Original Articles Korean Circulation J 1999;2911:1201-1211 성인자원자에서 B 방식초음파를이용해측정한 경동맥내막중막두께의분포 이선규 1 황희영 1 김형식 1 장미선 1 이은주 1 강문호 2 고광곤 3 The Carotid Artery Intima-Media Thickness Measured with B-Mode Ultrasonography in Adult Volunteers Seon-Kyu Lee, MD 1, Hee Young Hwang, MD 1, Hyung Sik Kim, MD 1, Mi-Sun Chang, MD 1, Eun-Joo Lee, MD 1, Moon Ho Kang, MD 2 and Kwang Kon Koh, MD 3 1 Department of Radiology, 2 Endocrinology, 3 Cardiology, Gachon Medical School Gil Medical Center, Inchon, Korea ABSTRACT ObjectivesThe purposes of this study were 1) to correlate the carotid intima-medial thickness (IMT) with risk factors of atherosclerosis, 2) to demonstrate the standarized methods of B-mode ultrasound (US) scanning of carotid artery and IMT measurement. Materials and MethodsBilateral carotid arteries of 95 adult volunteers were scanned using 12 MHz linear probe. The mean of bilateral IMT was regarded as the volunteer's IMT, which was measured on the far wall of distal common carotid artery. The normality test for measured IMT and correlation tests between IMT and various known risk factors of atherosclerosis including age, end-systolic blood pressure, end-diastolic blood pressure, fasting blood glucose level, body mass index, life-style data and lipid profiles were performed. Inter-observer and intra-observer variability were evaluated through correlation tests on 20 randomly sampled data. ResultsThe measured IMT showed normal distribution (mean0.673 mm, SD 0.1, p0.494) and the 95th percentile was 0.830 mm. The systolic blood pressure (r0.101) and body mass index (r0.200) showed positive correlation but they did not show statistically significant relationships with IMT (p>0.05). The age showed statistically significant correlation (r0.585, p<0.001), but the other risk factors did not show statistically significant correlation with IMT. The correlation coefficients of inter-observer and intra-observer variability on IMT measurement were 0.8770 and 0.9213, respectively. ConclusionThe diagnostic criteria for early carotid atherosclerosis using B-mode US could be estimated from our data. Our measurement protocols showed high reproducibility. The associations between most risk factors that did not show statistically significant correlation in our study and IMT should be confirmed in a populationbased study. Korean Circulation J 1999;2911:1201-1211 KEY WORDSAtherosclerosis Carotid artery disease Ultrasonics. 1201
서론 대상및방법 1202 Table 1. Age distribution of 95 adult volunteers Range years Number % 2029 6 6.3 3039 31 32.6 4049 31 32.6 5059 22 23.2 60 5 5.3 95 100 Korean Circulation J 1999;2911:1201-1211
Fig. 1. Diagram of measurement of carotid artery intima-media thickness (IMT). A Simplified diagram of carotid artery, defining segments of arterial walls taken by B-mode ultrasound. ICA internal carotid artery, ECA external carotid artery, CCA common carotid artery, Bulb carotid bulb. B The IMT is defined as a distance between lumen intima interface and media adventitia interface at the far wall of carotid artery. Note, thickness of intimal layer (*) of near wall looks thicker than that of far wall due to interphase echo. 측정하였다. 대상 혈관의 원위벽에서, 혈관 내강과 내막 경계면에서 중막과 외막의 경계면 간의 거리를 IMT로 정의하였다(Fig. 1). IMT는 총경동맥이 경동맥 팽대부 로 이행하는 부위에서 총경동맥의 근부위 쪽으로 1 cm 의 범위를 측정하였다. 측정할 1 cm 범위를 영상에 포 함되어 있는 거리 측정 기준선을 사용하여, 측정 부위 에 표시하고, 이 범위를 2 mm 간격으로 나누어서 모두 5번을 측정하여(Fig. 2) 그 평균을 각 경동맥의 IMT로 삼았으며, 연구 대상자의 IMT는 양쪽 경동맥의 IMT 를 평균한 값으로 정의하였다. IMT와의 연관성을 조사할 위험 인자들은 측정방법 에 따른 자료들과 생활 습관 자료로 크게 분류하였으며, 측정 방법에 따른 자료들은 혈액학적 지표와 신체 측정 에 따른 기초 분석 자료로 나누어서 분석하였다. 생활 습관 자료에서는 흡연, 음주 및 운동 여부 등을 파악하 Fig. 2. Digitized B-mode ultrasnongraphy of carotid artery. The magnified image outlined by white box demonstrates the segment of distal common cartid artery and a white ruler beneath the far wall indicates 1 cm portion of a vessel. Five double arrows represent intima-media thickness of measured segments, separated by 2.5 mm intervals. 여, 각 군 별 IMT의 분포를 비교하였다. 연구 대상들 며, 운동 여부는 땀을 흘릴 정도로 하는 운동 을 기준 의 현재 생활 습관 중에서 동맥 경화와 관련되어 있는 으로 하여, 전혀 운동을 하지 않는다, 약간 한다(1주 것으로 알려진, 흡연, 음주 및 운동 여부 등을 파악하여, 일에 3회 이하) 및 많이 한다(1주일에 4회 이상) 의 각 군 별 IMT의 분포를 비교하였다. 흡연은 전혀 담 세 군으로 나누었다. 배를 핀 적이 없다, 담배를 핀다 및 담배를 피운 적 동맥 경화의 위험 인자 중, 혈액학적 지표를 얻기 위 이 있으나 5개월 이상 금연하고 있다 의 세 군으로 분 해 혈액 검사를 시행하였다. 혈액 검사는 초음파 검사와 류하였고, 음주는 전혀 술을 마시지 않는다, 약간 마 같은 날에 시행하였고, 적어도 10시간의 공복 후, 오전 신다(1주일에 1회 이하, 1회 음주시 맥주 1병 이하) 중으로 채혈하도록 했으며, 임상 병리 검사실에서 총 및 많이 마신다(1주일에 2번 이상 음주) 로 나누었으 콜레스테롤, HDL-콜레스테롤, 트리글리세라이드를 측 1203
