Alcohol consumption and coronary artery calcium in middle-aged Japanese men

Associations of High-Density Lipoprotein Particle and High-Density Lipoprotein Cholesterol With Alcohol Intake, Smoking, and Body Mass Index - The INTERLIPID Study

BACKGROUND

Recently, high-density lipoprotein particles (HDL-P) have been found to be more strongly inversely associated with coronary artery disease (CAD) risk than their counterpart, HDL cholesterol (HDL-C). Given that lifestyle is among the first targets in CAD prevention, we compared the associations of HDL-P and HDL-C with selected lifestyle factors. Methods and Results: We examined 789 Japanese participants of the INTERLIPID Study: men (n=386) and women (n=403) aged 40-59 years in 1996-1998. Participants treated for dyslipidemias were excluded. Lifestyle factors included alcohol intake, smoking amount, and body mass index (BMI). Multivariable linear regression was used for cross-sectional analyses of these factors with HDL-P, HDL-C, HDL-P size subclasses (small, medium and large) and mean HDL-P size. In men, higher alcohol intake was associated with higher HDL-P and higher HDL-C. The associations of alcohol, however, were strongest with HDL-P. A higher smoking amount tended to be associated with lower HDL-P and HDL-C. In contrast, BMI was not associated with HDL-P, but was strongly inversely associated with HDL-C. While alcohol intake favored larger mean HDL-P size, smoking and BMI favored a lipid profile with smaller HDL-P subclasses and overall smaller mean HDL-P size. Similar, but generally weaker results were observed in women.

CONCLUSIONS

Although both HDL-P and HDL-C are parameters of HDL, they have different associations with alcohol, smoking and BMI.

Association of alcohol consumption and aortic calcification in healthy men aged 40-49 years for the ERA JUMP Study

BACKGROUND AND AIMS

Several studies have reported a significant inverse association of light to moderate alcohol consumption with coronary heart disease (CHD). However, studies assessing the relationship between alcohol consumption and atherosclerosis have reported inconsistent results. The current study was conducted to determine the relationship between alcohol consumption and aortic calcification.

METHODS

We addressed the research question using data from the population-based ERA-JUMP Study, comprising of 1006 healthy men aged 40-49 years, without clinical cardiovascular diseases, from four race/ethnicities: 301 Whites, 103 African American, 292 Japanese American, and 310 Japanese in Japan. Aortic calcification was assessed by electron-beam computed tomography and quantified using the Agatston method. Alcohol consumption was categorized into four groups: 0 (non-drinkers), ≤1 (light drinkers), >1 to ≤3 (moderate drinkers) and >3 drinks per day (heavy drinkers) (1 drink = 12.5 g of ethanol). Tobit conditional regression and ordinal logistic regression were used to investigate the association of alcohol consumption with aortic calcification after adjusting for cardiovascular risk factors and potential confounders.

RESULTS

The study participants consisted of 25.6% nondrinkers, 35.3% light drinkers, 23.5% moderate drinkers, and 15.6% heavy drinkers. Heavy drinkers [Tobit ratio (95% CI) = 2.34 (1.10, 4.97); odds ratio (95% CI) = 1.67 (1.11, 2.52)] had significantly higher expected aortic calcification score compared to nondrinkers, after adjusting for socio-demographic and confounding variables. There was no significant interaction between alcohol consumption and race/ethnicity on aortic calcification.

CONCLUSIONS

Our findings suggest that heavy alcohol consumption may be an independent risk factor for atherosclerosis.

Significant inverse association of equol-producer status with coronary artery calcification but not dietary isoflavones in healthy Japanese men

