Beyond BMI: Obesity and Lung Disease

Elevated GFI1 in Alveolar Macrophages Suppresses ACOD1 Expression and Exacerbates Lipopolysaccharide-Induced Lung Injury in Obesity

To investigate the mechanisms behind the worsening of acute lung injury (ALI) in obesity, transcriptomic sequencing is performed, and significantly reduced mRNA levels of Aconitate Decarboxylase 1 (ACOD1) in the lung tissue of high-fat diet (HFD) mice are found. Clinical samples are collected, an ALI model is established in HFD mice, and both human and mouse samples are analyzed, revealing a significant decrease in ACOD1 expression in lung tissue and alveolar macrophages in obesity. Further in vivo and in vitro experiments show that ACOD1 knockdown worsens lung injury, inflammation, and oxidative stress, while ACOD1 overexpression alleviates these effects. Moreover, nuclear factor erythroid 2-related factor 2 (Nrf2) inhibition diminishes the protective effects of ACOD1 overexpression in ALI exacerbated by obesity. Additionally, in the context of obesity, growth factor independent 1 (GFI1) protein levels are elevated in alveolar macrophages, and its knockdown leads to upregulated ACOD1 expression. Therefore, this study suggests that ACOD1 downregulation in alveolar macrophages is a key factor in worsening ALI in obesity, likely driven by GFI1 upregulation.

Associated Factors and Pulmonary Function Outcomes of Preserved Ratio Impaired Spirometry: A Scoping Review

Background

Preserved ratio impaired spirometry (PRISm) is a common but understudied abnormal pulmonary function state and is strongly associated with poor health outcomes. However, there is a lack of uniformity in defining the factors and pulmonary function outcomes associated with PRISm.

Objective

This scoping review aims to elucidate the associated factors and pulmonary function outcomes of PRISm, thereby enhancing healthcare professionals' understanding of PRISm and laying the groundwork for its prevention and treatment.

Methods

This scoping review follows the 5-step framework developed by Arksey and O'Malley. Literature on PRISm was systematically searched from databases including PubMed, Embase, CINAHL, the Cochrane Library, Web of Science, CNKI, and Wan Fang, spanning from inception to July 2024. Inclusion and exclusion criteria were applied to enroll relevant studies. Data were extracted, collected, summarized, and reported.

Results

A total of 38 studies were included. The analysis revealed that associated factors for PRISm encompass possible pathogenic factors (older age, female, lower education level, smoking, obesity, etc), comorbidity associations (asthma, diabetes, cardiovascular diseases, etc), and disease characteristic factors (disease burden, physical performance, radiological characteristics, etc). The pulmonary function status of the PRISm population is unstable, making progression to airflow obstruction (AFO) more likely than in the normal population. PRISm exhibits multiple subgroups (incident or stable PRISm, definite PRISm or PRISm with AFO, non-restrictive or restrictive PRISm, etc) and significant differences exist in pulmonary function outcomes among different subgroups.

Conclusion

This scoping review offers a more comprehensive understanding of PRISm. It is recommended that future research focus on a deeper investigation of the pulmonary function of PRISm, elucidating its pathophysiological characteristics, and proposing new strategies for its prevention and treatment. Furthermore, more research is needed in low-income and middle-income economies to understand PRISm comprehensively.

The J-shaped relationship between body roundness index and adult asthma: insights from NHANES 2001-2018

Background

Many studies have used Body Mass Index (BMI) to define obesity and examine its potential link to adult asthma. However, BMI overlooks body fat distribution, which may significantly impact health. Unlike BMI, the Body Roundness Index (BRI) can more accurately reflect body fat distribution. Therefore, this study examined BRI's relationship with asthma prevalence in U.S. adults.

Methods

This study was based on data from the National Health and Nutrition Examination Survey (NHANES) between 2001 and 2018 and covered 40,052 adult participants. Participants were categorized into four quartile groups based on their BRI levels: Quartile 1 (1.05, 3.80); Quartile 2 (3.80, 5.06); Quartile 3 (5.06, 6.61); Quartile 4 (6.61, 23.48). The association between BRI and asthma prevalence was assessed via weighted multivariate logistic regression, smoothed curve fitting, threshold effects, subgroup, and sensitivity analysis. BRI's predictive power was compared to BMI and waist circumference using z-scores.

