Smoking and secondhand smoke exposure and carotid intima-media thickness: Baseline data from the Aidai Cohort Study in Japan.

INTRODUCTION: Epidemiological evidence regarding the relationship between smoking and secondhand smoke (SHS) exposure and carotid intima-media thickness (CIMT) has been limited in Asian populations. Employing baseline data from the Aidai Cohort Study, Japan, we evaluated the evidence in this cross-sectional study. METHODS: Study subjects were 727 men aged 35-88 years and 1297 women aged 34-85 years. Information on smoking, SHS exposure, and confounders was obtained through a self-administered questionnaire. An automated carotid ultrasonography device was used to measure the right and left CIMT. The greatest CIMT measurement in the left or right common carotid artery was considered the maximum CIMT, and a maximum CIMT >1.0 mm was indicative of carotid wall thickening. Age, alcohol consumption, leisure time physical activity, hypertension, dyslipidemia, diabetes mellitus, body mass index, waist circumference, employment, and education level were adjusted at one time. RESULTS: The prevalence of carotid wall thickening was 13.0%. The prevalence of never smoking was 30.5% in men and 90.1% in women. Among those who had never smoked, the prevalence of never SHS exposure at home and work was 74.3% and 48.2% in men and 38.3% and 56.3% in women, respectively. Active smoking and pack-years of smoking were independently positively related to carotid wall thickening regardless of sex, although the association with current smoking in women was not significant. Independent positive relationships were shown between former smoking and pack-years of smoking and maximum CIMT in men but not in women. No significant relationships were found between SHS exposure at home and work and carotid wall thickening or maximum CIMT in either men or women. CONCLUSIONS: Active smoking, especially pack-years of smoking, was positively associated with carotid wall thickening in both sexes. Such positive associations with maximum CIMT were found only in men; however, interactions between smoking and sex were not significant.

Fish and Polyunsaturated Fatty Acid Intake and Carotid Intima-Media Thickness in Japan: the Aidai Cohort Study in Yawatahama, Uchiko, Seiyo, and Ainan.

AIM: Epidemiological evidence regarding the relationship between fish and fatty acid intake and carotid intima-media thickness (CIMT) has been limited and inconsistent. The current cross-sectional study investigated this issue using baseline data from the Aidai Cohort Study. METHODS: Study subjects were 2024 Japanese men and women aged 34-88 years. Right and left CIMT were measured at the common carotid artery using an automated carotid ultrasonography device. Maximum CIMT was defined as the largest CIMT value in either the left or right common carotid artery. Carotid wall thickening was defined as a maximum CIMT value ＞1.0 mm. RESULTS: The prevalence of carotid wall thickening was 13.0%. In men, intake of n-3 polyunsaturated fatty acids (PUFA) was independently positively related to the prevalence of carotid wall thickening, while no associations were found between intake of fish and the other fatty acids and carotid wall thickening or maximum CIMT. In women, intake levels of fish, n-3 PUFA, eicosapentaenoic acid, docosahexaenoic acid, and arachidonic acid were independently inversely associated with carotid wall thickening and intake levels of fish, n-3 PUFA, α-linolenic acid, n-6 PUFA, and linoleic acid were independently inversely associated with the maximum CIMT. No significant relationships were found between intake of total fat, saturated fatty acids, or monounsaturated fatty acids and carotid wall thickening or maximum CIMT regardless of sex. CONCLUSIONS: In women, higher intake of fish and n-3 and n-6 PUFA may be associated with a lower prevalence of carotid wall thickening and a decrease in maximum CIMT.

Education and household income and carotid intima-media thickness in Japan: baseline data from the Aidai Cohort Study in Yawatahama, Uchiko, Seiyo, and Ainan.

BACKGROUND: Epidemiological evidence for the relationship between education and income and carotid intima-media thickness (CIMT) has been limited and inconsistent. The present cross-sectional study investigated this issue using baseline data from the Aidai Cohort Study. METHODS: Study subjects were 2012 Japanese men and women aged 34-88 years. Right and left CIMT were measured at the common carotid artery using an automated carotid ultrasonography device. Maximum CIMT was defined as the largest CIMT value in either the left or right common carotid artery. Carotid wall thickening was defined as a maximum CIMT value > 1.0 mm. RESULTS: The prevalence of carotid wall thickening was 13.0%. In participants under 60 years of age (n = 703) and in those aged 60 to 69 years (n = 837), neither education nor household income was associated with carotid wall thickening or with maximum CIMT. Among those aged 70 years or older (n = 472), however, higher educational level, but not household income, was independently related to a lower prevalence of carotid wall thickening: the multivariate-adjusted odds ratio for high vs. low educational level was 0.43 (95% confidence interval 0.21-0.83, p for trend = 0.01). A significant inverse association was observed between education, but not household income, and maximum CIMT (p for trend = 0.006). CONCLUSIONS: Higher educational level may be associated with a lower prevalence of carotid wall thickening and a decrease in maximum CIMT only in participants aged 70 years or older.