Equol, a metabolite of the dietary isoflavone daidzein, is produced by the action of gut bacteria in some individuals who are termed as equol-producers. It is proposed to have stronger atheroprotective properties than dietary isoflavones. We examined a cross-sectional association of dietary isoflavones and equol-producer status with coronary artery calcification (CAC), a biomarker of coronary atherosclerosis, among men in Japan. A population-based sample of 272 Japanese men aged 40-49 years recruited from 2004 to 2007 was examined for serum isoflavones, serum equol, CAC and other factors. Equol-producers were classified as individuals having a serum level of equol >83 nm. The presence of CAC was defined as a coronary Ca score ≥10 Agatston units. The associations of dietary isoflavones and equol-producers with CAC were analysed using multiple logistic regression. The median of dietary isoflavones, equol and CAC were 512·7 (interquartile range (IQR) 194·1, 1170·0), 9·1 (IQR 0·10, 33·1) and 0·0 (IQR 0·0, 1·0) nm, respectively. Prevalence of CAC and equol-producers was 9·6 and 16·0 %, respectively. Dietary isoflavones were not significantly associated with CAC. After multivariable adjustment, the OR for the presence of CAC in equol-producers compared with equol non-producers was 0·10 (95 % CI 0·01, 0·90, P<0·04). Equol-producers had significantly lower CAC than equol non-producers, but there was no significant association between dietary isoflavones and CAC, suggesting that equol may be a key factor for atheroprotective properties of isoflavones in Japanese men. This finding must be confirmed in larger studies or clinical trials of equol that is now available as a dietary supplement.

Cross-sectional comparison of coronary artery calcium scores between Caucasian men in the United States and Japanese men in Japan: the multi-ethnic study of atherosclerosis and the Shiga epidemiological study of subclinical atherosclerosis

The incidence of coronary heart disease in the United States has declined, and prevalences of several coronary disease risk factors have become comparable to those in Japan. Therefore, the burden of coronary atherosclerosis may be closer among younger persons in the 2 countries. We aimed to compare prevalences of coronary atherosclerosis, measured with coronary artery calcium scores, between men in the 2 countries by age group (45-54, 55-64, or 65-74 years). We used community-based samples of Caucasian men in the United States (2000-2002; n = 1,067) and Japanese men in Japan (2006-2008; n = 832) aged 45-74 years, stratifying them into groups with 0, 1, 2, or ≥3 of the following risk factors: current smoking, overweight, diabetes, dyslipidemia, and hypertension. We calculated adjusted odds ratios of US Caucasian men's having Agatston scores of ≥10, ≥100, and ≥400 with reference to Japanese men. Overall, the odds of Caucasian men having each Agatston cutoff point were greater. The ethnic difference, however, became smaller in younger age groups. For example, adjusted odds ratios for Caucasian men's having an Agatston score of ≥100 were 2.05, 2.43, and 3.86 among those aged 45-54, 55-64, and 65-74 years, respectively. Caucasian men in the United States had a higher burden of coronary atherosclerosis than Japanese men, but the ethnic difference was smaller in younger age groups.

A cross-sectional association of obesity with coronary calcium among Japanese, Koreans, Japanese Americans, and U.S. whites

AIMS

Conflicting evidence exists regarding whether obesity is independently associated with coronary artery calcium (CAC), a measure of coronary atherosclerosis. We examined an independent association of obesity with prevalent CAC among samples of multi-ethnic groups whose background populations have varying levels of obesity and coronary heart disease (CHD).

METHODS AND RESULTS

We analysed a population-based sample of 1212 men, aged 40-49 years free of clinical cardiovascular disease recruited in 2002-06; 310 Japanese in Japan (JJ), 294 Koreans in South Korea (KN), 300 Japanese Americans (JA), and 308 Whites in the USA (UW). We defined prevalent CAC as an Agatston score of ≥10. Prevalent CAC was calculated by tertile of the body mass index (BMI) in each ethnic group and was plotted against the corresponding median of tertile BMI. Additionally, logistic regression was conducted to examine whether an association of the BMI was independent of conventional risk factors. The median BMI and crude prevalence of CAC for JJ, KN, JA, and UW were 23.4, 24.4, 27.4, and 27.1 (kg/m2); 12, 11, 32, and 26 (%), respectively. Despite the absolute difference in levels of BMI and CAC across groups, higher BMI was generally associated with higher prevalent CAC in each group. After adjusting for age, smoking, alcohol, hypertension, lipids, and diabetes mellitus, the BMI was positively and independently associated with prevalent CAC in JJ, KN, UW, but not in JA.

CONCLUSION

In this multi-ethnic study, obesity was independently associated with subclinical stage of coronary atherosclerosis among men aged 40-49 years regardless of the BMI level.

