Smoking and reverse causation create an obesity paradox in cardiovascular disease

Obesity paradox: is a high body mass index positively influencing survival outcomes in gynecological cancers? A systematic review and meta-analysis

OBJECTIVE

Obesity represents an exponentially growing preventable disease leading to different health complications, particularly when associated with cancer. In recent years, however, an 'obesity paradox' has been hypothesized where obese individuals affected by cancer counterintuitively show better survival rates. The aim of this systematic review and meta-analysis is to assess whether the prognosis in gynecological malignancies is positively influenced by obesity.

METHODS

This study adheres to PRISMA guidelines and is registered with PROSPERO. Studies reporting the impact of a body mass index (BMI) of >30 kg/m2 compared with <30 kg/m2 in patients with gynecological cancers listed in PubMed, Google Scholar and ClinicalTrials.gov were included in the analysis. The Quality Assessment of Diagnostic Accuracy Studies 2 tool (QUADAS-2) was used for quality assessment of the selected articles.

RESULTS

Twenty-one studies were identified for the meta-analysis, including 14 108 patients with cervical, ovarian, or endometrial cancer. There was no benefit in 5-year overall survival for obese patients compared with non-obese patients (OR 1.2, 95% CI 1.00 to 1.44, p=0.05; I2=71%). When pooling for cancer sub-groups, there were no statistically significant differences in 5-year overall survival in patients with cervical cancer and 5-year overall survival and progression-free survival in patients with ovarian cancer. For obese women diagnosed with endometrial cancer, a significant decrease of 44% in 5-year overall survival (p=0.01) was found, with no significant difference in 5-year disease-free survival (p=0.78).

CONCLUSION

According to the results of the present meta-analysis, a BMI of ≥30 kg/m2 does not have a positive prognostic effect on survival compared with a BMI of <30 kg/m2 in women diagnosed with gynecological cancers. The existence of the 'obesity paradox' in other fields, however, suggests the importance of further investigations with prospective studies.

The Prognostic Value of Advanced Lung Cancer Inflammation Index in Elderly Patients with Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

This study aimed to investigate the predictive value of advanced lung cancer inflammation index (ALI) for major adverse cardiovascular events (MACEs) in elderly patients with acute coronary syndrome (ACS).A total of 586 ACS patients undergoing percutaneous coronary intervention (PCI) over 65 years old between January 2017 and December 2018 were retrospectively collected. The patients were divided into two groups by the optimal cutoff value of ALI. Spearman rank correlation coefficient was used to evaluate the correlation between ALI and the Global Registry of Acute Coronary Events (GRACE). Time-dependent receiver operating characteristic (ROC) curves, Cox survival analysis, and Kaplan Meier curves were used to assess the predictive value of ALI for MACEs.Spearman's nonparametric test revealed a moderate correlation between ALI and the GRACE (r: -0.417, P < 0.001). Time-dependent ROC curves showed that the area under the curve for ALI was 0.751 (95% CI, 0.699-0.798) in predicting MACEs, higher than Geriatric Nutritional Risk Index (0.531, 95% CI 0.435-0.627) and Prognostic Nutritional Index (0.590, 95% CI 0.505-0.676), and for combined diagnostic models (ALI + GRACE) was 0.913, (95% CI 0.875 - 0.942, P < 0.001). Multivariate Cox analysis demonstrated that ALI (HR: 0.974, 95% CI: 0.952-0.996, P = 0.017) was an independent risk factor for MACEs. Kaplan Meier survival analysis showed that the cumulative incidence of MACEs was significantly higher in elderly ACS patients with lower ALI (log-rank test, P < 0.001).ALI could be a nutrition-inflammation indicator with independent predictive value for long-term MACEs of elderly ACS patients after PCI.

The Relationship of Waist Circumference with the Morbidity of Cardiovascular Diseases and All-Cause Mortality in Metabolically Healthy Individuals: A Population-Based Cohort Study

Background

This study explores the relationship between waist circumference and morbidity of cardiovascular diseases (CVD) and all-cause mortality in metabolically healthy individuals.

Methods

A cohort of 5775 metabolically healthy participants from the 2001-2014 US National Health and Nutrition Examination Survey and National Death Index database was tracked over a median period of 81 months. These participants were divided into quartiles (Q1, Q2, Q3, Q4) based on increasing waist circumference. To compensate for missing covariates, multivariate multiple imputation methods were used. Adjusted logistic regression models were employed to examine the correlation between waist circumference and cardiovascular disease prevalence. Furthermore, Kaplan-Meier curves and multivariable Cox regression analysis were utilized to evaluate the association between waist circumference and all-cause mortality, both qualitatively and quantitatively.

Results

The adjusted logistic regression model indicated that a 10 cm increase in waist circumference was associated with a 1.45 times higher prevalence of CVD. As a categorical variable, there was a significant upward trend in CVD incidence across quartiles of waist circumference. The adjusted odds ratios (95% confidence intervals) were 2.41 (1.13-5.53) for Q2, 2.65 (1.18-6.39) for Q3, and 2.53 (0.9-7.44) for Q4, compared to Q1. Notably, individuals with high waist circumference showed significantly poorer survival compared to those with low waist circumference (p = 0.008). The Cox regression analysis revealed that each 10 cm increase in waist circumference contributed to an ~8% increase in all-cause mortality.

Conclusions

This study underscores a positive correlation between waist circumference and both CVD morbidity and all-cause mortality in metabolically healthy individuals. The findings highlight the significance of routinely monitoring waist circumference for effective CVD risk management, regardless of metabolic health status.

Pulmonary Embolism in Patients Admitted With Takotsubo Cardiomyopathy: Prevalence and Associated In-Hospital Adverse Events

Introduction  Takotsubo cardiomyopathy (TCM) is a poorly understood condition typically characterized by abnormal left ventricular wall motion without causative coronary artery disease and typically presents in post-menopausal women after the experience of a physical or emotional stressor. The pathophysiology of TCM is complex and multifactorial, resulting in complications with varied severity; one of the most concerning complications is thromboembolism, specifically, pulmonary embolism (PE), which is understudied in its relation to TCM. The purpose of this study was to characterize and evaluate the real-world prevalence and outcomes of PE in TCM. Methods  Data were derived from the National Inpatient Sample database from January 2016 to December 2019. The primary outcomes assessed were baseline and hospital admission characteristics and comorbidities for patients with TCM with and without PE. Outcomes for TCM patients with PE and predictors of mortality in TCM were also analyzed. Results  PE developed in 788 of 40,120 patients with TCM (1.96%). After multivariate adjustment, PE was found to be independently associated with intracardiac thrombus (adjusted odds ratio (aOR) 2.067; 95% confidence interval (CI): 1.198-3.566; p = 0.009) and right heart catheterization (RHC) (aOR: 1.971; 95% CI: 1.160-3.350; p = 0.012). Mortality in patients with TCM was associated with, among other factors, age in years at admission (aOR: 1.104; 95% CI: 1.010-1.017; p = 0.001), African American race (aOR: 1.191; 95% CI: 1.020-1.391; p = 0.027), Asian or Pacific Islander race (aOR: 1.637; 95% CI: 1.283-2.090; p = 0.001), coagulopathy (aOR: 3.393; 95% CI: 2.889-2.986; p = 0.001), liver disease (aOR: 1.446; 95% CI: 1.147-1.824; p = 0.002), atrial fibrillation (aOR: 1.460; 95% CI: 1.320-1.615; p = 0.001), and pulmonary embolism (aOR: 2.217; 95% CI: 1.781-2.760; p = 0.001). Conclusion  In a large cohort of patients admitted with TCM, we found the prevalence of PE to be 1.96%. PE, along with comorbidities such as coagulopathy and atrial fibrillation, was found to be a significant predictor of mortality in this patient cohort.

Lifestyle and host determinants of antitumor immunity and cancer health disparities

Lifestyle factors exert profound effects on host physiology and immunology. Disparities in cancer outcomes persist as a complex and multifaceted challenge, necessitating a comprehensive understanding of the interplay between host environment and antitumor immune responses. Determinants of health - such as obesity, diet, exercise, stress, or sleep disruption - have the potential for modification, yet some exert long-lasting effects and may challenge the notion of complete reversibility. Herein we review intersectional considerations of lifestyle immunity and the impact on tumor immunology and disparities in cancer outcomes, with a focus on obesity.

