Relation Between Obesity and Survival in Patients Hospitalized for Pulmonary Arterial Hypertension (from a Nationwide Inpatient Sample Database 2003 to 2011)

Pulmonary hypertension and insulin resistance: a mechanistic overview

Pulmonary arterial hypertension (PAH) is a vascular remodeling disease, characterized by increased blood pressure levels in pulmonary circulation, leading to a restriction in the circulation flow and heart failure. Although the emergence of new PAH therapies has increased survival rates, this disease still has a high mortality and patients that receive diagnosis die within a few years. The pathogenesis of PAH involves multiple pathways, with a complex interaction of local and distant cytokines, hormones, growth factors, and transcription factors, leading to an inflammation that changes the vascular anatomy in PAH patients. These abnormalities involve more than just the lungs, but also other organs, and between these affected organs there are different metabolic dysfunctions implied. Recently, several publications demonstrated in PAH patients a disturbance in glucose metabolism, demonstrated by higher levels of glucose, insulin, and lipids in those patients. It is possible that a common molecular mechanism can have a significant role in this connection. In this regard, this narrative review intends to focus on the recent papers that mainly discuss the molecular determinants between insulin resistance (IR) associated PAH, which included obesity subclinical inflammation induced IR, PPAR gamma and Adiponectin, BMPR2, mitochondrial dysfunction and endoplasmic reticulum stress. Therefore, the following review will summarize some of the existing data for IR associated PAH, focusing on the better understanding of PAH molecular mechanisms, for the development of new translational therapies.

The beneficial effects of balloon pulmonary angioplasty for patients with chronic thromboembolic pulmonary hypertension are accompanied by increased body mass index and improved nutritional status

Although balloon pulmonary angioplasty (BPA) improves pulmonary hypertension and the prognosis of patients with chronic thromboembolic pulmonary hypertension (CTEPH), subsequent changes in body mass index (BMI), nutritional status, and appetite have not been fully investigated. This retrospective study aimed to clarify changes in BMI, nutritional status, and appetite after BPA. Fifty-two consecutive patients with CTEPH who underwent complete revascularization with BPA between July 2014 and July 2023 and were available for follow-up were evaluated. We compared the presence or absence of increased appetite, BMI change, and nutritional status before and after BPA treatment. BPA significantly improved the mean pulmonary artery pressure from 37.4 ± 8.7 mmHg to 18.7 ± 2.8 mmHg and the partial pressure of oxygen from 61.6 ± 9.3 mmHg to 82.8 ± 9.9 mmHg (both p < 0.001). Appetite was increased in 82.7% of the patients. BMI significantly increased from 23.9 ± 3.7 kg/m2 to 24.9 ± 3.7 kg/m2 (p < 0.001). As a nutritional indicator, the Geriatric Nutritional Risk Index increased from 105.3 ± 10.2 to 108.3 ± 8.3 (p < 0.001). The median Controlling Nutritional Status scores showed no significant change but the range was significantly improved from 0-9 to 0-3 (p = 0.006). In conclusion, patients with CTEPH show improved oxygenation and hemodynamics, increased BMI, and improved nutritional status following BPA. This sequence of changes may help improve patient prognosis.

Effect of Obesity on Mortality in Pulmonary Hypertension-A Systematic Review and Meta-Analysis

Obesity is reported to have a protective effect on mortality in pulmonary hypertension (PH), a phenomenon known as obesity paradox. However, the data are conflicting, with some studies showing decreased mortality while other studies found no effect of obesity on mortality. Therefore, we performed a systematic review and meta-analysis to examine whether there is an association between obesity and mortality in PH. Only patients with PH diagnosed by right heart catheterization were included. We also performed a sub-group analysis of subjects with pre-capillary PH only. A total of six studies met the inclusion criteria, with a sample size of 13,987 patients. Obese subjects had lower mortality compared to non-obese subjects in the combined pre- and post-capillary PH group (hazard ratio 0.79, 95% CI 0.66-0.95, p = 0.01). While obesity was associated with reduction in mortality in the pre-capillary PH group (hazard ratio 0.77, 95% CI 0.60 to 0.98, p = 0.03), this was not uniform across all studies.

Influence of Obesity on Coronary Artery Disease and Clinical Outcomes in the ADVANCE Registry

BACKGROUND

The relationship between body size and cardiovascular events is complex. This study utilized the ADVANCE (Assessing Diagnostic Value of Noninvasive FFR_CT in Coronary Care) Registry to investigate the association between body mass index (BMI), coronary artery disease (CAD), and clinical outcomes.

METHODS

The ADVANCE registry enrolled patients undergoing evaluation for clinically suspected CAD who had >30% stenosis on cardiac computed tomography angiography. Patients were stratified by BMI: normal <25 kg/m², overweight 25-29.9 kg/m², and obese ≥30 kg/m². Baseline characteristics, cardiac computed tomography angiography and computed tomography fractional flow reserve (FFR_CT), were compared across BMI groups. Adjusted Cox proportional hazards models assessed the association between BMI and outcomes.