Influence of cigarette smoking on coronary artery and aortic calcium among random samples from populations of middle-aged Japanese and Korean men

BACKGROUND

Cigarette smoking is a risk factor of coronary heart disease. Vascular calcification such as coronary artery calcium (CAC) and aortic calcium (AC) is associated with coronary heart disease. The authors hypothesised that cigarette smoking is associated with coronary artery and aortic calcifications in Japanese and Koreans with high smoking prevalence.

METHODS

Random samples from populations of 313 Japanese and 302 Korean men aged 40-49 years were examined for calcification of the coronary artery and aorta using electron beam CT. CAC and AC were quantified using the Agatston score. The authors examined the associations of cigarette smoking with CAC and AC after adjusting for conventional risk factors and alcohol consumption. Current and past smokers were combined and categorised into two groups using median pack-years as a cut-off point in each of Japanese and Koreans. The never-smoker group was used as a reference for the multiple logistic regression analyses.

RESULTS

The ORs of CAC (score ≥10) for smokers with higher pack-years were 2.9 in Japanese (p<0.05) and 1.3 in Koreans (non-significant) compared with never-smokers. The ORs of AC (score ≥100) for smokers with higher pack-years were 10.4 in Japanese (p<0.05) and 3.6 in Koreans (p<0.05).

CONCLUSION

Cigarette smoking with higher pack-years is significantly associated with CAC and AC in Japanese men, while cigarette smoking with higher pack-years is significantly associated with AC but not significantly with CAC in Korean men.

Coronary artery calcification by computed tomography in epidemiologic research and cardiovascular disease prevention

Both American and European guidelines recommend coronary artery calcification (CAC) as a tool for screening asymptomatic individuals at intermediate risk for coronary heart disease (CHD). These recommendations are based on epidemiologic studies mostly in the United States. We review (1) the use of CAC in primary prevention of CHD in the United States, (2) epidemiologic studies of CAC in asymptomatic adults outside of the United States, and (3) international epidemiologic studies of CAC. This review will not consider clinical studies of CAC among patients or symptomatic individuals. US studies have shown that CAC is a strong independent predictor of CHD in both sexes among middle-aged and old age groups, various ethnic groups, and individuals with and without diabetes and that CAC plays an important role in reclassifying individuals from intermediate to high risk. Studies in Europe support these conclusions. The Electron-Beam Tomography, Risk Factor Assessment Among Japanese and US Men in the Post-World-War-II birth cohort (ERA JUMP) Study is the first international study to compare subclinical atherosclerosis, including CAC among Japanese, Japanese Americans, Koreans, and whites. It showed that as compared with whites, Japanese had lower levels of atherosclerosis, whereas Japanese Americans had similar or higher levels. CAC is being increasingly used as a screening tool for asymptomatic individuals in Europe and the United States. CAC is a powerful research tool, because it enables us to describe differences in atherosclerotic burden across populations. Such research could identify factors responsible for differences among populations, which may improve CHD prevention.

Alcohol consumption and aortic arch calcification in an older Chinese sample: the Guangzhou Biobank Cohort Study

OBJECTIVE

To examine the association between alcohol consumption and aortic arch calcification (AAC) in an older Chinese sample.

METHODS

In 27,844 older people aged 50-85, socioeconomic position and lifestyle factors were assessed by a questionnaire. The presence and severity of AAC were diagnosed from chest X-ray by two experienced radiologists.

RESULTS

In men, the risk for AAC increased significantly in frequent or excessive drinkers [adjusted odds ratio (OR)=1.36 (95% confidence interval (CI) 1.16-1.59) and 1.49 (1.21-1.83) for those who drank >5 times/week and those who drank excessively, respectively] (P for trend from 0.002 to 0.001). When AAC was analyzed as an outcome variable with 3 categories of severity, significant dose-response relations between the severity of AAC and alcohol consumption were observed, with those who drank frequently (>5/week) or excessively having more serious AAC (P for trend=0.03 and 0.02, respectively). No significant association was found in women as few drank excessively.

CONCLUSION

The presence and severity of AAC were associated with quantity or frequency of alcohol consumption in a dose-response pattern, suggesting that alcohol drinking, even when moderate, has no benefit for AAC. Excessive drinking increased the risk of AAC by 50% compared to never drinkers.