The Taiwanese Map of Axial Spondyloarthritis: Living with the Condition

Background and Objective: The International Map of Axial Spondyloarthritis (IMAS) explores the physical, psychological, and social experiences of patients with axial spondyloarthritis (axSpA). This initiative is now being expanded to Taiwan as the Taiwanese Map of Axial Spondyloarthritis (TMAS). We aim to provide rheumatologists with insights into the perspectives of Taiwanese patients, enabling physicians to better understand the unmet needs of these patients and optimize their management. Materials and Methods: The TMAS is a cross-sectional study gathering data through an online survey of axSpA patients, promoted by the Ankylosing Spondylitis Caring Society of R.O.C. (ASCARES), conducted from July 2017 to March 2018 by Ipsos, and analyzed by the Health & Territory Research (HTR) group of the University of Seville. The questionnaire includes 99 questions that cover domains such as patient profile, diagnosis, habits/lifestyle, employment status, physical/psychological health status, social support, use of healthcare services, and treatments. Results: A total of 112 axSpA patients were included in this survey. The mean age was 38.6 years and 75.0% were male. The average diagnostic delay was 3 years, and 19.6% reported extra-articular manifestations. Out of the 49 respondents who reported HLA-B27 information, 35 were HLA-B27-positive. The disease burden was high, with a mean BASDAI score of 4.9 and 75.9% having a mild to moderate degree of spinal stiffness. Furthermore, they were socially and psychologically burdened, with 88.4% experiencing work-related issues and 25.9% suffering from anxiety. Conclusions: The TMAS sheds light on the overall perspective of axSpA patients in Taiwan. The TMAS shows shorter diagnostic delay compared to patients from the EMAS. However, high disease activity and significant psychological distress still trouble the patients, causing functional impairments and even leading to career failures. Understanding the perspective of axSpA patients can help rheumatologists adjust treatment strategies to their unmet needs and improve their disease outcomes.

The Influence of Obesity on Outcomes with Immune Checkpoint Blockade: Clinical Evidence and Potential Biological Mechanisms

Immune checkpoint blockade (ICB) is a mainstay of treatment for advanced cancer, yet tumor response and host toxicity are heterogenous in those patients who receive ICB. There is growing interest in understanding how host factors interact with tumor intrinsic properties and the tumor microenvironment to influence the therapeutic index with ICB. Obesity, defined by body mass index, is a host factor associated with improved outcomes in select cancers when treated with ICB. While the biological mechanism for this obesity paradox is not fully understood, pre-clinical and translational studies suggest obesity may potentially impact tumor metabolism, inflammation, and angiogenesis. Herein, we summarize clinical studies that support an obesity paradox with ICB, explore potential biological mechanisms that may account for the obesity paradox, and address methodological challenges to consider when studying obesity and treatment outcomes.

Unfolding the reality of the smoking paradox in a South Asian cohort of patients presenting with ST-elevation acute coronary syndrome undergoing primary percutaneous coronary intervention

Objectives

Smoking is a potent risk factor for coronary artery disease, but there is controversy about its protective nature in terms of prognosis in ST-elevation acute coronary syndrome patients undergoing primary percutaneous coronary intervention. So, the main objective of this study is to unfold this controversy in a South Asian population in terms of clinical angiographic parameters and its in-hospital outcomes.

Methods

In this study, we included 1756 consecutive patients diagnosed with ST-elevation acute coronary syndrome undergoing primary percutaneous coronary intervention. Patients were classified into smokers and non-smokers, and the in-hospital mortality rate was compared. Multivariable logistic regression analysis was performed to evaluate the paradoxical role of smoking.

Results

Smokers were younger (53.78 ± 11.16 years vs 56.43 ± 11.17 years; p < 0.001) and more frequently men (98.7% vs 69.9%; p < 0.001) and had less diabetes (19.6% vs 44.8%; p < 0.001) and hypertension (38.5% vs 64.9%; p < 0.001). Smokers presented less frequently in Killip III (5.6% vs 8.1%; p < 0.001) and Killip IV (2.5% vs 4.8%; p < 0.001). Smokers mostly had single vessel disease (41.7% vs 34.4%; p = 0.013), whereas non-smokers had the multi-vessel disease and frequently presented with total occlusion of the culprit vessel (64.6% vs 58.8%; p = 0.040). Smokers have significantly lesser mortality (1.8% vs 4.3%; p = 0.009) compared to non-smokers with an odds ratio of 0.41 (95% confidence interval (CI): 0.21-0.82, p = 0.011); however, adjusted odds ratio on multivariable analysis was 0.67 (95% CI: 0.31-1.41, p = 0.290).

Conclusions

The paradoxical protective role of smoking is the confounding effect of mainly younger age, less coronary artery disease burden, lower prevalence of diabetes and hypertension, and lower Killip III/IV at presentation.

Obesity and renal cell carcinoma: Biological mechanisms and perspectives

Obesity, defined by body mass index (BMI), is an established risk factor for specific renal cell carcinoma (RCC) subtypes such as clear cell RCC, the most common RCC histology. Many studies have identified an association between obesity and improved survival after diagnosis of RCC, a potential "obesity paradox." Clinically, there is uncertainty whether improved outcomes observed after diagnosis are driven by stage, type of treatment received, or artifacts of longitudinal changes in weight and body composition. The biological mechanisms underlying obesity's influence on RCC are not fully established, but multiomic and mechanistic studies suggest an impact on tumor metabolism, particularly fatty acid metabolism, angiogenesis, and peritumoral inflammation, which are known to be key biological hallmarks of clear cell RCC. Conversely, high-intensity exercise associated with increased muscle mass may be a risk factor for renal medullary carcinoma, a rare RCC subtype that predominantly occurs in individuals with sickle hemoglobinopathies. Herein, we highlight methodologic challenges associated with studying the influence of obesity on RCC and review the clinical evidence and potential underlying mechanisms associating RCC with BMI and body composition.

The Impact of Nonalcoholic Fatty Liver Disease on Severe Community-Acquired Pneumonia Outcomes

Community-acquired pneumonia (CAP) is one of the leading causes of morbidity and mortality, while nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease. NAFLD is associated with systemic changes in immune response, possibly linked to CAP severity. However, the impact of NAFLD on CAP outcomes has not been determined. The aim of this study was to evaluate clinical course, complications and outcomes of severe CAP requiring ICU treatment in patients with NAFLD in the pre-COVID-19 era. A retrospective cohort study included 138 consecutively hospitalized adult patients with severe CAP admitted to the ICU during a 4-year period: 80 patients with NAFLD and 58 controls. Patients with NAFLD more frequently presented with ARDS (68.7% vs. 43.1%), and required invasive mechanical ventilation (86.2% vs. 63.8%), respiratory ECMO (50% vs. 24.1%), and continuous renal replacement therapy (62.5% vs. 29.3%). Mortality was significantly higher in the NAFLD group (50% vs. 20.7%), and the time from hospital admission to death was significantly shorter. In survival analysis, NAFLD (HR 2.21, 95%CI 1.03-5.06) was associated with mortality independently of other components of metabolic syndrome. In conclusion, our study identified NAFLD as an independent predictor of mortality in patients with severe CAP.

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.

Associations between Body Mass Index, Waist Circumference, and Myocardial Infarction in Older Adults Aged over 75 Years: A Population-Based Cohort Study

Background and Objectives: Body mass index (BMI) is widely used as a standard screening method for obesity and an indicator of related diseases. However, its inability to distinguish between lean body mass and body fat limits its utility. This limitation may be more prominent in older populations, wherein age-related sarcopenia and increased visceral fat due to the redistribution of adipose tissue may preclude a precise estimation of obesity. Many studies suggest that waist circumference (WC) is more strongly related to obesity-related diseases. There are also different opinions on whether the obesity paradox is real or a result of confusing interpretations. This study seeks to determine the association between myocardial infarction (MI), BMI, and WC in older adults and to determine if BMI and WC can reliably predict the risk of cardiovascular disease. Materials and Methods: We conducted a cohort study of older Korean adults aged over 75 years registered in the National Health Insurance System Senior database. Results: The results from the analysis using model 5, which was adjusted for each study variable, showed that the lower the BMI, the higher the hazard ratio (HR) of MI and vice versa. On the other hand, groups with lower than normal WC showed lower HR; even if it was higher, the difference was not statistically significant. Those with abdominal obesity tended to have an increased HR of MI. Conclusions: This study found that HR for MI has a negative relationship with BMI, whereas it has a positive relationship with WC. Furthermore, WC is a more appropriate indicator for predicting the risk of MI in the older population.