RESULTS

Among 5014 patients, 2166 (43.2%) had a normal BMI, 1883 (37.6%) were overweight, and 965 (19.2%) were obese. Patients with obesity were younger and more likely to have comorbidities, including diabetes and hypertension (all P<0.001), but were less likely to have obstructive coronary stenosis (65.2% obese, 72.2% overweight, and 73.2% normal BMI; P<0.001). However, the rate of hemodynamic significance, as indicated by a positive FFR_CT, was similar across BMI categories (63.4% obese, 66.1% overweight, and 67.8% normal BMI; P=0.07). Additionally, patients with obesity had a lower coronary volume-to-myocardial mass ratio compared with patients who were overweight or had normal BMI (obese BMI, 23.7; overweight BMI, 24.8; and normal BMI, 26.3; P<0.001). After adjustment, the risk of major adverse cardiovascular events was similar regardless of BMI (all P>0.05).

CONCLUSIONS

Patients with obesity in the ADVANCE registry were less likely to have anatomically obstructive CAD by cardiac computed tomography angiography but had a similar degree of physiologically significant CAD by FFR_CT and similar rates of adverse events. An exclusively anatomic assessment of CAD in patients with obesity may underestimate the burden of physiologically significant disease that is potentially due to a significantly lower volume-to-myocardial mass ratio.

Impact of Rapid Weight Loss after Bariatric Surgery in Systemic Inflammatory Response and Pulmonary Hemodynamics in Severely Obese Subjects with Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) can be associated with obesity. The excessive production of proinflammatory mediators by dysfunctional adipocytes may enhance remodeling of the pulmonary vasculature and worsen pulmonary hemodynamics. This study aimed to describe the changes in pulmonary arterial pressures and systemic inflammation in patients with obesity with PH after bariatric surgery (BaS).

STUDY DESIGN

In this retrospective cohort study, we compared patients with PH who underwent BaS from 2008 to 2018 at our institution (group 1) to a group of severely obese patients with PH (group 2). Echocardiographic right ventricular systolic pressure (RVSP) was used as an indirect measurement of pulmonary arterial pressures. Red blood cell distribution width (RDW) was used as a marker of systemic inflammation.

RESULTS

A total of 40 patients were included, 20 per group. In group 1, the RVSP decreased from 44.69 ± 7.12 mmHg to 38.73 ± 12.81 mmHg (p = 0.041), and the RDW decreased from 15.22 ± 1.53 to 14.41 ± 1.31 (p = 0.020). In group 2, the RVSP decreased from 60.14 ± 18.08 to 59.15 ± 19.10 (0.828), and the RDW increased from 15.37 ± 1.99 to 15.38 ± 1.26 (0.983). For both groups, we found a positive correlation between RVSP and RDW changes, although the correlation was not statistically significant.

CONCLUSIONS

Previous studies suggest BaS could be a safe and effective procedure to achieve weight loss in obese patients with PH, with an additional modest improvement in pulmonary hemodynamics. The results of this study reinforce this observation and suggest that such improvement could be related to a decrease in systemic inflammation. Further prospective studies with bigger samples are needed to better understand these findings.

Association Between Body Mass Index and 30-Day Mortality in Patients with Pulmonary Hypertension Undergoing Non-cardiothoracic, Non-obstetric Surgery

INTRODUCTION

Evidence regarding the association between body mass index (BMI) and outcomes in non-cardiothoracic, non-obstetric surgery patients with pulmonary hypertension (PHTN) is limited. We aimed to investigate the association between BMI and 30-day mortality in non-cardiothoracic, non-obstetric surgery patients with pulmonary hypertension.

MATERIAL AND METHODS

We performed a secondary analysis of non-cardiothoracic, non-obstetric procedures on patients with PHTN between 2007 and 2013 at a single institution. Multivariable logistic regression models were used to estimate the association between BMI and 30-day mortality. Interaction and stratified analyses were conducted according to age, sex, PHTN medical therapy, anticipated inpatient or outpatient post-procedure status, procedure length > 2 h, open surgical approach, and PHTN severity class.

RESULTS

A total of 513 participants were included, with men accounting for 55.8% of the sample; the 30-day mortality was 1.9%. In the multivariate regression models, BMI was significantly associated with 30-day mortality after adjusting for potential covariates. A 1 kg/m² increase in BMI was associated with a 15% decrease in 30-day mortality (adjusted OR = 0.85, 95% CI: 0.73-0.98, P = 0.03). Stratified analyses indicated that this negative correlation was robust.

CONCLUSIONS

In this study, we found that low BMI is associated with increased risk of death in patients undergoing non-cardiothoracic, non-obstetric surgery requiring general anesthesia. Further studies are needed to confirm our findings.

BMI and Treatment Response in Patients With Pulmonary Arterial Hypertension

Background

Obesity is increasingly prevalent in pulmonary arterial hypertension (PAH) but is associated with improved survival, creating an “obesity paradox” in PAH. It is unknown if the improved outcomes could be attributable to obese patients deriving a greater benefit from PAH therapies.

Research Question

Does BMI modify treatment effectiveness in PAH?