Life stress and atherosclerosis: a pathway through unhealthy lifestyle

OBJECTIVE

To examine the relationship between a general measure of chronic life stress and atherosclerosis among middle aged adults without clinical cardiovascular disease via pathways through unhealthy lifestyle characteristics.

METHODS

We conducted an analysis of The Multi-Ethnic Study of Atherosclerosis (MESA). The MESA collected in 2000 includes 5,773 participants, aged 45-84. We computed standard regression techniques to examine the relationship between life stress and atherosclerosis as well as path analysis with hypothesized paths from stress to atherosclerosis through unhealthy lifestyle. Our outcome was sub-clinical atherosclerosis measured as presence of coronary artery calcification (CAC).

RESULTS

A logistic regression adjusted for potential confounding variables along with the unhealthy lifestyle characteristics of smoking, excessive alcohol use, high caloric intake, sedentary lifestyle, and obesity yielded no significant relationship between chronic life stress (OR 0.93, 95% CI 0.80-1.08) and CAC. However, significant indirect pathways between chronic life stress and CAC through smoking (p = .007), and sedentary lifestyle (p = .03) and caloric intake (.002) through obesity were found.

CONCLUSIONS

These results suggest that life stress is related to atherosclerosis once paths of unhealthy coping behaviors are considered.

Cholesteryl ester transfer protein, coronary calcium, and intima-media thickness of the carotid artery in middle-age Japanese men

The relation between cholesteryl ester transfer protein (CETP) levels and atherosclerosis is controversial. We examined whether the serum CETP levels were associated with subclinical atherosclerosis, independent of its most common gene variant, in a sample of Japanese men. A population-based cross-sectional study of 250 Japanese men aged 40 to 49 years was conducted to assess the intima-media thickness of the carotid artery, coronary artery calcium, serum CETP levels, and the CETP D442G gene variant. Compared with the lowest CETP quartile, the multivariate adjusted odds ratio for coronary artery calcium was 0.77 (95% confidence interval 0.18 to 3.36), 0.96 (95% confidence interval 0.27 to 3.40), and 3.49 (95% confidence interval 1.05 to 11.6) with increasing CETP quartiles. The serum CETP quartiles were also positively associated with the intima-media thickness of the carotid artery (adjusted mean 602, 616, 615, and 646 mum for the lowest to top quartile, respectively). The findings remained unchanged after additional adjustment for the CETP D442G gene variant. No significant difference was found in the prevalence of coronary artery calcium or in the mean intima-media thickness of the carotid artery between participants with and without the CETP D442G gene variant.

Marine-derived n-3 fatty acids and atherosclerosis in Japanese, Japanese-American, and white men: a cross-sectional study

OBJECTIVES

We sought to examine whether marine-derived n-3 fatty acids are associated with less atherosclerosis in Japanese versus white populations in the U.S.

BACKGROUND

Marine-derived n-3 fatty acids at low levels are cardioprotective through their antiarrhythmic effect.

METHODS

A population-based cross-sectional study in 281 Japanese (defined as born and living in Japan), 306 white (defined as white men born and living in the U.S.), and 281 Japanese-American men (defined as Japanese men born and living in the U.S.) ages 40 to 49 years was conducted to assess intima-media thickness (IMT) of the carotid artery, coronary artery calcification (CAC), and serum fatty acids.

RESULTS

Japanese men had the lowest levels of atherosclerosis, whereas whites and Japanese Americans had similar levels. Japanese had 2-fold higher levels of marine-derived n-3 fatty acids than whites and Japanese Americans in the U.S. Japanese had significant and nonsignificant inverse associations of marine-derived n-3 fatty acids with IMT and CAC prevalence, respectively. The significant inverse association with IMT remained after adjusting for traditional cardiovascular risk factors. Neither whites nor Japanese Americans had such associations. Significant differences between Japanese and whites in multivariable-adjusted IMT (mean difference 39 mum, 95% confidence interval [CI]: 21 to 57mum, p < 0.001) and CAC prevalence (mean difference 10.7%, 95% CI: 2.9% to 18.4%, p = 0.007) became nonsignificant after we adjusted further for marine-derived n-3 fatty acids (22 mum, 95% CI: -1 to 46 mum, p = 0.065 and 5.0%, 95% CI: -5.3% to 15.4%, p = 0.341, respectively).

