The impact of inflammation on the obesity paradox in coronary heart disease

Obesity and the obesity paradox in abdominal aortic aneurysm

Obesity, characterized by its complexity and heterogeneity, has emerged as a significant public health concern. Its association with increased incidence and mortality of cardiovascular diseases stems not only from its complications and comorbidities but also from the endocrine effects of adipose tissue. Abdominal aortic aneurysm (AAA), a chronic inflammatory condition, has been closely linked to obesity. Intriguingly, mild obesity appears to confer a protective effect against AAA mortality, whereas severe obesity and being underweight do not, giving rise to the concept of the "obesity paradox". This review aims to provide an overview of obesity and its paradoxical relationship with AAA, elucidate its underlying mechanisms, and discuss the importance of preoperative weight loss in severely obese patients with AAA.

Low HDL cholesterol and the eNOS Glu298Asp polymorphism are associated with inducible myocardial ischemia in patients with suspected stable coronary artery disease

BACKGROUND

The endothelial nitric oxide synthase (eNOS) gene deficiency is known to cause impaired coronary vasodilating capability in animal models. In the general clinical population, the eNOS gene polymorphisms, able to affect eNOS activity, were associated with cardiometabolic risk features and prevalence of coronary artery disease (CAD).

AIM

To investigate the association of eNOS Glu298Asp gene polymorphism, cardiometabolic profile, obstructive CAD and inducible myocardial ischemia in patients with suspected stable CAD.

METHODS

A total of 506 patients (314 males; mean age 62 ± 9 years) referred for suspected CAD was enrolled. Among these, 325 patients underwent stress ECG or cardiac imaging to assess the presence of inducible myocardial ischemia and 436 patients underwent non-invasive computerized tomography or invasive coronary angiography to assess the presence of obstructive CAD. Clinical characteristics and blood samples were collected for each patient.

RESULTS

In the whole population, 49.6% of patients were homozygous for the Glu298 genotype (Glu/Glu), 40.9% heterozygotes (Glu/Asp) and 9.5% homozygous for the 298Asp genotype (Asp/Asp). Obstructive CAD was documented in 178/436 (40.8%) patients undergoing coronary angiography while myocardial ischemia in 160/325 (49.2%) patients undergoing stress testing. Patients with eNOS Asp genotype (Glu/Asp + Asp/Asp) had no significant differences in clinical risk factors and in circulating markers. Independent predictors of obstructive CAD were age, gender, obesity, and low HDL-C. Independent predictors of myocardial ischemia were gender, obesity, low HDL-C and Asp genotype. In the subpopulation in which both stress tests and coronary angiography were performed, the Asp genotype remained associated with increased myocardial ischemia risk after adjustment for obstructive CAD.

CONCLUSION

In this population, low-HDL cholesterol was the only cardiometabolic risk determinant of obstructive CAD. The eNOS Glu298Asp gene polymorphism was significantly associated with inducible myocardial ischemia independently of other risk factors and presence of obstructive CAD.

Metabolically healthy obesity, transition from metabolic healthy to unhealthy status, and carotid atherosclerosis

BACKGROUND

Evidence of the effects of metabolically healthy obesity (MHO) on atherosclerosis is limited; the transition effects of metabolic health and obesity phenotypes have been ignored. We examined the association between metabolic health and the transition to atherosclerosis risk across body mass index (BMI) categories in a community population.

METHODS

This cross-sectional study was based on a national representative survey that included 50,885 community participants aged ≥40 years. It was conducted from 01 December 2017 to 31 December 2020, in 13 urban and 13 rural regions across Hunan China. Metabolic health was defined as meeting less than three abnormalities in blood pressure, glucose, high-density lipoprotein cholesterol, triglycerides, or waist circumference. The participants were cross-classified at baseline based on their metabolic health and obesity. In addition, the relationship between atherosclerosis and transitions in metabolic health status based on 4733 participants from baseline to the second survey after 2 years was considered. The relationship between metabolic health status and the risk of transition to Carotid atherosclerosis (CA) was assessed using logistic regression and Cox proportional hazards regression analyses.