Results

Of the study population, 5,605 participants had asthma (13.99% prevalence). After adjusting for possible confounders, the results showed that higher BRI was linked to greater asthma prevalence (OR = 1.41, 95% CI:1.27, 1.56, p < 0.0001). A J-shaped relationship between BRI and asthma prevalence (p-nonlinearity = 0) was found, with asthma prevalence rising significantly when BRI surpassed 4.34. BRI outperformed BMI and waist circumference in predicting asthma (BRI: OR = 1.180; BMI: OR = 1.169; W.C.: OR = 1.166). Subgroup and sensitivity analyses confirmed our results' robustness.

Conclusion

Adult asthma prevalence increases with increasing BRI levels, showing a J-shaped relationship. Keeping BRI under 4.34 is vital for lowering asthma prevalence, especially for overweight or obese individuals. In addition, BRI outperformed BMI and waist circumference in predicting asthma occurrence.

Relationship Between Plasma Leptin Levels and Airflow Limitation in the Small and Medium Airways in Young Adults

Background/Objectives: To determine the relationship between plasma leptin levels and airflow limitation (AFL) in the small and medium airways of young adults according to their body composition (BC). Methods: To determine AFL, the following measurements were taken: forced expiratory volume in the first second (FEV1), forced expiratory flow between 25-75% (FEF25-75%), airway resistance (Raw), and specific airway resistance (sRaw). The measured BC variables were body mass index (BMI), body fat percentage (%BF), trunk fat percentage (TF%), and fat-free mass (FFM). Plasma leptin was measured using the ELISA technique. Results: In total, 83 participants (40 male and 43 female) aged 21.55 ± 2.08 years were evaluated. Leptin was significantly higher in women than men (p < 0.01). When relating leptin to lung function variables, FEV1 and FEF25-75% showed a significant inverse relationship (p < 0.01), and Raw and sRaw showed a direct and significant relationship (p < 0.01). Female participants with a BF% and leptin higher than their p75 were observed to have a higher risk of increased sRaw (OR = 1.0; OR = 1.15, respectively), regardless of age, and participants with an FFM% higher than their p75 had a lower risk of increased sRaw (OR = 0.71), regardless of gender and age. Conclusions: There is an inverse relationship between FEV1, FEF25-75%, and a direct relationship between Raw and sRaw with leptin. For female participants with a higher BF%, higher FFM%, and leptin, the risk of developing Raw and sRaw was found to be modified.

Incidence, Risk Factors, and Long-Term Outcomes for Extubation Failure in ICU in Patients With Obesity: A Retrospective Analysis of a Multicenter Prospective Observational Study

BACKGROUND

To our knowledge, no large observational study has compared the incidence and risk factors for extubation failure within 48 h and during ICU stay in the same cohort of unselected critically ill patients with and without obesity.

RESEARCH QUESTION

What are the incidence and risk factors of extubation failure in patients with and without obesity?

STUDY DESIGN AND METHODS

In the prospective multicenter observational Practices and Risk Factors for Weaning and Extubation Airway Failure in Adult Intensive Care Unit: A Multicenter Trial (FREEREA) study in 26 ICUs, the primary objective was to compare the incidence of extubation failure within 48 h in patients with and without obesity. Secondary objectives were to describe and to identify the independent specific risk factors for extubation failure using first a logistic regression model and second a decision tree analysis.

RESULTS

Of 1,370 extubation procedures analyzed, 288 (21%) were performed in patients with obesity and 1,082 (79%) in patients without obesity. The incidence of extubation failure within 48 h among patients with or without obesity was 23 of 288 (8.0%) vs 118 of 1,082 (11%), respectively (unadjusted OR, 0.71; 95% CI, 0.45-1.13; P = .15); alongside patients with obesity receiving significantly more noninvasive ventilation [87 of 288 (30%) vs 233 of 1,082 (22%); P = .002] and physiotherapy [165 of 288 (57%) vs 527 of 1,082 (49%); P = .02] than patients without obesity. Risk factors for extubation failure also differed according to obesity status: female sex (adjusted OR, 4.88; 95% CI, 1.61-13.9; P = .002) and agitation before extubation (adjusted OR, 6.39; 95% CI, 1.91-19.8; P = .001) in patients with obesity, and absence of strong cough before extubation (adjusted OR, 2.38; 95% CI, 1.53-3.84; P = .0002) and duration of invasive mechanical ventilation before extubation (adjusted OR, 1.03/d; 95% CI, 1.01-1.06; P = .01) in patients without obesity. The decision tree analysis found similar risk factors.

INTERPRETATION

Our findings indicate that anticipation and application of preventive measures for patients with obesity before and after extubation led to similar rates of extubation failure among patients with and without obesity.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT02450669; URL: www.

