Potential of Carotid Enlargement as a Useful Indicator Affected by High Blood Pressure in a Large General Population of a Japanese City

Abstract

Background and Purpose —Few studies have examined whether there is a relationship between carotid arterial diameter and cardiovascular risk factors in a large general population. The aim of this study was to investigate cross-sectionally whether, in a randomly selected general large population of a Japanese city, there is a relationship between common carotid artery (CCA) diameter and conventional cardiovascular risk factors. Methods —The subjects of the present study were randomly selected from the residents of the city of Suita, located in the second largest urban area of Japan, and consisted of 2284 men and 2568 women aged 30 to 89 years. The outer and inner CCA diameters and intima-media thickness (IMT) of CCA were detected and measured by a single physician with high-resolution ultrasonography. We assessed cross-sectionally by age/sex group the relationships between IMT or CCA diameters and cardiovascular risk factors, especially blood pressure levels divided into 3 groups: the normal group of subjects had a diastolic blood pressure (DBP) <85 mm Hg and systolic blood pressure (SBP) <130 mm Hg and were not taking antihypertensive medication; the high group of subjects had DBP ≥90 mm Hg and/or SBP ≥140 mm Hg and/or were taking antihypertensive medication; and the moderate group consisted of all other subjects. Results —The outer and inner CCA diameters for the high group were significantly ( P <0.05) enlarged in comparison with those for the moderate and normal groups in all age/sex groups of both sexes after adjustment for body mass index, pack-years of smoking, alcohol consumption, and total serum cholesterol. Multiple regression analysis showed that age, body mass index, SBP, pack-years of smoking, alcohol consumption, and IMT were positively and significantly ( P <0.005) related to both outer and inner CCA diameters in both sexes except for between alcohol consumption and outer CCA diameter in women and showed that only serum total cholesterol level was negatively and significantly ( P <0.01) related to inner CCA diameter in both sexes. Conclusions —Our present study showed that the outer and inner CCA diameters correlated with conventional cardiovascular risk factors, including high blood pressure and IMT. These findings suggest that the outer and inner CCA diameters may be a useful indicator of carotid atherosclerosis, particularly in relation to high blood pressure.