The Association of Subclinical Coronary Atherosclerosis With Abdominal and Total Obesity in Asymptomatic Men

Effect of eplerenone in patients with heart failure and reduced ejection fraction: potential effect modification by abdominal obesity. Insight from the EMPHASIS-HF trial

AIMS

An excessive production of aldosterone influences outcome in patients with heart failure (HF) and in obese patients. Findings from laboratory studies suggest that chronic aldosterone blockade maybe more beneficial in abdominally obese HF-prone rats. In the current study, we investigated if the clinical response to a mineralocorticoid receptor antagonist in mildly symptomatic HF patients varied by abdominal obesity.

METHODS AND RESULTS

A total of 2587 NYHA class II, reduced ejection fraction HF (HFrEF) patients enrolled in the EMPHASIS-HF trial were randomly assigned to eplerenone and placebo. In this post hoc analysis, patients were categorized according to waist circumference (WC) (normal if WC < 102 cm in men and < 88 cm in women; abdominal obesity if WC ≥ 102 cm in men and ≥ 88 cm women). The potential statistical interaction between the treatment and WC was assessed on the primary endpoint of death from cardiovascular causes or hospitalization for HF and other secondary endpoints. Over a median follow-up of 21 months, a significant benefit of eplerenone for the primary outcome was noted in both normal [hazard ratio (HR) 0.77, 95% confidence interval (CI) 0.61-0.98, P = 0.03] and increased (HR 0.48, 95% CI 0.37-0.63, P < 0.0001) WC subgroups, but the latter patients appeared to receive greater benefit than patients with normal WC (P for interaction = 0.01). This suggests a significant quantitative (treatment effect varies in magnitude by subgroup, but is always in same direction) rather than a qualitative interaction (direction of the treatment effect varies by subgroup) between eplerenone and WC in the adjusted analysis. Mean doses of eplerenone, blood pressure and serum potassium changes and adverse events were similar between WC subgroups.

CONCLUSION

In EMPHASIS-HF, eplerenone improved outcomes in HFrEF patients with and without abdominal obesity, although the benefit appeared to be more pronounced among those with abdominal obesity. The findings are potentially hypothesis generating and need to be replicated in other HFrEF populations.

Meta-analysis of the relation of body mass index to all-cause and cardiovascular mortality and hospitalization in patients with chronic heart failure

Clinical studies have indicated the existence of an "obesity paradox" in patients with chronic heart failure (HF), that is, reduced mortality in patients who have elevated body mass index (BMI) scores compared with normal-weight reference groups. The aim of this study was to investigate the relation of BMI with all-cause and cardiovascular (CV) mortality and hospitalization in patients with chronic HF though a systematic review and meta-analysis of published research. PubMed, the Cumulative Index to Nursing and Allied Health Literature, Cochrane Central, Scopus, web of science and Embase were searched for studies reporting rates of total mortality, cardiac mortality, and risk for hospitalization in patients with HF in various BMI categories (<20 kg/m(2) [low], 20 to 24.9 kg/m(2) [normal reference], 25 to 29.9 kg/m(2) [overweight], 30 to 34.9 [obese], and ≥35 kg/m(2) [severely obese]). Event rates were compared using a forest plot of relative risk (RR) using a random-effects model assuming interstudy heterogeneity. Two study investigators independently reviewed the 124 reports retrieved and identified 6 for final analyses (n = 22,807). After a mean follow-up period of 2.85 years, the risk for adverse events was highest in patients with low BMIs: total mortality RR 1.27 (95% confidence interval [CI] 1.17 to 1.37), CV mortality RR 1.20 (95% CI 1.01 to 1.43), and hospitalization RR 1.19 (95% CI 1.09 to 1.30). Risk for CV mortality and hospitalization was lowest in overweight patients (RR 0.79, 95% CI 0.70 to 0.90, and RR 0.92, 95% CI 0.86 to 0.97, respectively). Increasing degree of obesity failed to achieve a statistically significant effect on CV mortality (RR 0.82, 95% CI 0.64 to 1.05, and RR 0.71, 95% CI 0.50 to 1.01, for obese and severely obese, respectively) and on hospitalization (RR 0.99, 95% CI 0.92 to 1.07, and RR 1.28, 95% CI 0.88 to 1.87, for obese and severely obese, respectively). In conclusion, risk for total mortality and CV mortality and hospitalization was highest in patients with chronic HF who were underweight as defined by low BMI, whereas risk for CV mortality and hospitalization was lowest in overweight subjects.

Relationship of body mass index with total mortality, cardiovascular mortality, and myocardial infarction after coronary revascularization: evidence from a meta-analysis

OBJECTIVE

To investigate the relationship of body mass index (BMI) with total mortality, cardiovascular (CV) mortality, and myocardial infarction (MI) after coronary revascularization procedures (coronary artery bypass grafting [CABG] and percutaneous coronary intervention [PCI]).