The relative impact of underweight, overweight, smoking, and physical inactivity on health and associated costs in Indonesia: propensity score matching of a national sample

Background

Indonesia is in the middle of a rapid epidemiological transition with an ageing population and increasing exposure to risk factors for chronic conditions. This study examines the relative impacts of obesity, tobacco consumption, and physical inactivity, on non-communicable diseases multimorbidity, health service use, catastrophic health expenditure (CHE), and loss in employment productivity in Indonesia.

Methods

Secondary analyses were conducted of cross-sectional data from adults aged ≥ 40 years (n = 12,081) in the Indonesian Family Life Survey 2014/2015. We used propensity score matching to assess the associations between behavioural risk factors and health service use, CHE, employment productivity, and multimorbidity.

Results

Being obese, overweight and a former tobacco user was associated with a higher number of chronic conditions and multimorbidity (p < 0.05). Being a former tobacco user contributed to a higher number of outpatient and inpatient visits as well as CHE incidences and work absenteeism. Physical inactivity relatively increased the number of outpatient visits (30% increase, p < 0.05) and work absenteeism (21% increase, P < 0.06). Although being underweight was associated with an increased outpatient care utilisation (23% increase, p < 0.05), being overweight was negatively associated with CHE incidences (50% decrease, p < 0.05).

Conclusion

Combined together, obesity, overweight, physical inactivity and tobacco use contributed to an increased number of NCDs as well as medical costs and productivity loss in Indonesia. Interventions addressing physical and behavioural risk factors are likely to have substantial benefits for individuals and the wider society in Indonesia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-08546-6.

Four-way decomposition of effect of cigarette smoking and body mass index on serum lipid profiles

Objective

Smoking and obesity are established risk factors of dyslipidemia, however, the interplay between them has not been well studied. This study aims to explore the joint effect of smoking and body mass index (BMI) on serum lipid profiles.

Methods

The study consisted of 9846 Chinese adults (mean age = 49.9 years, 47.6% males, 31.2% ever smokers), based on the China Health and Nutrition Survey. Serum lipid profiles included total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein A (APO-A), and apolipoprotein B (Apo-B). The joint effect of smoking and BMI on serum lipids were examined by the four-way decomposition analysis and multivariate linear regression models.

Results

The four-way decomposition showed that the interplay between smoking and BMI was complicated. There was only indirect effect (the mediated effect) between smoking and BMI on TC, LDL-C and APO-B. The pure indirect effect was -0.023 for TC, -0.018 for LDL-C, and -0.009 for APO-B. For TG, HDL-C and APO-A, the interaction effect was dominant. The reference interaction (the interactive effect when the mediator is left to what it would be in the absence of exposure) was 0.474 (P < 0.001) for TG, -0.245 (P = 0.002) for HDL-C, and -0.222 (P < 0.001) for APO-A, respectively. The effect of BMI on TG, HDL-C and APO-A were significantly higher in smokers than in nonsmokers (TG: 0.151 in smokers versus 0.097 in nonsmokers, HDL-C: -0.037 versus -0.027, APO-A: -0.019 versus -0.009, P for difference < 0.001 for all).

Conclusion

These findings illustrate the joint effects of smoking and BMI on serum lipid profiles. There were significant interaction effects of smoking and BMI on TG, HDL-C and APO-A, while BMI maybe a mediator for the association of smoking with TC, LDL-C and APO-B. The effects between them were rather complex. Smoking cessation is necessary, especially for those overweight.

Obesity paradox in joint replacement for osteoarthritis - truth or paradox?

Obesity is associated with an increased risk of cardiovascular disease (CVD) and other adverse health outcomes. In patients with pre-existing heart failure or coronary heart disease, obese individuals have a more favourable prognosis compared to individuals who are of normal weight. This paradoxical relationship between obesity and CVD has been termed the 'obesity paradox'. This phenomenon has also been observed in patients with other cardiovascular conditions and diseases of the respiratory and renal systems. Taking into consideration the well-established relationship between osteoarthritis (OA) and CVD, emerging evidence shows that overweight and obese individuals undergoing total hip or knee replacement for OA have lower mortality risk compared with normal weight individuals, suggesting an obesity paradox. Factors proposed to explain the obesity paradox include the role of cardiorespiratory fitness ("fat but fit"), the increased amount of lean mass in obese people, additional adipose tissue serving as a metabolic reserve, biases such as reverse causation and confounding by smoking, and the co-existence of older age and specific comorbidities such as CVD. A wealth of evidence suggests that higher levels of fitness are accompanied by prolonged life expectancy across all levels of adiposity and that the increased mortality risk attributed to obesity can be attenuated with increased fitness. For patients about to have joint replacement, improving fitness levels through physical activities or exercises that are attractive and feasible, should be a priority if intentional weight loss is unlikely to be achieved.

No obesity paradox in patients with community-acquired pneumonia - secondary analysis of a randomized controlled trial

Background

Obesity is associated with an increased risk for several chronic conditions and mortality. However, there are data in support of beneficial outcome in acute medical conditions such as community-acquired pneumonia (CAP), termed “obesity paradox”. The aim of this study was to test the association of BMI with clinical outcomes in a large randomized clinical trial of patients hospitalized with CAP.

Design and Methods

In total, 773 patients hospitalized with CAP were included in this study. Patients were stratified into four groups according to their baseline BMI (underweight <18.5, normal weight 18.5–25, overweight 25–30, and obese >30 kg/m²). The primary endpoint was time to clinical stability (TTCS). Secondary endpoints included 30-day mortality, ICU admission rate, CAP complications, and duration of antibiotic treatment.

Results

BMI and TTCS had a U-shaped association with shortest TTCS among patients at an overweight BMI of 28 kg/m². In patients with obesity, there was a trend towards reduced hazards to reach clinical stability when compared to patients with normal weight (HR 0.82; 95%CI, 0.67–1.02; p = 0.07). In underweight BMI group TTCS was prolonged by 1 day (HR 0.63; 95%CI, 0.45–0.89; p = 0.008). There was no difference in mortality or ICU admission rates between BMI groups (p > 0.05). While in the underweight BMI group the total duration of antibiotic treatment was prolonged by 2.5 days (95%CI, 0.88–4.20, p = 0.003), there was no difference in patients with obesity.

Conclusions

The overweight BMI group had shortest time to clinical stability. While underweight patients face adverse clinical outcomes, there is neither beneficial, nor adverse outcome in patients with obesity hospitalized for CAP.

ClinicalTrials.gov (registration no. NCT00973154).

Impact of BMI on Long-Term Outcomes in Patients with ST-Segment Elevation Myocardial Infarction after Primary Percutaneous Coronary Intervention

AIM

Obesity paradox remains a point of debate in ST-segment elevation myocardial infarction (STEMI) patients. The aim of this study was to examine the relationship between body mass index (BMI) and clinical outcomes in STEMI patients undergoing primary percutaneous coronary intervention (PPCI).

METHODS

Outcomes were assessed in 1429 STEMI patients undergoing PPCI between January 2009 and January 2010 in Beijing. Patients were classified into 6 groups according to age (the younger and elderly groups consisting of patients ≤65 and > 65 years old) and baseline BMI (normal weight, BMI < 24 kg/m²; overweight, 24 kg/m² ≤BMI < 28 kg/m²; obese, BMI ≥ 28 kg/m²). The primary outcome was death, acute myocardial infarction (AMI), or revascularization.

