C-reactive protein and risk of atrial fibrillation in East Asians.

AIMS: Inflammation has been suggested to play a role in the pathogenesis of atrial fibrillation (AF). It is uncertain whether C-reactive protein, a robust inflammatory marker, is associated with AF incidence in Asians with lower levels of C-reactive protein compared with western population. This study aimed to determine the association between C-reactive protein and risk of AF in a large population of Koreans. METHODS AND RESULTS: A total of 402 946 Koreans were enrolled in a health screening programme from January 2002 to December 2013. Among them, 210 208 subjects were analysed during the mean follow-up of 4.59 years (1 062 513 person-years). Atrial fibrillation was identified by electrocardiography at every visits. Atrial fibrillation was identified in 561 subjects (0.1%) at baseline. The median (inter-quartile) baseline C-reactive protein levels were higher in subject with AF than in those without AF [0.9 mg/L (0.4-0.9) vs. 0.4 mg/L (0.2-1.0), P < 0.001]. Subjects in the highest quartile of C-reactive protein had more AF than those in the lowest quartile [adjusted odds ratio (OR) 2.02, 95% confidence interval (CI) 1.45-2.81; P< 0.001]. During a mean follow-up of 4.59 years, AF developed in 261 subjects (0.1%). The highest quartile of baseline C-reactive protein had a 1.68-fold (95% CI 1.06-2.67) increased risk of AF than the lowest quartile in multivariate Cox regression analysis. CONCLUSION: Baseline C-reactive protein levels are significantly associated with the prevalence of AF and the risk of AF in Korean populations even C-reactive protein concentrations are substantially lower than reported in white populations.

Association between cotinine-verified smoking status and hypertension in 167,868 Korean adults.

PURPOSE: Previous studies showed inconsistent results concerning the relationship between chronic smoking and blood pressure. Most of the studies involved self-reported smoking status. This study was performed to evaluate the association of urinary cotinine or self-reported smoking status with hypertension and blood pressure in Korean adults. MATERIALS AND METHODS: Among individuals enrolled in the Kangbuk Samsung Health Study and Kangbuk Samsung Cohort Study, 167,868 participants (men, 55.7%; age, 37.5 ± 6.9 years) between 2011 and 2013 who had urinary cotinine measurements were included. Individuals with urinary cotinine levels ≥50 ng/mL were defined as cotinine-verified current smokers. RESULTS: The prevalence of hypertension and cotinine-verified current smokers in the overall population was 6.8% and 22.7%, respectively (10.0% in men and 2.8% in women for hypertension: 37.7% in men and 3.9% in women for cotinine-verified current smokers). In a multivariate regression analysis adjusted for age, sex, body mass index, waist circumference, alcohol drinking, vigorous exercise, and diabetes, cotinine-verified current smoking was associated with lower prevalence of hypertension compared with cotinine-verified never smoking (OR[95% CI], 0.79 [0.75, 0.84]). Log-transformed cotinine levels and unobserved smoking were negatively associated with hypertension, respectively (0.96 [0.96, 0.97] and 0.55 [0.39, 0.79]). In a multivariate linear regression analysis, the cotinine-verified current smoking was inversely associated with systolic and diastolic blood pressure (BP) (regression coefficient[95% CI], -1.23[-1.39, -1.07] for systolic BP and -0.71 [-0.84, -0.58] for diastolic BP). In subgroup analyses according to sex, the inverse associations between cotinine-verified current smoking and hypertension were observed only in men. CONCLUSIONS: This large observational study showed that cotinine-verified current smoking and unobserved smoking were inversely associated with hypertension in Korean adults, especially only in men.

Association between cigarette smoking and diabetes mellitus using two different smoking stratifications in 145 040 Korean individuals: Self-reported questionnaire and urine cotinine concentrations.

BACKGROUND: Although previous studies have assessed the relationship between smoking and diabetes using self-reported questionnaires, interpretations may be limited by an underestimation of the actual smoking population. This study evaluated the relationship between smoking and diabetes using both self-reported questionnaires and urine cotinine concentrations. METHODS: The present cross-sectional study enrolled 145 040 Koreans in Kangbuk Samsung Health and Cohort Studies between 2011 and 2013. Urinary cotinine was measured after a 10-hour smoking-free period. Cotinine-verified current smoking was defined as a urinary cotinine concentrations ≥50 ng/mL. RESULTS: Overall diabetes prevalence in self-reported (4.5% vs 1.6%) and cotinine-verified (4.4% vs 2.1%) current smokers was higher than in self-reported and cotinine-verified never smokers. Multivariate regression analysis showed that cotinine-verified current smoking (odds ratio [OR] 1.25; 95% confidence interval [CI] 1.13-1.38), self-reported former smoking (OR 1.16; 95% CI 1.01-1.33) and current smoking (OR 1.33; 95% CI 1.17-1.50) were associated with increased diabetes compared with cotinine-verified and self-reported never smoking. Unobserved smoking (OR 1.79; 95% CI 1.20, 2.66) also increased the odds for diabetes. There were no significant sex interactions in the analyses. CONCLUSIONS: This study shows that self-reported former and current smoking, cotinine-verified current smoking, and unobserved smoking (i.e. self-reported never smoking with urine cotinine >50 ng/mL) are all associated with increased diabetes prevalence. These findings suggest that cotinine could provide additional information when assessing cardiometabolic risks, such as diabetes.

