Tsutomu Fukumoto

Correlation of ultrasound-measured common carotid artery stiffness with pathological findings.

To quantitatively and noninvasively evaluate common carotid atherosclerosis in a series of patients, we measured the stiffness parameter beta, which represents the mechanical properties of the vessel. beta was calculated from the relationship between blood pressure and the diameter of the artery as measured by an ultrasonic, phase-locked, echotracking system. Increases in the severity grade of atherosclerosis as subsequently determined at autopsy were correlated with increased beta values in 60 common carotid arteries (r = .68). Patients with beta values greater than 13 had a pathological diagnosis of atherosclerosis in the common carotid artery. The sensitivity of this discrimination ratio was 80%, and the specificity was 80% as well. Thus, beta shows promise as a useful diagnostic indicator for detecting asymptomatic common carotid atherosclerosis.

Relationship Between Ultrasound Assessment of Arterial Wall Properties and Blood Pressure

Physical properties of an artery can be described in terms of stiffness, distensibility, and compliance. Changes in these properties can predict atherosclerosis disease, but it is necessary to identify an index that is independent of changes in blood pressure. We measured common carotid artery diameter and pulsatile change with an ultrasonic phase- locked, echo-tracking system in 7 subjects whose mean brachial blood pressure had varied 15 mm Hg or more within a month. Patients taking antihypertensive agents were excluded from the study. We measured changes in arterial diameter (n=41) at least four times during the study period and calculated the pressure-strain elastic modulus (Ep), distensibility coefficient (DC), cross-sectional compliance (CC) and stiffness parameter (β) from inner diameter, its pulsatile change, and blood pressure. The correlation coeffi cients of mean blood pressure with each index are as follows: Ep, 0.53; DC, 0.58; CC, 0.63; β, 0.21. When mean blood pressure increased 1 mm Hg, the change in each index at 100 mm Hg was as follows: Ep, 1.48 ±1.30%; DC, -1.05 ±0.97%; CC, -0.69 ±0.90%; β, 0.45 ±1.11%. Among the four indices that measure the properties of the arterial walls, stiffness parameter β was the least dependent on blood pressure. Thus, it appears to have usefulness as an index of arterial wall sclerosis.

Common carotid artery wall properties in Takayasu's arteritis.

The vessel wall properties of the common carotid artery have been noninvasively and quantitatively assessed with an ultrasonic instrument. Stiffness parameter β, which repre sents the mechanical properties of the vessel, was calculated from the relationship between blood pressure and the diameter of the artery. There are no reports that quan titatively assess wall properties in Takayasus arteritis. The authors compared, in vivo, the vessel wall properties of the common carotid artery in 14 patients with Takayasus arteritis versus those in 60 normal subjects (controls). They measured changes in the inner diameter of the artery between systole and diastole with an ultrasonic, phase-locked, echo-tracking system. β was significantly higher in Takayasus arteritis than in normal subjects (better than a 99% confidence interval). The findings for each decade were as follows: 3rd decade (20s): 35.7 ±28.9 vs 5.01-6.46, P=0.0001; 4th decade (30s): 19.5 ±9.71 vs 6.09-7.80, P=0.02; 5th decade (40s): 26.2 ±11.3 vs 7.26-9.28, P=0.0001; 6th decade (50s): 19.1 ±4.27 vs 8.66-11.25, P=0.0001. Takayasus arteritis significantly impaired the mechanical performance of the common carotid artery. Thus, β shows promise as a useful diagnostic indicator of Takayasus arteritis.

Relationship between the three kinds of healthy habits and the metabolic syndrome

SUMMARY OBJECTIVES In 2005, the diagnostic criteria for Japan-specific metabolic syndrome were published. The representative health habits are Breslows seven healthy practices, Morimotos eight items and Ikedas six healthy habits. We investigated the prevalence of metabolic syndrome related with life-style strongly among these three sets of healthy habit. METHODS Cross-sectional study was conducted for the prevalence of metabolic syndrome by practicing these healthy habits. 20,776 Japanese individuals visited the Health Science Center at Jikei University Hospital in Japan for medical check-ups. Subjects were divided into 8 groups based on gender and age (females in their 30s, 40s, 50s and 60s, and males in their 30s, 40s, 50s and 60s). Participants completed a simple, self-administered lifestyle questionnaire based on the three sets of healthy habits. Subjects were divided into three groups (poor, moderate and favorable) according to each of the healthy habit criteria. RESULTS Significant differences were observed among 10 groups for Breslows seven healthy practices, 4 groups for Morimotos eight items, and 13 groups for Ikedas six healthy habits. Ikedas six healthy habits showed the most significant differences among the three sets of habits. CONCLUSIONS Among the three methods tested, to practice more Ikedas healthy habits were the most useful for metabolic syndrome.