Past history of obesity (overweight by WHO criteria) is associated with an increased risk of nonfatal acute myocardial infarction: a case-control study in Japan

Epicardial Adipose Tissue Thickness and Its Association With the Presence and Severity of Coronary Artery Disease in Clinical Setting: A Cross-Sectional Observational Study

Background

Obesity is an important risk factor for atherosclerotic cardiovascular disease (ASCVD). Estimation of visceral adipose tissue is important and several methods are available as its surrogate. Although correlation of epicardial adipose tissue (EAT) with visceral adipose tissue as estimated by magnetic resonance imaging (MRI) and/or CT is excellent, it is costlier and cumbersome. EAT can be accurately measured by two-dimensional (2D) echocardiography. It tends to be higher in patients with acute coronary syndrome than in subjects without coronary artery disease (CAD) and in those with stable angina. It also carries advantage as index of high cardiometabolic risk as it is a direct measure of visceral fat rather than anthropometric measurements. The present study evaluated the relationship of EAT to the presence and severity of CAD in clinical setting.

Methods

In this prospective, single-center study conducted in the Department of Cardiology, LPS Institute of Cardiology, Kanpur, India, 549 consecutive patients with acute coronary syndrome or chronic stable angina were enrolled. Sensitivity, specificity, and receiver operating characteristic (ROC) curve were estimated to find cut-off value of EAT thickness for diagnosing CAD using coronary angiographic findings as gold standard.

Results

Patients were diagnosed as CAD group (n = 464, 60.30 ± 8.36 years) and non-CAD group (n = 85, 54.42 ± 11.93 years) after assessing coronary angiograms. The EAT was measured at end-systole from the PLAX views of three cardiac cycles on the free wall of the right ventricle. Lesion was significant if > 50% in left main and > 70% in other coronary arteries. The mean EAT thickness in CAD group was 5.10 ± 1.06 and in non-CAD group was 4.36 ± 1.01 which was significant (P = 0.003). Significant correlation was demonstrated between EAT thickness and presence of CAD (P < 0.003). Higher EAT was associated with severe CAD and presence of multivessel disease. By ROC analysis, EAT > 4.65 mm predicated the presence of significant coronary stenosis by 71.6% sensitivity and 73.1% specificity.

Conclusion

EAT thickness measured using transthoracic echocardiography (TTE) significantly correlates with the presence and severity of CAD. It is sensitive, easily available, and cost-effective and assists in the risk stratification and may be an additional marker on classical risk factors for CAD.

Associations between metabolic syndrome and mortality from cardiovascular disease in Japanese general population, findings on overweight and non-overweight individuals. Ibaraki Prefectural Health Study

BACKGROUND

The impact of being overweight, as a component of the metabolic syndrome (MetS), for cardiovascular disease (CVD) mortality was investigated and compared with the predictive value of MetS by 2 different definitions.

METHODS AND RESULTS

A 12-year prospective study of 30,774 Japanese men and 60,383 women aged 40-79 years was conducted. The multivariate hazard ratio (HR; 95% confidence interval) of total CVD mortality for overweight subjects with >or=2 additional risk factors with reference to subjects with 0 of 4 MetS components was 1.83 (1.41-2.38) for men and 1.90 (1.45-2.49) for women, and for non-overweight subjects with >or=2 additional risk factors 1.75 (1.38-2.24) and 1.97 (1.52-2.55), respectively. The proportion of excess CVD deaths in the latter group was 1.5-fold higher than that in the former group. Multivariate HRs of coronary heart disease and total CVD mortality for MetS by the modified criteria of the American Heart Association/National Heart, Lung, and Blood Institute were 1.62 (1.31-2.00) and 1.23 (1.09-1.39), respectively, for men and 1.32 (1.05-1.65) and 1.12 (1.00-1.25), respectively, for women. The respective HRs for MetS by the International Diabetic Federation definition did not reach statistical significance, except for coronary heart disease in men.

CONCLUSIONS

Non-overweight individuals with metabolic risk factors, as well as overweight individuals with such factors, should be targeted to reduce the CVD burden in the general population.