PATIENTS AND METHODS

Systematic search of studies was conducted using PubMed, CINAHL, Cochran CENTRAL, Scopus, and the Web of Science databases. We identified studies reporting the rate of MI, CV mortality, and total mortality among coronary artery disease patients' postcoronary revascularization procedures in various BMI categories: less than 20 (underweight), 20-24.9 (normal reference), 25-29.9 (overweight), 30-34.9 (obese), and 35 or more (severely obese). Event rates were compared using a random effects model assuming interstudy heterogeneity.

RESULTS

A total of 36 studies (12 CABG; 26 PCI) were selected for final analyses. The risk of total mortality (relative risk [RR], 2.59; 95% CI, 2.09-3.21), CV mortality (RR, 2.67; 95% CI, 1.63-4.39), and MI (RR, 1.79; 95% CI, 1.28-2.50) was highest among patients with low BMI at the end of a mean follow-up period of 1.7 years. The risk of CV mortality was lowest among overweight patients (RR, 0.81; 95% CI, 0.68-0.95). Increasing degree of adiposity as assessed by BMI had a neutral effect on the risk of MI for overweight (RR, 0.92; 95% CI, 0.84-1.01), obese (RR, 0.99; 95% CI, 0.85-1.15), and severely obese (RR, 0.93; 95% CI, 0.78-1.11) patients.

CONCLUSION

After coronary artery disease revascularization procedures (PCI and CABG), the risk of total mortality, CV mortality, and MI was highest among underweight patients as defined by low BMI and CV mortality was lowest among overweight patients.

Abdominal obesity is associated with heart disease in dogs

BACKGROUND

The relationship between overall obesity and fat distribution in dogs and the development of heart disease is unclear. In the present study we evaluated the association between overall obesity and fat distribution and clinical heart disease by morphometric and computed tomography (CT)-based measurements. Body condition score (BCS), modified body mass index (MBMI, kg/m2), waist-to-hock-to-stifle distance ratio (WHSDR), waist-to-ilium wing distance ratio (WIWDR), and waist-to-truncal length ratio (WTLR) were compared between dogs with (n = 44) and without (n = 43) heart disease using receiver operating characteristic (ROC) analysis. Intra-abdominal fat (IAF) and subcutaneous fat (SQF) were measured in dogs with (n = 8) and without (n = 9) heart disease at the center of the fourth and fifth lumbar vertebrae by CT.

RESULTS

BCS was similar between heart disease and healthy groups (3.6 ± 0.2 vs. 3.3 ± 0.1, P = 0.126). The following morphometric measurements were greater in the heart disease group compared with healthy canines: MBMI (65.0 ± 4.5 vs. 52.5 ± 3.7 kg/m2, respectively, P = 0.035); WIWDR (4.1 ± 0.1 vs. 3.1 ± 0.1, P < 0.01); and WTLR (1.25 ± 0.04 vs. 1.05 ± 0.04, P < 0.01). However, there was no significant difference in WHSDR (3.6 ± 0.1 vs. 3.7 ± 0.2, P = 0.875). Interestingly, IAF was significantly increased in dogs with heart disease compared with healthy dogs (23.5 ± 1.5% vs. 19.4 ± 1.2%, P = 0.039) whereas SQF was similar between two groups (35.5 ± 2.7% vs. 38.6 ± 3.5%, P = 0.496). Of the five morphometric indices studied, WIWDR and WTLR provided acceptable discrimination for diagnosing heart disease in dogs, with areas under the ROC curve of 0.778 (95% confidence interval [CI]:0.683-0.874) and 0.727 (95% CI:0.619-0.835), respectively.

CONCLUSIONS

Our data indicate that abdominal obesity, rather than overall obesity, is associated with heart disease in dogs. Measurements of both WIWDR and WTLR are particular useful for detection of an abdominal obesity in dogs.

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.

Association between obesity, high-sensitivity C-reactive protein ≥2 mg/L, and subclinical atherosclerosis: implications of JUPITER from the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

High-sensitivity C-reactive protein (hsCRP) levels are closely associated with abdominal obesity, metabolic syndrome, and atherosclerotic cardiovascular disease. The Justification for the Use of Statins in Primary Prevention: An Intervention Trial Evaluating Rosuvastatin (JUPITER) trial has encouraged using hsCRP ≥2 mg/L to guide statin therapy; however, the association of hsCRP and atherosclerosis, independent of obesity, remains unknown.

METHODS AND RESULTS

We studied 6760 participants from the Multi-Ethnic Study of Atherosclerosis (MESA). Participants were stratified into 4 groups: nonobese/low hsCRP, nonobese/high hsCRP, obese/low hsCRP, and obese/high hsCRP. Using multivariable logistic and robust linear regression, we described the association with subclinical atherosclerosis, using coronary artery calcium (CAC) and carotid intima-media thickness (cIMT). Mean body mass index was 28.3±5.5 kg/m(2), and median hsCRP was 1.9 mg/L (0.84 to 4.26). High hsCRP, in the absence of obesity, was not associated with CAC and was mildly associated with cIMT. Obesity was strongly associated with CAC and cIMT independently of hsCRP. When obesity and high hsCRP were both present, there was no evidence of multiplicative interaction. Similar associations were seen among 2083 JUPITER-eligible individuals.