RESULTS

In this study, the mean age of the participants was 60.7 years (standard deviation [SD], 10.91), 53.0% were female, and 51.2% had CA. As compared with metabolically healthy normal weight (MHN), those with MHO phenotype (odd ratio [OR] 1.10, 95% confidence interval [CI] 1.02-1.21), metabolically unhealthy normal weight (OR 1.27, 95% CI 1.19-1.35), metabolically unhealthy overweight (OR 1.41, 95% CI 1.33-1.48), and metabolically unhealthy obese (OR 1.54, 95% CI 1.44-1.64) had higher risk for CA. However, during the follow-up of 2 years, almost 33% of the participants transitioned to a metabolically unhealthy status. As compared with stable healthy normal weight, transition from metabolically healthy to unhealthy status (hazard ratios [HR] 1.21, 95% [CI] 1.02-1.43) and stable metabolically unhealthy overweight or obesity (MUOO) (HR 1.32, 95% CI 1.17-1.48) were associated with higher risk of CA.

CONCLUSIONS

In the community population, obesity remains a risk factor for CA despite metabolic health. However, the risks were highest for metabolically unhealthy status across all BMI categories. A large proportion of metabolically healthy overweight or participants with obesity converts to an unhealthy phenotype over time, which is associated with an increased risk of CA.

Sex differences in the relationship between body mass index and outcome in myocardial infarction

BACKGROUND

The data on sex-related differences regarding the body mass index (BMI) in patients with myocardial infarction (MI) are rare and inconclusive. We aimed to assess sex differences in the relationship between BMI and 30-day mortality in men and women with MI.

METHODS

A single-center retrospective study of 6453 patients with MI who underwent PCI was performed. Patients were divided into five BMI categories and these were compared. The relationship between BMI and 30-day mortality was assessed in men and women.

RESULTS

An L-shaped relationship between BMI and mortality was observed in men (p=0.003) with the highest mortality rate (9.4%) in normal weight patients and the lowest in patients with obesity grade I (5.3%). In women, similar mortality was found in all BMI categories (p=0.42). After adjustment for potential confounders, the negative association between BMI category and 30-day mortality was found in men, but not in women (p=0.033 and p=0.13, respectively). Overweight men had a 33% lower risk of death within 30 days compared to normal weight patients (OR 0.67,95%CI 0.46-0.96;p=0.03). Other BMI categories in men had a similar mortality risk to the normal weight category.

CONCLUSIONS

Our results suggest that the relationship between BMI and outcome in patients with MI is different in men and women. We found an L-shaped relationship between BMI and 30-day mortality in men, but no relationship was observed in women. The obesity paradox was not found in women. Sex itself could not explain this differential relationship, and the underlying cause is likely multifactorial.

Obesity Paradox: Fact or Fiction?

PURPOSE OF REVIEW

Obesity is related to several comorbidities such as type 2 diabetes mellitus, cardiovascular disease, heart failure, and various types of cancers. While the detrimental effect of obesity in both mortality and morbidity has been well established, the concept of the obesity paradox in specific chronic diseases remains a topic of continuous interest. In the present review, we examine the controversial issues around the obesity paradox in certain conditions such as cardiovascular disease, several types of cancer and chronic obstructive pulmonary disease, and the factors that may confound the relation between obesity and mortality.

RECENT FINDINGS

We refer to the obesity paradox when particular chronic diseases exhibit an interesting "paradoxical" protective association between the body mass index (BMI) and clinical outcomes. This association, however, may be driven by multiple factors among which the limitations of the BMI itself; the unintended weight loss precipitated by chronic illness; the various phenotypes of obesity, i.e., sarcopenic obesity or the athlete's obesity phenotype; and the cardiorespiratory fitness levels of the included patients. Recent evidence highlighted that previous cardioprotective medications, obesity duration, and smoking status seem to play a role in the obesity paradox. The obesity paradox has been described in a plethora of chronic diseases. It cannot be emphasized enough that the incomplete information received from a single BMI measurement may interfere with outcomes of studies arguing in favor of the obesity paradox. Thus, the development of carefully designed studies, unhampered by confounding factors, is of great importance.

Fat-Free Mass and Body Fat in Patients with Myocardial Infarction Who Underwent Percutaneous Coronary Intervention