CONCLUSIONS

Very high levels of marine-derived n-3 fatty acids have antiatherogenic properties that are independent of traditional cardiovascular risk factors and may contribute to lower the burden of atherosclerosis in Japanese, a lower burden that is unlikely the result of genetic factors.

The evidence for dietary prevention and treatment of cardiovascular disease

During the past few decades numerous studies have reported the atherogenic potential of saturated fatty acids, trans-fatty acids, and cholesterol, and beneficial effects of fiber, phytostanols/phytosterols, n-3 fatty acids, a Mediterranean diet, and other plant-based approaches. The purpose of this article is to provide a comprehensive and systematic review of the evidence associated with key dietary factors and risk of cardiovascular disease-an umbrella term encompassing diseases that affect the heart and blood vessels, including coronary heart disease, coronary artery disease, dyslipidemia, and hypertension-in conjunction with the work of the American Dietetic Association Evidence Analysis Library review on diet and lipids, updated with new evidence from the past 2 years. The criteria used and results cited provide scientific rationale for food and nutrition professionals and other health professionals for counseling patients. Details of these searches are available within the American Dietetic Association Evidence Analysis Library online (http://adaevidencelibrary.com). Potential mechanisms and needs for future research are summarized for each relevant nutrient, food, or food component.

Coronary artery calcification in Japanese men in Japan and Hawaii

Explanations for the low prevalence of atherosclerosis in Japan versus the United States are often confounded with genetic variation. To help remove such confounding, the authors compared coronary artery calcification (CAC), a marker of subclinical atherosclerosis, between Japanese men in Japan and Japanese men in Hawaii. Findings were based on risk factors and CAC measured from 2001 to 2005 in 311 men in Japan and 300 men in Hawaii. Men were aged 40-50 years and without cardiovascular disease. After age adjustment, there was a threefold excess in the odds of prevalent CAC scores of > or = 10 in Hawaii versus Japan (relative odds = 3.2, 95% confidence interval: 2.1, 4.9). Whereas men in Hawaii had a generally poorer risk factor profile, men in Japan were four times more likely to smoke cigarettes (49.5% vs. 12.7%, p < 0.001). In spite of marked risk factor differences between the samples, none of the risk factors explained the low amounts of CAC in Japan. After risk factor adjustment, the relative odds of CAC scores of > or = 10 in Hawaii versus Japan was 4.0 (95% confidence interval: 2.2, 7.4). Further studies are needed to identify factors that protect against atherosclerosis in Japanese men in Japan.

To drink or not to drink? That is the question

Numerous studies have used a J-shaped or U-shaped curve to describe the relationship between alcohol use and total mortality. The nadir of the curves based on recent meta-analysis suggested optimal benefit at approximately half a drink per day. Fewer than 4 drinks per day in men and fewer than 2 per day in women appeared to confer benefit. Reductions in cardiovascular death and nonfatal myocardial infarction were also associated with light to moderate alcohol intake. Although some studies suggested that wine had an advantage over other types of alcoholic beverages, other studies suggested that the type of drink was not important. Heavy drinking was associated with an increase in mortality, hypertension, alcoholic cardiomyopathy, cancer, and cerebrovascular events, including cerebrovascular hemorrhage. Paradoxically, light-to-moderate alcohol use actually reduced the development of heart failure and did not appear to exacerbate it in most patients who had underlying heart failure. Numerous mechanisms have been proposed to explain the benefit that light-to-moderate alcohol intake has on the heart, including an increase of high-density lipoprotein cholesterol, reduction in plasma viscosity and fibrinogen concentration, increase in fibrinolysis, decrease in platelet aggregation, improvement in endothelial function, reduction of inflammation, and promotion of antioxidant effects. Controversy exists on whether alcohol has a direct cardioprotective effect on ischemic myocardium. Studies from our laboratory do not support the concept that alcohol has a direct cardioprotective effect on ischemic/reperfused myocardium. Perhaps the time has come for a prospectively randomized trial to determine whether 1 drink per day (or perhaps 1 drink every other day) reduces mortality and major cardiovascular events.

