ORIGINAL ARTICLE Lower BMI cutoff for assessing the prevalence of metabolic syndrome in Thai population Apilak Worachartcheewan Æ Chanin Nantasenamat Æ Chartchalerm Isarankura-Na-Ayudhya Æ Phannee Pidetcha Æ Virapong Prachayasittikul Received: 23 May 2009 / Accepted: 14 July 2009 / Published online: 1 August 2009 Ó Springer-Verlag 2009 Abstract This article investigates the prevalence of metabolic syndrome (MS) and the benefits of lowered body mass index (BMI) cutoff point for assessing MS prevalence in a large, nationally representative population sample comprising of 15,365 Thai adults from metropolitan Bangkok who received annual checkup. Prevalence of MS was characterized using the International Diabetes Feder- ation criteria and BMI C25 kg/m 2 as cutoff revealed that 26.63% of male and 14.90% of female subjects had MS and the prevalence was age dependent. Traditional BMI cutoff of C30 kg/m 2 underestimated MS prevalence in Thai population while BMI C25 kg/m 2 was found to be a suitable solution. Common combinations of MS compo- nents were identified in order to find common occurrences that may be implicated in the development of diabetes and/ or cardiovascular diseases. Keywords Metabolic syndrome  IDF  BMI  Diabetes  Cardiovascular disease Introduction Metabolic syndrome (MS) is defined as a cluster of meta- bolic abnormalities (e.g. central obesity, dyslipidemia, hyperglycemia, and hypertension), which predisposes an individual to increased risks of cardiovascular diseases and type 2 diabetes [1]. Over the past century, advents in sci- ence and technology have brought about significant chan- ges in the environment, society, behaviors, and lifestyles. Such transformations have led to striking increase in obesity and diabetes [2] as well as cardiovascular diseases [3]. Therefore, efforts to curb further expansion of these diseases through public health actions rely on accurate assessment of the prevalence of MS. The World Health Organization (WHO) diabetes group had provided the first global definition of metabolic syn- drome in 1999 [4]. Since then, the criteria for defining those with MS have been issued by many groups of orga- nization [5–11]. Geographical distribution, ethnic and socio-population are also accounted for defining MS besides the degree of obesity, hypertension and diabetes condition. Characterization of MS according to the Inter- national Diabetes Federation (IDF) criteria requires the use of central obesity as the first criteria followed by a set of two or more metabolic abnormalities. The typical para- meter for meeting this first requirement is the waist circumference; however, BMI can also be used in place of waist circumference as both parameters were found to be significantly correlated [12]. The cutoff for obesity as outlined by the WHO is BMI C30 kg/m 2 . It has been pointed out that such cutoffs was not suitable for Asian populations due to differences in anthropometry, race/eth- nic, percentage of body fat, and dietary behavior [13]. In efforts to foster appropriate classification of obesity in Asia, the cutoff criteria was redefined by the Steering Committee of the Regional office for the Western Pacific Region of WHO, the International Association for the Study of Obesity and the International Obesity Taskforce where cutoffs for defining overweight and obese individ- uals were changed from 25 and 30 to 23 and 25, A. Worachartcheewan  C. Nantasenamat  C. Isarankura-Na-Ayudhya  V. Prachayasittikul (&) Department of Clinical Microbiology, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand e-mail: mtvpr@mahidol.ac.th P. Pidetcha Center of Medical Laboratory Services, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand 123 Acta Diabetol (2010) 47 (Suppl 1):S91–S96 DOI 10.1007/s00592-009-0137-0