Study Design and Methods

Using individual participant data, a meta-analysis was conducted of phase III, randomized, placebo-controlled trials of treatments for PAH submitted for approval to the U.S. Food and Drug Administration from 2000 to 2015. Primary outcomes were change in 6-min walk distance (6MWD) and World Health Organization (WHO) functional class.

Results

A total of 5,440 participants from 17 trials were included. Patients with overweight and obesity had lower baseline 6MWD and were more likely to be WHO functional class III or IV. Treatment was associated with a 27.01-m increase in 6MWD (95% CI, 21.58-32.45; P < .001) and lower odds of worse WHO functional class (OR, 0.58; 95% CI, 0.48-0.70; P < .001). For every 1 kg/m² increase in BMI, 6MWD was reduced by 0.66 m (P = .07); there was no significant effect modification of treatment response in 6MWD according to BMI (P for interaction = .34). Higher BMI was not associated with odds of WHO functional class at end of follow-up; however, higher BMI attenuated the treatment response such that every 1 kg/m² increase in BMI increased odds of worse WHO functional class by 3% (OR, 1.03; P for interaction = .06).

Interpretation

Patients with overweight and obesity had lower baseline 6MWD and worse WHO functional class than patients with normal weight with PAH. Higher BMI did not modify the treatment response for change in 6MWD, but it attenuated the treatment response for WHO functional class. PAH trials should include participants representative of all weight groups to allow for assessment of treatment heterogeneity and mechanisms.

The Association of Body Mass Index With Mortality Among Pulmonary Hypertension Patients: A Systematic Review and Meta-Analysis of Cohort Studies

Objective

To run a systematic review and meta-analysis of related studies on body mass index (BMI) and the risk of death among pulmonary hypertension (PH) patients, as well as, to shed light on the shape and strength of the dose-response association.

Methods

Studies published up to Jun 2021 in scientific databases such as Scopus, and PubMed as well as Google Scholar were searched. Cohort studies that reported risk estimates for at least two categories of BMI or per certain increase in BMI in relation to mortality in PH patients were included. Summary relative risks were determined with random effects models. Non-linear relationship was discovered with dose-response analysis.

Results

All in all, 15 cohort studies were selected. The number of participants was 127,215 out of which 73,999 were reported dead. The summary RR for mortality per a 5-unit increment in BMI was 0.83 (95% confidence interval 0.77–0.89; I² = 75.6%, n = 9) among PH patients. There was a non-linear dose-response relation between BMI and mortality in PH patients (P_{non−linearity} < 0.001), with the lowest risk being at BMI 32–38 kg/m².

Conclusion

Higher BMI is related to decreased risk of mortality among PH patients and the lowest point of the curve was seen at BMI 32–38.

Obesity survival paradox in patients hospitalized with community-acquired pneumonia. Assessing sex-differences in a population-based cohort study

AIM

To assess the effect of obesity status (no obesity/obesity/ morbid obesity) on hospital outcomes (length of hospital stay [LOHS] and in-hospital mortality [IHM]), among patients hospitalized with community-acquired pneumonia (CAP) and according to sex.

METHODS

We conducted a retrospective cohort study based on national hospital discharge data of all subjects aged≥ 18 years hospitalized with CAP in Spain from 2016 to 2019.

RESULTS

We identified 519,750 hospital discharges with CAP. The prevalence of obesity was 6.38% and 1.78%. for morbid obesity. The mean age was higher for patients without obesity followed by those with obesity and morbid obesity (74.61, 72.5 and 70.2 years respectively; p<0.001). The mean number of comorbidities was similar for patients with obesity and morbid obesity (2.30 and 2.29) and significantly higher than for non-obese individuals (2.10). The crude IHM was higher among the non-obese patients (12.71%) followed by those with morbid obesity (8.56%) and obesity (7.72%), without finding differences between men and women. Among men, after multivariable logistic regression analysis, the probability of dying in the hospital was significantly lower for those with obesity (Adjusted-OR 0.59;95%CI 0.55-0.63) and morbid obesity (Adjusted-OR 0.62;95%CI 0.54-0.71) compared with non-obese. The protective effect of obesity (Adjusted-OR 0.71;95%CI 0.67-0.75) and morbid obesity (Adjusted OR 0.73;95%CI 0.66-0.8) was also observed among women.

CONCLUSIONS

Obese and obesity morbid patients with CAP have a lower risk of IHM than non-obese patients, without sex differences in this association. These data confirm the existence of the obesity paradox in this patient population.