Weight change and incident metabolic syndrome in Iranian men and women; a 3 year follow-up study

Background

Although the association of weight gain and developing metabolic syndrome (MetS) has been reported in the Western and Asian populations, data on the gender-stratified effects of weight change (including weight loss) on incident MetS and its components in the Middle East Caucasians is still scarce.

Methods

A total of 1431 men and 2036 women aged ≥ 20 years with BMI > 18.5 kg/m² were followed over 3 years. Multivariate logistic regression analysis was used to estimate the relative risk (RR) of MetS and its components (the Adult Treatment Panel III definition) associated with gender-stratified quintiles of percent weight change. Subjects with MetS at baseline were excluded for analyzing the RR of MetS.

Results

There was 20.4% (95% CI, 19.6–21.2) age-adjusted incident MetS (18.4% male vs. 23.1% women). In men, mild weight gain (WG) predicted high waist circumference (WC) and high triglyceride; moderate WG predicted MetS (RR 2.5, 95% CI 1.4–4.3), high WC and high blood pressure (BP); large WG predicted MetS (RR 3.2, 95% CI 1.8–5.7) and its components, except for high fasting plasma glucose. In women, mild WG predicted MetS (RR 2.5, 95% CI 1.4–4.3), high WC and high BP; moderate WG predicted Mets (RR 4.6, 95% CI 2.7–8.0), high WC and high triglyceride; large WG predicted MetS (RR 6.6, 95% CI 3.8–11.3) and its components except for low HDL-cholesterol. Mild weight loss had protective effect on high WC in both genders and MetS in men (RR 0.5, 95% CI 0.26–0.97, P = 0.04).

Conclusion

Weight change showed different effects on MetS in men and women. In women, mild WG predicted MetS; however, mild weight loss was protective against MetS in men and high WC in both genders.

Age- and gender-related differences in correlations between abdominal obesity and obesity-related metabolic risk factors in Japanese

BACKGROUND

There have been conflicting data regarding the relationship between obesity and coronary heart disease (CHD) in Japan. Obesity was reported to be a risk factor of CHD in young and middle-aged males, but not in females or older males. The age- and gender-related differences in the correlations between obesity and obesity-related metabolic risk factors might contribute to these conflicting data.

METHODS

Medical check-up data from 1,360 men and 821 women were divided into younger (= or < 51-year-old) and older (> 51-year-old) groups according to the median age and Spearman's correlation coefficients between waist circumference (WC) and obesity-related metabolic risk factors were calculated.

RESULTS

The correlation coefficients between WC and triglyceride and between WC and high-sensitivity C-reactive protein (hs-CRP) were significantly stronger in younger men than in older men. There was no statistically significant difference in correlation coefficients between younger and older women. The correlation coefficients between WC and triglyceride, WC and HDL cholesterol, WC and hs-CRP, WC and gamma glutamyltransferase, and WC and alanine aminotransferase (ALT) were significantly stronger in younger men than in younger women. The correlation coefficient between WC and ALT was significantly stronger in older men than in older women. And the correlations between WC and SBP, WC and DBP, and WC and GGT tended to be stronger in younger men than in older men.

CONCLUSION

The correlations between abdominal obesity and obesity-related metabolic risk factors were stronger in younger men than in older men and women among Japanese.

Comparison of clinical characteristics and arterial remodeling by intravascular ultrasonic imaging in three age groups (< or =55, 56 to 69 and > or =70 years) of Japanese patients with acute myocardial infarction

Recent epidemiologic, pathologic, and intravascular ultrasound (IVUS) studies have shown that there are differences in coronary risk factors or plaque morphology between younger and older patients with acute myocardial infarctions (AMIs). This study examined clinical background and plaque morphology using IVUS in younger and older adults with AMIs in Japan. The study population consisted of 96 patients with AMIs, for whom preinterventional IVUS images were obtained. Patients were classified into 3 groups: a young group (aged < or =55 years), a middle-aged group (aged 56 to 69 years), and an old group (aged > or =70 years). The remodeling index was defined as the ratio of the external elastic membrane area at the culprit lesion to the external elastic membrane area at the proximal reference site. Expansive remodeling was defined as a remodeling index >1.05 and constrictive remodeling as a remodeling index <0.95. The frequency of hypercholesterolemia was significantly different among the 3 age groups. Total cholesterol (p <0.001), low-density lipoprotein cholesterol (p <0.005), and triglyceride (p <0.05) levels and body mass index (p <0.001) in the young group were significantly higher than in the old group. On IVUS images, constrictive remodeling was most common in the young group, whereas expansive remodeling occurred most commonly in the middle-aged and old groups. In conclusion, this study demonstrated that patients with AMIs in the young group had higher levels of hypercholesterolemia, obesity, and constrictive remodeling compared with those in the old group. The differences in arterial remodeling of the culprit lesions between younger and older patients with AMIs may reflect different biologic mechanisms of plaque activation and destabilization.

