The Heart Failure Overweight/Obesity Survival Paradox: The Missing Sex Link

Is There a Sex-Related Difference in the Obesity Paradox in Systolic Heart Failure? Sex-Related Difference in the Obesity Paradox

PURPOSE

Obesity is often associated with better clinical outcomes in heart failure (HF). This so-called obesity paradox remains controversial. The aim of present study was to investigate the prognostic value of obesity in patients hospitalized for systolic HF.

MATERIALS AND METHODS

We performed a pooled analysis of data from two multicenter, observational HF studies. Patients hospitalized for systolic HF were eligible for the present study. We divided the subjects into two groups, a normal body mass index (BMI) group and a high BMI group. Study endpoints included all-cause mortality and any re-hospitalization within 1 year.

RESULTS

We enrolled 3145 patients (male, 1824; female, 1321). The high BMI group was significantly associated with lower 1-year mortality rate [odds ratio (OR), 0.543; 95% confidence interval (CI), 0.355-0.832] after adjusting for age, hypertension, diabetes, ischemic HF, previous myocardial infarction, serum creatinine level, anemia, and ejection fraction in men. After adjustment for clinical characteristics, high BMI was not significantly associated with 1-year mortality (OR, 0.739; 95% CI, 0.450-1.216) or 1-year re-hospitalization (OR, 0.958; 95% CI, 0.696-1.319) in women.

CONCLUSION

In pooled analysis of data from two Korean HF registries, the high BMI group was independently associated with lower 1-year mortality rate from systolic HF, especially in men.

Obesity paradox in patients undergoing coronary intervention: A review

There is strong relationship between obesity and cardiovascular disease including coronary artery disease (CAD). However, the literature has shown better outcomes in higher obese patients who undergo percutaneous cardiovascular interventions for CAD, a phenomenon known as the obesity paradox (OX). In this review, we performed extensive search for OX in patients undergoing percutaneous coronary intervention. We also discussed possible mechanism OX and disparities in different race and sex.

Management of cardiovascular diseases in patients with obesity

The management of cardiovascular diseases (CVD) in patients with obesity presents numerous challenges. Obesity has a negative effect on almost all of the major CVD risk factors, and adversely influences cardiovascular structure and function. Patients who are overweight or obese have a higher incidence of almost all CVDs compared with patients who are of normal weight. However, those who are overweight or obese seem to have a better short-term and medium-term prognosis after major CVD events and interventional procedures or cardiac surgeries than leaner patients, a phenomenon termed the 'obesity paradox'. In considering the mechanisms underlying this paradox, we review evidence of the deleterious consequences of obesity in patients with coronary heart disease, and the limited data on the benefits of weight loss in patients with CVD. Additional studies are needed on the efficacy of purposeful weight loss on cardiovascular outcomes to determine the ideal body composition for patients with CVD.

Effect of bariatric surgery on heart failure

INTRODUCTION

Obesity increases the risk of heart failure (HF), which continues to be a significant proportion of all cardiovascular diseases and affects increasingly younger populations. The cross-talk between adipose and the heart involves insulin resistance, adipokine signaling and inflammation, with the capacity of adipose tissue to mediate hemodynamic signals, promoting progressive cardiomyopathy. Areas covered: From a therapeutic perspective, there is not yet a single obesity-related pathway that when addressed, can ameliorate cardiomyopathy in obese patients and this is a matter of ongoing research. There is poor evidence of the beneficial long-term effect of small nonsurgical intentional weight loss on HF outcomes, in contrast to the field of HF accompanying severe obesity where observational studies have shown that bariatric surgery is associated with improved cardiac structure/function in severely obese patients with HF and preserved ejection fraction (HFpEF) as well as with improved cardiac structure/function in those with HF and reduced ejection fraction (HFrEF). Few studies report positive outcomes in subjects with obesity and HF, both severe, who underwent bariatric surgery as a rescue treatment, including bridge to heart transplantation. Expert commentary: The fast growing prevalence of obesity will continue to require the development of appropriate interventions directed at controlling or slowing pathways of cardiac damage in these patients, but at present, bariatric surgery should be considered an option to try to decrease morbidity associated with HF in severely obese adults.

Obesity paradox in heart failure patients - Female gender characteristics-KAMC-single center experience

Background/Introduction

The correlation between low body mass index (BMI) and congestive heart failure (obesity paradox) has been described in the literature; However, the association between BMI and clinical outcome measures is not well characterized. Little is known about CHF in the Middle Eastern female population; most of the gender-specific information on heart failure comes from higher income “Western” countries.

Objectives

We aimed to identify the correlation between heart failure patients especially those with low BMI and clinical/safety outcome measures with focusing on female patients subgroup characteristics.