Association between Brachial-Ankle Pulse Wave Velocity as a Marker of Arterial Stiffness and Body Mass Index in a Chinese Population

Objectives: Arterial stiffness is widely accepted as an important predictor of cardiovascular disease (CVD) development. While obesity is generally associated with increased CVD risk, there is evidence that overweight patients with existing CVD may have better clinical outcomes than their lean counterparts. Our study sought to observe any potential association between brachial−ankle pulse wave velocity (BAPWV), a marker of arterial stiffness related to CVD risk, and Body Mass Index (BMI), a crude and widely used measure of obesity. Methods: Adult individuals (n = 857) assessed for routine CV risk were included and grouped according to their BMI (<25 kg/m2: normal; 25−30 kg/m2: overweight, ≥30 kg/m2: obese). Their anthropometric parameters, brachial cuff pressures, and BAPWV were measured. Results: Brachial pressure was significantly higher as BMI increased. BAPWV showed a positive linear association with systolic (r = 0.66, p < 0.01), mean (r = 0.60, p < 0.01), diastolic (r = 0.51, p < 0.01), and pulse (r = 0.53, p < 0.01) pressures. However, a linear relationship between BMI and BAPWV was only apparent in males aged <50 years (p = 0.01) and in females aged ≥50 years (p < 0.01). In individuals with similar brachial systolic pressure, BAPWV was higher in normal-weight subjects compared to overweight−obese ones. Conclusions: This conflicting finding is attributed to an overestimation of the degree of arterial stiffness as a measure of CVD risk in individuals with a less ‘healthy’ BMI. This suggests that BMI may not the appropriate obesity indicator to assess CV risk. Our finding emphasizes the importance of establishing a non-linear relationship between CVD risk, age, and BMI, taking into account apparent sex differences, to predict future CV events. While this finding may suggest a lower degree of stiffness in large arteries of overweight−obese subjects compared to their normal-weight counterparts, the potential implications for individuals with higher BMI need be explored further.

The Association of Body Mass Index With the Risk of Pulmonary Hypertension in Adults: A Systematic Review and Meta-Analysis of Observational Studies

Backgrounds

Findings regarding the association of body mass index (BMI) with pulmonary hypertension (PH) are conflicting, and there is no systematic review and meta-analysis to summarize the results. Therefore, the purpose of this systematic review and meta-analysis is to assess this relationship.

Methods

To detect the relevant articles, PubMed, Scopus, and Google Scholar were searched until February 2021. Included essays were pooled using a random-effect model. Cochrane Q-test and I²-test was applied to assess between-study heterogeneity.

Results

Fourteen articles (eight cross-sectional and four cohort studies) were included in the meta-analysis. The meta-analysis of comparing highest vs. lowest BMI categories did not indicate a significant association between BMI and PH (Summary Effect Estimate: 1.59 (95% CI: 0.50, 5.07, I² = 92.3). Furthermore, The summary risk estimate for a one-unit increment in BMI was 1.01 (95 % CI: 0.99, 1.03), with high heterogeneity, I² = 73.5 %, P heterogeneity <0.001). Subgroup analysis showed significant positive association between BMI and the risk of PH in studies controlled for cofounders, and studies with higher sample sizes (≥2,000).

Conclusion

There is no significant association between BMI and risk of pulmonary hypertension. Further studies are required to confirm these findings.

Association of nutritional status and mortality risk in patients with primary pulmonary hypertension

Malnutrition plays a crucial role in pulmonary hypertension (PH). The prognostic nutritional index (PNI) is a reliable indicator for nutritional status assessment. However, its relationship with mortality risk in PH patients has not yet been investigated. This study analyzed data from the Patient Registry for Primary PH. PNI was calculated through albumin and lymphocyte counts. Subjects with missing data for PNI calculation were excluded. The primary endpoint was all‐cause mortality. Cox proportional hazard model was used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs). Of the 317 patients records available in the registry, we finally included 136 patients. The average age of the included subjects was 40.56 (14.91) years and 63.24% (86/136) were female. In our analysis of Cox regression, per 1‐point increment of PNI was associated with 4% decreased risk of mortality in PH patients (age‐ and sex‐adjusted HR: 0.96, 95% CI: 0.93–0.98, p = 0.002). We further categorized these subjects by quartiles of PNI. Compared to quartile 4, the age‐ and sex‐adjusted HRs of death for quartiles 1, 2, and 3 were 2.39 (95% CI: 1.21–4.72, p = 0.01), 2.25 (95% CI: 1.15–4.39, p = 0.02), and 1.72 (95% CI: 0.84–3.52, p = 0.14). In addition, logistic regression analyses suggested a positive correlation of PNI with total lung capacity (β = 0.98, p = 0.002) and forced expiratory volume in 1 min (β = 1.53, p = 0.03). This study demonstrates that low PNI was associated with an increased risk of death in PH patients. These findings help to enlighten our understanding of the nutritional status and adverse outcomes in PH patients.