RESULTS

On long-term follow-up (mean follow-up of 59 months), 13.9% of patients experienced the adverse event. Multivariate logistic regression analyses showed that low BMI was a significant predictor of the primary outcome only in the younger group. The odds ratio for overweight in comparison with normal weight was 0.741 (95% CI: 0.413-0.979; p = 0.038), the odds radio for obesity in comparison with normal-weight patients was 0.508 (95% CI: 0.344-0.750; p = 0.016) in the younger group. In the elderly group, diabetes, hypertension, triple disease, regular exercise, angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blockers (ARBs) use after discharge, and bleeding complication were associated with primary outcome.

CONCLUSION

The obesity paradox was recognized only in the younger age group in STEMI patients undergoing PPCI.

Association Between Obesity and Lower Short- and Long-Term Mortality in Coronary Care Unit Patients: A Cohort Study of the MIMIC-III Database

INTRODUCTION

Obesity has long been considered an independent risk factor for cardiovascular diseases (CVD), even in the COVID-19 pandemic. However, recent studies have found that a certain degree of obesity may be beneficial for patients who have already suffered from CVD, which is called the "obesity paradox". Our objective was to investigate whether the obesity paradox existed in coronary care unit (CCU) patients and the relationship between body mass index (BMI) and short- and long-term mortality.

METHODS

We performed a cohort analysis of 3,502 adult CCU patients from the Medical Information Mart for Intensive Care III (MIMIC-III) database. The patients were divided into four groups according to the WHO BMI categories. Both multivariable logistic regression and Cox regression were used to reveal the relation between BMI and mortality. Subgroup analyses were performed based on Simplified Acute Physiology Score (SAPS) and age.

RESULTS

After adjusting for confounders, obese patients had 33% and 30% lower mortality risk at 30-day and 1-year (OR 0.67, 95% CI 0.51 to 0.89; HR 0.70, 95% CI 0.59 to 0.83; respectively) compared with normal-weight patients, while the underweight group were opposite, with 141% and 81% higher in short- and long-term (OR 2.41, 95% CI 1.37 to 4.12; HR 1.81, 95% CI 1.34 to 2.46; respectively). Overweight patients did not have a significant survival advantage at 30-day (OR 0.91, 95% CI 0.70 to 1.17), but did have a 22% lower mortality risk at 1-year (HR 0.78; 95% CI 0.67 to 0.91). The results were consistent after being stratified by SAPS and age.

CONCLUSION

Our study supports that obesity improved survival at both 30-day and 1-year after CCU admission, and the obesity paradox existed in CCU patients.

Obesity Duration, Severity, and Distribution Trajectories and Cardiovascular Disease Risk in the Atherosclerosis Risk in Communities Study

Background Research examining the role of obesity in cardiovascular disease (CVD) often fails to adequately consider heterogeneity in obesity severity, distribution, and duration. Methods and Results We here use multivariate latent class mixed models in the biracial Atherosclerosis Risk in Communities study (N=14 514; mean age=54 years; 55% female) to associate obesity subclasses (derived from body mass index, waist circumference, self-reported weight at age 25, tricep skinfold, and calf circumference across up to four triennial visits) with total mortality, incident CVD, and CVD risk factors. We identified four obesity subclasses, summarized by their body mass index and waist circumference slope as decline (4.1%), stable/slow decline (67.8%), moderate increase (24.6%), and rapid increase (3.6%) subclasses. Compared with participants in the stable/slow decline subclass, the decline subclass was associated with elevated mortality (hazard ratio [HR] 1.45, 95% CI 1.31, 1.60, P<0.0001) and with heart failure (HR 1.41, 95% CI 1.22, 1.63, P<0.0001), stroke (HR 1.53, 95% CI 1.22, 1.92, P=0.0002), and coronary heart disease (HR 1.36, 95% CI 1.14, 1.63, P=0.0008), adjusting for baseline body mass index and CVD risk factor profile. The moderate increase latent class was not associated with any significant differences in CVD risk as compared to the stable/slow decline latent class and was associated with a lower overall risk of mortality (HR 0.85, 95% CI 0.80, 0.90, P<0.0001), despite higher body mass index at baseline. The rapid increase latent class was associated with a higher risk of heart failure versus the stable/slow decline latent class (HR 1.34, 95% CI 1.10, 1.62, P=0.004). Conclusions Consideration of heterogeneity and longitudinal changes in obesity measures is needed in clinical care for a more precision-oriented view of CVD risk.

Healthy Lifestyle and Mortality Among Adults Receiving Hemodialysis: The DIET-HD Study

RATIONALE & OBJECTIVE

A healthy lifestyle promotes cardiovascular health and reduces cardiac-related mortality in the general population but its benefits for people receiving maintenance hemodialysis are uncertain.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

5,483 of 9,757 consecutive adults receiving maintenance hemodialysis (January 2014 to June 2017, median dialysis vintage: 3.6 yrs) in a multinational private dialysis network and with complete lifestyle data.

EXPOSURES

Based on the American Heart Association's recommendations for cardiovascular prevention, a modified healthy lifestyle score was the sum of four components addressing use of smoking tobacco, physical activity, diet, and control of systolic blood pressure.

OUTCOMES

Cardiovascular and all-cause mortality.

ANALYTICAL APPROACH

Adjusted proportional hazards (aHRs) regression analyses with country as a random effect to estimate the associations between lifestyle score (low [0-2 points] as the referent, medium [3-5], and high [6-8]) and mortality. Associations were expressed as aHRs with 95% confidence intervals (CIs).

RESULTS

During a median of 3.8 years (17,451 person-years in total), there were 2,163 deaths, of which 826 were related to cardiovascular disease. Compared to patients with a low lifestyle score, the aHRs (95% CIs) for all-cause mortality among those with medium and high lifestyle scores were 0.75 (0.65-0.85) and 0.64 (0.54-0.76), respectively. Compared to patients with a low lifestyle score, the aHRs (95% CIs) for cardiovascular mortality among those with medium and high lifestyle scores were 0.73 (0.59-0.91) and 0.65 (0.49-0.85), respectively.

LIMITATIONS

Self-reported lifestyle, data-driven approach.

CONCLUSIONS

A healthier lifestyle is associated with lower all-cause and cardiovascular mortality among patients receiving maintenance hemodialysis.

Obesity and Cardiomyopathy

While much has been written about the syndrome of diabetic cardiomyopathy, clinicians and research scientists are now beginning to realize that an entirely unique syndrome exists, albeit with several commonalities to the diabetic syndrome, that being obesity cardiomyopathy. This syndrome develops independent of such comorbidities as hypertension, myocardial infarction and coronary artery disease; and it is characterized by specific alterations in adipose tissue function, inflammation and metabolism. Recent insights into the etiology of the syndrome and its consequences have focused on the roles played by altered intracellular calcium homeostasis, reactive oxygen species, and mitochondrial dysfunction. A timely and comprehensive review by Ren, Wu, Wang, Sowers and Zhang (1) identifies unique mechanisms underlying this syndrome, its relationship to heart failure and the recently identified incidence of COVID-19-related cardiovascular mortality. Importantly, the review concludes by advancing recommendations for novel approaches to the clinical management of this dangerous form of cardiomyopathy.

Challenging the obesity paradox: extreme obesity and COPD mortality in the SUMMIT trial

Populations with COPD demonstrate higher survival in overweight and obese compared with normal weight; the “obesity paradox”. Relationships in less-severe COPD are unclear, as is the impact of cardiovascular risk, and few studies include individuals at extremes of obesity.

 We examined the relationship between body mass index (BMI; defined as underweight: <20 kg·m⁻², normal: 20–25 kg·m⁻², overweight: 25– <30 kg·m⁻², obese class I: 30– <35 kg·m⁻², class II: 35– <40 kg·m⁻² and class III: ≥40 kg·m⁻²), morbidity, and mortality in the SUMMIT trial population (n=16 485), characterised by moderate COPD and heightened cardiovascular risk with a substantial proportion with class III obesity. The association between BMI category and time to event was modelled via proportional hazards (reference normal weight) adjusted for demographics and cardiorespiratory disease.

 Consistent with the paradox, underweight individuals demonstrated higher mortality (hazard ratio (HR) 1.31 (95% CI 1.04–1.64)), with lower mortality among overweight (HR 0.62 (95% CI 0.52–0.73)) and obese class I (HR 0.75 (95% CI 0.62–0.90)). However, mortality increased in obese class III (HR 1.36 (95% CI 1.00–1.86)). Death was primarily attributable to cardiovascular causes.