CONCLUSION

High hsCRP, as defined by JUPITER, was not associated with CAC and was mildly associated with cIMT in the absence of obesity. In contrast, obesity was associated with both measures of subclinical atherosclerosis independently of hsCRP status.

A prospective study of abdominal obesity and coronary artery calcium progression in older adults

OBJECTIVE

Little is known about obesity measurements and coronary artery calcium (CAC) progression in older adults. We examined the sex-specific association between measures of body size and fat distribution with CAC progression.

SUBJECTS AND METHODS

Participants were 156 men and 182 women (mean age 67 yr) without known heart disease who had electron-beam computed tomography for CAC at baseline and again 4.5 yr later. Obesity assessments were weight, height, body mass index, waist and hip circumference, waist to hip ratio, waist to height ratio, sc and visceral adipose tissue (SAT, VAT), and SAT to VAT ratio based on abdominal electron-beam computed tomography. CAC progression was defined as categorical (square root increased on total CAC volume score > or = 2.5 mm(3)) and continuous variables.

RESULTS

During the follow-up, 55% of men and 38.5% of women had CAC progression. Increased waist to hip ratio (> or = 0.9 for men, > or = 0.85 for women) and waist to height ratio (> or = 0.55 for men, > or = 0.54 for women) were positively and independently associated with CAC progression [median (interquartile range)] [60.8 (145) vs. 10.8 (56) mm(3), P = 0.002 and 50 (153) vs. 22(84) mm(3), P = 0.03, respectively]. In women but not men, an increased waist circumference (> 88 cm) independently predicted CAC progression (odds ratio 3.0 95% confidence interval 1.03-8.0, P = 0.04), whereas VAT to SAT ratio predicted CAC progression in men but not women (odds ratio 2.8 95% confidence interval 1.01-7.8, P = 0.04).

CONCLUSION

In this study of older adults without known heart disease, abdominal obesity was an independent predictor of CAC progression. These results point to the importance of using clinical measurements of abdominal obesity to identify individuals at increased risk for atherosclerosis.

Mitochondrial dysfunction in atherosclerosis

Increased production of reactive oxygen species in mitochondria, accumulation of mitochondrial DNA damage, and progressive respiratory chain dysfunction are associated with atherosclerosis or cardiomyopathy in human investigations and animal models of oxidative stress. Moreover, major precursors of atherosclerosis-hypercholesterolemia, hyperglycemia, hypertriglyceridemia, and even the process of aging-all induce mitochondrial dysfunction. Chronic overproduction of mitochondrial reactive oxygen species leads to destruction of pancreatic beta-cells, increased oxidation of low-density lipoprotein and dysfunction of endothelial cells-factors that promote atherosclerosis. An additional mechanism by which impaired mitochondrial integrity predisposes to clinical manifestations of vascular diseases relates to vascular cell growth. Mitochondrial function is required for normal vascular cell growth and function. Mitochondrial dysfunction can result in apoptosis, favoring plaque rupture. Subclinical episodes of plaque rupture accelerate the progression of hemodynamically significant atherosclerotic lesions. Flow-limiting plaque rupture can result in myocardial infarction, stroke, and ischemic/reperfusion damage. Much of what is known on reactive oxygen species generation and modulation comes from studies in cultured cells and animal models. In this review, we have focused on linking this large body of literature to the clinical syndromes that predispose humans to atherosclerosis and its complications.

Associations between aortic calcification and components of body composition in elderly men

OBJECTIVE

To investigate associations among body composition, cardiovascular risk factors, and atherosclerosis in middle-aged and elderly men for the identification of potential pathogenic links.

RESEARCH METHODS AND PROCEDURES

The study included 168 white men 44 to 86 years old. Severity of aortic calcification (AC) was graded on lateral radiographs, and body fat and lean mass were measured by DXA. Information on demographic and lifestyle characteristics also was gathered.

RESULTS

A strong and independent inverse association was found between AC and peripheral lean mass (PLM), even after adjusting for age and BMI (p < 0.05). Independently of the influence of PLM, AC was directly correlated with truncal fat mass (p < 0.05). Furthermore, AC was inversely associated with tertiles of the free androgen index (p < 0.05). In a multiple regression model, age and serum cholesterol (p < 0.01) contributed directly, and truncal fat mass tended also to contribute directly (p = 0.09), whereas PLM contributed borderline inversely (p = 0.06) to the variation of AC (R = 0.635, p < 0.0001).

DISCUSSION

Severity of AC is strongly dependent on age and further modulated by an array of traditional cardiovascular risk factors. Sarcopenia and truncal fat mass are reciprocal correlates of atherosclerosis of borderline statistical significance in multivariate models. To clarify whether sarcopenia is an atherogenic risk factor or rather a parallel consequence of low-grade inflammation also promoting atherogenic trends, further longitudinal studies in larger sample sizes of men and women are needed.