Diabetes & Metabolic Syndrome: Clinical Research & Reviews 3 (2009) 189–191
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Editorial
Will we now play harmonious melodies or will the cacophony start again?
Will the recent publication of A Joint Interim Statement ‘‘Harmonizing the Metabolic Syndrome’’ [1] by the International Diabetes Federation Task Force on Epidemiology and Prevention; National Heart, Lung, and Blood Institute; American Heart Association; World Heart Federation; International Atherosclerosis Society; and International Association for the Study of Obesity, which is said to have ironed out the creases between the definitions of the metabolic syndrome especially the IDF [2] and the AHA/NHLBI [3] versions which were in most common use, really bring about harmony? At the outset, let me make it clear that I was a member of the ‘‘harmonization’’ team and that I firmly believe in its relevance, especially as a cost effective method of finding those with an increased lifetime risk to diabetes and atherosclerotic cardiovascular disease. One has to accept that the pandemics continue unabated and that the major burden will be felt in developing and transitional countries least equipped to bear the health costs as well as the socioeconomic burden of these pandemics. But will the harmonization allow melodious music to be heard or are we in for another round of cacaphonic debates? One has to accept that most of those involved in the harmonization process were already ‘‘believers’’ and it was just a matter of ironing out some creases so as to smoothen things up. The two associations most adamantly antagonistic of the metabolic syndrome, the American Diabetes Association (ADA) [4,5] as well as the European Association for the Study of Diabetes (EASD) [4,5], were not involved and they certainly do not seem to be having second thoughts on this. Janus like, one can also ask if the harmonization was a real change in color or merely a whitewash. Whilst it does remove some of the discrepancy which in reality only affected research and prevalence data with numerous research papers using either of the two definitions, often in similar populations, leading to an inability to come to any conclusion about the true prevalence, and this is something which even the interim report accepts that the harmonization was necessary for international comparisons and to facilitate the finding more about its etiology. The major aspect which was harmonized to some extent was the role of waist measures, although here again an argument can be made that this was more of ‘‘coming closer rather than coming together!’’ The IDF [2] had insisted on the presence of a predetermined waist measure as a sine qua non for the diagnosis, whilst the AHA/ NHLBI [3] felt that it should be only one of the five criteria, three of which had to be met to justify the diagnosis.
Moreover, there was no agreement on the definition of abdominal obesity between the IDF and AHA/NHLBI. The IDF recommended that the threshold for waist circumference to define abdominal obesity in people of European origin (Europids) should be 94 cm for men and 80 cm for women; the AHA/NHLBI, in contrast, recommended cut points of 102 and 88 cm, respectively, for the 2 sexes. This is understandable as this definition was essentially U.S. population centric and was based on the National Institute of Health Clinical Guidelines [6]. The IDF guidelines [2] also stressed the need to adopt different values for waist measurement in different ethnic groups based on the relationship of waist measurement either to the other metabolic syndrome components or to longer-term outcome studies such as those on the risk of type 2 diabetes mellitus and CVD. This, again, was a correct view considering that an international federation has to take a wider global perspective. After the harmonization, the IDF has accepted that it would not ask for the presence of a predetermined waist measure as a sine qua non for the diagnosis and would accept a diagnosis of metabolic syndrome if any three of the five criteria were met. At the same time, it insisted on the use of ethnic and country specific criteria for waist measures even if this be only one of the five requirements. On its part, the AHA/NHLBI would recognize an increased risk for CVD and diabetes at waist circumference thresholds of 94cms in men and 80 cms for women and identify these as optional cutoff points for individuals or populations with increased insulin resistance [1]. It is clear that there are, and will continue to be, differences between sexes and ethnic groups. Taking a global perspective, the risk associated with a particular waist measurement will differ in different populations (Tables 1 and 2). At the same time, serious concerns have been raised that removing the sine qua non would dramatically increase the numbers with metabolic syndrome in many countries especially in the poor and developing countries which would bear the greatest burden of this pandemic. This is extremely important from a health economic viewpoint. As it is not practical to put in place universal prevention plans, it becomes an immediate priority to try and identify subjects with the metabolic syndrome so that one can target these subjects to lifestyle and other treatment strategies to prevent or delay the onset of T2DM and cardiovascular disease. But if the numbers increase significantly, then the borders between expenditure of national medical resources for clinical intervention (eg, nutritional and physical activity counseling) and public health intervention would be blurred making efforts to implement preventive