Fish consumption and early atherosclerosis in middle-aged men

To investigate the association between fish consumption and early atherosclerosis, we analyzed the relationship between fish consumption and average intima-media thickness (AveIMT) by carotid ultrasound in middle-aged Japanese men. Participants were 250 randomly selected, community-based Japanese men aged 40 to 49 years without a prior history of cardiovascular disease. AveIMT was calculated from the mean of 1-cm lengths of both the right and the left carotid arteries at 8 locations. A lifestyle survey was carried out using a self-administered questionnaire including the frequency of fish intake. There were 147 men in the fewer than 4 times per week fish consumption group and 103 men in the 4 or more times per week group. The mean AveIMT was significantly higher in the low fish consumption group than in the high fish consumption group (0.623+/-0.068 vs 0.605+/-0.065 mm, P=.03). After adjustment for age, waist circumference, pack-years of smoking, alcohol consumption, diabetes, and lipid-lowering medications, the significant difference in the AveIMT between the 2 groups remained. However, after further adjustment for low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, and C-reactive protein in the model, the significant difference disappeared. Fish consumption may be protective against early atherosclerosis in middle-aged men, probably through its beneficial effects on inflammation.

Associations of obesity measures with metabolic risk factors in a community-based population in Japan

BACKGROUND

The association of obesity measures (ie, body mass index (BMI), waist circumference (WC) and waist-to hip ratio (WHR)) with metabolic risk factors in community-based populations has not been well studied.

METHODS AND RESULTS

In the present study 759 men and 1,255 women aged between 30 and 79 years, without histories of stroke or coronary heart diseases, were dichotomized at the medians of BMI-WHR, WC-WHR and BMI-WC. The accumulation of 4 metabolic risk factors (risk _ sum) were examined: high blood pressure (> or =130/85 mmHg or on antihypertensive therapy); high triglycerides (> or =170 mg/dl); low high-density lipoprotein-cholesterol (<40 mg/dl); and impaired glucose tolerance (hemoglobin A1c > or =5.6% or on antidiabetic therapy). BMI and WC correlated well in both men (r=0.871) and women (r=0.874). All 3 obesity measures related with the metabolic risk factors. The area under the receiver-operating characteristic curve for BMI, WC and WHR to predict the risk _ sum > or =2 for men was 0.683, 0.709, and 0.700, respectively, and 0.715, 0.739, and 0.746, respectively, for women.

CONCLUSIONS

BMI may be used instead of WC if the latter is not available. When WC is measured, hip circumference also should be measured because the WHR may be the most valuable measure of obesity.

Regular alcohol consumption improves insulin resistance in healthy Japanese men independent of obesity

BACKGROUND

There is a great deal of controversy surrounding the relationship between alcohol consumption and insulin resistance. This association may be further confounded by the presence of obesity. We aimed to clarify whether regular alcohol consumption improves insulin resistance in healthy Japanese men and whether obesity affects this relationship.

METHODS

We examined 1029 men (ages 24 to 87 y) who had undergone medical checkups. They were divided into non-obese (body mass index (BMI) <25 kg/m(2)) or obese subjects (BMI > or =25 kg/m(2)) and further classified into non-regular drinkers (NRD), moderate drinkers (MD; 1-6 days/week), and daily drinkers (DD; 7 days/week). The homeostasis model assessment of insulin resistance (HOMA-IR) and other cardiac risk factors were compared between the groups.

RESULTS

In both non-obese and obese men, alcohol consumption decreased HOMA-IR in a dose-dependent manner, although HOMA-IR was about 2 times greater in obese men compared to non-obese men in any category (p<0.001). Stepwise logistic regression analysis revealed that alcohol consumption was the independent negative risk factor for HOMA-IR [OR, 0.576 (95% C.I. 0.402-0.824), p=0.003] after adjusting for age, BMI, systolic blood pressure, smoking status, LDL-cholesterol, HDL-cholesterol, and liver dysfunction.

CONCLUSIONS

Regular alcohol consumption improves insulin resistance in healthy Japanese men independent of obesity.