CLINICALTRIALS

gov.

Nutritional Discrepancies Among Inpatients and Outpatients Diagnosed with Hypertension

Objectives: Arterial hypertension (AH) is one of the most common disorders affecting the human population. The diet of patients with AH can influence the course of the disease and prognosis. The aim of this study was to investigate the differences in nutrition in hospitalised and non-hospitalised hypertensive patients, compared to control groups of non-hypertensive patients from the same medical centres. Methods: Patients from nine centres-six hospitals and three ambulatory care centres-were surveyed. The Questionnaire for the Assessment of Dietary Habits, Lifestyle, and Nutrition Knowledge (KomPAN) was administered by interviewers. Results: Complete results were obtained from 172 hospitalised and 63 non-hospitalised patients. A significantly higher mean body mass index was found for the hypertensive patients (p < 0.001), and a higher unhealthy diet index score was also shown for the hypertensive patients (p = 0.003). Over and above this, a lower mean health-promoting diet index score was found in the hospitalised group (who were on a hospital diet) for the hypertensive patients (p = 0.018). Summary: The study highlights a strong positive correlation between body mass index (BMI) and arterial hypertension (AH), with patients exhibiting higher BMI levels compared to a control group. A BMI of over 25 significantly increases the likelihood of developing AH, and obesity is associated with a higher risk in both men and women. Conclusions: The study indicates that a hospital diet may not be suitable for people with AH. Further research should be conducted to obtain reliable results. Clinical implications: The study showed which factors should be considered when composing a diet for people with hypertension, the relevance of which was demonstrated in the discussion. The study shows that the problem that clinicians have been struggling with for years is still present and inadequately remedied.

The negative association between weight-adjusted-waist index and lung functions: NHANES 2007-2012

Obesity is a common public health issue worldwide, and its negative impact on lung function has garnered widespread attention. This study sought to investigate the possible association between a new obesity metric, the weight-adjusted waist index (WWI), and lung functions, providing a basis for the monitoring and protection of lung functions. We conducted a cross-sectional evaluation, analyzing data from adults in the U.S. gathered through the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2012. To explore the correlation between WWIs and lung functions, we utilized a multivariate logistic regression model with appropriate weighting to ensure accuracy. Smooth curve fitting also helped to confirm the linear nature of this relationship. Subgroup analyses were conducted to confirm the uniformity and dependability of the results. Our study included data from 13,805 adults in the United States. Multivariate linear regression analysis revealed that, in the fully adjusted model, higher WWIs were negatively correlated with forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), FEV1/FVC, peak expiratory flow rate (PEF), and forced expiratory flow rate (FEF) 25%-75% (β = -0.63; 95% confidence interval [CI] [-0.71, -0.55]; β = -0.55; 95% CI [-0.62, -0.48]; β = -0.02; 95% CI [-0.03, -0.01]; β = -1.44; 95% CI [-1.65, -1.23]; β = -0.52; 95% CI [-0.65, -0.39], respectively). Additionally, when analyzing the WWI as a categorical variable, a significant downward trend in the FVC, FEV1, PEF, and FEF 25%-75% was observed from Q2 to Q4 as the WWI increased (trend P < 0.05). Subgroup analysis showed stronger associations between WWI and lung functions, particularly among younger, non-Hispanic white, male participants, and current smokers. Our results indicate that elevated WWI is strongly associated with declining lung functions, demonstrating the importance of long-term monitoring and tracking of WWIs.

Ultra-processed foods intake in relation to metabolic health status, serum brain-derived neurotrophic factor and adropin levels in adults

BACKGROUND

In recent years, there has been a lot of discussion over the impact of ultra-processed foods (UPFs) intake on overall health of subjects. However, the association between UPFs intake and metabolic unhealthy (MU) status is still in a state of ambiguity. The current study assessed the relationship between UPFs intake and MU status with regard to brain-derived neurotrophic factor (BDNF) and adropin levels.

METHODS

A sample of Iranian adults (aged 20-65 years) was selected to participate in this cross-sectional study using a multistage cluster random-sampling method. UPFs intake was assessed by a validated food frequency questionnaire and NOVA classification. Concentrations of metabolic parameters, BDNF and adropin were determined through fasting blood samples. MU status was assessed according to the criteria proposed by Wildman.