Echocardiographic epicardial fat thickness and coronary artery disease

BACKGROUND

The association between epicardial fat and coronary artery disease has not been evaluated. The objective of the present study was to evaluate the relationship of echocardiographic epicardial fat to the presence and severity of coronary artery disease in a clinical setting.

METHODS AND RESULTS

Two hundred and three consecutive patients who underwent echocardiography and diagnostic coronary angiography were studied. The epicardial fat thickness on the free wall of the right ventricle was measured at end-diastole from the parasternal long-axis views of 3 cardiac cycles. Coronary angiograms were analyzed for the extent and severity of coronary artery disease using Gensini's score. The patients were divided into 2 groups according to the fourth quartile of epicardial fat thickness (Group I <7.6 mm; Group II > or =7.6 mm). There were no significant differences in the baseline characteristics except for waist circumference (p=0.023). Significant correlations were demonstrated between epicardial fat thickness and age (r=0.332, p<0.001), C-reactive protein (r=0.182, p=0.009), body mass index (r=0.142, p=0.044) and waist circumference (r=0.229, p=0.001). The patients with a higher epicardial fat thickness were associated with a high Gensini's score (p=0.014). Multivariate analysis showed that age (odds ratio (OR) 5.29, p=0.003), epicardial fat thickness (OR 10.53, p=0.004), diabetes (OR 8.06, p=0.006) and smoking (OR 14.65, p=0.015) were independent factors affecting significant coronary artery stenosis.

CONCLUSIONS

Epicardial fat thickness was significantly correlated with the severity of coronary artery disease in patients with known coronary artery disease.

Current Status of the Background of Patients With Coronary Artery Disease in Japan

BACKGROUND

Although the morbidity and mortality of coronary artery disease (CAD) vary widely with race and lifestyle, Japanese CAD patients have been clinically managed according to the guidelines of Western countries. To draft guidelines specifically for Japanese CAD patients, a database that describes how Japanese CAD patients are currently managed and the outcomes of those managements practices is required.

METHODS AND RESULTS

Patients diagnosed as having 75% or higher stenosis according to the American Heart Association classification in at least 1 branch of the coronary arteries by cardiac catheterization were enrolled in the study. Of 15,628 patients screened from April 2000 to March 2001, 13,812 of them met the inclusion criteria and were followed up for a mean period of 2.7 years. The incident rate of events was 62.8 per 1,000 patients-year including all-cause mortality of 17.5 and total cardiac events of 47.4 per 1,000 patients-year which is much higher than previous reports in Japan. The incident rate of acute myocardial infarction in this study cohort was 7.5 events per 1,000 patients-year.

CONCLUSION

The database provides a large body of information on Japanese CAD patients who have significant coronary atherosclerosis diagnosed by coronary angiography, which will be useful for planning future randomized controlled trials.

Relation of Obesity to Acute Myocardial Infarction in Japanese Patients Differences in Gender and Age

BACKGROUND

It remains uncertain whether obesity is an independent risk factor for coronary heart disease in young adults, as well as adults, in Japan.

METHODS AND RESULTS

In the present study, 1,260 cases of acute myocardial infarction (AMI) and 3,775 community controls were recruited from the AMI-Kyoto Multi-Center Risk Study and Kyoto Citizen's Health and Nutrition Study, respectively. Obesity and other risk factors were retrospectively examined between cases and controls in each subgroup of young males (20-40 years), middle-aged males or females (40-60 years), older males or females (60-80 years), and very old males or females (80-100 years). In young, middle-aged, and older males, as well as in older females, cases had a higher body mass index (BMI) than controls. In young males, as well as in middle-aged and older females, cases had a higher prevalence of smoking than controls. Except for very old males, the prevalences of hypercholesterolemia, hypertension, and diabetes mellitus were higher in each subgroup of cases than in controls. Multivariate logistic regression analysis revealed that obesity (BMI >or=25) was an independent risk for AMI in young and middle-aged males, but not in females, whereas smoking was an independent risk for AMI in middle-aged and older females as well as in older males.