The association between self-reported versus nicotine metabolite-confirmed smoking status and coronary artery calcification.

OBJECTIVE: There are no data comparing the relationship between coronary artery calcification and self-reported and cotinine-verified smoking. This study was carried out to evaluate the relationship between coronary artery calcium (CAC) and urinary cotinine or self-reported smoking status in Korean adults. PARTICIPANTS AND METHODS: Study participants included 22 797 individuals (19 181 men; mean age±SD 39.2±7.1 years) who were enrolled in the Kangbuk Samsung Health Study and Kangbuk Samsung Cohort Study between 2011 and 2013, and who had urinary cotinine and CAC measurements. Cotinine-verified current smokers were defined as having a urinary cotinine level of above 50 ng/ml. RESULTS: The prevalence of never smokers, former smokers, and current smokers according to the self-reported questionnaires was 44.6, 24.2, and 31.2%, respectively, and that of cotinine-verified current smokers was 30.2%. The prevalence of the presence of CAC in self-reported current smokers was higher than that in self-reported never/former smokers (13.7 vs. 10.2%, P<0.001), and that in cotinine-verified current smokers was higher than that in cotinine-verified never smokers (14.0 vs. 10.2%, P<0.001). A multivariate logistic regression model adjusted for the variables with univariate relationships showed that self-reported former smokers and current smokers had significantly increased odds ratio (OR) for the presence of CAC compared with self-reported never smokers [OR (95% confidence interval): 1.20 (1.03-1.40) in former smokers and 1.29 (1.11-1.50) in current smokers]. Cotinine-verified current smokers also showed a significant association with the presence of CAC [1.23 (1.12-1.35)]. Furthermore, log-transformed cotinine levels increased the OR for the presence of CAC [1.03 (1.01-1.05)]. CONCLUSION: This study is the first large cohort study to show that both self-reported and cotinine-verified smoking is associated independently with the presence of CAC in Korean adults.

Relationship of cotinine-verified and self-reported smoking status with metabolic syndrome in 116,094 Korean adults.

BACKGROUND: No study has reported the relationship between cotinine-verified and self-reported smoking status with metabolic syndrome (MetS). OBJECTIVE: This study was performed to evaluate the relationship between urinary cotinine-verified and self-reported smoking status with MetS and determine the effects of unobserved smokers on MetS in Korean adults. METHODS: A total of 116,094 individuals (66,875 men and 49,219 women) with mean age of 36.7 ± 6.8 years included in Kangbuk Samsung Health Study and Kangbuk Samsung Cohort Study between 2011 and 2013 who had urinary cotinine measurements were enrolled. Cotinine-verified current smoking was defined as urinary cotinine level of above 50 ng/mL. Unobserved smoking was defined as urinary cotinine level of above 50 ng/mL in self-reported never smokers. RESULTS: The overall prevalence rates of cotinine-verified current smokers and MetS were 22.9% and 10.5%, respectively. The misclassification rate to cotinine-verified current smokers among self-reported never smokers was 1.7%. A multivariate logistic regression model adjusted for variables with univariate relationship (model 1) showed that cotinine-verified current smokers significantly increased the odds ratio for MetS compared with cotinine-verified never smokers (odds ratio [95% confidence interval], 1.30 [1.23, 1.37]). Log-transformed cotinine levels were also associated with MetS (1.04 [1.03, 1.05]). However, the association was not significant in the previously mentioned model including the traditional 5 components of MetS (model 2). Unobserved smokers significantly increased the ORs for MetS in both model 1 (1.43 [1.23, 1.67]) and model 2 (1.57 [1.06, 2.33]). CONCLUSION: This study shows that unobserved smoking and cotinine-verified current smoking are associated with MetS but urinary cotinine could be 1 conditional factor that interacts with traditional MetS components.

Absence of association between gallstone and coronary artery calcification.