A retrospective case-control cohort analysis of comorbidity and health expenditure in hospitalized adults diagnosed with obesity utilizing ICD-10 diagnostic coding

The cost and comorbidity of obesity in hospitalized inpatients, is less known. A retrospective study of patients presenting to a large district hospital in Western Sydney (April 2016-February 2017) using clinical, pathological as well as diagnostic coding data for obesity as per ICD-10. Of 43 212 consecutive hospital presentations, 390 had an obesity-coded diagnosis (Ob, 0.90%), of which 244 were gender and age-matched to a non-obesity coded cohort (NOb). Weight and BMI were higher in the Ob vs NOb group (126 ± 37 vs 82 ± 25 kg; BMI 46 ± 12 vs 29 ± 8 kg/m² , P < .001) with a medical record documentation rate of 62% for obesity among Ob. The Ob cohort had 2-5× higher rates of cardiopulmonary and metabolic complications (P < .001), greater pharmacologic burden, length of stay (LOS, 225 vs 89 hours, P < .001) and stay in intensive care but no differences in the prevalence of mental disorders. Compared with BMI <35 kg/m² , inpatients with BMI >35 kg/m² were 5× more likely to require intensive care (OR 5.08 [1.43-27.3, 95% CI], P = .0047). The initiation of obesity-specific interventions by clinical teams was very low. People with obesity who are admitted to hospital carry significant cost and complications, yet obesity is seldom recognized as a clinical entity or contributor.

A review of rodent models for metabolic syndromes and pulmonary hypertension

PURPOSE

Emerging evidence suggests that metabolic disorders, such as diabetes and obesity, may affect the pathogenesis and development of pulmonary hypertension (PH), and therefore some treatments could be beneficial for both disorders. The present study investigates whether such metabolic diseases increase susceptibility to PH in rodent models, and identifies which models are suitable for research on PH and its potential therapeutic candidates. It also explores whether particular PH model can worsen the metabolic parameters.

RESULTS

A review of 200 interventions on a variety of animal models was performed. The advantages of various diabetes (obesity)-related procedures, including dietary and genetic modifications, intended to provoke 'spontaneous' PH were reviewed, as well as the effects of combinations of such procedures with common PH models, with the aim of exacerbating pulmonary artery remodeling, right ventricle hypertrophy and hemodynamics. The paper describes the efficacy of particular agents toward PH-related lesions, according to particular study protocols (animal model, dosage schedule).

CONCLUSIONS

A wide range of diabetes (obesity)-related animal models are used for pre-clinical studies on PH and several factors should be considered when planning research; special attention should be paid to the linkage between the molecular background of the disease, the rationale for a particular animal model and the molecular activity of the tested agent.

Evaluation of code-based algorithms to identify pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension patients in large administrative databases

Large administrative healthcare (including insurance claims) databases are used for various retrospective real-world evidence studies. However, in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension, identifying patients retrospectively based on administrative codes remains challenging, as it relies on code combinations (algorithms) and the accuracy for patient identification of most of them is unknown. This study aimed to assess the performance of various algorithms in correctly identifying patients with pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension in administrative databases. A systematic literature review was performed to find publications detailing code-based algorithms used to identify pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension patients. PheValuator, a diagnostic predictive modelling tool, was applied to three US claims databases, yielding models that estimated the probability of a patient having the disease. These models were used to evaluate the performance characteristics of selected pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension algorithms. With increasing algorithm complexity, average positive predictive value increased (pulmonary arterial hypertension: 13.4–66.0%; chronic thromboembolic pulmonary hypertension: 10.3–75.1%) and average sensitivity decreased (pulmonary arterial hypertension: 61.5–2.7%; chronic thromboembolic pulmonary hypertension: 20.7–0.2%). Specificities and negative predictive values were high (≥97.5%) for all algorithms. Several of the algorithms performed well overall when considering all of these four performance parameters, and all algorithms performed with similar accuracy across the three claims databases studied, even though most were designed for patient identification in a specific database. Therefore, it is the objective of a study that will determine which algorithm may be most suitable; one- or two-component algorithms are most inclusive and three- or four-component algorithms identify most precise pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension populations, respectively.

Obesity in Pulmonary Arterial Hypertension (PAH): The Pulmonary Hypertension Association Registry (PHAR)

RATIONALE

Obesity is associated with pulmonary arterial hypertension (PAH), but its impact on outcomes such as health-related quality of life (HRQoL), hospitalizations and survival is not well understood.

OBJECTIVES

To assess the effect of obesity on health-related quality of life (HRQoL), hospitalizations and survival in patients with PAH.

METHODS

We performed a cohort study of adults with PAH from the Pulmonary Hypertension Association Registry, a prospective multicenter registry. Multivariate linear mixed effects regression was used to examine the relationship between weight categories and HRQoL using the Short Form-12 (SF-12) and emPHasis-10 (e10). We used multivariable negative binomial regression to estimate hospitalization incidence rate ratios (IRRs) and Cox regression to estimate hazard ratios (HRs) for transplant-free survival by weight status.

RESULTS

767 subjects were included: mean age of 57 years, 74% female, 33% overweight and 40% obese, with median follow-up duration of 527 days. Overweight and obese patients had higher baseline e10 scores (worse HRQoL), which persisted over time (p<0.001). The overweight and obese have a trend towards increased incidence of hospitalizations compared to normal weight (IRR 1.34, 95% confidence interval (95%CI) 0.94-1.92 and 1.33, 95%CI 0.93-1.89, respectively). Overweight and obese patients had lower risk of transplant or death as compared to normal weight patients (HR 0.45, 95%CI 0.25-0.80 and 0.39, 95%CI 0.22-0.70, respectively).