 Within a large, multinational cohort with moderate COPD and increased cardiovascular risk, the phenomenon of reduced mortality with obesity did not persist at BMI >40 kg·m⁻², suggesting that obesity may not remain protective at the extremes in this population.

In a population with moderate COPD, at heightened cardiovascular risk and containing a substantial proportion of individuals with BMI ≥40 kg/m², BMI and mortality demonstrate a U-shaped (rather than J-shaped) relationshiphttps://bit.ly/3hDztI6

What's new in pulmonary hypertension clinical research: lessons from the best abstracts at the 2020 American Thoracic Society International Conference

In this conference paper, we review the 2020 American Thoracic Society International Conference session titled, "What's New in Pulmonary Hypertension Clinical Research: Lessons from the Best Abstracts". This virtual mini-symposium took place on 21 October 2020, in lieu of the annual in-person ATS International Conference which was cancelled due to the COVID-19 pandemic. Seven clinical research abstracts were selected for presentation in the session, which encompassed five major themes: (1) standardizing diagnosis and management of pulmonary hypertension, (2) improving risk assessment in pulmonary arterial hypertension, (3) evaluating biomarkers of disease activity, (4) understanding metabolic dysregulation across the spectrum of pulmonary hypertension, and (5) advancing knowledge in chronic thromboembolic pulmonary hypertension. Focusing on these five thematic contexts, we review the current state of knowledge, summarize presented research abstracts, appraise their significance and limitations, and then discuss relevant future directions in pulmonary hypertension clinical research.

Morbid obesity but not obesity is associated with increased mortality in patients undergoing endoscopic retrograde cholangiopancreatography: A national cohort study

Background

The relationship between body weight and outcomes of endoscopic retrograde cholangiopancreatography (ERCP) is unclear.

Objectives

This study aimed to investigate the impact of obesity and morbid obesity on mortality and ERCP‐related complications in patients who underwent ERCP.

Methods

We conducted a US population‐based retrospective cohort study using the Nationwide Readmissions Databases (2013–2014). A total of 159,264 eligible patients who underwent ERCP were identified, of which 137,158 (86.12%) were normal weight, 12,522 (7.86%) were obese, and 9584 (6.02%) were morbidly obese. The primary outcome was in‐hospital mortality. The secondary outcomes were the length of stay, total cost, and ERCP‐related complications. Multivariate analysis and propensity score (PS) matching analysis were performed. The analysis was repeated in a restricted cohort to eliminate confounders.

Results

Patients with morbid obesity, as compared to normal‐weight patients, were associated with a significantly higher in‐hospital mortality (hazard ratio [HR]: 5.54; 95% confidence interval [CI]: 1.23–25.04). Obese patients were not associated with significantly different mortality comparing to normal weight (HR: 1.00; 95% CI: 0.14–7.12). Patients with morbid obesity were also found to have an increased length of hospital stay and total cost. The rate of ERCP‐related complications was comparable among the three groups except for a higher cholecystitis rate after ERCP in obese patients.

Conclusions

Morbid obesity but not obesity was associated with increased mortality, length of stay, and total cost in patients undergoing ERCP.

Established knowledge on this subject

1. Obesity is a prevalent phenomenon.

2. The impact of obesity and morbid obesity on mortality in patients undergoing ERCP remains unclear.

Significant and/or new findings of this study?

1. Morbid obesity but not obesity was associated with increased mortality in patients undergoing ERCP.

Obesity cardiomyopathy: evidence, mechanisms, and therapeutic implications

The prevalence of heart failure is on the rise and imposes a major health threat, in part, due to the rapidly increased prevalence of overweight and obesity. To this point, epidemiological, clinical, and experimental evidence supports the existence of a unique disease entity termed “obesity cardiomyopathy,” which develops independent of hypertension, coronary heart disease, and other heart diseases. Our contemporary review evaluates the evidence for this pathological condition, examines putative responsible mechanisms, and discusses therapeutic options for this disorder. Clinical findings have consolidated the presence of left ventricular dysfunction in obesity. Experimental investigations have uncovered pathophysiological changes in myocardial structure and function in genetically predisposed and diet-induced obesity. Indeed, contemporary evidence consolidates a wide array of cellular and molecular mechanisms underlying the etiology of obesity cardiomyopathy including adipose tissue dysfunction, systemic inflammation, metabolic disturbances (insulin resistance, abnormal glucose transport, spillover of free fatty acids, lipotoxicity, and amino acid derangement), altered intracellular especially mitochondrial Ca²⁺ homeostasis, oxidative stress, autophagy/mitophagy defect, myocardial fibrosis, dampened coronary flow reserve, coronary microvascular disease (microangiopathy), and endothelial impairment. Given the important role of obesity in the increased risk of heart failure, especially that with preserved systolic function and the recent rises in COVID-19-associated cardiovascular mortality, this review should provide compelling evidence for the presence of obesity cardiomyopathy, independent of various comorbid conditions, underlying mechanisms, and offer new insights into potential therapeutic approaches (pharmacological and lifestyle modification) for the clinical management of obesity cardiomyopathy.

Factors predicting 31-year survival among a population cohort in Northern Finland

We evaluated the survival of a subarctic population and the significance of traditional risk factors for mortality, causes of death and their seasonal variation from the period of 1984-2014. By the end of 2014 (follow-up), 644 (34.4% from 1,869) participants had died (42.1% of cardiovascular causes, 22.4% of neoplastic diseases). The average age at death±SD was 74.6±11.4 years for women (n=284) and 70.2±12.0 years for men (n=360). After adjusting for baseline age, the major risk factors predicting death were male sex (hazard ratio [HR] 1.80; 95% confidence interval [CI] 1.54-2.10), current smoking (HR 1.85; 95% CI 1.58-2.17), obesity (HR 1.75; 95% CI 1.45-2.12), high blood pressure (HR 1.46; 95% CI 1.24-1.72), cardiovascular disease (HR 1.62; 95% CI 1.36-1.93) and depression (HR 1.61; 95% CI 1.21-2.14) at baseline.The most common causes of death and the main risk factors predicting death in this population were the same as reported globally. Lifestyle factors had an important impact in predicting survival. The most common causes of death were the same for men and women. There was no significant difference in overall mortality rate between winter and summer, but cerebrovascular and pulmonary causes of death were more common during winter.

Examining the obesity paradox: A moderating effect of fitness on adipose endocrine function in older adults

Despite evidence linking obesity with increased mortality, older adults with excessive adiposity seem protected, resulting in a so-called obesity paradox. Obesity is characterized by leptin resistance, which contributes to increased risk of all-cause mortality. Therefore, lifestyle factors, such as physical fitness, that lower leptin independent of adiposity may be confounding the obesity paradox. To investigate this, we evaluated whether physical fitness moderated the relationship between leptin and adiposity. We found older adults with higher fitness had lower body mass (r(39) = -0.43, p < 0.01), leptin (r(39) = -0.29, p = 0.03) and inflammation (IL-1β: (r(39) = -0.69, p < 0.01); TNF-α: (r(39) = -0.30, p = 0.03)). Fitness moderated the relationship between leptin and adiposity (F(5, 37) = 3.73, p < 0.01, R² = 0.33) to reveal the obesity paradox in moderately and high fit individuals (b = 216.24, t(37) = 1.46, p = 0.15; b= -88.10, t(37) = -0.49, p = 0.63) but not in low fit individuals. These results show the link between obesity and mortality may not be dependent on total adiposity, but rather on endocrine function and adipocyte leptin secretion. These results have important implications for older adults struggling to maintain healthy body composition and suggest that fitness may promote overall wellbeing.

