Contribution of cardiorespiratory fitness to the obesity paradox

The Obesity Mortality Paradox in Patients with Pulmonary Embolism: Insights from a Tertiary Care Center

Background: While obesity is associated with an increased risk of venous thromboembolism (VTE), there is some data to suggest that higher BMI is also associated with decreased all-cause mortality in patients with a pulmonary embolism (PE). Methods: Using PE Response Team (PERT) activation data from a large tertiary hospital between 27 October 2020 and 28 August 2023, we constructed a multivariate Cox proportional hazards model to assess the association between obesity as a dichotomous variable (defined as BMI ≥ 30 vs. BMI 18.5-29.9), BMI as a continuous variable, and 30-day PE-related mortality. Results: A total of 248 patients were included in this analysis (150 with obesity and 98 who were in the normal/overweight category). Obesity was associated with a lower risk of 30-day PE-related mortality (adjusted HR 0.29, p = 0.036, 95% CI 0.09-0.92). A higher BMI was paradoxically associated with a lower risk of PE-related mortality (HR = 0.91 per 1 kg/m2 increase, p = 0.049, 95% CI 0.83-0.999). Conclusions: In our contemporary cohort of patients with a PERT activation, obesity was associated with a lower risk of PE-related mortality.

The Metabolic Syndrome, a Human Disease

This review focuses on the question of metabolic syndrome (MS) being a complex, but essentially monophyletic, galaxy of associated diseases/disorders, or just a syndrome of related but rather independent pathologies. The human nature of MS (its exceptionality in Nature and its close interdependence with human action and evolution) is presented and discussed. The text also describes the close interdependence of its components, with special emphasis on the description of their interrelations (including their syndromic development and recruitment), as well as their consequences upon energy handling and partition. The main theories on MS's origin and development are presented in relation to hepatic steatosis, type 2 diabetes, and obesity, but encompass most of the MS components described so far. The differential effects of sex and its biological consequences are considered under the light of human social needs and evolution, which are also directly related to MS epidemiology, severity, and relations with senescence. The triggering and maintenance factors of MS are discussed, with especial emphasis on inflammation, a complex process affecting different levels of organization and which is a critical element for MS development. Inflammation is also related to the operation of connective tissue (including the adipose organ) and the widely studied and acknowledged influence of diet. The role of diet composition, including the transcendence of the anaplerotic maintenance of the Krebs cycle from dietary amino acid supply (and its timing), is developed in the context of testosterone and β-estradiol control of the insulin-glycaemia hepatic core system of carbohydrate-triacylglycerol energy handling. The high probability of MS acting as a unique complex biological control system (essentially monophyletic) is presented, together with additional perspectives/considerations on the treatment of this 'very' human disease.

The Unrestrained Overeating Behavior and Clinical Perspective

Obesity-related co-morbidities decrease life quality, reduce working ability, and lead to early death. In the adult population, eating addiction manifests with excessive food consumption and the unrestrained overeating behavior, which is associated with increased risk of morbidity and mortality and defined as the binge eating disorder (BED). This hedonic intake is correlated with fat preference and the total amount of dietary fat consumption is the most potent risk factor for weight gain. Long-term BED leads to greater sensitivity to the rewarding effects of palatable foods and results in obesity fatefully. Increased plasma concentrations of non-esterified free fatty acids and lipid-overloaded hypertrophic adipocytes may cause insulin resistance. In addition to dietary intake of high-fat diet, sedentary lifestyle leads to increased storage of triglycerides not only in adipose tissue but also ectopically in other tissues. Lipid-induced apoptosis, ceramide accumulation, reactive oxygen species overproduction, endoplasmic reticulum stress, and mitochondrial dysfunction play role in the pathogenesis of lipotoxicity. Food addiction and BED originate from complex action of dopaminergic, opioid, and cannabinoid systems. BED may also be associated with both obesity and major depressive disorder. For preventing morbidity and mortality, as well as decreasing the impact of obesity-related comorbidities in appropriately selected patients, opiate receptor antagonists and antidepressant combination are recommended. Pharmacotherapy alongside behavioral management improves quality of life and reduces the obesity risk; however, the number of licensed drugs is very few. Thus, stereotactic treatment is recommended to break down the refractory obesity and binge eating in obese patient. As recent applications in the field of non-invasive neuromodulation, transcranial magnetic stimulation and transcranial direct current stimulation are thought to be important in image-guided deep brain stimulation in humans. Chronic overnutrition most likely provides repetitive and persistent signals that up-regulate inhibitor of nuclear factor kappa B (NF-κB) kinase beta subunit/NF-κB (IKKβ/NF-κB) in the hypothalamus before the onset of obesity. However, how the mechanisms of high-fat diet-induced peripheral signals affect the hypothalamic arcuate nucleus remain largely unknown.

The obesity paradox in intracerebral hemorrhage: a systematic review and meta-analysis

Background

Intracerebral hemorrhage (ICH) has a mortality rate which can reach 30-40%. Compared with other diseases, obesity is often associated with lower mortality; this is referred to as the 'obesity paradox'. Herein, we aimed to summarize the studies of the relations between obesity and mortality after ICH.

Method

For this systematic review and meta-analysis (PROSPERO registry CRD42023426835), we conducted searches for relevant articles in both PubMed and Embase. Non-English language literature, irrelevant literature, and non-human trials were excluded. All included publications were then qualitatively described and summarized. Articles for which quantitative analyses were possible were evaluated using Cochrane's Review Manager.

Results

Ten studies were included. Qualitative analysis revealed that each of the 10 studies showed varying degrees of a protective effect of obesity, which was statistically significant in 8 of them. Six studies were included in the quantitative meta-analysis, which showed that obesity was significantly associated with lower short-term (0.69 [0.67, 0.73], p<0.00001) and long-term (0.62 [0.53, 0.73], p<0.00001) mortality. (Data identified as (OR [95%CI], p)).

Conclusion

Obesity is likely associated with lower post-ICH mortality, reflecting the obesity paradox in this disease. These findings support the need for large-scale trials using standardized obesity classification methods.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023426835, identifier CRD42023426835.

Association of Cardiovascular Disease in Patients with Mycosis Fungoides and Sézary Syndrome Compared to a Matched Control Cohort

Mycosis fungoides/Sézary syndrome (MF/SS) produces a low-grade chronic inflammatory state that may be associated with an increased risk of cardiovascular (CV) events, as seen in other chronic, systemic dermatologic diseases. To assess this association, a retrospective, cross-sectional study was designed in which 421 patients with a biopsy-proven diagnosis of MF/SS were compared with a control cohort of 4,210 age-, gender-, and race-matched patients randomly selected from the National Health and Nutritional Evaluation Survey database. The MF/SS cohort had a 14% prevalence of CV events, which was not statistically different from the control population's prevalence of 13%. In the MF/SS cohort, a multivariable logistic regression model showed that older patients (OR = 1.05 for each year of age, 95% confidence interval = 1.02-1.07) and those diagnosed with hypertension (OR = 3.40, 95% confidence interval = 1.71-6.75) had a higher risk of a CV event (P < 0.001). Risk factors such as gender, race, smoking, diabetes, and obesity were not significantly associated with CV events. Findings suggest that in the MF/SS population, advancing age and hypertension are risk factors for CV events, requiring clinical recognition and management. In addition, further research is needed to understand the complex interplay of how chronic inflammation in MF/SS impacts the immune development of CV disease.

Obesity Paradox in Lung Diseases: What Explains It?

BACKGROUND

Obesity is a globally increasing health problem that impacts multiple organ systems and a potentially modifiable risk factor for many diseases. Obesity has a significant impact on lung function and is strongly linked to the pathophysiology that contributes to lung diseases. On the other hand, reports have emerged that obesity is associated with a better prognosis than for normal weight individuals in some lung diseases, including pneumonia, acute lung injury/acute respiratory distress syndrome, chronic obstructive pulmonary disease, and lung cancer. The lesser mortality and better prognosis in patients with obesity is known as obesity paradox. While obesity paradox is both recognized and disputed in epidemiological studies, recent research has suggested possible mechanisms.

SUMMARY

In this review, we attempted to explain and summarize these factors and mechanisms, including immune response, pulmonary fibrosis, lung function, microbiota, fat and muscle reserves, which are significantly altered by obesity and may contribute to the obesity paradox in lung diseases. We also discuss contrary literature that attributes the "obesity paradox" to confounding.

KEY MESSAGES

The review will illustrate the possible role of obesity in the prognosis or course of lung diseases, leading to a better understanding of the obesity paradox and provide hints for further basic and clinical research in lung diseases.

