Lin et al. BMC Public Health 2010, 10:747 http://www.biomedcentral.com/1471-2458/10/747 treatment effects. For some persons with one or two MetS components, it was possible that they could have utilized corrective options including lifestyles changes [37] or medications such as antihypertensive [38] or lipids lowering agents [39]. Those actions might lead to protective effects [40], and therefore, the true risk of MetS development might be underestimated in this early-middle-aged population. Naturally, this is a work- place follow-up survey for relatively healthy workers. Thus, the application of our conclusions to the general population should be cautious. On the other hand, sta- tistically, our findings of MetS component combinations were based on low case numbers, which might have resulted in a low number bias. Thus, larger sample population studies are needed in the future. In sum, a workplace-based MetS screening program simultaneously allows for finding out cases and for asses- sing risk of MetS development. MetS component count and combination can be used in predicting MetS devel- opment for participants potentially at risk. For MetS pre- vention, any increase in the number of MetS components should be avoided. Since central obesity plays a pivotal role and high blood pressure synergistically potentiates other risk factors toward MetS development, efforts to address these two easily measurable risk factors must be prioritized in workplace MetS management programs. Abbreviations COB: central obesity; HBP: high blood pressure; Hyper-GL: hyperglycemia; Hyper-TG: hypertriglyceridemia; Low-HDL: Low-HDL cholesterolemia; SI: synergistic index; Acknowledgements The authors would like to acknowledge the data provided by Hsiao Tun-Jen M.D., PhD and the personnel of the Center of Health Management, Tao- Yuan General Hospital for their full support and generous assistance. Author details 1Health Management Center, Tao-Yuan General Hospital, Tao-Yuan, Taiwan. 2Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan. 3School of Medicine, Fu Jen Catholic University, Taipei, Taiwan. 4Department of Family Medicine, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan. 5Department of Internal Medicine, Tao-Yuan General Hospital, Tao-Yuan, Taiwan. 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