Effects of a Lacto-Ovo-Vegetarian Diet on the Plasma Lipidome and Its Association with Atherosclerotic Burden in Patients with Coronary Artery Disease-A Randomized, Open-Label, Cross-over Study

A vegetarian diet has been associated with a lower risk of coronary artery disease (CAD). Plasma triacylglycerols, ceramides, and phosphatidylcholines may improve prediction of recurrent coronary events. We sought to investigate effects of a lacto-ovo-vegetarian diet (VD) on plasma lipidome in CAD patients and simultaneously assess associations of plasma lipids with the extent of coronary atherosclerotic burden. We analyzed 214 plasma lipids within glycerolipid, sphingolipid, and sterol lipid classes using lipidomics from a randomized controlled, crossover trial comprising 31 CAD patients on standard medical therapy. Subjects completed a four-week intervention with VD and isocaloric meat diet (MD), separated by a four-week washout period. The VD increased levels of 11 triacylglycerols and lowered 7 triacylglycerols, 21 glycerophospholipids, cholesteryl ester (18:0), and ceramide (d18:1/16:0) compared with MD. VD increased triacylglycerols with long-chain polyunsaturated fatty acyls while decreased triacylglycerols with saturated fatty acyls, phosphatidylcholines, and sphingomyelins than MD. The Sullivan extent score (SES) exhibited on coronary angiograms were inversely associated with triacylglycerols with long-chain unsaturated fatty acyls. Phosphatidylcholines that were lower with VD were positively associated with SES and the total number of stenotic lesions. The VD favorably changed levels of several lipotoxic lipids that have previously been associated with increased risk of coronary events in CAD patients.

Impact of Obesity in Hospitalized Patients with Heart Failure: A Nationwide Cohort Study

OBJECTIVES

Obesity and cardiovascular disease remain significant burdens on the overall provision of health care in the United States. Obesity has been shown to be a direct risk factor for heart failure (HF). We conducted a nationwide cohort study to assess the short-term impact of obesity in hospitalized patients with HF.

METHODS

We identified 1,520,871 encounters with a primary diagnosis of HF in the 2013-2014 Nationwide Readmission Database. We excluded patients younger than 18 years (n = 2755), hospitalized patients discharged in December (n = 126,137), patients with missing mortality information (n = 477), missing length of stay (LOS; n = 91), patients who were transferred to another hospital (n = 38,489), and patients with conflicting body weight information (n = 7757). Multivariable logistic regression was used to evaluate the association between baseline characteristics (including the presence of obesity) and in-hospital mortality, as well as 30-day readmission rates.

RESULTS

The overall in-patient mortality rate was 2.8% (n = 37,927). Obese patients had numerically a lower mortality (1.8%) compared with the nonobese patients (3.1%); however, the difference in risk was not significant on multivariable analysis (hazard ratio 0.97, 95% confidence interval 0.94-1.01). In the overall cohort, 20.6% (n = 269,988) were readmitted within 30 days. The risk of 30-day readmission was significantly lower in obese patients (19.4%) compared with nonobese patients (20.9%) (odds ratio 0.85, 95% confidence interval 0.84-0.86). Obese patients had longer LOSs (median of 5 days [3-7] vs 4 days [2-6], P < 0.001) and higher costs of index admission (median of $27,206 [$16,027-$48,316] vs $23,339 [$13,698-$41,982], P < 0.001) compared with nonobese patients.

CONCLUSIONS

In this cross-sectional study of patients hospitalized for HF in the United States, obesity was not associated with a higher risk of inpatient mortality, but it was associated with a lower 30-day readmission rate. Obese patients with HF, however, had longer LOSs and higher costs of index admission. Our findings support the obesity paradox seen in patients with HF.

Path Analysis on Determinants of Childhood Obesity and Associated Risk Factors of Cardiovascular, Renal, and Hepatic Diseases: The CASPIAN-V Study

The interaction between several lifestyle and obesogenic environmental factors is considered as the main underlying factor for the escalating trend of childhood obesity and its adverse consequences. In this study, we assessed the mutual influence of lifestyle habits and body mass index (BMI) as well as risk factors for cardiometabolic, hepatic, and renal disorders to define the causality power of each item. This nationwide cross-sectional study was conducted as the fifth round of a school-based surveillance program. Overall, 14,800 students living in Iran were studied, and blood samples were obtained from 4,200 of them. Demographic factors, anthropometric and biochemical measures were used to define lifestyle-related latent variables as well as cardiac, renal, and hepatic risk indicators. Total, direct, and indirect effects between factors were analyzed using the standardized regression weights for each pathway. Data from 14,274 students (participation rate of 99%) and 3,843 blood samples were included. All of the latent variables had a significant direct effect on BMI, with the most potent effect of unhealthy nutrition (β ≅ 0.63) in boys and girls. BMI has significant direct effects on risk indicators of cardiovascular, renal, and hepatic diseases with the most powerful effect on cardiovascular risk factors (β ≅  − 0.08). The most important predisposing factor for obesity was unhealthy nutrition, whereas increased activity, adequate sleep, and better hygiene had protective roles. BMI shows the strongest association with indicator of cardiovascular diseases. These findings underscore the importance of implementing public health programs for the prevention of chronic noncommunicable diseases.

Body-mass index and long-term risk of sepsis-related mortality: a population-based cohort study of 0.5 million Chinese adults

BACKGROUND

Sepsis represents a major worldwide healthcare burden. However, how body-mass index (BMI) is related to the long-term risk of sepsis-related mortality in low- and middle-income countries remains uncertain.

METHODS

We examined the associations of sepsis-related mortality with both baseline BMI and waist circumference (WC) using data from China Kadoorie Biobank, a prospective cohort recruited during 2004-2008 and followed up to December 2016. After excluding participants with chronic obstructive pulmonary disease, tuberculosis, cancer, heart disease, and stroke, and omitting the first 3 years of follow-up, 440,763 participants remained for analysis.

RESULTS

During a median follow-up of 10.0 years, 1957 sepsis-related deaths (3,134,870 person-years) were included for analysis. Compared with reference BMI of 22.5 to < 25.0 kg/m², the multivariable-adjusted hazard ratios (HRs) for sepsis-related mortality were 2.42 (95% CIs 2.07-2.84) for BMI of < 18.5, 1.59 (1.36-1.85) for 18.5 to < 20.0, 1.21 (1.06-1.38) for 20.0 to < 22.5, 0.97 (0.83-1.13) for 25.0 to < 27.5, 0.98 (0.80-1.21) for 27.5 to < 30.0, and 1.22 (0.93-1.60) for ≥ 30.0 kg/m². Further adjustment for WC led to slightly augmentation of the effect size for the lower BMI groups and null association in the obese group. In the association analysis between WC and sepsis-related mortality, compared with the middle quintile group, only the highest quintile group showed an increased risk of sepsis-related mortality after adjusted for BMI (HR = 1.54; 95% CI 1.28-1.84).

CONCLUSIONS

Underweight, lower normal weight, and abdominal obesity are associated with increased future risk of sepsis-related mortality over 10 years in the Chinese population. The double burden of underweight and obesity indicates a heavy sepsis burden faced by low- and middle-income countries.

Body mass index and all-cause mortality in older adults: A scoping review of observational studies

In older age, body composition changes as fat mass increases and redistributes. Therefore, the current body mass index (BMI) classification may not accurately reflect risk in older adults (65+). This study aimed to review the evidence on the association between BMI and all-cause mortality in older adults and specifically, the findings regarding overweight and obese BMI. A systematic search of the OVID MEDLINE and Embase databases was conducted between 2013 and September 2018. Observational studies examining the association between BMI and all-cause mortality within a community-dwelling population aged 65+ were included. Seventy-one articles were included. Studies operationalized BMI categorically (n = 60), continuously (n = 8) or as a numerical change/group transition (n = 7). Reduced risk of mortality was observed for the overweight BMI class compared with the normal BMI class (hazard ratios [HR] ranged 0.41-0.96) and for class 1 or 2 obesity in some studies. Among studies examining BMI change, increases in BMI demonstrated lower mortality risks compared with decreases in BMI (HR: 0.83-0.95). Overweight BMI classification or a higher BMI value may be protective with regard to all-cause mortality, relative to normal BMI, in older adults. These findings demonstrate the potential need for age-specific BMI cut-points in older adults.

[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.