There are no data on the effects of fat-free mass (FFM) and body fat (BF) on prognosis in patients with myocardial infarction (MI). We investigated the effects of FFM and BF (which were estimated using formulas rather than direct measurements) on 30-day and long-term all-cause mortality in patients with MI who underwent percutaneous coronary intervention. We analyzed data from 6,453 patients with MI. The patients were divided into 2 categories (high/low) according to the fat-free mass index (FFMI) and 2 categories (low/high) according to the BF. The resultant 4 patient groups: HighFFMI-LowBF, HighFFMI-HighBF, LowFFMI-LowBF, and LowFFMI-HighBF, were compared. The lowest crude mortality after 30 days and in the long term was observed in the HighFFMI-LowBF group (3.0%,9.8%, respectively), followed by the HighFFMI-HighBF group (6.6%, 27.0%, respectively), the LowFFMI-LowBF group (10.4%, 36.0%, respectively), and the LowFFMI-HighBF group (14.7%, 56.8%, respectively). The difference was significant (p <0.0001), as was the difference between groups. After adjustment, the FFMI-BF groups independently predicted 30-day mortality (p = 0.003), but the risk was similar in all groups. Compared with the HighFFMI-LowBF group, the long-term mortality risk was similar in the HighFFMI-HighBF group (hazard ratio [HR] 1.11, 95% confidence interval [CI] 0.84 to 1.47, p = 0.47), but the LowFFMI-LowBF and LowFFMI-HighBF patients had a higher risk (HR 1.59, 95% CI 1.20 to 2.11, p = 0.001, HR 1.40, 95% CI 1.03 to 1.91, p = 0.033, respectively). Body composition predicted mortality better than body mass index in patients with MI. Mortality appeared to be inversely related to FFM, with patients with low FFM and low BF having a particularly high mortality risk. The body composition groups also confirmed the obesity paradox.

Obesity, Body Composition, and Sex Hormones: Implications for Cardiovascular Risk

Cardiovascular disease (CVD) continues to be the leading cause of death in adults, highlighting the need to develop novel strategies to mitigate cardiovascular risk. The advancing obesity epidemic is now threatening the gains in CVD risk reduction brought about by contemporary pharmaceutical and surgical interventions. There are sex differences in the development and outcomes of CVD; premenopausal women have significantly lower CVD risk than men of the same age, but women lose this advantage as they transition to menopause, an observation suggesting potential role of sex hormones in determining CVD risk. Clear differences in obesity and regional fat distribution among men and women also exist. While men have relatively high fat in the abdominal area, women tend to distribute a larger proportion of their fat in the lower body. Considering that regional body fat distribution is an important CVD risk factor, differences in how men and women store their body fat may partly contribute to sex-based alterations in CVD risk as well. This article presents findings related to the role of obesity and sex hormones in determining CVD risk. Evidence for the role of sex hormones in determining body composition in men and women is also presented. Lastly, the clinical potential for using sex hormones to alter body composition and reduce CVD risk is outlined. © 2022 American Physiological Society. Compr Physiol 12:1-45, 2022.

Obesity paradox and aging

BACKGROUND

In association with the rapid lengthening of life expectancy and the ever-rising prevalence of obesity, many studies explored in the elderly the phenomenon usually defined as the obesity paradox.

OBJECTIVE AND METHODS

This article is a narrative overview of seventy-two papers (1999-2019) that investigated the obesity paradox during the aging process. Twenty-nine documents are examined more in detail.

RESULTS

The majority of studies suggesting the existence of an obesity paradox have evaluated just BMI as an index of obesity. Some aspects are often not assessed or are underestimated, in particular body composition and visceral adiposity, sarcopenic obesity, and cardio fitness. Many studies support that central fat and relative loss of fat-free mass may become relatively more important than BMI in determining the health risk associated with obesity in older ages.

CONCLUSION

Inaccurate assessments may lead to a systematic underestimation of the impact of obesity on morbidity and premature mortality and, consequently, to clinical behaviors that are not respectful of the health of elderly patients. Knowledge of the changes in body composition and fat distribution will help to better understand the relationship between obesity, morbidity, and mortality in the elderly.

LEVEL OF EVIDENCE

Level V, narrative overview.

An obesity paradox in patients with myocardial infarction undergoing percutaneous intervention

BACKGROUND AND AIMS

Data concerning the relationship between body mass index (BMI) and outcome in myocardial infarction (MI) patients are inconclusive. Long-term data on the influence of BMI on survival in patients with MI who have undergone percutaneous intervention (PCI) are lacking. We aimed to assess the effect of different categories of BMI on long-term mortality.

METHODS AND RESULTS

A single-center retrospective study of 6496 patients with MI who underwent PCI was performed. Patients were divided into six categories according to their BMI and these were compared. All-cause mortality was assessed over a median period of 6.0 years. An inverse J-shaped relationship was observed between BMI and long-term mortality. The lowest mortality was observed in patients with class I obesity. The patients with a BMI below 25.0 kg/m² were more likely to die than patients with class I obesity. A gradual decrease in BMI below 25.0 kg/m² was associated with a progressively increased risk of dying, with underweight patients showing a 2.18-fold increase in mortality risk. An obesity paradox was present. In addition, the patients with class III obesity had a more than 70% higher long-term mortality risk as compared to the reference group. Both lower and higher degrees of BMI were found to be harmful in patients with MI who underwent PCI.