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Editorial / Diabetes & Metabolic Syndrome: Clinical Research & Reviews 3 (2009) 189–191
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Table 1 Diagnostic criteria for metabolic syndrome [1]. Measure (any three of the five criteria below constitute a diagnosis of metabolic syndrome). Measure
Categorical cut points
Central obesity Raised triglycerides# Reduced HDL cholesterol# Raised blood pressure Elevated fasting plasma glucose
Population and country specific definitions >150 mg/dl (1.7 mmol/l) or on specific treatment for this lipid disorder <40 mg/dl (1.0 mmol/l) in men, <50 mg/dl (1.3 mmol/l) in women or on specific treatment for reduced HDL-C 130 mmHg systolic blood pressure or 85 mmHg diastolic blood pressure or on treatment for previously diagnosed hypertension Fasting plasma glucose## 100 mg/dl (5.6 mmol/l) or on drug treatment for elevated glucose
HDL-C indicates high-density lipoprotein cholesterol. (#) It is recommended that IDF cutoff points be used for non-Europeans and either the IDF or AHA/NHLBI cut of points be used people of European origin until more data is available. (#) The most commonly used drugs for elevated triglycerides and reduced HDL-C are fibrates and nicotinic acid. A patient taking one of these drugs can be presumed to have high triglycerides and low HDL-C. High dose n 3 fatty acids presumes high triglycerides. (##) Almost all patients with Type 2 DM will have the metabolic syndrome by the proposed criteria.
Table 2 Current recommended waist circumference thresbolds for abdominal obesity by organization. Population
Organization
Population Europid Caucasian
IDF WHO
United States Cninada European Asian (including Japanese) Asian Japanese China Middle East, Mediterranean SubSaharan African Ethnic Central and South American
AHA.OCHLBI (ATP III)* Health Canada European Cardiovascular Societies IDF WHO Japanese Obesity Society Cooperative Task Force IDF IDF IDF
Recommended waist circumference threshold for abdominal obesity Men 94 cm 94 cm (increased risk) 102 cm ((still higher risk) 102 cm 102 cm 102 cm 90 cm 90 cm 85 cm 85 cm 94 cm 94 cm 90 cm
Women 80 cm 80 cm (increased risk) 88 cm (still higher risk) 88 cm 88 cm 88 cm 80 cm 80 cm 90 cm 80 cm 80 cm 80 cm 80 cm
* Recent AHA/NHLBI Guidelines for metabolic syndrome recognize an increased risk for CVD and diabetes at waist circumference thresholds of 94 cm in men and 80 cm for women and identify these as optional cutoff points for individuals or populations with increased insulin resistance [1].
measures against T2DM and ASCVD unfeasible in many countries which also have major communicable or acute care disease problems to manage. The argument can also be made that the Interim Statement also does not answer many of the key questions which had been raised by the ADA and the EASD [4,5], as well as some others [7–16], about the metabolic syndrome. Most of these have been answered repeatedly [17–26] and this statement [1] vehemently reiterates many of the arguments which have been made in defense of the metabolic syndrome in the past, and rightly so. One cannot keep answering queries ad nauseum! But as has been said, ‘‘For those who believe, no proof is necessary. . ..for those who do not, no proof is enough!’’ One would sincerely hope that the ADA and the EASD now take a step forward and thrash out a consensus on the metabolic syndrome with the proponents so that we can leave this controversy behind us and get on with our work which is to stem this rising pandemic [27]. Later. . ..may be too Late! References [1] A joint interim statement of the International Diabetes Federation Task Force on Epidemiology and Prevention; National Heart, Lung, and Blood Institute; American Heart Association; World Heart Federation; International Atherosclerosis Society; and International Association for the Study of Obesity, Alberti K, Eckel R, Grundy S, Zimmet P, Cleeman J, Donato K, et al., Harmonizing the metabolic syndrome. Circulation 2009;120:1640–5. [2] Alberti K, Zimmet P, Shaw J. IDF Epidemiology Task Force Consensus Group. The metabolic syndrome: a new worldwide definition. Lancet 2005;366: 1059–62. [3] Grundy S, Cleeman J, Daniels S, Donato K, Eckel R, Franklin B, et al. American Heart Association; National Heart, Lung, and Blood Institute. Diagnosis and management of the metabolic syndrome: an American Heart Association/ National Heart, Lung, and Blood Institute Scientific Statement [published corrections appear in Circulation 2005; 112:e297 and Circulation 2005;112: e298]. Circulation 2005;112:2735–52.