Association between cardiorespiratory fitness and low back pain is anxiety-dependent: A prospective cohort study among adults and older adults

To investigate the relationship between low back pain and cardiorespiratory fitness (CRF) among participants with and without self-report anxiety. Participants were 13,080 individuals (86.6% men; 44.7 ± 9.3 years). CRF was quantified as maximal treadmill test duration and was grouped for analysis as low (lowest 20% of treadmill test duration), moderate (middle 40%), and high (upper 40%). Cox regression analysis was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) between low back pain and CRF according to the presence/absence of self-report anxiety. During an average of 5.7 ± 5.1 years of follow-up, 2,965 cases of low back pain were identified. Participants with self-report anxiety and low CRF had 3.7 times (HR: 3.7; 95%CI: 1.7-8.2) more risk for having low back pain when compared with participants with self-report anxiety and high CRF. Additionally, among participants with self-reported anxiety, moderate CRF was associated with an 70% greater risk of having low back pain than those with high CRF (HR: 1.7; 95%CI: 1.1-3.2). For participants without self-reported anxiety, no association was found between the risk of having low back pain and CRF. According to the results identified in the present study, participants with self-reported anxiety who had low and moderate CRF had higher risks of low back pain than those with high CRF.

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.

Body mass index versus surrogate measures of central adiposity as independent predictors of mortality in type 2 diabetes

BACKGROUND

An "obesity paradox" for mortality has been shown in chronic disorders such as diabetes, and attributed to methodological bias, including the use of body mass index (BMI) for obesity definition. This analysis investigated the independent association of BMI versus surrogate measures of central adiposity with all-cause mortality in individuals with type 2 diabetes.

METHODS

The Renal Insufficiency And Cardiovascular Events Italian Multicentre Study is a prospective cohort study that enrolled 15,773 patients in 19 Italian centres in 2006-2008. Exposures were BMI and the surrogate measures of central adiposity waist circumference (WC), waist-to-height ratio (WHtR), and A Body Shape Index (ABSI). Vital status was retrieved on 31 October 2015 for 15,656 patients (99.3%), RESULTS: Age- and sex-adjusted hazard ratios and 95% confidence intervals were significantly higher in BMI-based underweight (1.729 [1.193-2.505), P = 0.004), moderately obese (1.214 [1.058-1.392), P = 0.006) and severely obese (1.703 [1.402-2.068), P < 0.0001), lower in overweight (0.842 [0.775-0.915), P < 0.0001) and similar in mildly obese (0.950 [0.864-1.045), P = 0.292), compared to normal-weight individuals. When further adjusting for smoking, physical activity (PA), and comorbidities, risk was lower also in mildly obese versus normal-weight patients. The BMI-mortality relationship did not change after sequentially excluding ever smokers, individuals with comorbidities, and those died within two years from enrollment and when analyzing separately participants below and above the median age. Conversely, a paradox relationship was observed among inactive/moderately inactive, but not moderately/highly active patients. Mortality risk adjusted for age, gender, smoking, PA and comorbidities was significantly higher in the highest tertile of WC (1.279 [1.089-1.501], P = 0.003), WHtR (1.372 [1.165-1.615], P < 0.0001), and ABSI (1.263 [1.067-1.495], P = 0.007) versus the lowest tertile. However, risk was lower in the intermediate versus lowest tertile for WC (0.823 [0.693-0.979], P = 0.028), similar for WHtR, and higher, though not significantly, for ABSI.

CONCLUSIONS

An "overweight paradox" remained after controlling for age, smoking, and comorbidities, arguing against a collider bias or reverse causation. However, it could be partly explained by confounding from PA level, possibly through its impact on lean mass and cardiorespiratory fitness. No obesity paradox was observed with WHtR and especially ABSI, which predicted mortality risk associated with central adiposity better than WC. Trial registration ClinicalTrials.gov, NCT00715481, 15 July, 2008.

Survival benefit of overweight patients undergoing MitraClip® procedure in comparison to normal-weight patients

BACKGROUND

The number of MitraClip® implantations increased significantly in recent years. Data regarding the impact of weight class on survival are sparse.

HYPOTHESIS

We hypothesized that weight class influences survival of patients treated with MitraClip® implantation.

METHODS

We investigated in-hospital, 1-year, 3-year, and long-term survival of patients successfully treated with isolated MitraClip® implantation for mitral valve regurgitation (MR) (June 2010-March 2018). Patients were categorized by weight classes, and the impact of weight classes on survival was analyzed.

RESULTS

Of 617 patients (aged 79.2 years; 47.3% females) treated with MitraClip® implantation (June 2010-March 2018), 12 patients were underweight (2.2%), 220 normal weight (40.1%), 237 overweight (43.2%), and 64 obesity class I (11.7%), 12 class II (2.2%), and 4 class III (0.7%). Preprocedural Logistic EuroScore (21.1 points [IQR 14.0-37.1]; 26.0 [18.5-38.5]; 26.0 [18.4-39.9]; 24.8 [16.8-33.8]; 33.0 [25.9-49.2]; 31.6 [13.1-47.6]; p = .291) was comparable between groups. Weight class had no impact on in-hospital death (0.0%; 4.1%; 1.5%; 0.0%; 7.7%; 0.0%; p = .189), 1-year survival (75.0%; 72.0%; 76.9%; 75.0%; 75.0%; 33.3%; p = .542), and 3-year survival (40.0%; 36.8%; 38.2%; 48.6%; 20.0%; 33.3%; p = .661). Compared to normal weight, underweight (hazard ratio [HR]: 1.35 [95% confidence interval [CI]: 0.65-2.79], p = .419), obesity-class I (HR: 0.93 [95% CI: 0.65-1.34], p = .705), class II (HR: 0.39 [95% CI: 0.12-1.24], p = .112), and class III (HR: 1.28 [95% CI: 0.32-5.21], p = .726) did not affect long-term survival. In contrast, overweight was associated with better survival (HR: 1.32 [95% CI: 1.04-1.68], p = .023).

CONCLUSION

Overweight affected the long-term survival of patients undergoing MitraClip® implantation beneficially compared to normal weight.

Body fat percentage, cardiorespiratory fitness and arterial blood pressure in children and adolescents: a longitudinal analysis

Background

A better understanding of how cardiorespiratory fitness (CRF) and adiposity interact to associate with arterial blood pressure over time remains inconclusive. Thus, the aim of the present study was to examine whether changes in CRF moderates the association between body fat percentage (BF%) and arterial blood pressure in children and adolescents.

Methods

This is an observational longitudinal study with 407 children and adolescents aged 8–17 years followed-up for three years from a city in Southern Brazil. Participants were evaluated in 2011 and 2014. CRF was measured by validated field-based tests following the Projeto Esporte Brazil protocols and peak oxygen uptake (VO_2peak) was estimated. BF% was determined by the measures of tricipital and subscapular skinfolds using equations according to sex. Systolic and diastolic blood pressure (SBP, DBP) were measured with a sphygmomanometer according to standard procedures. Moderation analyses included multiple linear regression models adjusted for sex, age, pubertal status, height, socioeconomic level, skin color, and the arterial blood pressure variable itself at baseline.

Results

It was observed a significant inverse association between VO_2peak at baseline with SBP (β = − 0.646 CI95% = − 0.976  − 0.316) and DBP (β = − 0.649 CI95% = − 0.923  − 0.375) at follow-up and a positive association between BF% at baseline with SBP (β = 0.274; CI95% = 0.094 0.455) and DBP (β = 0.301; CI95% = 0.150 0.453) at follow-up. In addition, results indicated a significant interaction term between changes in VO_2peak and BF% at baseline with both SBP (p = 0.034) and DBP at follow-up (p = 0.011), indicating that an increase of at least 0.35 mL/kg/min and 1.78 mL/kg/min in VO_2peak attenuated the positive relationship between BF% with SBP and DBP.

Conclusion

CRF moderates the relationship between BF% and SBP and DBP in children and adolescents.

The Obesity Paradox in Chronic Heart Disease and Chronic Obstructive Pulmonary Disease

Obesity in recent years has become an epidemic. A high body mass index (BMI) is one of today's most crucial population health indicators. BMI does not directly quantify body fat but correlates well with easier body fat measurements. Like smoking, obesity impacts multiple organ systems and is a major modifiable risk factor for countless diseases. Despite this, reports have emerged that obesity positively impacts the prognosis of patients with chronic illnesses such as chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD), a phenomenon known as the Obesity Paradox. This article attempts to explain and summarize this phenomenon.

As it stands, two theories explain this paradox. The muscle mass hypothesis states that obese patients are better adapted to tide through acute exacerbations due to increased reserve because of greater muscle mass. The other theory focuses on brown adipose tissue and its anti-inflammatory effects on the body.

We performed a literature review on research articles published in English from 1983 to the present in the following databases - PubMed, Elsevier, and Google Scholar. The following search strings and Medical Subject Headings (MeSH) terms were used: "Obesity," "Heart Failure," "COPD," and "Cardio-Respiratory Fitness." In this review, we looked at the obesity paradox in Heart Failure and COPD. We summarized the current literature on the Obesity Paradox and reviewed its relationship with Cardio-Respiratory Fitness.