CONCLUSION

The obesity paradox was present in a very long-term follow-up of patients with MI who underwent PCI. However, both lower and higher BMI values are harmful, and an inverse J-shaped relationship between BMI and outcome was observed.

Predicted Skeletal Muscle Mass and 4-Year Cardiovascular Disease Incidence in Middle-Aged and Elderly Participants of IKARIA Prospective Epidemiological Study: The Mediating Effect of Sex and Cardiometabolic Factors

The sex-specific effect of skeletal muscle mass (SMM) index (SMI) on 4-year first fatal/non-fatal cardiovascular disease (CVD) event in free-of-disease individuals was examined. In 2009, n = 1411 inhabitants (mean age = 64(12)) from Ikaria were selected. Follow-up was performed in 2013. SMI was created to reflect SMM through appendicular skeletal muscle mass (indirectly calculated through formulas) divided by body mass index (BMI). Fifteen and six tenths percent of participants exhibited CVD (19.8% in men/12% in women, p = 0.002). Significant U-shape trends were observed in participants >65 years old and women irrespective to age confirmed through multi-adjusted Cox regression analysis; in age >65 years, Hazard Ratio (HR)_{(2nd vs. 1st SMI tertile)} = 0.80, 95% Confidence Interval (95%CI) (0.45, 0.96) and in women HR_{(2nd vs. 1st SMI tertile)} = 0.71, 95% CI (0.33, 0.95), while, as for the 3rd SMI tertile, no significant trends were observed. Mediation analysis revealed that mediators of the aforementioned associations in men were the arterial distensibility and total testosterone, while, in women, inflammation, insulin resistance, and arterial distensibility. High SMM accompanied by obesity may not guarantee lower CVD risk. Specific cardiometabolic factors seem to explain this need for balance between lean and fat mass.

Acute Cardiovascular Events Associated With Influenza in Hospitalized Adults : A Cross-sectional Study

BACKGROUND

Influenza may contribute to the burden of acute cardiovascular events during annual influenza epidemics.

OBJECTIVE

To examine acute cardiovascular events and determine risk factors for acute heart failure (aHF) and acute ischemic heart disease (aIHD) in adults with a hospitalization associated with laboratory-confirmed influenza.

DESIGN

Cross-sectional study.

SETTING

U.S. Influenza Hospitalization Surveillance Network during the 2010-to-2011 through 2017-to-2018 influenza seasons.

PARTICIPANTS

Adults hospitalized with laboratory-confirmed influenza and identified through influenza testing ordered by a practitioner.

MEASUREMENTS

Acute cardiovascular events were ascertained using discharge codes from the International Classification of Diseases (ICD), Ninth Revision, Clinical Modification, and ICD, 10th Revision. Age, sex, race/ethnicity, tobacco use, chronic conditions, influenza vaccination, influenza antiviral medication, and influenza type or subtype were included as exposures in logistic regression models, and marginal adjusted risk ratios and 95% CIs were estimated to describe factors associated with aHF or aIHD.

RESULTS

Among 89 999 adults with laboratory-confirmed influenza, 80 261 had complete medical record abstractions and available ICD codes (median age, 69 years [interquartile range, 54 to 81 years]) and 11.7% had an acute cardiovascular event. The most common such events (non-mutually exclusive) were aHF (6.2%) and aIHD (5.7%). Older age, tobacco use, underlying cardiovascular disease, diabetes, and renal disease were significantly associated with higher risk for aHF and aIHD in adults hospitalized with laboratory-confirmed influenza.

LIMITATION

Underdetection of cases was likely because influenza testing was based on practitioner orders. Acute cardiovascular events were identified by ICD discharge codes and may be subject to misclassification bias.

CONCLUSION

In this population-based study of adults hospitalized with influenza, almost 12% of patients had an acute cardiovascular event. Clinicians should ensure high rates of influenza vaccination, especially in those with underlying chronic conditions, to protect against acute cardiovascular events associated with influenza.

PRIMARY FUNDING SOURCE

Centers for Disease Control and Prevention.

The obesity paradox in the stress echo lab: fat is better for hearts with ischemia or coronary microvascular dysfunction

BACKGROUND

Obesity is an independent risk factor for coronary artery disease (CAD), but once CAD has developed it has been associated with improved survival ("obesity paradox").

