Carotid intima-media thickness and plaque characteristics as a risk factor for stroke in Japanese elderly men.
OBJECTIVE
Few cohort studies have examined the association of carotid intima-media thickness (IMT) and plaque characteristics with the risk of stroke in apparently healthy persons. We examined the relationship of carotid IMT and the surface, morphology, and calcification of carotid plaques with the incidence of stroke among Japanese men.


METHODS
Carotid IMT and plaque were evaluated bilaterally with ultrasonography in 1289 men aged 60 to 74 years without a previous stroke or coronary heart disease. In this cohort, the subsequent incidence of stroke was investigated.


RESULTS
During the 4.5-year follow-up, 34 strokes occurred. The multivariate-adjusted relative risk (95% CI) for the highest versus lowest quartiles of maximum IMT of the common carotid artery (CCA; > or =1.07 versus < or =0.77 mm) was 3.0 (1.1 to 8.3) for stroke. The combination of CCA and internal carotid artery (ICA) wall thickness was a better predictor of the risk of stroke than was CCA wall thickness alone. Men with a plaque, defined as a focal wall thickness of > or =1.5 mm, in the ICA had a 3-fold higher risk of stroke than those without a plaque, and the plaque surface irregularity further increased the stroke risk. A significant excess risk of stroke was confined to men with an uncalcified plaque.


CONCLUSIONS
Increased IMT of the CCA and an uncalcified plaque in the ICA, as assessed by ultrasonography, are risk factors for stroke in elderly Japanese men.
Kitamura
Akihiko
A
Osaka Medical Center for Health Science and Promotion, 1-3-2 Nakamichi, Higashinari-ku, Osaka 537-0025, Japan. xkita@kenkoukagaku.jp
Iso
Hiroyasu
H
Imano
Hironori
H
Ohira
Tetsuya
T
Okada
Takeo
T
Sato
Shinichi
S
Kiyama
Masahiko
M
Tanigawa
Takeshi
T
Yamagishi
Kazumasa
K
Shimamoto
Takashi
T
D000368:Aged; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology*; D017539:Tunica Intima / Q000000981:diagnostic imaging; D014463:Ultrasonography