Comparison of time-matched aerobic, resistance or combined exercise training in women living with obesity: a protocol for a pilot randomised controlled trial-the EXOFFIT (Exercise for Obesity in Females to increase Fitness) study

INTRODUCTION

Obesity in women has more than doubled in the past thirty years. Increasing research suggests that increased cardiorespiratory fitness (CRF) can largely attenuate the negative health risks associated with obesity. Though previous literature suggests that combined training may be the most effective for improving CRF in adults with obesity, there is minimal research investigating the efficacy of combined and resistance programmes in women with obesity. This article outlines a protocol for a parallel pilot study which aims to evaluate the feasibility and efficacy of three exercise modalities in women with obesity for increasing CRF and strength and improving body composition and other health outcomes (i.e. quality of life).

METHODS AND ANALYSIS

Sixty women (aged 18-50) with obesity (body mass index [BMI] ≥ 30 and/or waist circumference ≥ 88 cm) who are physically inactive, have no unstable health conditions and are safe to exercise will be recruited from September 2021 to December 2022. The main outcome will be feasibility and acceptability of the intervention and procedures. Trial feasibility outcomes will be evaluated to determine if a definitive trial should be undertaken. Trial acceptability will be explored through follow-up qualitative interviews with participants. Secondary outcomes will include CRF (predicted VO2 max), anthropometrics (i.e. BMI), strength (5RM bench press, leg dynamometry, grip strength) and other health outcomes (i.e., pain). Participants will be block randomised into one of four trial arms (aerobic exercise, resistance training and combined training groups, non-active control group) and measurements will be completed pre- and post-intervention. The exercise groups will receive an individualised supervised exercise programme for 3× sessions/week for 12 weeks. The change in mean values before and after intervention will be calculated for primary and secondary outcomes. ANOVA and t-tests will be applied to evaluate within-group and between-group differences. If sufficient participants are recruited, the data will be analysed using ANCOVA with the age and BMI as covariates.

DISCUSSION

This pilot will provide data on the feasibility and acceptability of trial procedures and of the programmes' three progressive time-matched exercise interventions (aerobic, resistance and combined) for women living with obesity, which will help inform future research and the potential development of a full-scale randomised clinical trial.

TRIAL REGISTRATION

ISRCTN, ISRCTN13517067 . Registered 16 November 2021-retrospectively registered.

Impact of training modes on fitness and body composition in women with obesity: A systematic review and meta-analysis

OBJECTIVE

This study aimed to assess the effectiveness of different exercise modalities and determine the optimal exercise prescription for improving cardiorespiratory fitness, body composition, and metabolic health of women with obesity.

METHODS

A systematic review of randomized controlled trials (RCTs) published between January 1988 and October 2020 was conducted. The RCTs were screened using the following inclusion criteria: 1) participants: women aged 18 to 65 years with BMI > 30 kg/m² and without comorbidities; 2) intervention: exercise; 3) comparison: non-intervention control; and 4) outcomes measures: cardiorespiratory fitness (maximal oxygen consumption), body composition (i.e., body weight, percentage body fat), and/or metabolic measures (i.e., blood pressure, cholesterol).

RESULTS

A total of 20 RCTs with a total of 2,062 participants were included. Although the results showed that any form of exercise was more effective than control, improvements in fitness and body composition were modest. Aerobic exercise (vigorous and moderate intensity) appeared most promising for improving fitness and body weight, whereas low-load resistance training resulted in the largest improvements in body fatness.

CONCLUSIONS

In women living with obesity, aerobic exercise was consistently effective in improving fitness and body composition. Although both resistance training and combined exercise interventions appear promising, more research is needed to evaluate their efficacy and determine an optimal exercise prescription for this population.

Influence of Waist-to-Hip Ratio on the Prognosis of Heart Failure Patients With Revascularized Coronary Heart Disease

Background: Heart failure (HF) is considered one of the most common complications of coronary heart disease (CHD), with a higher incidence of readmission and mortality. Thus, exploring the risk factors related to the prognosis is necessary. Moreover, the effect of the waist-to-hip ratio (WHR) on HF patients with revascularized CHD is still unclear. Thus, we aimed to assess the influence of WHR on the prognosis of HF patients with revascularized CHD. Methods: We collected data of HF patients with revascularized CHD who were referred to the Cardiac Rehabilitation Clinic of PLA Hospital from June 30, 2015, to June 30, 2019. Cox proportional hazard regression analysis was used to determine the relationship between WHR and prognosis of HF patients with revascularized CHD. Patients were divided into higher and lower WHR groups based on the cutoff WHR value calculated by the X-tile software. Cox regression analysis was used to analysis the two groups. We drew the receiver operating characteristic curve (ROC) of WHR and analyzed the differences between the two groups. Endpoints were defined as major adverse cardiac events (MACE) (including all-cause mortality, non-fatal myocardial infarction, unscheduled revascularization, and stroke). Results: During the median follow-up of 39 months and maximum follow-up of 54 months, 109 patients were enrolled, of which 91.7% were males, and the mean age was 56.0 ± 10.4 years. WHR was associated with the incidence of MACE in the Cox regression analysis (p = 0.001); an increase in WHR of 0.01 unit had a hazard ratio (HR) of 1.134 (95%CI: 1.057-1.216). The WHR cutoff value was 0.93. Patients in the higher WHR group had a significantly higher risk of MACE than those in the lower WHR group (HR = 7.037, 95%CI: 1.758-28.168). The ROC area under the curve was 0.733 at 4 years. Patients in the higher WHR group had a higher body mass index (BMI; 26.7 ± 3.5 vs. 25.4 ± 2.4, P = 0.033) than patients in the lower WHR group. Conclusions: WHR is an independent risk factor of the long-term prognosis of Chinese HF patients with revascularized CHD. Patients with WHR ≥ 0.93 require intensified treatment. Higher WHR is related to higher BMI and ΔVO2/ΔWR.

Criterion-Related Validity of Field-Based Fitness Tests in Adults: A Systematic Review

We comprehensively assessed the criterion-related validity of existing field-based fitness tests used to indicate adult health (19–64 years, with no known pathologies). The medical electronic databases MEDLINE (via PubMed) and Web of Science (all databases) were screened for studies published up to July 2020. Each original study’s methodological quality was classified as high, low and very low, according to the number of participants, the description of the study population, statistical analysis and systematic reviews which were appraised via the AMSTAR rating scale. Three evidence levels were constructed (strong, moderate and limited evidence) according to the number of studies and the consistency of the findings. We identified 101 original studies (50 of high quality) and five systematic reviews examining the criterion-related validity of field-based fitness tests in adults. Strong evidence indicated that the 20 m shuttle run, 1.5-mile, 12 min run/walk, YMCA step, 2 km walk and 6 min walk test are valid for estimating cardiorespiratory fitness; the handgrip strength test is valid for assessing hand maximal isometric strength; and the Biering–Sørensen test to evaluate the endurance strength of hip and back muscles; however, the sit-and reach test, and its different versions, and the toe-to-touch test are not valid for assessing hamstring and lower back flexibility. We found moderate evidence supporting that the 20 m square shuttle run test is a valid test for estimating cardiorespiratory fitness. Other field-based fitness tests presented limited evidence, mainly due to few studies. We developed an evidence-based proposal of the most valid field-based fitness tests in healthy adults aged 19–64 years old.

Association between Cardiorespiratory Fitness and Circulating Proteins in 50-Year-Old Swedish Men and Women: a Cross-Sectional Study

BACKGROUND AND AIMS

A strong cardiorespiratory fitness is suggested to have beneficial effects on cardiovascular risk; the exact mechanisms underlying the cardioprotective effects of fitness remain uncertain. Our aim was to investigate associations between cardiorespiratory fitness and multiple plasma proteins, in order to obtain insights about physiological pathways associated with the effects of exercise on cardiovascular health.

METHODS

In the Prospective investigation of Obesity, Energy and Metabolism (POEM) study (n=444 adults aged 50 years, 50% women), cardiorespiratory fitness was measured by a maximal exercise test on bicycle ergometer with gas exchange (VO₂peak) normalized for body lean mass (dual-energy X-ray absorptiometry (DXA)). We measured 82 cardiovascular proteins associated with cardiovascular pathology and inflammation in plasma samples with a proximity extension assay.

RESULTS

In sex-adjusted linear regression, VO₂peak was associated with 18 proteins after Bonferroni correction for multiple testing (p<0.0006). Following additional adjustment for fat mass (DXA), fasting glucose (mmol/L), low-density lipoprotein (LDL, mmol/L), smoking status, waist/hip ratio, blood pressure (mmHg), education level, and lpnr (lab sequence number), higher VO₂peak was significantly associated with lower levels of 6 proteins: fatty-acid binding protein-4 (FABP4), interleukin-6 (IL-6), leptin, cystatin-B (CSTB), interleukin-1 receptor antagonist (IL-1RA), and growth differentiation factor 15 (GDF-15), and higher levels of 3 proteins: galanin, kallikrein-6 (KLK6), and heparin-binding EGF-like growth factor (HB-EGF), at nominal p-values (p<0.05).