Weight History in Clinical Practice: The State of the Science and Future Directions

Eliciting a weight history can provide clinically important information to aid in treatment decision-making. This view is consistent with the life course perspective of obesity and the aim of patient-centered care, one of six domains of health care quality. However, thus far, the value and practicality of including a weight history in the clinical assessment and treatment of patients with obesity have not been systematically explored. For these reasons, the Clinical Committee of The Obesity Society established a task force to review and assess the available evidence to address five key questions. It is concluded that weight history is an essential component of the medical history for patients presenting with overweight or obesity, and there are strong and emerging data that demonstrate the importance of life stage, duration of exposure to obesity, maximum BMI, and group-based trajectory modeling in predicting risk for increased morbidity and mortality. Consideration of these and other patient-specific factors may improve risk stratification and clinical decision-making for screening, counseling, and management. Recommendations are provided for the key elements that should be included in a weight history, and several needs for future clinical research are outlined.

The impact of confounding on the associations of different adiposity measures with the incidence of cardiovascular disease: a cohort study of 296 535 adults of white European descent

Aims

The data regarding the associations of body mass index (BMI) with cardiovascular (CVD) risk, especially for those at the low categories of BMI, are conflicting. The aim of our study was to examine the associations of body composition (assessed by five different measures) with incident CVD outcomes in healthy individuals.

Methods and results

A total of 296 535 participants (57.8% women) of white European descent without CVD at baseline from the UK biobank were included. Exposures were five different measures of adiposity. Fatal and non-fatal CVD events were the primary outcome. Low BMI (≤18.5 kg m⁻²) was associated with higher incidence of CVD and the lowest CVD risk was exhibited at BMI of 22–23 kg m⁻² beyond, which the risk of CVD increased. This J-shaped association attenuated substantially in subgroup analyses, when we excluded participants with comorbidities. In contrast, the associations for the remaining adiposity measures were more linear; 1 SD increase in waist circumference was associated with a hazard ratio of 1.16 [95% confidence interval (CI) 1.13–1.19] for women and 1.10 (95% CI 1.08–1.13) for men with similar magnitude of associations for 1 SD increase in waist-to-hip ratio, waist-to-height ratio, and percentage body fat mass.

Conclusion

Increasing adiposity has a detrimental association with CVD health in middle-aged men and women. The association of BMI with CVD appears more susceptible to confounding due to pre-existing comorbidities when compared with other adiposity measures. Any public misconception of a potential ‘protective’ effect of fat on CVD risk should be challenged.

Take home figure

Investigation of the Obesity Paradox in Chronic Obstructive Pulmonary Disease, According to Smoking Status, in the United States

An obesity paradox in chronic obstructive pulmonary disease (COPD), whereby overweight/obese individuals have improved survival, has been well-described. These studies have generally included smokers. It is unknown whether the paradox exists in individuals with COPD arising from factors other than smoking. Nonsmoking COPD is understudied yet represents some 25%-45% of the disease worldwide. To determine whether the obesity paradox differs between ever- and never-smokers with COPD, 1,723 adult participants with this condition were examined from 2 iterations of the National Health and Nutrition Examination Survey (1988-1994, 2007-2010), with mortality outcomes followed through December 2011. Using Cox proportional hazards models, adjusted for sociodemographic factors, lung function, and survey cycle, ever/never-smoking was found to modify the association between body mass index and hazard of death. Compared with normal-weight participants, overweight/obese participants had lower hazard of death among ever-smokers (for overweight, adjusted hazard ratio (aHR) = 0.56, 95% confidence interval (CI): 0.43, 0.74; for obesity, aHR = 0.66, 95% CI: 0.48, 0.92), but never-smokers did not (overweight, aHR = 1.41, 95% CI: 0.66, 3.03; obesity, aHR = 1.29, 95% CI: 0.48, 3.48). An obesity paradox appeared to be absent among never-smokers with COPD. This, to our knowledge, novel finding might be explained by pathophysiological differences between smoking-related and nonsmoking COPD or by smoking-associated methodological biases.

Trends of Cardiac Complications in Patients With Rheumatoid Arthritis: Analysis of the United States National Inpatient Sample; 2005-2014

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory condition. Chronic inflammation is associated with atherosclerosis, hypertension, diabetes, chronic obstructive pulmonary disease (COPD), chronic kidney disease. But sparse data are available regarding the trends of cardiovascular diseases and complications in RA. We conducted a National Inpatient Sample database analysis to demonstrate the trends of cardiac complications in patients with RA.

METHODS

We used National Inpatient Sample data from 2005 to 2014 to identify admissions with the diagnosis of RA and identified who had associated cardiovascular complications also. The International Classification of Diseases-9th Revision-Clinical Modification codes were used for the diagnoses of RA; congestive heart failure (CHF), acute myocardial infarction (AMI), and atrial fibrillation (AF).

RESULTS

A statistically significant increasing trend of AMI, CHF, and AF was found. Independent predictors of mortality in RA patients with AMI were age (OR 1.03, CI 1.02-1.04; P < 0.001), COPD (OR 1.67, CI 1.40-2.00; P < 0.001), cerebrovascular disease (OR 2.207, CI 1.71-2.86; P < 0.001), renal disease (OR 1.42, CI 1.16-1.75; P = 0.001), and alcohol abuse (OR 2.73, CI 1.73-4.32; P < 0.001). Independent predictors of mortality in RA patients with CHF were age (odds ratio [OR] 1.02, confidence interval [CI] 1.017-1.024; P < 0.001]), COPD (OR 1.09, CI 1.01-1.18; P = 0.023), cerebrovascular disease (OR 1.67, CI 1.44-1.95; P < 0.001), renal disease (OR 1.16, CI 1.07-1.27; P = 0.001). Independent predictors of mortality in RA patients with AF were age (OR 1.02, CI 1.02-1.03; P < 0.001), race (OR 1.16, CI 1.02-1.31; P = 0.022), COPD (OR 1.56, CI 1.42-1.71; P < 0.001), peripheral arterial disease (OR 1.34, CI 1.16-1.53; P < 0.001), cerebrovascular disease (OR 2.27, CI 1.0-2.58; P < 0.001), renal disease (OR 1.60, CI 1.44-1.80; P < 0.001). The mortality trend has increased significantly in the CHF (P = 0.025) and AF (P = 0.042) groups during this study period.

CONCLUSIONS

We have found a significant increase in trend of cardiovascular complications in RA patients. The proportion of patients, with cardiovascular comorbidities, have also been increased significantly.

Interactions of Behavioral Changes in Smoking, High-risk Drinking, and Weight Gain in a Population of 7.2 Million in Korea

OBJECTIVES

To identify simultaneous behavioral changes in alcohol consumption, smoking, and weight using a fixed-effect model and to characterize their associations with disease status.

METHODS

This study included 7 000 529 individuals who participated in the national biennial health-screening program every 2 years from 2009 to 2016 and were aged 40 or more. We reconstructed the data into an individual-level panel dataset with 4 waves. We used a fixed-effect model for smoking, heavy alcohol drinking, and overweight. The independent variables were sex, age, lifestyle factors, insurance contribution, employment status, and disease status.

RESULTS

Becoming a high-risk drinker and losing weight were associated with initiation or resumption of smoking. Initiation or resumption of smoking and weight gain were associated with non-high-risk drinkers becoming high-risk drinkers. Smoking cessation and becoming a high-risk drinker were associated with normal-weight participants becoming overweight. Participants with newly acquired diabetes mellitus, ischemic heart disease, stroke, and cancer tended to stop smoking, discontinue high-risk drinking, and return to a normal weight.

CONCLUSIONS

These results obtained using a large-scale population-based database documented interactions among lifestyle factors over time.

Trajectory of Smoking and Incidence of Atherosclerotic Cardiovascular Disease among Korean Young Adult Men

Introduction: Smoking among young adults is associated with atherosclerotic cardiovascular disease (ASCVD) in middle age. Our aim was to analyze the trajectory of smoking in young adults and analyze the effects of the trajectory group on incident ASCVD. Methods: This study was conducted among 60,709 young adult men aged 20–29 years who received health screening every two years from 1992–2004. Trajectory analysis was performed through smoking survey data measured 7 times during this period. ASCVD, including ischemic heart disease (IHD) and stroke events were confirmed from 2005–2015. The association between the trajectory group and ASCVD risk was analyzed using Cox proportional hazard models, controlling for covariates and mediators. Results: Trajectory analysis showed that smoking categorized into five groups as follows: Group 1 (28.3%), low steady; Group 2 (14.7%), lowering; Group 3 (17.3%), high steady; Group 4 (15.6%), rise and fall; and Group 5 (24.2%), very high steady. The model performance of the trajectory model (Akaike information criterion; AIC = 51,670.78) with mediators was better than the model (AIC = 51,847.85) without mediators. Group 5 showed a 49% higher risk of ASCVD than Group 1. The risk of IHD was 1.63-times higher for Group 5 and 1.31-times higher for Group 4, compared to Group 1. Compared to Group 1, Group 5 had a 1.36- and 1.58-times higher risk for total stroke and ischemic stroke, respectively. Conclusions: In young adult men, the multiple measured trajectory model with mediators was far more informative than one-time smoking for explaining the association with cardiovascular disease.

