Association of carotid intima media thickness with cigarette smoking in hypertensive Chinese adults

Objective: Smoking is an established risk factor for atherosclerotic disease. However, the degree of the cigarette smoking-induced damage varies from individual to individual, partly due to the between-individual difference in genetic makeup. The aim of this study was to identify genetic loci influencing the effect of cigarette smoking on carotid intima-media thickness (IMT) by performing a genome-wide association smoking-by-SNP interaction analysis. Methods and results: Genome-wide genotyping was performed using the Affymetrix SNP array 6.0 among 1,010 individuals who underwent B-mode ultrasound examination of carotid IMT from the population-based Northern Manhattan Study. Cigarette pack-years was calculated as number of years smoked multiplied by number of cigarettes smoked per day, then divided by 20. After quality control, a total of 722,379 single nucleotide polymorphisms (SNPs) were included in the final analysis. Generalized linear modeling was conducted to look for smoking-by-SNP interaction on carotid IMT while controlling for age, sex, hypertension, diabetes, dyslipidemia, body mass index, waist-to-hip ratio, and the top 3 principal components estimated to capture ancestry by EIGENSTRAT. Ten SNPs near or within 5 genes showed an interactive effect with cigarette smoking on IMT with a p value <1.0E-5. Among them, 3 SNPs (including 1 exonic splice enhancer SNP rs3751283, P=8.3E-7) are near or within regulator of chromosome condensation and BTB domain containing protein 1 (RCBTB1) gene on 13q14. Specifically, for SNP rs3751283, the mean IMT was substantially increased among CC-carriers (0.70 mm, 0.76 mm, 0.81 mm for 0, <20, and ≥20 cigarette pack-years, respectively, P=2.6E-6), slightly increased with smoking pack-years among TC-carriers (0.72 mm, 0.74 mm, 0.75 mm for 0, <20, and ≥20 cigarette pack-years, respectively, P=0.03), but very similar (0.73 mm) among TT-carriers for the three smoking groups (P=0.84). Conclusion: Our genome-wide interaction analysis reveals multiple genes, especially RCBTB1, that may modify the effect of smoking on carotid IMT. These genes will be further evaluated in our full dataset with additional genotyping. Also, larger independent studies are needed to validate these findings.

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Higher dietary and serum carotenoid levels are associated with lower carotid intima–media thickness in middle-aged and elderly people

British Journal Of Nutrition ◽

10.1017/s0007114517003932 ◽

2018 ◽

Vol 119 (5) ◽

pp. 590-598 ◽

Cited By ~ 2

Author(s):

Cheng Wang ◽

Rui Qiu ◽

Yi Cao ◽

Wei-fu Ouyang ◽

Hua-bin Li ◽

...

Keyword(s):

Carotid Artery ◽

Intima Media Thickness ◽

Carotid Intima Media Thickness ◽

Cross Sectional Study ◽

Chinese Adults ◽

Total Carotenoids ◽

Cross Sectional ◽

Media Thickness ◽

Mean Differences ◽

Serum Carotenoids

AbstractSeveral studies have suggested that higher carotenoid levels may be beneficial for atherosclerosis patients, but few studies have examined this relationship in the Chinese population. This cross-sectional study examined the association between the levels of carotenoids in diet and serum and carotid intima–media thickness (IMT) in Chinese adults aged 50–75 years in Guangzhou, China. Dietary intake was assessed using a FFQ. HPLC was used to assay the serum concentrations of α-carotene, β-carotene, lutein+zeaxanthin, β-cryptoxanthin and lycopene. The IMT at the common carotid artery (CCA) and bifurcation of the carotid artery was measured by B-mode ultrasound. A total of 3707 and 2947 participants were included in the analyses of dietary and serum carotenoids. After adjustment for demographic, socio-economic and lifestyle factors, all the serum carotenoids levels except lycopene were found to be inversely associated with the IMT at the CCA and bifurcation (Ptrend<0·001 to 0·013) in both men and women. The absolute mean differences in the IMT between the subjects in the extreme quartiles of serum carotenoid levels were 0·034 mm (α-carotene), 0·037 mm (β-carotene), 0·032 mm (lutein+zeaxanthin), 0·030 mm (β-cryptoxanthin), 0·015 mm (lycopene) and 0·035 mm (total carotenoids) at the CCA; the corresponding values were 0·025, 0·053 0·043, 0·050, 0·011 and 0·042 mm at the bifurcation. The favourable associations were also observed between dietary carotenoids (except lycopene) and the CCA IMT. In conclusion, elevated carotenoid levels in diet and serum are associated with lower carotid IMT values (particular at the CCA) in Chinese adults.

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