BACKGROUND AND AIMS: Gallstone has been suggested to be associated with cardiovascular disease (CVD). Coronary artery calcification (CAC) is an excellent value to predict future CVD. The aim of this study was to evaluate the association between gallstone and CAC. METHODS: Data were analyzed from an occupational cohort of 46,893 subjects (37,557 men and 9336 women) between 2011 and 2014. Participants with cancer or CVD histories or missing data at baseline were excluded from the study. Gallstone was diagnosed by ultrasound-documentation. Multivariate logistic analysis was conducted to examine the relationship between gallstone and CAC. RESULTS: The total population who had gallstone was 1426 (3.1%). In multivariate analysis, odds ratios (OR) for gallstone were not different according to CAC score groups in men and women. In addition, gallstone was not associated with higher OR for CAC in men and women. CONCLUSIONS: Gallstone was not associated with CAC in both Korean men and women.

Relationship of Echocardiographic Epicardial Fat Thickness and Epicardial Fat Volume by Computed Tomography with Coronary Artery Calcification: Data from the CAESAR Study.

BACKGROUND AND AIMS: No study has assessed the association between echocardiographic epicardial fat thickness (EFT) and computed tomography (CT)-based epicardial fat volume (EFV) and coronary artery calcification. The aim of this study is to evaluate the association between EFT and EFV and coronary artery calcification. METHODS: Among the 2,299 individuals enrolled in the CArdiometabolic risk, Epicardial fat, and Subclinical Atherosclerosis Registry (CAESAR) study, 2,276 (1,851 men; mean age 45 ± 8.9 years) who underwent echocardiographic EFT and CT-based EFV measurements and obtained a coronary artery calcium score (CACS) were included in this study. RESULTS: The overall prevalence of CAC >0 was 19.3%. EFT was significantly correlated with EFV (r = 0.374, p <0.001) but the k statistic showed only slight agreement (k = 0.146, p <0.001). Multivariate regression analyses adjusted for age, sex, body mass index, waist circumference, systolic blood pressure, daily alcohol intake, smoking status, and vigorous exercise and glucose, blood urea nitrogen, uric acid, total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, high-sensitivity C reactive protein, and hemoglobinA1c levels revealed that an increase in the absolute values of EFT and EFV was significantly associated with the presence of coronary artery calcium (ORs [95% CIs], 2.023 [1.282-3.193] and 1.785 [1.173-2.716], respectively) and CACS (standardized ß values = 0.082 and 0.061, p = 0.001 and 0.042, respectively). CONCLUSION: These results show that EFT and EFV are associated with coronary artery calcification in Korean adults despite the relatively weak correlation between EFT and EFV.

Bacterial diversity in the human saliva from different ages.

To obtain primary idea on oral bacterium species that are generally present in periodotally healthy Koreans, the oral bacterial flora in the saliva of four periodontally healthy Koreans at different ages (5, 32, 35, 65) was investigated in this study. For this investigation, 16SrRNA gene clone libraries were generated from the saliva of the four healthy Koreans, and 50 clones were randomly selected from each saliva clone library and sequenced. Totally, 37 different kinds of bacterial 16S rRNA gene sequences were identified based on sequence homology search through GenBank database. The 37 kinds of saliva clone sequences were classified to 14 genera and 2 uncultured and 1 unidentified bacteria. Among the 14 identified genera, Streptococcus, Prevotella, and Veillonella were common genera, and Streptococcus was dominant genus that accounted for 7 different species. Among the seven Streptococcus species, S. salivarius appeared as the most common species. More numbers of species belonging to the genera Streptococcus and Prevotella was present in saliva from ages 32 and 35. While saliva from ages 5 and 65 showed more numbers of species belonging to the genera Rothia, including potential pathogenic species. Overall, saliva of a young child and a senior showed higher bacterial diversity than that of young adults.

Relationship of epicardial fat thickness and nonalcoholic fatty liver disease to coronary artery calcification: From the CAESAR study.