CONCLUSIONS

Obesity is significantly associated with AMI, independent of the classic coronary risk factors, in young and middle-aged males. These findings support the current emphasis on controlling obesity to prevent coronary events in young Japanese male adults.

Risk factors and the incidence of coronary artery disease in young middle-aged Japanese men: results from a 10-year cohort study

OBJECTIVE

The objective of this study was to elucidate the relationship between risk factors and the coronary artery disease (CAD) in young middle-aged Japanese men.

METHODS

A cohort study of 2,764 young middle-aged Japanese men aged 3544 (mean+/-SD: 42.3+/-2.5) years based on a 10-year followup to identify the risk factors for the occurrence of CAD was conducted. There were 35 cases of CAD during the follow up; 25 myocardial infarctions and 10 angina pectoris. The Cox Proportional hazard model was used to identify the independent risk factors for CAD. Adjustment was made for variables including age, body mass index, smoking habit, systolic blood pressure, total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), fasting plasma glucose (FPG), and triglyceride.

RESULTS

TC, low HDLC, and FPG were identified as significant independent risk factors for CAD. Adjusted hazard ratio (HR) of a high level of TC> or = 220 (mg/dl) for CAD was 5.46 (95% confidence interval (CI): 1.9617.51) and that of a high level of HDLC<50(mg/dl) was 9.01 (95%CI: 1.1372.17), and a high level of FPG> or = 110 (mg/dl) was 2.94 (95%CI: 1.228.23). Considering the combination of these risk factors, adjusted HR for CAD of the subjects who had 2 risk factors was 8.37 (95%CI: 2.2131.65).

CONCLUSIONS

Using the database of young middle-aged Japanese men, TC, low HDLC, and FPG were found to be important risk factors for CAD, and the combination of these risk factors was associated with CAD.

Characteristics of Metabolic and Lifestyle Risk Factors in Young Japanese Patients With Coronary Heart Disease A Comparison With Older Patients

Coronary heart disease (CHD) is recognized as a lifestyle-related disease and is the second leading cause of death in Japan. However, the cardiac risk factor profile of young patients with CHD has not been clarified in suburban areas of Japan. Our study aimed to determine metabolic and lifestyle risk factors in young patients and compare them with older patients living in suburban areas of Nagano Prefecture. A multicenter study was conducted in 86 young (aged less than 40 years) and 91 older (aged 50 years and over) patients diagnosed with CHD from 1992 to 2002. There was a strong association between obesity and the occurrence of CHD events in young patients (odds ratio = 3.61, P = 0.006). Lifestyle in the young patients was characterized by a lack of physical activity and regular physical activity was found to decrease the risk of the CHD events in these patients (odds ratio = 0.31, P = 0.030). In older patients, hypertension was identified as an independent risk factor for CHD events. The results of the present study have demonstrated that obesity and a lack of regular physical exercise are independent risk factors for CHD events in younger patients. Thus, the data may be useful for the effective screening of high-risk individuals and the development of educational programs for the prevention of CHD, especially in younger Japanese.

Leg fat percentage correlates negatively with coronary atherosclerosis

BACKGROUND

Visceral fat is related to coronary atherosclerosis, but little is known about the relation between coronary atherosclerosis and percent body fat accumulated in different parts of the body.

METHODS AND RESULTS

The subjects were 100 consecutive patients with demonstrated electrocardiographic ischemic changes. Coronary atherosclerosis was assessed using Gensini's coronary score (CS), and for body fat distribution dual energy X-ray absorptiometry was used. The parameters measured were serum lipid concentrations, body weight, body mass index, percent total fat, trunk fat percent, arm fat percent and leg fat percent. Trunk fat percent correlated significantly with CS (p<0.01), and concentrations of low-density lipoprotein cholesterol (LDL-C) (p<0.01) and very low-density lipoprotein cholesterol (VLDL-C) (p<0.05) in men and women. Leg fat percent correlated negatively with CS in both men and women (p<0.01 for each). Concentrations of both LDL-C and VLDL-C correlated positively with CS in both men and women (p<0.01).