Body mass index and all-cause mortality in patients with atrial fibrillation: insights from the China atrial fibrillation registry study

BACKGROUND

Impact of body mass index (BMI) on all-cause mortality in atrial fibrillation (AF) patients remains controversial.

METHODS

A total of 10,942 AF patients were prospectively enrolled and categorized into four BMI groups: underweight (BMI < 18.5 kg/m²), normal weight (BMI 18.5-24 kg/m²), overweight (BMI 24-28 kg/m²) and obesity (BMI ≥ 28 kg/m²). The primary outcome was all-cause mortality. Different Cox proportional hazards models were performed to evaluate the association between BMI and all-cause mortality.

RESULTS

During a median follow-up of 30 months (IQR 18-48 months), 862 deaths events occurred. Compared to normal BMI, higher BMI was associated with a lower mortality risk (overweight: HR 0.70; 95% CI 0.61-0.81, P < 0.0001 and obesity: HR 0.54; 95% CI 0.44-0.67, P < 0.0001) and lower BMI was associated with a higher mortality risk (HR 2.23, 95% CI 1.67-2.97, P < 0.0001).

CONCLUSION

A reversed relationship between BMI and all-cause mortality in AF patients was found. Higher risk of mortality was observed in underweight patients compared to patients with a normal BMI, while overweight and obese patients had a lower risk of all-cause mortality.

CLINICAL TRIAL REGISTRATION

URL: http://www.chictr.org.cn/showproj.aspx?proj=5831. Unique identifier: ChiCTR-OCH-13003729.

Body Mass Index and Clinical Outcomes in Large Vessel Occlusion Acute Ischemic Stroke after Endovascular Therapy

Background and Purpose

Several reports have described lower mortality rates in overweight or obese patients as compared to normal weight ones. In the past decade, several studies have investigated the phenomenon, commonly known as the obesity paradox, with mixed results thus far. We sought to determine whether outcomes differ between patients with large vessel occlusion strokes (LVOS) after endovascular therapy (ET) according to their body mass index (BMI).

Methods

We reviewed our prospectively collected endovascular database at a tertiary care academic institution. All patients that underwent ET for acute LVOS were categorized according to their BMI into 4 groups: (1) underweight (BMI < 18.5), (2) normal weight (BMI = 18.5-25), (3) overweight (BMI = 25-30), and (4) obese (BMI > 30). Baseline characteristics, procedural radiological as well as outcome parameters where compared.

Results

A total of 926 patients qualified for the study, of which 20 (2.2%) were underweight, 253 (27.3%) had a normal weight, 315 (34%) were overweight, and 338 (36.5%) were obese. When compared with normal weight (reference), overweight patients were younger, had higher rates of dyslipidemia and diabetes and higher glucose levels, while obese patients were younger, less often smokers, and had higher rates of hypertension and diabetes and higher glucose levels. Other baseline and procedural characteristics were comparable. The rates of successful reperfusion (modified treatment in cerebral ischemia, 2b-3), parenchymal hematomas, 90-day good clinical outcomes (modified Rankin scale, 0-2), and 90-day mortality were comparable between groups. On multivariate analysis, BMI was not associated with good outcomes nor mortality.

Conclusion

In patients treated with mechanical thrombectomy, BMI is not associated with outcomes. However, patients who are overweight or obese have more comorbidities and a higher stroke risk and, thus, should strive for a normal weight.

The Association of Body Mass Index with Risk of Long-Term Revision and 90-Day Mortality Following Primary Total Hip Replacement: Findings from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

BACKGROUND

The influence of obesity on outcomes following total hip replacement is unclear. Restriction of total hip replacement on the basis of body mass index (BMI) has been suggested. The purpose of this study was to assess the influence of BMI on the risk of revision and 90-day mortality.

METHODS

This was a population-based, longitudinal cohort study of the National Joint Registry (NJR) for England, Wales, Northern Ireland and the Isle of Man. Using data recorded from April 2003 to December 2015, linked to Office for National Statistics data, we ascertained revision and 90-day mortality rates following primary total hip replacement by BMI category. The probability of revision was estimated using Kaplan-Meier methods. Associations of BMI with revision and mortality were explored using adjusted Cox proportional hazards regression models.

RESULTS

We investigated revision and 90-day mortality among 415,598 and 413,741 primary total hip replacements, respectively. Each data set accounts for approximately 52% of the total number of recorded operations in the NJR. Thirty-eight percent of the patients were classified as obese. At 10 years, class-III obese patients had the highest cumulative probability of revision (6.7% [95% confidence interval (CI), 5.5% to 8.2%]), twice that of the underweight group (3.3% [95% CI, 2.2% to 4.9%]). When the analysis was adjusted for age, sex, American Society of Anesthesiologists [ASA] grade, year of operation, indication, and fixation type, compared with patients with normal BMI, significantly elevated hazard ratios (HRs) for revision were observed for patients in the BMI categories of class-I obese (≥30 to <35 kg/m) (HR, 1.14 [95% CI, 1.07 to 1.22]), class-II obese (≥35 to <40 kg/m) (HR, 1.30 [95% CI, 1.19 to 1.40]), and class-III obese (≥40 to ≤60 kg/m) (HR, 1.43 [95% CI, 1.27 to 1.61]) (p < 0.0005 for all). Underweight patients had a substantially higher cumulative probability of 90-day mortality (1.17%; 95% CI, 0.86% to 1.58%) compared with patients with normal BMI (0.43%; 95% CI, 0.39% to 0.48%). The risk of 90-day mortality was significantly higher for the underweight group (HR, 2.09 [95% CI, 1.51 to 2.89]; p < 0.0005) and significantly lower for patients who were categorized as overweight (HR, 0.70; 95% CI, 0.61 to 0.81; p < 0.0005), class-I obese (HR, 0.69 [95% CI, 0.59 to 0.81]; p < 0.0005), and class-II obese (HR, 0.79 [95% CI, 0.63 to 0.98]; p = 0.049) compared with patients with normal BMI.

CONCLUSIONS

Although long-term revision rates following total hip replacement were higher among obese patients, we believe that the rates remained acceptable by contemporary standards and were balanced by a lower risk of 90-day mortality.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Obesity and Alzheimer's disease, does the obesity paradox really exist? A magnetic resonance imaging study

Mid-life obesity is an established risk factor for Alzheimer's disease (AD) dementia, whereas late-life obesity has been proposed as a protective state. Weight loss, which predates cognitive decline, might explain this obesity paradox on AD risk. We aimed to assess the impact of late life obesity on brain structure taking into account weight loss as a potential confounder. We included 162 elderly controls of the Alzheimer's Disease Neuroimaging Initiative (ADNI) with available 3T MRI scan. Significant weight loss was defined as relative weight loss ≥5% between the baseline and last follow-up visit. To be able to capture weight loss, only subjects with a minimum clinical and anthropometrical follow-up of 12 months were included. Individuals were categorized into three groups according to body mass index (BMI) at baseline: normal-weight (BMI<25 Kg/m2), overweight (BMI 25-30 Kg/m2) and obese (BMI>30 Kg/m2). We performed both an interaction analysis between obesity and weight loss, and stratified group analyses in the weight-stable and weigh-loss groups. We found a significant interaction between BMI and weight loss affecting brain structure in widespread cortical areas. The stratified analyses showed atrophy in occipital, inferior temporal, precuneus and frontal regions in the weight stable group, but increased cortical thickness in the weight-loss group. In conclusion, our data support that weight loss negatively confounds the association between late-life obesity and brain atrophy. The obesity paradox on AD risk might be explained by reverse causation.