AIM

To assess how obesity affects prognosis in patients with or without inducible ischemic regional wall motion abnormalities (RWMA) and/or abnormal coronary flow velocity reserve (CFVR) during stress echocardiography (SE).

METHODS

In an observational retrospective two- center study design, we analyzed 3249 consecutive patients (1907 men; age 66 ± 12 years; body mass index, BMI, 26.9 ± 4.1 kg/m²) with known (n = 1306) or suspected (n = 1943) CAD who underwent dipyridamole SE with simultaneous evaluation of RWMA and CFVR. All-cause death was the outcome end-point.

RESULTS

1075 patients were lean (BMI 18.5-24.9 kg/m²), 1523 overweight (BMI 25.0-29.9 kg/m²), and 651 obese (≥30.0 kg/m²). Ischemic test result for RWMA occurred in 28 (3%) lean, 69 (4%) overweight, and 28 (4%) obese patients (p = 0.03). An abnormal CFVR (≤2.0) was found in 281 (26%) lean, 402 (26%) overweight and 170 (26%) obese patients (p = 0.99). During 68 ± 44 months of follow-up, 496 (15%) patients died. At multivariable Cox analysis, BMI ≥ 30 was an independent predictor of reduced mortality in the 878 patients with stress-induced (≥2 segments) RWMA and/or CFVR abnormality (HR 0.58, 95% CI 0.40-0.84; p = 0.003), while showed no effect at univariate analysis in the 2371 patients with no RWMA and normal CFVR (HR 1.04, 95% CI 0.74-1.46; p = 0.84).

CONCLUSIONS

Obesity exerts a "paradoxical" protective effect in patients with stress-induced ischemia and/ or coronary microvascular dysfunction, and shows a neutral effect in patients with normal CFVR and no stress-induced RWMA.

Obesity and Coronary Heart Disease: Epidemiology, Pathology, and Coronary Artery Imaging

Overweight and obesity contribute to the development of cardiovascular disease (CVD) in general and coronary heart disease (CHD) in particular in part by their association with traditional and nontraditional CVD risk factors. Obesity is also considered to be an independent risk factor for CVD. The metabolic syndrome, of which central obesity is an important component, is strongly associated with CVD including CHD. There is abundant epidemiologic evidence of an association between both overweight and obesity and CHD. Evidence from postmortem studies and studies involving coronary artery imaging is less persuasive. Recent studies suggest the presence of an obesity paradox with respect to mortality in persons with established CHD. Physical activity and preserved cardiorespiratory fitness attenuate the adverse effects of obesity on CVD events. Information concerning the effect of intentional weight loss on CVD outcomes in overweight and obese persons is limited.

APOE - a genetic marker of comorbidity in subjects with morbid obesity

Background

In population-based studies, the genetic variability of the APOE E alleles have been associated with health outcomes. Health problems are common in subjects with obesity. This study explored associations between the APOE E alleles and comorbidity in subjects with morbid obesity.

Methods

The study included consecutive subjects referred for evaluation of bariatric surgery with morbid obesity (defined as BMI > 40 or > 35 kg/m² with complications related to obesity). The subjects followed a conservative weight loss program for 6 months before surgery and had a follow-up visit 12 months after surgery. Demographic data and a set psychosomatic scores (musculoskeletal pain, WHO-5 Well-Being Index, Rosenberg Self-Esteem Scale, Hopkins Symptom Check-list 10; Epworth Sleepiness Scale, and Fatigue Severity Scale) were collected, and blood samples were analysed for haematological and biochemical parameters and APOE alleles.

Results

One hundred and forty subjects (men/women: 32 (23%)/108 (77%) with mean age 43.0 (SD 8.7) years and BMI 42.1 (SD 3.8) kg/m² were included. One hundred and eight and 92 subjects had data after conservative treatment and 12 months after surgery, respectively. The prevalence of the APOE alleles were: E2E2: 1 (0.7%), E2E3: 13 (9.3%), E2E4: 4 (2.9%), E3E3: 71 (50.7%), E3E4: 47 (33.6%), and E4E4: 4 (2.9%). The prevalence rates were as anticipated in a Norwegian population. The weight loss during conservative treatment and after bariatric surgery was independent of E allele variability. E2 was associated with a significant or clear trend toward improvement of all psychosomatic disorders. There was a significant fall in CRP during the two treatment periods with weight loss. E2 and E4 were significantly associated with high and low CRP, respectively, but no associations were seen between CRP and comorbidity.

