本研究目的在調查台北市青少年代謝症候群盛行率，同時比較身體質量指數與腰圍在青少年代謝症候群的重要性。本研究於2003年經三階段等比例隨機抽樣後，共收集1562名11-15歲台北市國中生（764名男生及798名女生）。研究工具包括結構式自填問卷、身體理學檢查及血液生化值檢查等。青少年代謝症候群定義採修改後美國國家膽固醇教育計畫成人治療指引第三版（NCEP-ATPⅢ）之各變項性別及年齡別90百分位為切點。其中診斷標準包括：身體質量指數或腰圍≧90百分位、收縮壓或舒張壓≧90百分位、三酸甘油酯≧90百分位、高密度脂蛋白膽固醇≦10百分位及空腹血糖≧90百分位。研究結果發現台北市國中生代謝症候群盛行率在男生為4.8%，女生為3.9%。男生身體質量指數介於10-90百分位者其代謝症候群盛行率為2.1%，身體質量指數≧90百分位者盛行率為29.3%；腰圍介於10-90百分位及≧90百分位者其代謝症候群盛行率分別為1.6及33.3%。女生身體質量指數介於10-90百分位者代謝症候群盛行率為1.1%，身體質量指數≧90百分位者為28.4%；腰圍介於10-90百分位及腰圍≧90百分位者其代謝症候群盛行率分別為1.1及25.5%。經控制年齡、吸菸、飲酒及青春期發育等干擾因素後，男生身體質量指數每增加1單位其代謝症候群盛行率勝算比為1.43（95% CI：1.31-1.57），腰圍每增加1公分則為1.16（95% CI：1.12-1.20）。女生身體質量指數每增加1單位其代謝症候群盛行率勝算比為1.50（95%CI：1.35-1.67），腰圍每增加1公分則為1.19（95% CI：1.14-1.24）。進一步控制身體質量指數或腰圍後，男生腰圍每增加1公分其代謝症候群盛行率勝算比為1.14（95% CI：1.05-1.24）；女生身體質量指數每增加1單位其代謝症候群盛行率勝算比為1.36（95% CI：1.13-1.64）。本研究發現過重或肥胖學生代謝症候群盛行率明顯高於正常學生，其中男生腰圍及女生身體質量指數與代謝症候群有較高相關性。 （台灣家醫誌2007; 17: 27-37） The purpose of the current study was to evaluate the prevalence of the MS among junior high school students in Taipei City and to address the importance of body mass index (BMI) and/or waist circumference (WC) on the MS among junior high school students. After multi-stage random sampling, we enrolled a total of 1562 junior high school students in 2003 (764 boys and 798 girls), with an age range of 11 to 15 years. The modified NCEP-ATP III criteria for the MS include the following measures, specific for age and gender: blood pressure>90th percentile, fasting glucose > 90th percentile, TG>90th percentile, HDL-C<10th percentile, and BMI or WC>90th percentile. The overall prevalence of MS among these junior high school students was 4.8 % for boys and 3.9% for girls. Among boys, the prevalence of the MS was 2.1 % for a BMI>10th percentile or<90th percentile and 29.3% for a BMI>90th percentile and 1.6 % for a WC>10th percentile or<90th percentile and 33.3% for a WC>90th percentile. Among girls, the prevalence of MS was 1.1% for a BMI>10th percentile or<90th percentile and 28.4% for a BMI>90th percentile and 1.1% for a WC>10th percentile or<90th percentile and 25.5% for a WC>90th percentile. After adjusting for potential confounders, the odds ratios of MS for every 1 unit increase in BMI or 1 cm increase in WC was 1.43 (95% CI, 1.31-1.57) and 1.16 (95% CI, 1.12-1.20) for boys, respectively, and 1.50 (95% CI, 1.35-1.67) and 1.19 (95% CI, 1.14-1.24) for girls, respectively. Further, with adjustment for BMI or WC, the odds ratios of MS for every 1 cm increase in WC was 1.14 (95% CI, 1.05-1.24) for boys and for every 1 unit increase in BMI was 1.36 (95% CI, 1.13-1.64) for girls, respectively. From this survey, the prevalence of MS was significantly increased among junior high school students with an increased BMI or WC. However, WC was more significantly associated with the prevalence of MS than BMI in boys, and the BMI was more significantly associated with the prevalence of MS than WC in girls. （Taiwan J Fam Med 2007; 17: 27-37）