CONCLUSIONS

We identified multiple novel associations between cardiorespiratory fitness and plasma proteins involved in several atherosclerotic processes and key cellular mechanisms such as inflammation, energy homeostasis, and protease activity, which shed new light on how exercise asserts its beneficial effects on cardiovascular health. Our findings encourage additional studies in order to understand the underlying causal mechanisms for these associations.

Fitness vs. fatness as determinants of survival in non-institutionalized older adults: The EXERNET multi-center study

BACKGROUND

Physical fitness and body composition are important health indicators, nevertheless their combined pattern inter-relationships and their association with mortality are poorly investigated.

METHODS

This longitudinal study is part of the Spanish EXERNET-Elder project. Person-months follow-up were calculated from the interview date, performed between June 2008 and November 2009, until date of death or censoring on March 2018 (whichever came first). In order to be included, participants had to fulfill the following criteria: 1) be over 65 years old, 2) live independently at home, 3) not suffer dementia and/or cancer and 4) have a BMI above 18.5. Body fat and weight were assessed by a bioelectrical impedance analyzer. Fitness was measured with the Senior Fitness and the one leg static balance tests. The Spanish Death Index was consulted for the death's identification. Cluster analysis was performed to identify Fat-Fit patterns and traditional cut points and percentiles to create the Fat-Fit groups. Cox proportional hazards regression models were used to calculate the hazard ratios of death in clustered Fat-Fit patterns and in traditional Fat-Fit groups.

RESULTS

A total of 2299 older adults (76.8% of women) were included with a baseline mean age of 71.9 ± 5.2 years. A total of 196 deaths (8.7% of the sample) were identified during the 8 years of follow up. Four clustered Fat-Fit patterns (Low fat-Fit, Medium fat-Fit, High fat-Unfit and Low fat-Unfit) and nine traditional Fat-Fit groups emerged. Using the Low fat-Fit pattern as the reference, significantly increased mortality was noted in High fat-Unfit (HR: 1.68, CI: 1.06 - 2.66) and Low fat-Unfit (HR: 2.01, CI: 1.28 - 3.16) groups. All the traditional Fit groups showed lower mortality risk when compared to the reference group (obese-unfit group).

CONCLUSIONS

Physical fitness is a determinant factor in terms of survival in community-dwelling older adults, independently of adiposity levels.

Relation of Body Mass Index to Adverse Right Ventricular Mechanics

Although higher body mass index (BMI) is associated with adverse left ventricular morphology and functional remodeling, its possible association with right ventricular (RV) dysfunction has not been extensively evaluated. RV free wall longitudinal strain (RVLS) is emerging as an important tool to detect early RV dysfunction. This study aimed to investigate the independent effect of increased BMI on RVLS in a large sample of the general population without overt cardiac disease. We examined 1,085 participants (603 men, mean age 62 years) who voluntarily underwent an extensive cardiovascular health check-up. This included laboratory tests and speckle-tracking echocardiography to assess RVLS. The association between BMI and RVLS was determined by logistic regression analyses. The prevalence of abnormal RVLS (>-19.2%) was greatest in obese individuals (29.7%), followed by overweight (16.3%), and normal weight (10.6%, p <0.001). In multivariable analyses, BMI was significantly associated with abnormal RVLS (adjusted odds ratio [OR] = 1.07 per 1 kg/m², p = 0.033) independent of traditional cardiovascular risk factors, pertinent laboratory and echocardiographic parameters including RV size and pulmonary artery systolic pressure. In subgroup analyses, BMI was significantly associated with abnormal RVLS in men (adjusted OR 1.10 per 1 kg/m², p = 0.032) and younger (<65 years) participants (adjusted OR 1.13 per 1 kg/m², p = 0.011), but not in women and the elderly. In a sample of the general population, higher BMI was independently associated with subclinical RV dysfunction. Furthermore, an increased BMI may carry different risk for impaired RVLS depending on the age and sex.

Longitudinal Associations of Fitness and Obesity in Young Adulthood With Right Ventricular Function and Pulmonary Artery Systolic Pressure in Middle Age: The CARDIA Study

Background Low cardiorespiratory fitness (CRF) and obesity are risk factors for heart failure but their associations with right ventricular (RV) systolic function and pulmonary artery systolic pressure (PASP) are not well understood. Methods and Results Participants in the CARDIA (Coronary Artery Risk Development in Young Adults) study who underwent maximal treadmill testing at baseline and had a follow-up echocardiographic examination at year 25 were included. A subset of participants had repeat CRF and body mass index (BMI) assessment at year 20. The associations of baseline and changes in CRF and BMI on follow-up (baseline to year 20) with RV systolic function parameters (tricuspid annular plane systolic excursion, RV Doppler systolic velocity of the lateral tricuspid annulus), and PASP were assessed using multivariable-adjusted linear regression models. The study included 3433 participants. In adjusted analysis, higher baseline BMI but not CRF was significantly associated with higher PASP. Among RV systolic function parameters, higher baseline CRF and BMI were significantly associated with higher tricuspid annular plane systolic excursion and RV systolic velocity of the lateral tricuspid annulus. In the subgroup of participants with follow-up assessment of CRF or BMI at year 20, less decline in CRF was associated with higher RV systolic velocity of the lateral tricuspid annulus and lower PASP, while greater increase in BMI was significantly associated with higher PASP in middle age. Conclusions Higher CRF in young adulthood and less decline in CRF over time are each significantly associated with better RV systolic function. Higher baseline BMI and greater age-related increases in BMI are each significantly associated with higher PASP in middle age. These findings provide insights into possible mechanisms through which low fitness and obesity may contribute toward risk of heart failure.

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.

What exercise prescription is optimal to improve body composition and cardiorespiratory fitness in adults living with obesity? A network meta-analysis

Current international guidelines recommend people living with obesity should be prescribed a minimum of 300 min of moderately intense activity per week for weight loss. However, the most efficacious exercise prescription to improve anthropometry, cardiorespiratory fitness (CRF) and metabolic health in this population remains unknown. Thus, this network meta-analysis was conducted to assess and rank comparative efficacy of different exercise interventions on anthropometry, CRF and other metabolic risk factors. Five electronic databases were searched for randomized controlled trials (RCTs) that compared different exercise modalities to improve anthropometry, CRF and/or metabolic health in adults living with obesity. RCTs were evaluated using the Cochrane risk of bias tool. A random effects network meta-analysis was performed within a frequentist framework. Of the 6663 articles retrieved, 45 studies with a total 3566 participants were included. Results reveal that while any type of exercise intervention is more effective than control, weight loss induced is modest. Interventions that combine high-intensity aerobic and high-load resistance training exert beneficial effects that are superior to any other exercise modality at decreasing abdominal adiposity, improving lean body mass and increasing CRF. Clinicians should consider this evidence when prescribing exercise for adults living with obesity, to ensure optimal effectiveness.

Cardiorespiratory fitness in late adolescence and long-term risk of psoriasis and psoriatic arthritis among Swedish men

BACKGROUND

Psoriasis is a chronic immune-mediated disease and psoriatic arthritis is a common coexisting condition. Cardiorespiratory fitness is the overall capacity to perform exertion exercise. Low levels of cardiorespiratory fitness are associated with negative health outcomes. Individuals with psoriasis have lower cardiorespiratory fitness compared with individuals without psoriasis. There are no previous studies exploring the association between cardiorespiratory fitness and new-onset psoriasis and psoriatic arthritis.

METHODS

With the objective to investigate whether low cardiorespiratory fitness in late adolescence increases the risk for onset of psoriasis and psoriatic arthritis, a cohort of Swedish men in compulsory military service between 1968 and 2005 was created using data from the Swedish Military Service Conscription Register. Cardiorespiratory fitness, estimated by maximum capacity cycle ergometer testing at conscription, was divided into three groups: high, medium, and low. Diagnoses were obtained using the Swedish National Patient Register and cohort members were followed from conscription until an event, new-onset psoriasis or psoriatic arthritis, occurred, or at the latest until 31 December 2016. Cox regression models adjusted for confounders at conscription were used to obtain hazard ratios with 95% confidence intervals for incident psoriasis and psoriatic arthritis.

RESULTS

During the follow-up period (median follow-up time 31 years, range 0-48 years), 20,679 cases of incident psoriasis and 6,133 cases of incident psoriatic arthritis were found among 1,228,562 men (mean age at baseline 18.3 years). There was a significant association between low cardiorespiratory fitness and incident psoriasis and psoriatic arthritis (hazard ratio 1.35 (95% confidence interval 1.26-1.44) and 1.44 (95% confidence interval 1.28-1.63), respectively).

CONCLUSIONS

These novel findings suggest that low cardiorespiratory fitness at an early age is associated with increased risk of incident psoriasis and psoriatic arthritis among men, and highlight the importance of assessing cardiorespiratory fitness early in life.