Conclusions

The most marked finding was the association between E2 and improvement of all psychosomatic disorders. The positive and negative associations between CRP and E2 and E4, respectively, could indicate effects on inflammation and immunological reactions.

Association of obesity with arterial stiffness: The Multi-Ethnic Study of Atherosclerosis (MESA)

Arterial stiffness (AS) and obesity are recognized as important risk factors of cardiovascular disease (CVD). The purpose of this study was to investigate the relationship between AS and obesity. AS was defined as high augmentation index (AIx) and low elasticity (C1, large artery elasticity; C2, small artery elasticity) in participants enrolled in the Multi-Ethnic Study of Atherosclerosis at baseline. We compared AIx, C1, and C2 by body mass index (BMI) (< 25, 25-29.9, 30-39.9, ⩾ 40 kg/m²) and waist-hip ratio (WHR) (< 0.85, 0.85-0.99, ⩾ 1). The obesity-AS association was tested across 10-year age intervals. Among 6177 participants (62 ± 10 years old, 52% female), a significant inverse relationship was observed between obesity and AS. After adjustments for CVD risk factors, participants with a BMI > 40 kg/m² had 5.4% lower AIx (mean difference [Δ] = -0.82%; 95% CI: -1.10, -0.53), 15.4% higher C1 (Δ = 1.66 mL/mmHg ×10; 95% CI: 1.00, 2.33), and 40.2% higher C2 (Δ = 1.49 mL/mmHg ×100; 95% CI: 1.15, 1.83) compared to those with a BMI < 25 kg/m² (all p for trend < 0.001). Participants with a WHR ⩾ 1 had 5.6% higher C1 (∆ = 0.92 mL/mmHg ×10; 95% CI: 0.47, 1.37) compared to those with a WHR < 0.85. The WHR had a significant interaction with age on AIx and C2, but not with BMI; the inverse relationships of the WHR with AIx and C2 were observed only in participants < 55 years between the normal (WHR < 0.85) and the overweight (0.85 ⩽ WHR < 0.99) groups. Different associations of WHR and BMI with arterial stiffness among older adults should be further investigated.

Obesity and the Survival of Critically Ill Patients with Acute Kidney Injury: A Paradox within the Paradox?

The obesity epidemic is reflected by the rising number of obese patients requiring intensive care. Obesity is a recognized risk factor for the development of acute kidney injury (AKI) in critically ill patients. Both acute critical illness and AKI are associated with higher in-hospital mortality rates, and intensive care unit (ICU) patients suffering from AKI have an elevated risk of death. The relationships between obesity and mortality in critically ill paediatric and adult patients with or without AKI are less clear. Conflicting evidence exists regarding the potential impact of body mass index on the mortality of ICU patients with AKI. Some studies looking at the ICU outcomes of critically ill obese patients with AKI show reduced mortality and others show either no association or elevated mortality. Despite a high biologic plausibility of the proposed causal mechanisms, such as a greater haemodynamic stability and the protective cytokine, adipokine, and lipoprotein defence profiles associated with obesity, the inconsistency of the data suggests that the obesity paradox is a statistical fallacy and the result of chance, bias, and residual confounding variables in retrospective cohort analyses. Further prospective randomized trials are essential to elucidate the role of obesity and the mechanisms underlying a potential survival benefit of obesity in critically ill patients with AKI.

Obesity and 1-Year Mortality in Adults After Sepsis: A Systematic Review

PURPOSE

In recent years, researchers have noted an "obesity paradox," where individuals with obesity survive sepsis at higher rates than their nonobese counterparts. This systematic review summarizes the literature on studies examining the association between obesity and 1-year mortality among patients admitted with sepsis, severe sepsis, or septic shock.

MATERIALS AND METHODS

Using a comprehensive search strategy, a systematic review was conducted to identify studies examining the association of obesity and sepsis mortality. PubMed, Cumulative Index of Nursing and Allied Health Literature, and Elton B. Stephens Company host databases were searched for the terms sepsis, obesity, mortality, and adult.

RESULTS

The initial search identified 189 studies, 9 of which met inclusion criteria. Of these, four provided evidence that obese or very obese patients with sepsis have lower mortality than nonobese patients. Methodologic differences in the remaining five studies, which reported conflicting results, limit generalizability.

CONCLUSION

This systematic review on the association of obesity and sepsis mortality found three studies that demonstrated lower sepsis mortality among obese patients in the first 30 days and one showing that this protective effect extends up to 1 year. Given the increased number of patients surviving sepsis, it is important to consider long-term mortality and further describe the variables associated with increased survival.