CONCLUSIONS

In a large multicenter, prospective cohort of PAH, overweight and obese patients had worse disease-specific HRQoL despite better transplant-free survival compared to normal weight patients. Future interventions should address the specific needs of these patients.

Obesity and diabetes as comorbidities for COVID-19: Underlying mechanisms and the role of viral-bacterial interactions

Obesity and diabetes are established comorbidities for COVID-19. Adipose tissue demonstrates high expression of ACE2 which SARS- CoV-2 exploits to enter host cells. This makes adipose tissue a reservoir for SARS-CoV-2 viruses and thus increases the integral viral load. Acute viral infection results in ACE2 downregulation. This relative deficiency can lead to disturbances in other systems controlled by ACE2, including the renin-angiotensin system. This will be further increased in the case of pre-conditions with already compromised functioning of these systems, such as in patients with obesity and diabetes. Here, we propose that interactions of virally-induced ACE2 deficiency with obesity and/or diabetes leads to a synergistic further impairment of endothelial and gut barrier function. The appearance of bacteria and/or their products in the lungs of obese and diabetic patients promotes interactions between viral and bacterial pathogens, resulting in a more severe lung injury in COVID-19.

Individuals with Peripheral Artery Disease (PAD) and Type 1 Diabetes Are More Likely to Undergo Limb Amputation than Those with PAD and Type 2 Diabetes

BACKGROUND

Limited data exist comparing how type 1 diabetes mellitus (DM) and type 2 DM may have differential effects on peripheral artery disease (PAD) severity. We aimed to study the association of type of DM with the procedure utilized in hospitalizations with a diagnosis of PAD.

METHODS

We used the national inpatient sample databases from 2003 to 2014 to identify hospitalizations with a diagnosis of PAD and type 1 or type 2 DM. Logistic regression was utilized to evaluate the association between type of DM and procedure utilized (amputation-overall, major, endovascular revascularization, surgical revascularization).

RESULTS

We identified 14,012,860 hospitalizations with PAD diagnosis and DM, 5.6% (n = 784,720) had type 1 DM. The patients with type 1 DM were more likely to present with chronic limb-threatening ischemia (CLTI) (45.2% vs. 32.0%), ulcer (25.9% vs. 17.7%), or complicated ulcer (16.6% vs. 10.5%) (all p < 0.001) when compared to those with type 2 DM. Type 1 DM was independently and significantly associated with more amputation procedures (adjusted odds ratio = 1.12, 95% confidence interval [CI] I 1.08 to 1.16, p < 0.001). Overall, in-hospital mortality did not differ between the individuals with type 1 and type 2 DM. The overall mean (95% CI) length of stay (in days) was 6.6 (6.5 to 6.6) and was significantly higher for type 1 DM (7.8 [7.7 to 8.0]) when compared to those with type 2 DM (6.5 [6.4 to 6.6]).

CONCLUSION

We observed that individuals with PAD and type 1 DM were more likely to present with CLTI and ulcer and undergo amputation when compared to those with PAD and type 2 diabetes. Further studies are needed to better understand the underlying mechanisms behind these findings and to identify novel interventions to reduce the risk of amputation in patients with type 1 DM.

BMI Is Causally Associated With Pulmonary Artery Pressure But Not Hemodynamic Evidence of Pulmonary Vascular Remodeling

BACKGROUND

There is an unclear relationship of obesity to the pathogenesis and severity of pulmonary arterial hypertension (PAH) and pulmonary venous hypertension (PVH).

RESEARCH QUESTION

Is BMI casually associated with pulmonary artery pressure (PAP) and/or markers of pulmonary vascular remodeling?

STUDY DESIGN AND METHODS

The study design was a two-sample inverse-variance weighted Mendelian randomization. We constructed two BMI genetic risk scores from genome-wide association study summary data and deployed them in nonoverlapping cohorts of subjects referred for right heart catheterization (RHC) or echocardiography. A BMI highly polygenic risk score (hpGRS) optimally powered to detect shared genetic architecture of obesity with other traits was tested for association with RHC parameters including markers of pulmonary vascular remodeling. A BMI strict genetic risk score (sGRS) composed of high-confidence genetic variants was used for Mendelian randomization analyses to assess if higher BMI causes higher PAP.

RESULTS

Among all subjects, both directly measured BMI and hpGRS were positively associated with pulmonary arterial pressures but not markers of pulmonary vascular remodeling. Categorical analyses revealed BMI and hpGRS were associated with PVH but not PAH. Mendelian randomization of the sGRS supported that higher BMI is causal of higher systolic pulmonary artery pressure (sPAP). Sensitivity analyses showed sPAP-BMI sGRS relationship was preserved when either individuals with PAH or PVH were excluded. In the echocardiographic cohort, BMI and hpGRS were positively associated with estimated PAP and markers of left heart remodeling.

INTERPRETATION

BMI is a modifier of pulmonary hypertension severity in both PAH and PVH but is only involved in the pathogenesis of PVH.

