Published online before print September 13, 2007, doi: 10.1161/STROKEAHA.107.495325
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(Stroke. 2007;38:e152.)
© 2007 American Heart Association, Inc.
Letters to the Editor |
Definition of Metabolic Syndrome
Department of Internal Medicine, Niigata Prefectural Yoshida Hospital, Niigata, Japan
To the Editor:
Ninomiya et al reported that metabolic syndrome is a significant risk factor for cardiovascular disease in the Japanese middle-aged population (the Hisayama Study).1 They discussed that metabolic syndrome was not predictive for cardiovascular disease among diabetic women in the Japanese Diabetes Complications Study (JDCS),2 though it was consistently predictive of cardiovascular disease not only in both men and women but also in subjects with diabetes in the Hisayama Study, and speculated that this discrepancy resulted from the difference in the cutoff point of the waist circumference (WC) between the 2 studies. JDCS adopted the WC cutpoint proposed by the Japanese Society for the Study of Obesity (85 cm for men and 90 cm for women), which was criticized by us3 and Hayashi et al4 because of their inconsistent methodology, but Ninomiya et al adopted the WC definition for Asian populations (90 cm for men and 80 cm for women). Indeed, metabolic syndrome defined by either the National Cholesterol Education Program or the International Diabetes Federation revealed to be a significant risk factor for cardiovascular disease among Japanese diabetic women in JDCS by the reanalysis5 responding to my request.6 Cutpoints of WC are controversial not only in Asians but also in Europeans, and recently the Obesity Society, the American Society for Nutrition, and the American Diabetes Association jointly stated that though WC provides a unique indicator of body fat distribution, which can identify patients who are at increased risk of obesity-related cardiometabolic disease, the clinical usefulness of measuring WC is limited and further studies are needed to establish WC cutpoints, which will be complex because they are likely influenced by sex, race-ethnicity, age, BMI, and other factors.7 Therefore, I proposed a new definition of metabolic syndrome8 in which WC in the revised National Cholesterol Education Program criteria is replaced by C-reactive protein (0.65 mg/L as the cutpoint for Japanese9) not for the diagnosis at present but for future studies of this syndrome. Anthropometric markers of obesity such as BMI, WC, waist-to-hip ratio, and waist-to-height ratio are not direct causes for the clustering of the cardiometabolic risk factors but upstream factors indirectly leading to the clustering through metabolic susceptibility as illustrated by Grundy10 and should be used as simple, but not complex, tools for the screening of more proximal risk factors for cardiometabolic disease.
Acknowledgments
Disclosures
None.
References
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2. Sone H, Mizuno S, Fujii H, Yoshimura Y, Yamasaki Y, Ishibashi S, Katayama S, Saito Y, Ito H, Ohashi Y, Akanuma Y, Yamada N. Is the diagnosis of metabolic syndrome useful for predicting cardiovascular disease in Asian diabetic patients? Analysis from the Japanese Diabetes Complications Study. Diabetes Care. 2005; 28: 1463–1471.
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8. Oda E. The metabolic syndrome (Emperor) wears no clothes. Diabetes Care. 2006; 29: 2566.
9. Oda E, Oohara K, Abe A, Veeraveedu PT, Watanabe K, Kato K, Aizawa Y. The optimal cut-off point of C-reactive protein as an optional component of metabolic syndrome in Japan. Circ J. 2006; 70: 384–388.[CrossRef][Medline] [Order article via Infotrieve]
10. Grundy SM. Does a diagnosis of metabolic syndrome have value in clinical practice? Am J Clin Nutr. 2006; 83: 1248–1251.
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