Skeletal muscle mass in acute coronary syndrome prognosis: Gender-based analysis from Hellenic Heart Failure cohort

BACKGROUND AND AIMS

Predictive and prognostic ability of muscle mass in CVD settings is increasingly discussed. The gender-specific effect of skeletal muscle mass index (SMI) on 10-year recurrent fatal/non fatal cardiovascular disease (CVD) event of acute coronary syndrome (ACS) patients was evaluated.

METHODS AND RESULTS

In 2006-2009, n = 1000 consecutive patients (n = 222 women), hospitalized at the First Cardiology Clinic of Athens with ACS diagnosis and with symptoms and left ventricular function indicative of heart failure were selected. SMI was created to reflect skeletal muscle mass through appendicular skeletal muscle mass (indirectly calculated through population formulas) divided by body mass index (BMI). In the 10-year follow-up (2016), 55% of ACS patients experienced recurrent fatal/non fatal CVD events (53% in women vs.62% in men, p = 0.04). Patients in the 2nd SMI tertile (mostly overweight) had 10% lower risk for CVD recurrence (women:men rate ratio = 0.87) over their counterparts in the 1st (mostly normalweight) and 3rd tertile (mostly obese). Multivariate analysis revealed that ACS patients in the 2nd SMI tertile presented 46% and 85% lower CVD event risk over their counterparts in the 1st tertile (Hazard Ratio (HR) = 0.54, 95% Confidence Interval (95% CI) 0.30, 0.96, p = 0.002) and 3rd tertile (HR = 1.85, 95%CI 1.05, 2.94, p = 0.03). Gender-based analysis revealed that this trend remained significant only in women. Inflammatory markers had strong confounding effect.

CONCLUSION

A U-shape association between SMI and 10-year CVD event especially in women was highlighted. This work reveals gender-specific remarks for "obesity-lean paradox" in secondary prevention, implying that high muscle mass accompanied by obesity and excess adiposity may not guarantee better prognosis.

Obesity paradox in cardiovascular disease: where do we stand?

Obesity is associated with an increased risk of developing cardiovascular disease (CVD), particularly heart failure (HF) and coronary heart disease (CHD). The mechanisms through which obesity increases CVD risk involve changes in body composition that can affect hemodynamics and alters heart structure. Pro-inflammatory cytokines produced by the adipose tissue itself which can induce cardiac dysfunction and can promote the formation of atherosclerotic plaques. When obesity and HF or CHD coexist, individuals with class I obesity present a more favorable prognosis compared to individuals who are normal or underweight. This phenomenon has been termed the “obesity paradox.” Obesity is defined as an excess fat mass (FM), but individuals with obesity typically also present with an increased amount of lean mass (LM). The increase in LM may explain part of the obesity paradox as it is associated with improved cardiorespiratory fitness (CRF), a major determinant of clinical outcomes in the general population, but particularly in those with CVD, including HF. While increased LM is a stronger prognosticator in HF compared to FM, in patients with CHD excess FM can exert protective effects particularly when not associated with increased systemic inflammation. In the present review, we discuss the mechanisms through which obesity may increase the risk for CVD, and how it may exert protective effects in the setting of established CVD, with a focus on body composition. We also highlight the importance of measuring or estimating CRF, including body composition-adjusted measures of CRF (ie, lean peak oxygen consumption) for an improved risk status stratification in patients with CVD and finally, we discuss the potential non-pharmacologic therapeutics, such as exercise training and dietary interventions, aimed at improving CRF and perhaps clinical outcomes.

Obesity Paradox in Aging: From Prevalence to Pathophysiology

Recent advances in medical technology and health care have greatly improved the management for chronic diseases and prolonged human lifespan. Unfortunately, increased lifespan and the aging population impose a major challenge on the ever-rising prevalence of chronic diseases, in particular cardiometabolic stress associated with the pandemic obesity in our modern society. Although overweight and obesity are associated with incident cardiovascular diseases (CVD), including heart failure (HF), it paradoxically leads to a more favorable prognosis in patients with chronic HF, a phenomenon commonly defined as "obesity paradox". Numerous population-based and clinical studies have suggested possible explanations such as better metabolic reserve, smoking and disease-associated weight loss for obesity paradox. Recent evidence noticed a shift in obesity paradox with aging. While some studies have reported a more pronounced "obesity paradox" in the older patients, others have seen diminished cardiac benefits with overweight and obesity in the elderly patients with CVD. These findings suggested that a complex relationship among aging, metabolism, and HF severity/chronicity, which may explain the shift in obesity paradox in the elderly. Aging negatively affects body metabolism and cardiac function although its precise impact on obesity paradox remains elusive. To develop new strategies for cardiovascular health in the elderly, it is imperative to understand the precise role for aging on obesity-related CVD.

