bloomgarden, MD, reported on a presentation by Professor Ferrannini, one of the ADA/EASD paper authors, at the Endocrine Society's 85th Annual Meeting:
Glycemic abnormality predicts hypertension and increased blood pressure predicts glycemic abnormality, with hyperinsulinemia an important additional predictive factor, Ferrannini noted, further suggesting the usefulness of the concept of metabolic syndrome. He concluded that 'the syndrome itself is atherogenic,' but suggested that insulin resistance causes atherosclerosis via the 'intermediate phenotypes' of increased blood pressure, dyslipidemia, and abnormal glycemia, suggesting that therapy not be primarily directed at insulin resistance. The metabolic syndrome exists, and he asserted, 'It predicts itself so it's not just an innocent cluster.' Whether it is directly atherogenic is not clearly established, and whether it can be prevented is an important therapeutic question.
Unfortunately, the joint ADA/EASD statement was published before the detailed report of the IDF Consensus report on the metabolic syndrome appeared in print. Nevertheless, the key features of the IDF report were available and summarized on the IDF Web site. It is noteworthy that 2 of the main authors of the ADA/EASD statement were on or represented on the IDF group and signed up to their conclusions. In this commentary, we respond to the ADA/EASD statement in the light of deliberations of the IDF panel.