Pediatric Diabetes 2007: 8 (Suppl. 9): 48–54 All rights reserved # 2007 The Authors Journal compilation # 2007 Blackwell Munksgaard Pediatric Diabetes Review Article Metabolic syndrome in youths Amemiya S, Dobashi K, Urakami T, Sugihara S, Ohzeki T, Tajima N. Metabolic syndrome in youths. Pediatric Diabetes 2007: 8 (Suppl. 9): 48–54. Abstract: The metabolic syndrome (MetS), characterized by a clustering of cardiovascular disease and type 2 diabetes (T2DM) risk factors, has become prevalent in children and adolescents in recent years. However, the reported prevalence data on the MetS in youths has varied markedly, in large part, because of the disagreement among the variously proposed definitions of the MetS. Obesity is defined by using body mass index, waist circumference, or percent overweight, pointing to the need for standardized use of anthropometric variables to define obesity with a well-defined reference year for each ethnic population. In addition, slightly different cutoff values are used for triglycerides, high-density lipoprotein cholesterol, blood pressure, and fasting plasma glucose. Therefore, International Diabetes Federation recently proposed unified, easy-to-use criteria for diagnosing the MetS in youths. To provide insight into the mechanisms underlying the MetS in youths, the degree of insulin sensitivity/resistance and its correlation with the serum lipid and blood pressure levels have been evaluated. In addition, the serum levels of adipocytokines, such as adiponectin, leptin, tumor necrosis factor-a, resistin, interleukin-6, plasminogen activator inhibitor-1, and their correlation with childhood obesity have been extensively investigated. Recommendations for future research include exploring ways to assess visceral adiposity, to identify better biochemical markers for prediction of T2DM and disease progression, and to effectively intervene to prevent the MetS in youths. Shin Amemiya a , Kazushige Dobashi b , Tatsuhiko Urakami c , Shigetaka Sugihara d Takehiko Ohzeki e and Naoko Tajima f a Department of Pediatrics, Saitama Medical University, Saitama, Japan; b Department of Pediatrics, University of Occupational and Environmental Health, Kitakyushu, Japan; c Department of Pediatrics, Nihon University School of Medicine, Tokyo, Japan; d Department of Pediatrics, Tokyo Women’s Medical University Medical Center East, Tokyo, Japan; e Department of Pediatrics, Hamamatsu University School of Medicine, Hamamatsu, Japan; and f Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan Key words: Adiponectin – children – metabolic syndrome – obesity – prevalence Corresponding author: Naoko Tajima, MD Division of Diabetes, Metabolism and Endocrinology Department of Medicine Jikei University School of Medicine 3-25-8 Nishishinbashi Minato-ku, Tokyo 105-8461 Japan. Tel: 181 3 3433 1111 ext. 3240; fax: 1 81 3 3433 6613; e-mail: ntajima@jikei.ac.jp Submitted 6 July 2007. Accepted for publication 27 August 2007 The metabolic syndrome (MetS) in adults is defined as a clustering of cardiovascular and type 2 diabetes (T2DM) risk factors (1, 2). The recent interest in the MetS was stimulated by Reaven’s description of syndrome X in his Banting Lecture in 1988 (3). Other descriptions of the MetS followed: DeFronzo (4) re- ferred to its multifaceted nature while Kaplan (5) referred to it as the deadly quartet, and Matsuzawa (6) described it as the visceral fat syndrome. The con- stellation of metabolic abnormalities includes glucose intolerance (T2DM, impaired glucose tolerance, or impaired fasting glycemia), insulin resistance, central obesity, dyslipidemia, and hypertension, all of which are well-documented risk factors for cardiovascular disease (CVD). These conditions occur together in an individ- ual more often than what might be expected by chance. Although the cause of the syndrome is still not certain, numerous groups have attempted to define its 48