CONCLUSION

There is a difference between the effect of body fat in the legs and the trunk that suggests leg fat has an anti-atherosclerotic effect and a negative correlation with CS, and conversely, that trunk fat has a pro-atherosclerotic effect and correlates positively with CS.

Predictive factors in the success of intervention to treat obesity in elementary school children

BACKGROUND

Currently, a generalizable conclusion on the effectiveness of treatment programs for childhood obesity cannot be drawn, and how practical and effective the intervention strategies are remains a controversial subject.

METHODS AND RESULTS

In the present study 36 obese elementary school children who visited an intervention program at least 4 times were followed for 12 months or more. A stepwise regression analysis was performed using the decrease in the percent relative body weight (%RBW) at 12 months after the first visit as a dependent variable, and the decrease in the %RBW and nutritional data between 2 successive visits as independent variables. The analysis revealed 4 significant predictive factors: (1) a higher ratio of energy intake from protein (20%) recommended at the first visit, (2) a greater decrease in the %RBW between the first and second visits, (3) higher age, and (4) a higher concentration of alanine aminotransferase at the first visit.

CONCLUSION

Providing a strong motivation to change eating and activity behavior at the early stage of intervention and recommending diets with higher ratios of energy intake from protein are the most practical and effective strategies for treating obesity.

Long-Term Body Weight Fluctuation is Associated With Metabolic Syndrome Independent of Current Body Mass Index Among Japanese Men

BACKGROUND

The relation between weight fluctuation and the risk of cardiovascular disease (CVD) is fairly consistent, although the physiologic basis for the relationship is uncertain. In the present study the association between long-term weight fluctuation and the development of metabolic syndrome (MS), a potent CVD risk factor, was investigated.

METHODS AND RESULTS

A cross-sectional study of 664 Japanese men aged 40-49 years was conducted. The root mean square error around the slope of weight on age (weight - RMSE) was calculated by a simple linear regression model, in which the subject's actual weights at ages 20, 25, 30 years and 5 years prior to the study, as well as current weight, were dependent variables against the subject's age as the independent variable. Weight-RMSE was significantly and positively associated with the prevalence of each MS components (high blood pressure, hypertriglyceridemia, low-high density lipoprotein-cholesterol, high fasting glucose, and obesity). Such associations, as well as clustering of the MS component together with RMSE increase, were apparent among subjects with body mass index (BMI) <25 kg/m2, although the prevalence of MS or its components was much higher among overweight subjects (BMI >or=25 kg/m2).

CONCLUSIONS

Development of MS possibly explains the risk of CVD not only in overweight or obese persons, but also in normal-weight persons with large weight fluctuation.

In Normoglycemic Koreans, Insulin Resistance and Adipocity are Independently Correlated With High Blood Pressure

BACKGROUND

There is some controversy about the role of insulin resistance (IR) in the regulation of blood pressure (BP). Moreover, a large study of the association between BP and IR has not been conducted in normal glucose tolerance Asians. The present study investigated the relationships between IR, body mass index (BMI) and waist circumference and BP in normoglycemic Koreans.

METHODS AND RESULTS

Anthropometric indices of adiposity, metabolic variables (fasting serum insulin and a homeostasis model assessment (HOMA) index of insulin sensitivity), BP and several cardiovascular risk factors were measured during a cross-sectional survey of 49,076 normoglycemic Korean subjects. A high BP was defined as a systolic BP >/=140 mmHg or a diastolic BP >/=90 mmHg. The prevalence of high BP by HOMA grading was 0.985 (95% confidence interval (CI) 0.857-1.132, p=0.835), 1.180 (95% CI 1.032-1.350, p=0.016), 1.289 (95% CI 1.129-1.472, p<0.001), and 1.540 (95% CI 1.341-1.768, p<0.001) times higher in subjects in the second, third, fourth, and fifth quintiles, respectively, compared with those in the first quintile. In addition, age, sex, waist circumference and BMI were found to be significantly associated with a high BP.

CONCLUSION

IR, BMI and waist circumference are independently correlated with high BP in normoglycemic Koreans.