Methods

We performed group comparisons of statistically relevant variables using prospectively collected data of HFrEF patients hospitalized over a 12 month period.

Results

The 167 patients (Group I) enrolled by this study with mean age of 59.64 ± 12.9 years, an EF score of 23.96 ± 10.14, 62.9% had ischemic etiology, 12.5% were smoker, 18% had AF, 31.1% had received ICD/CRT-D and an estimated 8.85 ± 9.5 days length of stay (LOS). The low BMI group of patients (Group II) had means age of 58.7 ± 14.5 years, a significant lower EF score of 20.32 ± 8.58, significantly higher 30, 90 days readmission rates and in-house mortality (22%, 36.6% and 17.1% vs 10.2%, 20.4% and 6.6% respectively) and higher rates of CVA, TIA and unexplained syncope (19.5% vs 7.2%). Similarly, female patients with low BMI (Group IV) had lower EF score of 22.0 ± 53, higher 30,90 days readmission rates and in-house mortality (34.4%,43.8% and 25% vs 13.5%,21.6% and 5.4% respectively) and higher rates of CVA, TIA and unexplained syncope(10% vs 0%).

Conclusion

Our findings showed that heart failure patients with low BMI had poor adverse clinical outcome measures (poor EF, recurrent readmission, mortality and composite rates of CVA, TIA and unexplained syncope) which reflect the effect of obesity paradox in those patients with HFrEF. Female patient subgroup showed similar characteristic findings which also might reflect the value of gender-specific BMI related clinical outcomes.

A U-shaped association of body mass index and all-cause mortality in heart failure patients: A dose-response meta-analysis of prospective cohort studies

BACKGROUND AND AIMS

The role of body mass index (BMI) for the prognosis of heart failure (HF) patients remains to be a great interest for a long time. However, the precise effect of dose-response for BMI and mortality risk in patients with HF is still unclear. We conducted a dose-response meta-analysis to quantitatively assess the effect of BMI on all-cause mortality in subjects with HF.

METHODS

Fourteen prospective cohort studies included 13 508 death cases identified among 46 794 patients with HF.

RESULTS

The summary HR per 5 units increase in BMI was 0.95 (95% CI=0.92-0.97) with evidence of high heterogeneity (I² =90.10%, P_{heterogeneity} <.00001), and an U-shaped nonlinear relationship of BMI and risk of mortality from all-causes was revealed (P_nonlinearity =.0025). When stratified analyses were conducted, the heterogeneity in patients with HF aged more than 60 years decreased.

CONCLUSION

Heart failure patients with higher BMI (>28 kg/m² ) have a better survival, whereas underweight and those with severe obesity (eg, BMI>37 kg/m² ) have a higher mortality.

The obesity paradox: is it really a paradox? Hypertension

This article is a narrative overview of the role of hypertension on the relationships between obesity, morbidity, and mortality. We used as sources MEDLINE/PubMed, CINAHL, EMBASE, and Cochrane Library, from inception to March 2016. Key words include overweight, obesity, visceral obesity, obesity paradox, and hypertension. In addition, we hand-searched references from the retrieved articles. This work is one of the works of the topical collection "Obesity Paradox". The positive association between overweight, obesity, and cardiovascular diseases is well established, though this relation is typically U shaped with an increased risk in low-weight subjects or even a beneficial effect of overweight and obesity, the so-called "obesity paradox". In addition, the relationship between obesity and arterial hypertension has been demonstrated in both children and adults by many epidemiological studies. Moreover, weight reduction is followed by a decrease in blood pressure in many patients and ameliorates the cardiovascular risk profile. Recent studies using more appropriate obesity indices raise some doubt about the real significance of obesity paradox and there are several studies that central obesity shows either no protective or even a worse effect. These observations raise the question: what kind of obesity is protective and what kind of obesity is harmful? The studies of obesity paradox suffer from several methodological limitations: most of these are retrospective analyses or were not specifically designed to study obesity paradox as a primary goal; a few studies have data on preceding unintentional weight loss and on some particular confounding variables. In conclusion, more prospective and accurate studies are necessary to better elucidate the clinical importance of obesity paradox. When weight loss is functional to reduce hypertension and cardiovascular risk, it should be encouraged, while an unintentional weight in a patient with chronic diseases may indicate an unfavorable course.

BMI is inversely correlated to the risk of mortality in patients with type 2 diabetes hospitalized for acute heart failure: Findings from the Gulf aCute heArt failuRE (Gulf-CARE) registry

BACKGROUND

A U-shaped relationship has been reported between BMI and cardiovascular events among patients with acute heart failure (AHF). We hypothesized that an obesity paradox also governs the relationship between BMI and mortality in patients with type 2 diabetes (T2D) and AHF.