Overweight and Obesity in the French Army

INTRODUCTION

Today, the prevalence of overweight and obesity is, respectively, 49% and 17% among French adults. This research investigates their existence in the French Armed Forces, in terms of the impact on military operative response and military readiness. As no previous studies have evaluated the weight status of the whole French Armed Forces, this work assesses the situation for the first time in France.

MATERIAL AND METHODS

A prospective cross-sectional study was carried out between September 2016 and April 2017. A single anonymous questionnaire gathered the sociodemographic variables and usual care medical data. The source population was active duty members serving in units reporting to the South-Eastern French Regional Military Health Department.

RESULTS

Among 1,589 respondents, prevalence of overweight and obesity was, respectively, 38.7% and 10%. Mean waist circumference was 78.2 ± 9.1 cm for women and 89.1 ± 10.5 cm for men. A third of female military and one-fifth of male military had a measure bigger than the standard International Diabetes Federation. Age, sex, weekly fitness activity, and rank were significant independent predictors of body weight excess. Less than 5% of the study population reported a diagnosis of comorbidity: diabetes 2%, high blood pressure 1%, and dyslipidemia 1.5%.

CONCLUSIONS

As all armies, the French Armed Forces are affected by obesity. Nevertheless, the prevalence of obesity seems lower than in other Western armies. In the French army, as in the general population, obesity is correlated with socioeconomic status and level of education. However, compared to the general French population, there is less obesity and overweight in the French Armed Forces. Moreover, overweight and obese military members have a lower cardiovascular risk than their civilian counterparts. Enlistment standards, military occupational activity, and a mandatory high level of physical fitness could explain these different proportions of overweight and obesity. This raises the question of the protective effect of regular physical activity. Is this a serious way to fight against the growing prevalence of overweight and obesity in Western countries? Indeed, this is a significant public health issue, which also affects the military's quick response force capacity and strategic capabilities. Therefore, the identification of specific demographic characteristics should be considered in developing prevention programs.

Impact of obesity on adverse in-hospital outcomes in patients undergoing percutaneous mitral valve edge-to-edge repair using MitraClip® procedure - Results from the German nationwide inpatient sample

BACKGROUND AND AIM

The number of percutaneous edge-to-edge mitral regurgitation (MR) valve repairs with MitraClip® implantations increased exponentially in recent years. Studies have suggested an obesity survival paradox in patients with cardiovascular diseases. We investigated the influence of obesity on adverse in-hospital outcomes in patients with MitraClip® implantation.

METHODS AND RESULTS

We analyzed data on characteristics of patients and in-hospital outcomes for all percutaneous mitral valve repairs using the edge-to-edge MitraClip®-technique in Germany 2011-2015 stratified for obesity vs. normal-weight/over-weight. The nationwide inpatient sample comprised 13,563 inpatients undergoing MitraClip® implantations. Among them, 1017 (7.5%) patients were coded with obesity. Obese patients were younger (75 vs.77 years,P < 0.001), more often female (45.4% vs.39.5%,P < 0.001), had more often heart failure (87.1% vs.79.2%,P < 0.001) and renal insufficiency (67.0% vs.56.4%,P < 0.001). Obese and non-obese patients were comparable regarding major adverse cardiac and cerebrovascular events (MACCE) and in-hospital death. The combined endpoint of cardio-pulmonary resuscitation (CPR), mechanical ventilation and death was more often reached in non-obese than in obese patients with a trend towards significance (20.6%vs.18.2%,P = 0.066). Obesity was an independent predictor of reduced events regarding the combined endpoint of CPR, mechanical ventilation and death (OR 0.75, 95%CI 0.64-0.89,P < 0.001), but not for reduced in-hospital mortality (P = 0.355) or reduced MACCE rate (P = 0.108). Obesity class III was associated with an elevated risk for pulmonary embolism (OR 5.66, 95%CI 1.35-23.77,P = 0.018).

CONCLUSIONS

We observed an obesity paradox regarding the combined endpoint of CPR, mechanical ventilation and in-hospital death in patients undergoing MitraClip® implantation, but our results failed to confirm an impact of obesity on in-hospital survival or MACCE.

[The «obesity paradox» and its degree of proof]

The article gives a critical assessment of the so-called obesity paradox. Methodological errors that occur in the organization of studies that studied the obesity paradox and the formation of comparison groups are highlighted. There are also examples of the disappearance of the obesity paradox when taking into account additional risk factors. The organization of prospective studies or more careful consideration of all currently known risk factors for cardiovascular diseases (CVD) will significantly improve the results of the study of the effect of overweight and obesity on mortality in patients with CVD. Thus, despite the biological possibility of the existence of a positive effect of adipose tissue in CVD, the presence of a large number of errors identified in the analysis of the work of researchers obesity paradox require to reconsider the existence of this phenomenon, it should be taken into account the possibility that the obesity paradox may be a consequence of improper design studies to investigate this phenomenon.

The fitness versus body fat hypothesis in relation to hippocampal structure

The Fitness Versus Body Fat Hypothesis argues that cardiorespiratory fitness (CRF) plays a more important role in cardiovascular health than adiposity. It remains poorly understood whether CRF or adiposity accounts for a greater amount of variation in measures of brain health. We examined the contribution of CRF, adiposity, and their interaction with hippocampal structure. This study included 124 sedentary adults (M = 44.34) with overweight/obesity (Body Mass Index mean = 32.43). FMRIB's Integrated Registration and Segmentation Tool was used to segment the hippocampus. Using hierarchical regression, we examined whether CRF, assessed via a submaximal graded exercise test, or adiposity, assessed as percent body fat using dual-energy x-ray absorptiometry (DXA) was associated with left and right hippocampal volume. Vertex-wise shape analysis was performed to examine regional shape differences associated with CRF and adiposity. Higher CRF was significantly associated with greater left hippocampal volume (p = .031), with outward shape differences along the surface of the subiculum and CA1 regions. Adiposity was not associated with left or right hippocampal volume or shape. The interaction between adiposity and CRF was not significant. Neither CRF nor adiposity were associated with thalamus or caudate nucleus volumes or shapes, two control regions. Higher CRF, but not adiposity, was related to greater left hippocampal volume, with outward shape differences along the surface of the subiculum and CA1 regions in a midlife sample with overweight/obesity. These findings indicate that, within the context of obesity, CRF is an important contributor to hippocampal structure, highlighting the importance of interventions targeting CRF.

Survival Benefit of Obese Patients With Pulmonary Embolism

OBJECTIVE

To investigate the impact of obesity and underweight on adverse in-hospital outcomes in pulmonary embolism (PE).

PATIENTS AND METHODS

Patients diagnosed as having PE based on International Statistical Classification of Diseases and Related Health Problems, 10th Revision, German Modification code I26 in the German nationwide inpatient database were stratified for obesity, underweight, and normal weight/overweight (reference group) and compared regarding adverse in-hospital outcomes.

RESULTS

From January 1, 2011, through December 31, 2014, 345,831 inpatients (53.3% females) 18 years and older were included in this analysis; 8.6% were obese and 0.5% were underweight. Obese patients were younger (67.0 vs 73.0 years), were more frequently female (60.2% vs 52.7%), had a lower cancer rate (13.6% vs 20.5%), and were more often treated with systemic thrombolysis (6.4% vs 4.3%) and surgical embolectomy (0.3% vs 0.1%) vs the reference group (P<.001 for all). Overall, 51,226 patients (14.8%) died during in-hospital stay. Obese patients had lower mortality (10.9% vs 15.2%; P<.001) vs the reference group and a reduced odds ratio (OR) for in-hospital mortality (OR, 0.74; 95% CI, 0.71-0.77; P<.001) independent of age, sex, comorbidities, and reperfusion therapies. This survival benefit of obese patients was more pronounced in obesity classes I (OR, 0.56; 95% CI, 0.52-0.60; P<.001) and II (OR, 0.63; 95% CI 0.58-0.69; P<.001). Underweight patients had higher prevalence of cancer and higher mortality rates (OR, 1.15; 95% CI, 1.00-1.31; P=.04).

CONCLUSION

Obesity is associated with decreased in-hospital mortality rates in patients with PE. Although obese patients were more often treated with reperfusion therapies, the survival benefit of obese patients occurred independently of age, sex, comorbidities, and reperfusion treatment.

Physical fitness, musculoskeletal disorders and body mass index in transport drivers from Barranquilla, Colombia

Introduction: Sedentary work activities in urban transport drivers are associated with overweight and obesity, an increase in musculoskeletal discomfort related to work and a decrease in physical fitness.Objective: To determine physical fitness and musculoskeletal discomfort in urban transport drivers from Barranquilla, Colombia, based on their body mass index (BMI).Material and Methods: Cross-sectional study conducted in 231 urban transport drivers. Healthy physical fitness and presence of musculoskeletal symptoms were measured using the AFISAL-INEFC test battery and the Nordic Questionnaire developed by Kuorinka, respectively.Results: There were significant differences between drivers with normal BMI and overweight/obese drivers in abdominal strength and endurance (21.4±8.9 vs. 19.6±8.8 stooped, p=0.04), flexibility (36.1±7.3 cm vs. 33.6±7.1 cm, p=0.02), and aerobic capacity (1537.5±704.8 meters vs. 1249.1±346.6 meters, p=0.0001). Increased frequency of musculoskeletal discomfort was observed in subjects with BMI >25 kg/m2.Conclusions: Overweight and obesity are associated with poor physical fitness and the perception of musculoskeletal discomfort, which has negative implications for the personal and occupational well-being of these workers, generating a burden for companies and the Colombian health system.