[4] Kahn R, Buse J, Ferrannini E, Stern M. The metabolic syndrome: time for a critical appraisal: joint statement from the American Diabetes Association and the European Association for the Study of Diabetes. Diabetologia 2005;48: 1684–99. [5] Kahn R, Buse J, Ferrannini E, Stern M. The metabolic syndrome: time for a critical appraisal: joint statement from the American Diabetes Association and the European Association for the Study of Diabetes. Diabetes Care 2005; 28:2289–304. [6] Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults—the evidence report. National Institutes of Health. Obes Res 1998;6(Suppl. 2):51S–209S. [7] Kahn R. The metabolic syndrome (emperor) wears no clothes. Diabetes Care 2006;29:1693–6. [8] Gale E. The myth of the metabolic syndrome. Diabetologia 2005;48:1679–83. [9] Vinicor F, Bowman B. The metabolic syndrome: the emperor needs some consistent clothes: response to Davidson and Alexander. Diabetes Care 2004;27:1243. [10] Greenland P. Critical questions about the metabolic syndrome. Circulation 2005;112:3675–6. [11] Meigs J. The metabolic syndrome: may be a guidepost or detour to preventing type 2 diabetes and cardiovascular disease. BMJ 2003;327:61–2. [12] Reaven G. Insulin resistance, cardiovascular disease, and the metabolic syndrome: how well do the emperor’s clothes fit? Diabetes Care 2004;27: 1011–2. [13] Reaven G. The metabolic syndrome: requiescat in pace. Clin Chem 2005;51: 931–8. [14] Reaven G. Counterpoint: just being alive is not good enough. Clin Chem 2005;51:1354–7. [15] Reaven G. The metabolic syndrome: is this diagnosis necessary? Am J Clin Nutr 2006;83:1237–47. [16] Reaven G. The metabolic syndrome or the insulin resistance syndrome? Different names, different concepts, and different goals. Endocrinol Metab Clin North Am 2004;33:283–303. [17] Zimmet P, Alberti G. The metabolic syndrome: perhaps an etiologic mystery but far from a myth—where does the International Diabetes Federation stand? Medscape Diabetes Endocrinol 2005;7(2). Available at http://www.medscapecom/viewarticle/514211 [accessed November 1, 2009]. [18] International Diabetes Federation. Rationale for new IDF worldwide definition of metabolic Syndrome. Available at: http://www.idf.org/webdata/docs/ Metabolic_syndrome_rationale.pdf [last accessed November 1, 2009]. [19] Eckel R, Grundy S, Zimmet P. The metabolic syndrome. Lancet 2005;365: 1415–28. [20] Zimmet P, Alberti G, Shaw J. Mainstreaming the metabolic syndrome: a definitive definition. This new definition should assist both researchers and clinicians. Med J Aust 2005;183:175–6.
Editorial / Diabetes & Metabolic Syndrome: Clinical Research & Reviews 3 (2009) 189–191 [21] Grundy S. Does a diagnosis of metabolic syndrome have value in clinical practice? Am J Clin Nutr 2006;83:1248–51. [22] Grundy S. Does the metabolic syndrome exist? Diabetes Care 2006;29: 1689–92. [23] Grundy S. Does the metabolic syndrome exist? Diabetes Care 2006;29: 1689–92. [24] Grundy SM. Metabolic syndrome: connecting and reconciling cardiovascular and diabetes worlds. J Am Coll Cardiol 2006;47:1093–100. [25] Grundy S, Haffner S, Kunos G, Jensen M. Managing cardiometabolic risk: will new approaches improve success? Available at: http://www.medscape.com/ viewprogram/5700_pnt [last accessed November 1, 2009].
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[26] Sadikot S, Misra A. The metabolic syndrome: an exercise in utility or futility? Diabetes & Metabolic Syndrome. Clin Res Rev 2007;1:3–21. [27] Zimmet P, Alberti G, Shaw J. Global and societal implications of the diabetes epidemic. Nature 2001;414:782–7.
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