BACKGROUND: Epicardial fat and nonalcoholic fatty liver disease (NAFLD) are associated with subclinical atherosclerosis; however, the combined effect of both EAT and NAFLD on coronary artery calcium (CAC) is unclear. OBJECTIVE: The present study was performed to evaluate the association of both epicardial fat thickness (EFT) and NAFLD with CAC. METHODS: Among 2277 individuals enrolled in the CArdiometabolic risk, Epicardial fat, and Subclinical Atherosclerosis Registry (CAESAR) Study, 1473 individuals (1242 men, mean age, 44 ± 9 years) were included for analysis. Echocardiographic EFT and ultrasonographic fatty liver were measured. Individuals were divided into 4 groups according to EFT and NAFLD (group I: low EFT and without NAFLD; group II: low EFT and with NAFLD; group III: high EFT and without NAFLD; and group IV: high EFT and with NAFLD). RESULTS: The median EFT value (interquartiles) was 3.17 mm (2.58 mm, 3.85 mm), and the prevalence of NAFLD and CACS >0 was 46.0% and 16.8%, respectively. The prevalence of CACS >0 was 7.9%, 16.8%, 18.0%, and 26.0% in group I, II, III, and IV, respectively (P < .001). On multivariate regression after adjusting for variables with a univariate relationship (P < .20), group IV had a significantly higher OR for CACS >0, and the OR in group III was marginally significant, compared to group I (1.458 [0.795, 2.672], 1.744 [0.999, 3.046], and 1.864 [1.041, 3.337] for groups II, III, and IV, respectively). CONCLUSION: This study shows that both increased EFT and presence of NAFLD are associated with coronary artery calcification, and that increased EFT is more strongly related to CAC than NAFLD, in spite of NAFLD having greater cardiometabolic risk than EFT.

Association of epicardial fat volume and nonalcoholic fatty liver disease with metabolic syndrome: From the CAESAR study.

BACKGROUND AND AIMS: Epicardial adipose tissue or nonalcoholic fatty liver disease (NAFLD) can be one of putative risk factors for metabolic syndrome (MetS). However, there are no data assessing the associations of MetS with epicardial fat and NAFLD. The present study was performed to evaluate the combined effect of epicardial fat volume (EFV) and NAFLD on MetS in Korean adults. METHODS AND RESULTS: Computed tomographic EFV and ultrasonographic fatty liver were measured in 1472 individuals (1242 men: mean age, 44 ± 8.6 years) among a total of 2277 individuals enrolled in the CArdiometabolic risk, Epicardial fat, and Subclinical Atherosclerosis Registry (CAESAR). Subjects were divided into 4 groups according to EFV and NAFLD (group I: low EFV and without NAFLD; group II: low EFV and with NAFLD; group III: high EFV and without NAFLD; and group IV: high EFV and with NAFLD). The overall prevalence of MetS was 24.2%. The EFV levels and prevalence of NAFLD in individuals with MetS was significant higher than those without MetS (81.0 cm3 vs 57.3 cm3, P < .001; 75.6% vs 36.5%, P < .001). The multivariate regression analysis including the five components of MetS showed that Group IV had significantly higher odds ratios (ORs) for the presence of MetS compared with Group I (OR [95% CI], 2.10 [1.11-3.98]). In the model, EFV was associated with MetS (2.03 [1.17-3.52]) but NAFLD was not (1.38 [0.88-2.12]). CONCLUSION: This study showed that increased EFV and NAFLD are associated with the presence of MetS. However, EFV was more influenced by MetS than NAFLD despite NAFLD having more unfavorable metabolic and lipid profiles.

The association between epicardial fat thickness and coronary artery calcification according to blood pressure status in nonhypertensive individuals: From the CAESAR study.

BACKGROUND: Epicardial adipose tissue represents visceral adiposity, and the coronary artery calcium (CAC) score (CACS) has been suggested as a reasonable surrogate for coronary atherosclerosis. Epicardial fat thickness (EFT) and blood pressure status can be attributed to coronary artery calcification. OBJECTIVE: The present study was performed to evaluate the association between EFT and coronary artery calcification according to blood pressure status in nonhypertensive individuals. METHODS: The CACS and echocardiographic EFT measurement were performed in a total of 1878 nonhypertensive individuals (1535 men; mean age, 44 ± 8.3 years). Subjects were divided into quartiles according to EFT (≤2.575, 2.576-3.168, 3.169-3.900, and >3.900 mm) and into 2 groups according to the presence of CAC. Additionally, individuals were classified as normotensive (n = 1064) or prehypertensive (n = 814). RESULTS: The prevalence of CACS >0 group in prehypertensive individuals was 6.1%, 18.1%, 22.6%, and 29.9% in the lowest, second, third, and highest EFT quartiles, respectively (P < .001) and 7.3%, 13.1%, 14.0%, and 13.9% in the normotensive group (P = .050). On multivariate regression analysis, the second, third, and highest quartile EFT groups had higher odds ratios for the presence of CAC than that of the lowest quartile (odds ratio [95% confidence interval], 3.849 [1.215-12.194], 4.069 [1.235-13.412], and 4.383 [1.385-13.875], respectively), although only in prehypertensive individuals. Moreover, an increased absolute EFT level was also associated with increased CACS in prehypertensive individuals (standardized ß = 0.101, P = .035). CONCLUSION: This study showed an independent relationship between EFT and coronary artery calcification in nonhypertensive individuals, with variable differences in this association according to blood pressure status.