Smoking Status, Body Mass Index, Health-Related Quality of Life, and Acceptance of Life With Illness in Stable Outpatients With COPD

Smoking and obesity are important factors related to the etiology and clinical features of chronic obstructive pulmonary disease (COPD). The aim of this study was to carry out deeper analyses of the links between smoking status and body mass index as well as of the links between individual dimensions of health-related quality of life (QoL) and acceptance of life with disease in patients with COPD. Information about BMI, smoking status, clinical features of COPD, a COPD assessment test, and airflow obstruction indicators were obtained from 105 outpatients attending a pulmonary clinic. Analysis of covariance demonstrated that the subgroups of patients distinguished based on smoking status and BMI differed significantly in severity of Cough, Dyspnea, Limitation of daily activities, Lack of self-confidence, and Quality of sleep, independently of sociodemographic factors and clinical features of COPD. The results of our study suggest a certain path of the potential effects of obesity and smoking status on QoL. Risky health behaviors, such as smoking and at-risk body mass, only affect some aspects of health-related QoL.

Relationship of body mass index and waist circumference with clinical outcomes following percutaneous coronary intervention

BACKGROUND

A biphasic, U-shape relationship has been reported between body mass index (BMI) and clinical outcomes following percutaneous coronary intervention (PCI). However, the relationship between waist circumference (WC) and the cardiovascular risk following PCI has not been reported.

METHODS

A prospective cohort study was performed. A major adverse cardiac event (MACE) was defined as a composite of cardiac death (CD), nonfatal myocardial infarction (NFMI) and target vessel revascularization (TVR). Patients were evenly divided into 4 groups according to BMI (Q1BMI, Q2BMI, Q3BMI and Q4BMI) and WC (Q1WC, Q2WC, Q3WC and Q4WC).

RESULTS

A total of 1,421 patients were observed for 5 years. The risk of the composite events of CD and NFMI (CD/NFMI) was lower in the Q3WC and Q4WC groups than in the Q1WC group, whereas it was only marginally lower in the Q2BMI group than in the Q1BMI group (ANOVA, p = 0.062). The risk of MACE was highest in the Q1WC group and lowest in the Q3WC group; however, the risk of MACE did not differ among the 4 groups, according to BMI. Multivariate Cox-regression analyses showed that the risk of CD/NFMI gradually decreased with BMI (linear p = 0.030) and with WC (linear p = 0.015). The risks of TVR and MACEs that were driven by TVRs showed a distinguishing biphasic, U-shaped relationship with WC (nonlinear p = 0.009) but not with BMI (nonlinear p = 0.439). Landmark survival analysis showed that the incidences of CD and NFMI were higher in the lower BMI groups and lower WC groups than in the higher BMI groups and higher WC groups, respectively, until 1 year and did not differ afterward. In contrast, the incidence of MACE was highest in Q1WC and lowest in Q3WC (log-rank p = 0.003), whereas the incidence was not different among the groups according to BMI.

CONCLUSIONS

Both BMI and WC were associated with a lower risk of early episodes of CD and NFMI after PCI. In the late period after PCI, WC demonstrated a biphasic, U-shaped association between cardiovascular outcomes and adiposity, whereas BMI did not.

Does the obesity paradox predict functional outcome in intracerebral hemorrhage?

OBJECTIVEBeing overweight or mildly obese has been associated with a decreased risk of death or hospitalization in patients with cardiovascular disease. Similarly, overweight patients admitted to an intensive care unit (ICU) have improved survival up to 1 year after admission. These counterintuitive observations are examples of the "obesity paradox." Does the obesity paradox exist in patients with intracerebral hemorrhage (ICH)? In this study the authors examined whether there was an association between obesity and functional outcome in patients with ICH.METHODSThe authors analyzed 202 patients admitted to the neurological ICU (NICU) who were prospectively enrolled in the Columbia University ICH Outcomes Project between September 2009 and December 2012. Patients were categorized into 2 groups: overweight (body mass index [BMI] ≥ 25 kg/m2) and not overweight (BMI < 25 kg/m2). The primary outcome was defined as survival with favorable outcome (modified Rankin Scale [mRS] score 0-3) versus death or severe disability (mRS score 4-6) at 3 months.RESULTSThe mean age of the patients in the study was 61 years. The mean BMI was 28 ± 6 kg/m2. The mean Glasgow Coma Scale score was 10 ± 4 and the mean ICH score was 1.9 ± 1.3. The overall 90-day mortality rate was 41%. Among patients with a BMI < 25 kg/m2, 24% (17/70) had a good outcome, compared with 39% (52/132) among those with a BMI ≥ 25 kg/m2 (p = 0.03). After adjusting for ICH score, sex, do-not-resuscitate code status, and history of hypertension, being overweight or obese (BMI ≥ 25 kg/m2) was associated with twice the odds of having a good outcome compared with patients with BMI < 25 kg/m2 (adjusted odds ratio 2.05, 95% confidence interval 1.03-4.06, p = 0.04).CONCLUSIONSIn patients with ICH admitted to the NICU, being overweight or obese (BMI ≥ 25 kg/m2) was associated with favorable outcome after adjustment for established predictors. The reason for this finding requires further study.

Obesity paradox in peripheral artery disease

BACKGROUND & AIMS

Previous studies have suggested an obesity survival paradox in patients with peripheral artery disease (PAD). We investigated the influence of obesity and underweight on adverse in-hospital outcomes in PAD.

METHODS

Patients diagnosed with PAD based on ICD-code I70.2 of the German nationwide database were stratified for obesity, underweight and a reference group with normal-weight/over-weight and compared regarding adverse in-hospital outcomes.

RESULTS

Between 01/2005-12/2015, 5,611,484 inpatients (64.8% males) were diagnosed with PAD; of those, 8.9% were coded with obesity and 0.3% with underweight. Obese patients were younger (70 (IQR 63/76) vs. 73 (66/80) years, P < 0.001), more frequently female (36.7% vs. 35.1%, P < 0.001), had less cancer (4.9% vs. 7.9%, P < 0.001) and had less treatment with major amputation (2.6% vs. 3.2%, P < 0.001) compared to the reference group. Overall, 277 876 (5.0%) patients died in-hospital. Obese patients showed lower mortality rate (3.2% vs. 5.1%, P < 0.001) compared to the reference group and reduced risk of in-hospital mortality (OR, 0.617 [95%CI 0.607-0.627], P < 0.001). This "obesity paradox" was demonstrated in obesity classes I (OR, 0.475 [95%CI 0.461-0.490], P < 0.001), II (OR, 0.580 [95%CI 0.557-0.605], P < 0.001), and III (OR, 0.895 [95%CI 0.857-0.934], P < 0.001) and was independent of age, sex and comorbidities. Underweight patients revealed higher in-hospital mortality (6.0% vs. 5.1%, P < 0.001) compared to the reference group (OR, 1.179 [95%CI 1.106-1.257], P < 0.001) and showed higher prevalence of cancer (22.0% vs. 7.9%, P < 0.001).

CONCLUSIONS

Coding for obesity is associated with lower in-hospital mortality in PAD patients relative to those with normal-weight/over-weight. This obesity survival paradox was independent of age, gender and comorbidities and observed for all obesity classes.

Exercise Capacity and the Obesity Paradox in Heart Failure: The FIT (Henry Ford Exercise Testing) Project

OBJECTIVES

To assess the influence of exercise capacity and body mass index (BMI) on 10-year mortality in patients with heart failure (HF) and to synthesize these results with those of previous studies.

PATIENTS AND METHODS

This large biracial sample included 774 men and women (mean age, 60±13 years; 372 [48%] black) with a baseline diagnosis of HF from the Henry Ford Exercise Testing (FIT) Project. All patients completed a symptom-limited maximal treadmill stress test from January 1, 1991, through May 31, 2009. Patients were grouped by World Health Organization BMI categories for Kaplan-Meier survival analyses and stratified by exercise capacity (<4 and ≥4 metabolic equivalents [METs] of task). Associations of BMI and exercise capacity with all-cause mortality were assessed using multivariable-adjusted Cox proportional hazards models.

