川本 龍一, 山田 明弘, 小国 孝, 岡本 憲省

Ryuichi KAWAMOTO, Akihiro YAMADA, Takashi OGUNI, Kensyo OKAMOTO

町立野村病院内科

Department of Internal Medicine, Nomura Municipal Hospital

キーワード : Age differences , Carotid arterial wall thickness , Risk factors , Ultrasonography

We used ultrasonography to evaluate atherosclerotic lesions in the common carotid arteries of patients admitted to the hospital between September 1995 and May 1998 (238 men and 228 women averaging 68.3±13.5 years of age; range, 15 to 98 years) to study their relation with various risk factors for atherosclerosis. Patients were divided into three groups: those less than 65 years of age, the younger group, comprising 83 men and 53 women; those at least 65 but less than 75 years of age, the young-old group, comprising 78 men and 89 women; and those 75 years old or older, the old group, comprising 77 men and 86 women). Common carotid arterial wall thickness was determined by measuring the thickness of the intimal-medial complex, avoiding plaques on the rear-wall side of the common carotid artery (carotid arterial wall thickness) at two points each on both sides by ultrasonography (Hitachi EUB-565 and 7.5 MHz linear probe). Risk factors were evaluated by sex (male, 1; female, 2), age, body mass index, Brinkman index, blood pressure, total cholesterol (T-Chol), triglyceride (TG), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), uric acid, fasting blood sugar, presence or absence of diabetes mellitus, and use of antihypertensive medication. By setting carotid arterial wall thickness, denned as hypertrophic when it exceeds 1.0 mm, as the target variable, logistic regression analysis was conducted using various risk factors as explanatory variables. Sex (odds ratio, 0.27; 95% confidence interval, 0.10 to 0.74), age (1.10; 1.04 to 1.17) and HDL-C (0.95; 0.92 to 0.98) were significant independently contributing factors in the younger group, sex (0.13; 0.05 to 0.34), systolic blood pressure (1.02; 1.00 to 1.05) and T-Chol (1.02; 1.01 to 1.03) in the young-old group, and Brinkman index (1.00; 1.00 to 1.00), body mass index (1.15; 1.02 to 1.28), systolic blood pressure (1.03; 1.01 to 1.06), uric acid (1.38; 1.08 to 1.76), diabetes mellitus (4.36; 1.11 to 17.19) in the old group. These results suggest that ultrasonographically measured carotid arterial wall thickness was related to different risk factors in all three age groups, and point out the need to take age into consideration when addressing these problems.