Obesity Is Associated With Pulmonary Hypertension and Modifies Outcomes

Background

Experimental studies support a link between obesity and pulmonary hypertension (PH), yet clinical studies have been limited. This study sought to determine the association of obesity and pulmonary hemodynamic measures and mortality in PH.

Methods and Results

We examined patients undergoing right‐sided heart catherization (2005–2016) in a hospital‐based cohort. Multivariable regression models tested associations of body mass index and pulmonary vascular hemodynamics, with PH defined as mean pulmonary artery pressure >20 mm Hg, and further subclassified into precapillary, postcapillary, and mixed PH. Multivariable Cox models were used to examine the effect of PH and obesity on mortality. Among 8940 patients (mean age, 62 years; 40% women), 52% of nonobese and 69% of obese individuals had evidence of PH. Higher body mass index was independently associated with greater odds of overall PH (odds ratio, 1.34; 95% CI, 1.29–1.40; P<0.001 per 5‐unit increase in body mass index) as well as each PH subtype (P<0.001 for all). Patients with PH had greater risk of mortality compared with individuals without PH regardless of subgroup (P<0.001 for all). We found that obesity was associated with 23% lower hazard of mortality among patients with PH (hazard ratio, 0.77; 95% CI, 0.69–0.85; P<0.001). The effect of obesity was greatest among those with precapillary PH (hazard ratio, 0.57; 95% CI, 0.46–0.70; P<0.001), where obesity modified the effect of PH on mortality (P for interaction=0.02).

Conclusions

Obesity is independently associated with PH. PH is associated with greater mortality; this is modified by obesity such that obese patients with precapillary PH have lower mortality compared with nonobese counterparts. Further studies are needed to elucidate mechanisms underlying obesity‐related PH.

Association of history of heart failure with hospital outcomes of hyperglycemic crises: Analysis from a University hospital and national cohort

AIMS

The impact of a history of heart failure (HF) on the outcomes of hospitalization for hyperglycemic crises (diabetic ketoacidosis and hyperosmolar hyperglycemic syndrome) is unknown. We aimed to test the hypothesis that a history of HF has a deleterious impact on the outcomes of hospitalization for hyperglycemic crises.

METHODS

We used two different datasets: National Inpatient Sample database 2003-2014 and a single University hospital cohort 2007-2017, to identify all adult hospitalizations with a primary diagnosis of hyperglycemic crises. Multivariable regression models were used to analyze the outcomes of in-hospital mortality, length of hospital stay and transfer to nursing home or similar short-term facility between HF and no-HF hospitalizations.

RESULTS

Of the 1, 570,726 hyperglycemic crises related hospitalizations, a history of HF was present in 57, 520 (3.6%) hospitalizations. After multivariable risk-adjustment, HF group had a higher observed in-hospital mortality [0.4% vs. 0.2%; adjusted odds ratio (AOR) = 1.7, 95% CI 1.4 to 2.0, P < .001] and transfer to nursing home or similar short-term facility (3.9 vs. 2.8%, AOR = 1.4, 95% CI 1.3 to 1.5, P < .001) compared with no-HF group. Mean length of hospital stay [6.5 vs. 3.5 days; P < .001] was also higher for HF group than no-HF group. Data from the smaller University hospital cohort showed similar findings.

CONCLUSIONS

Patients with a history of HF may be an under-recognized high-risk group among patients hospitalized for hyperglycemic crisis. Additional studies are warranted to clarify risk elements and optimize the inpatient care of individuals with hyperglycemic crises.

The obesity paradox in pulmonary arterial hypertension: the Scottish perspective

Pulmonary arterial hypertension (PAH) is a rare disease characterised by progressive pulmonary vascular remodelling, resulting in right ventricular failure, which is the principal cause of death [1]. Excessive bodyweight is a well-established independent risk factor for the development of cardiovascular disease and mortality [2]. However, data have emerged for a variety of chronic cardiovascular diseases, particularly heart failure, showing lower long-term mortality in obese patients [3]. This has been termed the “obesity paradox”. It challenges clinical reasoning and the significant healthcare expenditure directed toward weight loss in the general population.

Analysis of pulmonary arterial hypertension patients in Scotland across 20 years supports a recent French study suggesting there is no protective effect from obesity for this disease, in contrast to emerging evidence from the USA and Chinahttp://bit.ly/34WCZ7W

Obesity paradox in cardiovascular disease: where do we stand?