METHODS

We studied 3-month and 12-month mortality in patients with T2D hospitalized for AHF according to 5 BMI categories: Underweight (<20kg/m²), normal weight (referent group, 20-24.9kg/m²), overweight, (25-29.9kg/m²), obese (30-34.9kg/m²) and severely obese (≥35kg/m²), in the Gulf aCute heArt failuRe rEgistry (GULF-CARE).

RESULTS

Among the 5005 participants in this cohort, 2492 (49.8%) had T2D. Underweight patients had a higher 3-month and 12-month mortality risk (OR 2.04, 95% CI [1.02-4.08]; OR 2.44, 95% CI [1.35-4.3]; respectively), compared to normal weight. Severe obesity was associated with a lower 3-month and 12-month mortality risk (OR 0.53, 95% CI [0.34-0.83]; OR 0.58, 95% CI [0.42-0.81]; respectively). After adjustment for several risk variables in 2 different models, the primary outcome was still significantly increased in underweight patients, and decreased in severely obese patients, at 3months and 12months. Further, the odds of mortality decreases with increasing BMI by 0.38 at 3months and at 0.45 at 12months in a near-linear shape (p=0.007; p=0.037; respectively).

CONCLUSIONS

In this cohort of patients with AHF, BMI was inversely correlated to the risk of mortality in patients with T2D. Moreover, severe obesity was associated with less mortality risk.

Obesity and Heart Failure: Focus on the Obesity Paradox

The escalating prevalence of obesity has been linked to substantial increases in both metabolic and cardiovascular disease. Nevertheless, the direct effects of obesity on cardiovascular health and function require further exploration. In particular, the relationship between obesity and cardiac function has received intense scrutiny. Although obesity increases the risk for development of heart failure (HF), it appears to exert a protective effect in patients in whom HF has already been diagnosed (the "obesity paradox"). The protective effects of obesity in patients with previously diagnosed HF are the focus of particularly intense research. Several explanations have been proposed, but most studies are limited by the use of body mass index to classify obesity. Because body mass index does not distinguish between fat mass, fat-free mass, and lean mass, individuals with similar body mass indices may have vastly different body composition. This article discusses the roles of body composition, diet, cardiorespiratory fitness, and weight loss in the development of cardiac dysfunction and HF and the potential protective role that body composition compartments might play in improving HF prognosis. Based on an intensive literature search (Pubmed, Google Scholar) and critical review of the literature, we also discuss how a multidisciplinary approach including a nutritional intervention targeted to reduce systemic inflammation and lean mass-targeted exercise training could potentially exert beneficial effects for patients with HF.

Complex relationship of obesity and obesity paradox in heart failure - higher risk of developing heart failure and better outcomes in established heart failure

Heart failure (HF) and obesity are major public health problems. Studies have shown that obesity may increase the risk of developing new HF but after patients have developed HF, obesity may be associated with improved outcomes. This paradoxical association of obesity with HF remains poorly understood. It is believed that the obesity paradox may in part be due to the inherent limitations of body mass index (BMI) as a measure of obesity. BMI may not appropriately measure important components of body mass like body fat, fat distribution, lean body mass, and body fluid content and may not be ideal for examining the relationship of body composition with health outcomes. Differentiating between body fat and lean body mass may explain some of the paradoxical association between higher BMI and better prognosis in patients with HF. Paradoxical outcomes in HF may also be due to phenotypes of obesity. Future studies need to develop and test metrics that may better measure body composition and may serve as a better tool for the estimation of the true association of obesity and outcomes in HF and determine whether the association may vary by obesity phenotypes. KEY MESSAGES Obesity predisposes to heart failure in all age groups. But obesity in heart failure is an area of controversy, because of obesity paradox, the apparent protective effect of overweight and mild obesity on mortality after development of heart failure. Traditional markers of obesity do not measure different components of body weight like muscle mass, fat, water, and skeletal weight. Body Mass Index in heart failure subjects does not measure accurately body fat or fluid retention. So new markers of obesity like visceral adiposity index, body composition analysis, sarcopenic status assessment may be helpful in the assessment of heart failure outcomes. Different phenotypes of obesity may be responsible for the different morbidity, mortality as well as therapeutic outcomes in heart failure.

Body habitus in heart failure: understanding the mechanisms and clinical significance of the obesity paradox

The prevalence of obesity among adults and children worldwide has reached epic proportions and has become a major independent risk factor for the development of heart failure (HF), in addition to a contributor of hypertension and cardiovascular disease. The implications of obesity in the development of HF involve adverse effects on cardiac structure and function. Despite all of this, in the setting of chronic HF, excess body mass is associated with improved clinical outcomes, demonstrating the presence of an obesity paradox. In this review, we will discuss the gender differences, global application, potential mechanisms and role of interventions based on fitness and purposeful weight loss as potential therapeutic strategies.