The impact of disease severity on paradoxical association between body mass index and mortality in patients with acute kidney injury undergoing continuous renal replacement therapy

BACKGROUND

Association between high body mass index (BMI) and survival benefit is confounded by comorbid conditions such as nutritional status and inflammation. Patients with acute kidney injury (AKI), particularly those receiving continuous renal replacement therapy (CRRT), are highly catabolic and more susceptible to loss of energy. Herein, we evaluated whether disease severity can modify the relationship between BMI and mortality.

METHODS

We conducted an observational study in 1144 patients who had undergone CRRT owing to various causes of AKI between 2010 and 2014. Patients were categorized into four groups; underweight (< 18.5 kg/m²), normal (18.5-22.99 kg/m²), overweight (23.0-24.99 kg/m²), and obesity (≥25 kg/m²) according to BMI classification by the Committee of Clinical Practice Guidelines and Korean Society for the Study of Obesity. More severe disease was defined as sepsis-related organ failure assessment (SOFA) score of ≥ a median value of 12. The study endpoint was death that occurred within 30 days after the initiation of CRRT.

RESULTS

The mean age was 63.2 years and 439 (38.4%) were females. The median BMI was 23.6 (20.9-26.2) kg/m². The obese group were younger and higher SOFA score than normal BMI group. In a multivariable Cox regression analysis, we found a significant interaction between BMI and SOFA score (P <  0.001). Furthermore, obese patients were significantly associated with a lower risk of death as compared to normal BMI group after adjusting confounding factors [hazard ratio (HR), 0.81; 95% confidence interval (CI), 0.68-0.97; P = 0.03]. This association was only evident among patients with high severity (HR, 0.61; 95% CI, 0.48-0.76, P <  0.001). In contrast, in those with low severity, survival benefit of high BMI was lost, whereas underweight was associated with an increased risk of death (HR, 1.74; 95% CI, 1.16-2.60; P = 0.007).

CONCLUSION

In this study, we found a survival benefit of high BMI in AKI patients undergoing CRRT, particularly in those with more disease severity; the effect was not observed in those with less disease severity.

High physical fitness is associated with reduction in basal- and exercise-induced inflammation

C-reactive protein (CRP) increases after strenuous exercise. It has been a concern that prolonged strenuous exercise may be harmful and induce a deleterious inflammatory response. The purpose of this study was to (a) assess and quantify the magnitude of CRP response following an endurance cycling competition in healthy middle-aged recreational cyclists. (b) Identify important determinants of this response. (c) Identify the relationship between CRP, myocardial damage (cardiac Troponin I (cTnI)), and myocardial strain (B-type natriuretic peptide [BNP]). (d) Identify the relationship between CRP and clinical events, defined as utilization of healthcare services or self-reported unusual discomfort. Race time was used as a measure of physical fitness. A total of 97 individuals (43±10 years of age, 74 [76%] males) were assessed prior to and 0, 3, and 24 hours following the 91-km mountain bike race "Nordsjørittet" (Sandnes, Norway, June 2013). There was a highly significant increase in CRP from baseline to 24 hours (0.9 (0.5-1.8) mg/L vs. 11.6 (6.0-17.5) mg/L (median[IQR]), P<.001), with no correlation of CRP to cTnI and BNP at any time-point. CRP was strongly correlated to race time at baseline (r=.38, P<.001) and at 24 hours following the race (r=.43, P<.001), In multivariate models, race time was an independent predictor of CRP both at baseline and at 24 hours (P<.01). There was no relationship between CRP levels and clinical events. In conclusion, high physical fitness was associated with reduction in both basal- and exercise-induced CRP. No adverse relationship was found between high intensity physical exercise, CRP levels, and outcomes.

Preventive Effects of Catechins on Cardiovascular Disease

Catechins are polyphenolic phytochemicals with many important physiological activities that play a multifaceted health care function in the human body, especially in the prevention of cardiovascular disease. In this paper, various experimental and clinical studies have revealed the role of catechins in the prevention and treatment of cardiovascular disorders, and we review the preventive effects of catechins on cardiovascular disease from the following aspects: Regulating lipid metabolism, regulating blood lipid metabolism, vascular endothelial protection, and reducing blood pressure.