心臟血管危險變項之探究式因素分析

Exploratory Factor Analysis of Cardiovascular Risks

背景及目的：心臟血管疾病(cardiovascular disease; CVD)危險變項有群集(clustering)現象，如代謝症候群(metabolic syndrome; MetS)。但為何同樣是C VD重要危險因子的總膽固醇及低密度脂蛋白膽固醇和其他重要危險因子不是代謝症候群的診斷項目，曾被美國糖尿病協會批判未說明清楚。方法：從2007年5月至12月間，以台中市某區域醫院接受全身健康檢查個案為對象，選取20歲以上，平均為47.9±11.8歲，共收集有效樣本579人，其中男性有367人(63.4%)。以探究式因素分析探討國人常用之心臟血管疾病的可改變危險變項，如抽菸、喝酒、運動等習慣、身體質量指數（代表身高及體重）、腰圍、總膽固醇、三酸甘油酯、高密度脂蛋白膽固醇(HDL-C)、低密度脂蛋白膽固醇(LDL-C)、空腹血糖、尿酸、天門冬胺酸胺基轉化酶、丙胺酸胺基轉化酶及平均動脈壓（取代收縮壓及舒張壓）等因子。結果：本研究共有16種變項，經處理過或分開高相關變項後進入因素分析，最後共有9-10種變項符合條件進入分析，所得結果為Kaiser-Meyer-Olkin Measure of Sampling Adequacy(KMO)值為0.6- 0.7，Bartlett 球形檢定值(Bartlett's test of sphericity)χ2皆達統計學上顯著差異，表示本分析樣本數足夠且因素分析之適切性良好，最後成功地組成3-5種類型因素(factor)，解釋變異量為52.0%-68.2%。在大部份條件下分析，有含美國國家膽固醇教育計畫成人治療準則第三次報告(NCEP ATP-Ⅲ)之5種指標之因素產生，命名為代謝因素(metabolic factor)。抽菸及喝酒皆形成一獨立因素，命名為習慣因素(habit factor)。結論：整體而言， 可發現在某些情況下有NCEP ATP-Ⅲ對M e tS之診斷準則群集現象，抽菸、喝酒及運動習慣、身體質量指數、尿酸、丙胺酸胺基轉化酶、總膽固醇及LDL-C不是代謝症候群的診斷準則。

Background and Objective: The National Cholesterol Education Program's Adult Treatment Panel Ⅲ Report (NCEP ATP-Ⅲ) showed clusters of modifiable cardiovascular disease (CVD) risk factors, yet total cholesterol LDL-C, and other important risk factors were not included. The American Diabetes Association criticized this by stating that there was no clear basis for including/excluding CVD risk factors. The aim of the present study was to explore this controversy using exploratory factor analysis. Methods: A total of 579 participants including 367 men and 212 women (mean age 47.9±11.8) who underwent health examinations in a regional hospital in Taichung Taiwan between May and December 2007 were included. Factor analysis (principal component analysis with variance maximization rotation and orthogonal rotation) was performed. The 16 measured modifiable cardiovascular risks included smoking, alcohol intake, exercise habit, body mass index (body height and weight), waist circumference, total cholesterol, triglycerides, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), fasting glucose, uric acid, aspartate aminotransferase, alanine aminotransferase (ALT) and mean arterial pressure (MAP) instead of systolic, as well as diastolic blood pressure. Results:Nine-10 highly congruent variables were included in the analyses to manage the highly variable correlations among the 16 defined variables. The Kaiser-Meyer-Olkin Measure of Sampling Adequacy was 0.6-0.7 and Bartlett's tests of sphericity all reached statistical significance. Three to five factors were extracted and the variances were 52.0%-68.2%. We found some of the clustering phenomenon for metabolic syndrome criteria as noted by NCEPATP Ⅲ. Smoking and alcohol intake made up a unique factor we named the habit factor. Conclusions: This study supported the finding of 5 cluster factors for as reported by NCEP ATP-Ⅲ. Smoking, alcohol intake, exercise habits, BMI, uric acid, ALT, total cholesterol and LDL-C were not t diagnostic criteria for the NCEP ATP-Ⅲ metabolic syndrome.