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

Relation of Obesity to Outcomes of Hospitalizations for Atrial Fibrillation

Obesity has been linked with increased incidence of atrial fibrillation (AF), but impact of presence of obesity on outcomes of hospitalizations for AF has not been investigated. We used the National Inpatient Sample database 2010 to 2014 to identify all adult hospitalizations aged ≥18years with a primary diagnosis of AF. Obese patients were identified using the co-morbidity variable for obesity, as defined in National Inpatient Sample databases. Multivariable logistic regression was used to compare in-hospital outcomes (mortality, acute stroke events) between obese and non-obese patients with AF. Of 431, 734 hospitalizations for AF, 66,138 (15.3%) were obese. Obese patients were younger and more likely to be African-Americans compared with non-obese patients. Despite being younger, obese patients had significantly higher prevalence of cardiovascular co-morbidities such as hypertension, diabetes mellitus, dyslipidemia, smoking, heart failure, and chronic renal failure (p <0.001 for all). After multivariate risk-adjustment, obese patients had a lower observed in-hospital mortality (0.5% vs 1.0%; unadjusted odds ratio = 0.52, 95% confidence interval [CI] 0.46 to 0.58, p <0.001; adjusted odds ratio = 0.83, 95% CI 0.73 to 0.94, p <0.001) and acute stroke events (0.4% vs 0.7%, unadjusted odds ratio = 0. 65, 95% CI 0.57 to 0.73, p < 0.001; adjusted odds ratio = 0.82, 95% CI 0.72 to 0.94) compared with non-obese patients. In conclusion, in this large retrospective analysis of an unselected nationwide cohort of patients hospitalized for AF, obese patients demonstrated lower risk-adjusted odds of in-hospital mortality and stroke events, consistent with an "obesity paradox."

Pulmonary vascular dysfunction in metabolic syndrome

Metabolic syndrome is a critically important precursor to the onset of many diseases, such as cardiovascular disease, and cardiovascular disease is the leading cause of death worldwide. The primary risk factors of metabolic syndrome include hyperglycaemia, abdominal obesity, dyslipidaemia, and high blood pressure. It has been well documented that metabolic syndrome alters vascular endothelial and smooth muscle cell functions in the heart, brain, kidney and peripheral vessels. However, there is less information available regarding how metabolic syndrome can affect pulmonary vascular function and ultimately increase an individual's risk of developing various pulmonary vascular diseases, such as pulmonary hypertension. Here, we review in detail how metabolic syndrome affects pulmonary vascular function.

Association Between BMI and Obesity With Survival in Pulmonary Arterial Hypertension

BACKGROUND

An obesity paradox, wherein patients who are obese have lower mortality, has been described in cardiopulmonary diseases, including pulmonary arterial hypertension (PAH). Our objective was to determine whether obesity and BMI are associated with mortality in patients with PAH.

METHODS

We assessed incident patients with idiopathic, drug-induced, and heritable PAH from the French Pulmonary Hypertension Network registry. Cox regression and Kaplan-Meier analysis were used to assess the association between BMI and obesity with all-cause mortality.

RESULTS

Of 1,255 patients included, 30% were obese. A higher proportion of women (65.1% vs 53.4%, P < .01), drug-induced PAH (28.9% vs 9.2%, P < .01), systemic hypertension, diabetes, and hypothyroidism were present in the obese group. More obese patients were in New York Heart Association class III (66.4% vs 57.1%), fewer were class IV (11.8% vs 16.9%, P < .01), and 6-min walk distance was lower (276 ± 121 vs 324 ± 146, P < .01). Right atrial pressure, pulmonary wedge pressure, and cardiac index were higher, whereas pulmonary vascular resistance was lower in patients who were obese. Neither BMI (hazard ratio [HR], 0.99; 95% CI, 0.97-1.01; P = .41) nor obesity (HR, 1.0; 95% CI, 0.99-1.01; P = .46) were associated with mortality in multivariable analyses. There was a significant interaction between age and obesity such that mortality increased among patients < 65 years of age who were morbidly obese (HR, 3.01; 95% CI, 1.56-5.79; P = .001).

CONCLUSIONS

Obesity was not associated with mortality in the overall population, but there was an age-obesity interaction with increased mortality among young patients who were morbidly obese. These results have implications for active weight management in younger patients who are morbidly obese who are otherwise candidates for lung transplantation.

Influence of Body Mass Index on Long-Term Survival After Cardiac Catheterization

We examined 18,654 patients who underwent cardiac catheterization in a single center to clarify the association between catheterization indication, body mass index (BMI), and long-term survival over a mean follow-up of 81 months. Patients were grouped by indication for catheterization: (a) acute coronary syndromes (ACS), 7,426 patients; (b) coronary artery disease (CAD) evaluation in stable clinical presentation, 6,911 patients; and (c) primarily non-CAD cardiac evaluations, 4,317 patients. Compared with normal weight, overweight and obesity (but not morbid obesity) was associated with lower risk of long-term mortality. Underweight patients had the greatest risk of mortality. After multivariate adjustment, survival benefit of the overweight and obese was retained in the ACS group [hazard ratio 0.86, 95% confidence interval (0.77-0.96), p = 0.006 and 0.79, (0.68-0.91), p = 0.001, respectively] and in overweight patients in the stable presentation CAD group [0.83, (0.72-0.94), p = 0.005], whereas there was no survival benefit in any of the BMI categories in those catheterized primarily for non-CAD indications. Further analysis of matched cohorts showed similar patterns of survival benefit of the overweight/obese. In conclusion, among patients who underwent cardiac catheterization, an inverse association between BMI and long-term mortality was observed, with the lowest risk noted in the overweight and obese population; the obesity paradox was principally demonstrated in patients with ACS, and was eliminated after covariate adjustment in those catheterized primarily for non-CAD indications.