Obesity paradox in heart failure: a heavy matter

Obesity and heart failure are two of the leading causes of morbidity and mortality in the world. The relationship between obesity and cardiovascular diseases is complex and not fully understood. While the risk of developing heart failure has been shown to be higher in patients who are obese, there is a survival advantage for obese and overweight patients compared with normal weight or low weight patients. This phenomenon was first described by Horwich et al. and was subsequently confirmed in other large trials. The advantage exists irrespective of the type, aetiology, or stage of heart failure. Patients with morbid obesity (body mass index >40 kg/m²), however, do not have the same survival advantage of their obese counterparts. There are several alternative indices of obesity available that may be more accurate than body mass index. The role of weight loss in patients with heart failure is unclear; thus, providing sound clinical advice to patients remains difficult. Future prospective trials designed to evaluate the link between obesity and heart failure will help us understand more fully this complex relationship.

From the BMI paradox to the obesity paradox: the obesity-mortality association in coronary heart disease

Despite a strong association between body weight and mortality in the general population, clinical evidence suggests better clinical outcome of overweight or obese individuals with established coronary heart disease. This finding has been termed the 'obesity paradox', but its existence remains a point of debate, because it is mostly observed when body mass index (BMI) is used to define obesity. Inherent limitations of BMI as an index of adiposity, as well as methodological biases and the presence of confounding factors, may account for the observed findings of clinical studies. In this review, our aim is to present the data that support the presence of a BMI paradox in coronary heart disease and then explore whether next to a BMI paradox a true obesity paradox exists as well. We conclude by attempting to link the obesity paradox notion to available translational research data supporting a 'healthy', protective adipose tissue phenotype. © 2016 World Obesity.

"Metabolically healthy" obesity: Prevalence, clinical features and association with myocardial ischaemia

OBJECTIVE

To evaluate the prevalence of the "metabolically healthy" (MH) or "metabolically unhealthy" (MU) obesity phenotypes and their association with cardiorespiratory fitness and inducible myocardial ischaemia.

METHODS

Individuals without known coronary artery disease undergoing myocardial perfusion single-photon emission computed tomography (MPS) were studied. Those without dyslipidemia, hypertension, or diabetes were considered MH, and when ≥1 of these was present, MU status was considered present. Summed stress and difference perfusion scores (SSS and SDS, respectively) were calculated; a SDS >1 defined ischaemic MPS.

RESULTS

MH patients were 35.0% of the nonobese population and 23.5% of the obese (p<0.001). The prevalence of ischaemia was not significantly different between MH patients with obesity or MH patients without obesity (10.9% vs 9.1%, p=0.3), except for patients with body mass index ≥40kg/m² (21.9%). MH obese patients were less frequently able to exercise and had lower exercise capacity than the nonobese patients.

CONCLUSIONS

The prevalence of myocardial ischaemia was not significantly different between MH obese or nonobese individuals, supporting the concept of the "metabolically healthy obesity". However, there are other factors involved, such as the ability to exercise, that influence the risk of myocardial ischaemia, limiting the "safety" of that obesity phenotype.

Obesity and Cardiovascular Disease: a Risk Factor or a Risk Marker?

In the USA, 69 % of adults are either overweight or obese and 35 % are obese. Obesity is associated with an increased incidence of various cardiovascular disorders. Obesity is a risk marker for cardiovascular disease, in that it is associated with a much higher prevalence of comorbidities such as diabetes, hypertension, and metabolic syndrome, which then increase the risk for cardiovascular disease. However, in addition, obesity may also be an independent risk factor for the development of cardiovascular disease. Furthermore, although obesity has been shown to be an independent risk factor for several cardiovascular diseases, it is often associated with improved survival once the diagnosis of the cardiovascular disease has been made, leading to the term "obesity paradox." Several pathways linking obesity and cardiovascular disease have been described. In this review, we attempt to summarize the complex relationship between obesity and cardiovascular disorders, in particular coronary atherosclerosis, heart failure, and atrial fibrillation.

Obesity and Prevalence of Cardiovascular Diseases and Prognosis-The Obesity Paradox Updated

The prevalence and severity of obesity have increased in the United States and most of the Westernized World over recent decades, reaching worldwide epidemics. Since obesity worsens most of the cardiovascular disease (CVD) risk factors, not surprisingly, most CVDs, including hypertension, coronary heart disease, heart failure, and atrial fibrillation, are all increased in the setting of obesity. However, many studies and meta-analyses have demonstrated an obesity paradox with regards to prognosis in CVD patients, with often the overweight and mildly obese having a better prognosis than do their leaner counterparts with the same CVD. The implication for fitness to markedly alter the relationship between adiposity and prognosis and the potential impact of weight loss, in light of the obesity paradox, are all reviewed.