RESULTS

During a mean follow-up of 10.1±4.6 years, 380 patients (49%) died. Kaplan-Meier survival plots revealed a significant positive association between BMI category and survival for exercise capacity less than 4 METs (log-rank, P=.05), but not greater than or equal to 4 METs (P=.76). In the multivariable-adjusted models, exercise capacity (per 1 MET) was inversely associated, but BMI was not associated, with all-cause mortality (hazard ratio, 0.89; 95% CI, 0.85-0.94; P<.001 and hazard ratio, 0.99; 95% CI, 0.97-1.01; P=.16, respectively).

CONCLUSION

Maximal exercise capacity modified the relationship between BMI and long-term survival in patients with HF, upholding the presence of an exercise capacity-obesity paradox dichotomy as observed over the short-term in previous studies.

Fatness and Fluctuating Body Weight: Effect on Central Vasculature

Weight Cycling (WC) is a prevalent behavior associated with adverse cardiovascular (CV) health. However, a 2010 review on the effects of WC and blood pressure (BP) determined that there was not enough evidence to draw definitive conclusions. Central BP is the principal predictor of CV risk compared to peripheral BP. The influence that WC may have specifically on central BP is unknown. Cross-sectional observation of self-reported history of WC on measures of CV health was undertaken. Seventy-five women completed a Weight and Lifestyle Inventory questionnaire, which is considered a reliable index of WC (r = 0.87, p < 0.001). Measures of visceral fat, BP, arterial stiffness, and VO2peak were taken. Regression equations were used to assess primary predictors of these outcomes. Seventy-five middle aged (39 ± 11 years), obese (32 ± 7 kg/m2), and relatively unfit (24 ± 8 ml·kg-1 min-1) women completed the study. Visceral fat was the strongest predictor of brachial systolic blood pressure (SBP; r2 = 0.283), brachial diastolic blood pressure (DBP; r2 = 0.176), central SBP (r2 = 0.375), and augmentation index (AIx; r2 = 0.535, all p < 0.001). VO2peak was the strongest predictor of central DBP (r2 = 0.062, p = 0.036) and augmentation pressure (AP; r2 = 0.491, p < 0.001). Weight cycling index was associated with visceral fat (r = 0.521, p < 0.001). Visceral fat was a mediator between WC and central SBP (confidence interval [CI] = 0.0053-0.0602), AP (CI = 0.0507-0.4915), AIx (CI = 0.0025-0.0699), and carotid-femoral pulse wave velocity (CI = 0.0115-0.1227; all p < 0.05). WC may increase visceral fat accumulation, which was associated with increased central SBP and measures of arterial stiffness.

Cardiovascular and Metabolic Heterogeneity of Obesity: Clinical Challenges and Implications for Management

The prevalence of obesity has increased globally over the last 2 decades. Although the body mass index has been a convenient and simple index of obesity at the population level, studies have shown that obesity defined by body mass index alone is a remarkably heterogeneous condition with varying cardiovascular and metabolic manifestations across individuals. Adipose tissue is an exquisitely active metabolic organ engaged in cross-talk between various systems; perturbation of adipose tissue results in a pathological response to positive caloric balance in susceptible individuals that directly and indirectly contributes to cardiovascular and metabolic disease. Inadequate subcutaneous adipose tissue expansion in the face of dietary triglycerides leads to visceral and ectopic fat deposition, inflammatory/adipokine dysregulation, and insulin resistance. Conversely, preferential fat storage in the lower body depot may act as a metabolic buffer and protect other tissues from lipotoxicity caused by lipid overflow and ectopic fat. Translational, epidemiological, and clinical studies over the past 30 years have clearly demonstrated a strong link between visceral and ectopic fat and the development of a clinical syndrome characterized by atherogenic dyslipidemia, hyperinsulinemia/glucose intolerance, hypertension, atherosclerosis, and adverse cardiac remodeling/heart failure. This relationship is even more nuanced when clinical entities such as metabolically healthy obesity phenotype and the obesity paradox are considered. Although it is clear that the accumulation of visceral/ectopic fat is a major contributor to cardiovascular and metabolic risk above and beyond the body mass index, implementation of fat distribution assessment into clinical practice remains a challenge. Anthropometric indexes of obesity are easily implemented, but newer imaging-based methods offer improved sensitivity and specificity for measuring specific depots. Lifestyle, pharmacological, and surgical interventions allow a multidisciplinary approach to overweight/obesity that may improve outcomes and align with a public health message to combat the growing epidemic of obesity worldwide and to build healthier lives free of cardiovascular diseases.

Body weight and mortality in COPD: focus on the obesity paradox

The positive association between overweight, obesity, and cardiovascular and all-cause mortality is well established, even though this relation is typically U shaped with an increased risk also in low-weight subjects. However, being overweight or obese has been associated with a better prognosis in subjects suffering from chronic diseases, id est the "obesity paradox". In both community-dwelling and hospitalized patients with COPD, several studies have reported a significant protective effect of obesity on all-cause mortality, indicating that also in obstructive pulmonary diseases, an obesity paradox may be present. Interestingly, the "paradox" is more evident for subjects with severe bronchial obstruction (i.e., a lower FEV1), while in mild-moderate conditions, the weight-related mortality shows a behavior similar to that observed in the general population. Several factors may confound the relation between COPD, obesity and mortality. The lower FEV1 found in obese people may be linked to a restrictive defect rather than to an obstructive one. Due to the modified chest wall mechanical properties-related to increased fat mass-obese COPD patients may present, respect to their lean counterpart, a lower lung hyperinflation which is associated with higher mortality. The traditional classification of COPD attributes to obese "blue bloaters" a low-grade emphysema in opposition to lean "pink puffers"; the fact that emphysema extent is related to mortality may bias the relationship between weight and survival. It is also to underline that the majority of the studies, consider BMI rather than body composition (a better predictor of mortality) when studying the intriguing relation between weight, COPD, and mortality. Reverse bias has also to be taken into account, hypothesizing that an unintentional weight loss may be the deleterious factor related to mortality, rather than considering obesity a protective one. Further prospective studies are needed to shed light on the complexity of this emerging issue.

LEVEL OF EVIDENCE

Level V: Narrative Review.

The introduction of simple cardiorespiratory fitness testing in overweight/obese type 2 diabetics: a pilot study

BACKGROUND

Low level of cardiorespiratory fitness has been recognized as an important independent and modifiable risk factor of increased morbidity and mortality. However, in standard outpatient settings, patients are not routinely screened for fitness and advantages of such testing for the management of type 2 diabetes have not been defined.AimTo describe the toleration of a fast, simple and practicable fitness test (2-min step-in-place test) by overweight/obese type 2 diabetics and their performance indicated by 2-min step-in-place test score (STS). To study short-term anthropometric, functional and metabolic changes following the implementation of the test in the selected population.

METHODS

A total of 33 overweight/obese type 2 diabetics underwent, besides routine examination at the outpatient clinic, the fitness test (group A). Patients were asked to increase their regular physical activity with focus on walking without change in diet and chronic medication. Three to four months later, the subjects were tested again. An identical number of age- and sex-matched obese diabetics followed in our outpatient clinic (without fitness testing), was randomly selected from the Hospital Information System (control group B).FindingsAll patients subjected to fitness testing completed the protocol successfully. STS score was found to have a considerable range with differences between males and females at the borderline of statistical significance. The data are compliant with lower aerobic endurance of obese diabetics compared with healthy population. Within study period, the tested group presented with improvements in STS (referring especially to the males) as well as in several laboratory parameters of glucose and lipid homeostasis, glomerular function and subclinical inflammation with no reflection in anthropometry. Group B demonstrated no significant change. In conclusion, 2-min step-in-place test is fast, undemanding and well-tolerated by patients and personnel. Following its validation based on cardiopulmonary exercise testing, the test may prove recommendable for screening or self-monitoring purposes.

Sex-specific differences in mortality and the obesity paradox of patients with myocardial infarction ages >70 y

OBJECTIVES

Recent studies suggest an obesity survival paradox in patients with acute myocardial infarction (MI). The aim of this study was to investigate the in-hospital mortality of patients aged ≥70 y with acute MI relative to sex and obesity.

METHODS

We selected patients ≥70 y of age with a diagnosis of acute MI based on the International Classification of Diseases (ICD) code I21 in the nationwide database of the Federal Statistical Office of Germany in 2014. We stratified the patients for sex and obesity versus nonobesity, and obesity classes I, II, and III. We compared the in-hospital mortality of these groups.

RESULTS

In 2014, 122 607 patients ≥70 y of age were diagnosed with acute MI in Germany. Among these inpatients 14 342 (11.7%) died during their in-hospital stay. The calculated incidence was 938.46 per 100 000 citizens. Overall, 7874 MI patients (6.4%) had an additional coded diagnosis of obesity; 513 of these patients (6.5%) died while in the hospital. The number of MI events was higher in men than in women (56.2 versus 43.8%), whereas mortality rate of the women exceeded that of the men (12.7 versus 10.9%). Obesity mitigated sex differences in mortality after MI. Overall mortality after acute MI was distinctly lower in all obesity classes relative to MI patients without coded obesity. Relative mortality risk was 0.45, 0.62, and 0.75 in obesity classes I, II, and III, respectively. The present results point to a pronounced obesity paradox in women.