자료분석및통계 대상자들의기초자료분석 Table 2. Comparison of risk factors between male and female volunteers Risk factors Sex Female N38 Male N57 Total N95 Age years* 45.87 10.17 41.95 8.97 43.31 9.64 Body mass index kg/m 2 23.81 3.47 24.24 3.94 24.07 3.75 Total cholesterol mg/dl 191.24 37.44 194.04 29.96 192.92 32.99 HDL-C mg/dl 51.05 12.05 47.07 8.59 48.66 10.25 LDL-C mg/dl 113.86 28.24 115.93 28.24 115.09 29.95 Triglyceride mg/dl 131.63 94.84 155.19 84.52 145.77 89.06 IMT mm 0.679 0.108 0.668 0.091 0.673 0.098 Fasting blood glucose mg/dl 97.95 8.45 99.74 8.18 99.02 8.28 End-systolic blood pressure mmhg 125.68 29.19 123.18 16.09 124.18 22.16 End-diastolic blood pressure mmhg 83.87 17.87 79.74 15.22 81.39 16.37 *p0.05, IMTintima-media thickness, HDL-CHDL-Cholesterol, LDL-CLDL Cholesterol 1204 Korean Circulation J 1999;2911:1201-1211
결과 Table 3. Comparison of life-style data Gategories Smoking Alcohol consumption Grades Number Mean IMT mm Never smoked 39 0.6891 Present smoker 43 0.6679 Past-smoker, but quit more than 5 months 13 0.6404 No history of alcohol consumption 39 0.6891 Minimum to moderate degree of alcohol consumption F:1/week, A:1 bottle of beer 37 0.6766 Heavy alcohol consumption F:2/week 19 0.6321 None 15 0.6829 Exercise till sweating Minimum to moderate F:3 75 0.5820 Heavy F:4 5 0.6530 Ffrequency, Aamount The ANOVA showed statistically no significant differences among the grades in all categories p0.05 Table 4. Comparison of IMT and risk factors Categories Classifications Number Mean IMT mm p-value Total cholesterol Normal 220 mg/dl 78 0.6713 Hypercholesterolemia 220 mg/dl 17 0.68 0.741 Triglyceride Noraml 200 mg/dl 77 0.6725 Hypertryglyceridemia 200 mg/dl 18 0.6742 0.950 HDL-cholesterol* Normal 35 mg/dl 92 0.6663 Hypo-HDL-cholesterolemia 35 mg/dl 3 0.8733 0.0234 LDL-cholesterol* Normal 160 mg/dl 90 0.6719 Hyper-LDL-cholesterolemia 160 mg/dl 5 0.6890 0.110 Blood pressure Normotensive 77 0.6636 Hypertension 18 0.7122 0.058 Body mass index Normal 25kg/m 2 65 0.6672 Obese 25Kg/m 2 30 0.6852 0.408 * Wilcoxon rank sum test End-Systolic Blood Pressure 160 mmhg or End-Diastolic Systolic Blood Pressure 95 mmhg The result of statistical test can not be validated due to small sample size of hypo-hdl-cholesterolemia n3 1205
고찰 Fig. 3. Histogram and normality curve shows normal distribution pattern of measured IMT. The 95 and 100 percentiles are indicated. Fig. 4. Plots of correlation of age with IMT. The graph shows linear positive correlation patterns. The correlation coefficient is 0.5850 and is statistically significant p0.0001. Table 5. Correlation coefficients between IMT and risk factors Categories Correlation coefficients p-value Categories Correlation coefficients p-value Body mass index 0.2 0.053 Fasting glucose 0.43 0.678 Age 0.585 0.001 HDL-cholesterol 0.140 0.177 End-systolic blood pressure 0.169 0.101 LDL-cholesterol 0.38 0.718 End-diastolic blood pressure 0.174 0.091 Triglyceride 0.008 0.937 Total cholesterol 0.05 0.963 1206 Korean Circulation J 1999;2911:1201-1211
Fig. 5. Inter-observer variability of measurement of IMT in 20 randomly selected images of distal common carotid artery. The graph shows linear positive correlation patterns. The correlation coefficient is 0.8770 and is statistically significant p0.0001. Fig. 7. Plots of correlations of IMT measured by ACAPS method with new method authors method. The graph shows linear positive correlation patterns. The correlation coefficient is 0.9355 and is statistically significant p0.0001. Fig. 6. Intra-observer variability of measurement of IMT in 20 randomly selected images of distal common carotid artery. The graph shows linear positive correlation patterns. The correlations coefficient is 0.9213 and is statistically significant p0.0001. 1207
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요약 연구목적 : 1209
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