CONCLUSIONS

Obesity is associated with lower in-hospital mortality in patients ≥70 y with MI relative to MI patients without coded obesity. Although women showed higher in-hospital mortality, sex differences were significantly attenuated by obesity. Women showed a pronounced obesity paradox in the higher obesity classes.

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.

Obesity Paradox in Lung Cancer Prognosis: Evolving Biological Insights and Clinical Implications

The survival rate of lung cancer remains low despite the progress of surgery and chemotherapy. With the increasing comorbidity of obesity in patients with lung cancer, new challenges are emerging in the management of this patient population. A key issue of interest is the prognostic effect of obesity on surgical and chemotherapeutic outcomes in patients with lung cancer, which is fueled by the growing observation of survival benefits in overweight or obese patients. This unexpected inverse relationship between obesity and lung cancer mortality, called the obesity paradox, remains poorly understood. The evolving insights into the heterogeneity of obesity phenotypes and associated biological connections with lung cancer progression in recent years may help explain some of the seemingly paradoxical relationship, and well-designed clinical studies looking at the causal role of obesity-associated molecules are expected. Here, we examine potential biological mechanisms behind the protective effects of obesity in lung cancer. We highlight the need to clarify the clinical implications of this relationship toward an updated intervention strategy in the clinical care of patients with lung cancer and obesity.

Combined Association of Cardiorespiratory Fitness and Body Fatness With Cardiometabolic Risk Factors in Older Norwegian Adults: The Generation 100 Study

Objective

To investigate the independent and combined associations of fitness and fatness with cardiometabolic risk factors in older Norwegian women and men.

Patients and Methods

We conducted a cross-sectional study of 505 women and 417 men aged 70 to 77 years enrolled in the Generation 100 study in Norway. Fitness was assessed as peak oxygen uptake and fatness as high body mass index (BMI; ≥25 kg/m²), waist circumference (WC) of 88 cm or greater for women and 102 cm or greater for men, and percent body fat (%BF) of 35% or greater and 25% or greater for women and men, respectively. High cardiometabolic risk was defined as the presence of 2 or more of the following risk factors: elevated triglyceride level, reduced high-density lipoprotein cholesterol concentration, elevated blood pressure, and elevated fasting glucose level or pharmacological treatment of these conditions.

Results

Receiver operating characteristic curve analyses identified fitness levels of less than 25.7 and less than 30.7 mL/kg per minute in women and men, respectively, as critical thresholds for having high cardiometabolic risk. Individuals with levels below these thresholds had an adjusted odds ratio of 2.77 (95% CI, 2.09-3.66) for having high cardiometabolic risk, while high BMI, WC, and %BF had odds ratios (95% CIs) of 3.58 (2.69-4.77), 3.06 (2.29-4.10), and 3.26 (2.47-4.30), respectively. In our combined analyses, being lean did not attenuate the cardiometabolic risk associated with low fitness, and combinations of low fitness and/or high BMI, WC, or %BF cumulatively increased cardiometabolic risk.

Conclusion

Low fitness and indication of fatness were independently and cumulatively associated with poor cardiometabolic health. Our results emphasize the importance of including both physical fitness and body fatness in the assessment of cardiometabolic risk and health promotion efforts in older adults.

Cardiorespiratory Fitness and Adiposity as Determinants of Metabolic Health-Pooled Analysis of Two Twin Cohorts

CONTEXT

The joint effects of cardiorespiratory fitness (CRF) and body composition on metabolic health are not well known.

OBJECTIVE

To examine the associations of CRF, fat-free mass index (FFMI), and fat mass index (FMI) with metabolic health in individual twins and controlling for genetic and shared environmental effects by studying monozygotic intrapair differences.

DESIGN, SETTING, AND PARTICIPANTS

Two cross-sectional samples of healthy adult monozygotic and dizygotic twins were drawn from population-based Danish and Finnish national twin registries (n = 996 and n = 309).

MAIN MEASURES

CRF was defined as VO2max divided by fat-free mass. Insulin sensitivity and acute insulin response indices were derived from an oral glucose tolerance test. A continuous metabolic syndrome score was calculated. Visceral and liver fat were measured in the Finnish sample. Associations were analyzed separately in both cohorts with multivariate linear regression and aggregated with meta-analytic methods.

RESULTS

Insulin sensitivity, acute insulin response, metabolic syndrome score, visceral, and liver fat amount had strong and statistically significant associations with FMI (|β| 0.53 to 0.79), whereas their associations with CRF and FFMI were at most weak (|β| 0.02 to 0.15). The results of the monozygotic intrapair differences analysis showed the same pattern.

CONCLUSIONS

Although FMI is strongly associated with worsening of metabolic health traits, even after controlling for genetic and shared environmental factors, there was little evidence for the effects of CRF or FFMI on metabolic health. This suggests that changing FMI rather than CRF or FFMI may affect metabolic health irrespective of genetic or early environmental determinants.

Body Mass Index and Mortality

Although the prevalence of obesity, a well-known risk factor for various chronic diseases such as hypertension, type 2 diabetes and dyslipidemia, is rapidly increasing worldwide, the association of obesity with all-cause mortality remains controversial. Many previous epidemiologic studies have demonstrated a U-shaped relationship between obesity and mortality, suggesting that there is an obesity paradox. However, recent large-scale meta-analyses found contradictory results that both overweight and obese subjects exhibited a significant increase in all-cause mortality. This review summarizes the key epidemiologic studies on the association of obesity with mortality and thoroughly examines the causes of the obesity paradox and the precautions needed in the interpretation of this clinical evidence.

Nonlinear association of BMI with all-cause and cardiovascular mortality in type 2 diabetes mellitus: a systematic review and meta-analysis of 414,587 participants in prospective studies

AIMS/HYPOTHESIS

The relationship between BMI and mortality has been extensively investigated in the general population; however, it is less clear in people with type 2 diabetes. We aimed to assess the association of BMI with all-cause and cardiovascular mortality in individuals with type 2 diabetes mellitus.

METHODS

We searched electronic databases up to 1 March 2016 for prospective studies reporting associations for three or more BMI groups with all-cause and cardiovascular mortality in individuals with type 2 diabetes mellitus. Study-specific associations between BMI and the most-adjusted RR were estimated using restricted cubic splines and a generalised least squares method before pooling study estimates with a multivariate random-effects meta-analysis.

RESULTS

We included 21 studies including 24 cohorts, 414,587 participants, 61,889 all-cause and 4470 cardiovascular incident deaths; follow-up ranged from 2.7 to 15.9 years. There was a strong nonlinear relationship between BMI and all-cause mortality in both men and women, with the lowest estimated risk from 31-35 kg/m² and 28-31 kg/m² (p value for nonlinearity <0.001) respectively. The risk of mortality at higher BMI values increased significantly only in women, whilst lower values were associated with higher mortality in both sexes. Limited data for cardiovascular mortality were available, with a possible inverse linear association with BMI (higher risk for BMI <27 kg/m²).

CONCLUSIONS/INTERPRETATION

In type 2 diabetes, BMI is nonlinearly associated with all-cause mortality with lowest risk in the overweight group in both men and women. Further research is needed to clarify the relationship with cardiovascular mortality and assess causality and sex differences.

Eat and Death: Chronic Over-Eating

Obesity-related co-morbidities decrease life quality, reduce working ability and lead to early death. The total amount of dietary fat consumption may be the most potent food-related risk factor for weight gain. In this respect, dietary intake of high-caloric, high-fat diets due to chronic over-eating and sedentary lifestyle lead to increased storage of triglycerides not only in adipose tissue but also ectopically in other tissues . Increased plasma concentrations of non-esterified free fatty acids and lipid-overloaded hypertrophic adipocytes may cause insulin resistance in an inflammation-independent manner. Even in the absence of metabolic disorders, mismatch between fatty acid uptake and utilization leads to the accumulation of toxic lipid species resulting in organ dysfunction. Lipid-induced apoptosis, ceramide accumulation, reactive oxygen species overproduction, endoplasmic reticulum stress, and mitochondrial dysfunction may play role in the pathogenesis of lipotoxicity. The hypothalamus senses availability of circulating levels of glucose, lipids and amino acids, thereby modifies feeding according to the levels of those molecules. However, the hypothalamus is also similarly vulnerable to lipotoxicity as the other ectopic lipid accumulated tissues. Chronic overnutrition most likely provides repetitive and persistent signals that up-regulate inhibitor of nuclear factor kappa B kinase beta subunit/nuclear factor kappa B (IKKβ/NF-κB) in the hypothalamus before the onset of obesity. However, the mechanisms by which high-fat diet induced peripheral signals affect the hypothalamic arcuate nucleus remain largely unknown. In this chapter, besides lipids and leptin, the role of glucose and insulin on specialized fuel-sensing neurons of hypothalamic neuronal circuits has been debated.