RESULTS

The overall prevalence of MU phenotype among study participants (n = 527) was 42.5%. Higher intake of UPFs was associated with elevated odds of MU status in multivariable-adjusted model (ORT3 vs. T1=1.88; 95%CI: 1.02-3.45). Moreover, a positive association was observed between UPFs intake and hypertriglyceridemia after controlling all confounders (ORT3 vs. T1=2.07; 95%CI: 1.15-3.73). However, each tertile increase in UPFs intake was not significantly associated with serum BDNF ([Formula: see text]=0.15; 95%CI: -0.05, 0.34; P = 0.14) and adropin ([Formula: see text]=-1.37; 95%CI: -6.16, 3.42; P = 0.58) levels in multivariable-adjusted linear regression models.

CONCLUSION

Our findings suggested that higher consumption of UPFs was related to increased likelihood of MU status among a sample of Iranian adults. Further longitudinal studies are needed to verify the directionality and generalizability of the results to all adult populations.

A clinician's guide to effects of obesity on childhood asthma and into adulthood

INTRODUCTION

Obesity, one of the most common chronic conditions affecting the human race globally, affects several organ systems, including the respiratory system, where it contributes to onset and high burden of asthma. Childhood onset of obesity-related asthma is associated with high persistent morbidity into adulthood.

AREAS COVERED

In this review, we discuss the disease burden in children and adults to highlight the overlap between symptoms and pulmonary function deficits associated with obesity-related asthma in both age ranges, and then discuss the potential role of three distinct mechanisms, that of mechanical fat load, immune perturbations, and of metabolic perturbations on the disease burden. We also discuss interventions, including medical interventions for weight loss such as diet modification, that of antibiotics and anti-inflammatory therapies, as well as that of surgical intervention on amelioration of burden of obesity-related asthma.

EXPERT OPINION

With increase in obesity-related asthma due to increasing burden of obesity, it is evident that it is a disease entity distinct from asthma among lean individuals. The time is ripe to investigate the underlying mechanisms, focusing on identifying novel therapeutic targets as well as consideration to repurpose medications effective for other obesity-mediated complications, such as insulin resistance, dyslipidemia and systemic inflammation.

Inter-cohort shifts in chronic disease, dementia, and mortality

Previous work using U.S. data has identified generational shifts, reflected in inter-cohort changes, in the incidence and prevalence of diseases in older ages. This study extends previous findings to England by examining similar results in memory complaints, heart conditions, stroke, diabetes, lung disease, and cancer using data from the English Longitudinal Study of Ageing (ELSA). We fit Cox proportional hazard models to the first eight waves (2002-2016) of the ELSA sample (n = 18,528). In addition to exploring shifts in disease incidence we also examine shifts in disease mortality. Both general and sex-related differences are examined. Disease incidence has increased for later-born cohorts in England, replicating similar trends in the U.S. Not all diseases showed differences between men and women, but when differences were identified, women had lower risks for disease. In comparison to the U.S. sample, disease trends in England are more negative (i.e. accelerated failure times) for more recently born cohorts. These results showing increasing incidence of disease among the later-born cohorts suggest the possibility of increased disease burden in coming years.

Implications of Airway Resistance and Conductance on the Respiratory Rate in individuals With Various Nutritional States Exposed To Exercise

Purpose

To determine how airway resistance (RAW) and airway conductance (GAW) affect inspiratory time (iT) and expiratory time (eT) in subjects with different nutritional states using the step test.

Methods

Forty-eight participants were recruited and divided into three groups: 16 normal weight (NW), 16 overweight (OW), and 16 obese (OB). A lung function test and anthropometric evaluation were performed. iT and eT were measured using a sonographic device before and after the step test.

Results

Body Mass Index (BMI) and Body Fat Percentage (BF%) were significantly higher (P<0.0001; P<0.0001, respectively) in OB group. RAW was significantly higher in the OB group (P=0.004), and GAW (P=0.004) was significantly lower in the same group. At rest, the Respiratory Rate (RR) was significantly higher in OB group (P<0.05), while iT and eT showed no significant differences. On the other hand, after the step test, eT was significantly lower (P=0.016), with the multiple linear regression model being the best predictor of post-exercise eT, including BF%/GAW and BF%/sGAW (explained variability of 15.7% and 14.6%, respectively).

Conclusion

Nutritional status can significantly impact lung function; at rest, there was a decrease in lung volumes and an increase in RR in OB subjects. In addition, there was a significant decrease in eT of OB subjects post-exercise. Finally, a significant relationship of BF%/GAW and BF%/sGAW with post-exercise eT was noted.

The Effects of High-Fat Diet and Flaxseed Oil-Enriched Diet on the Lung Parenchyma of Obese Mice

Omega-3 (ω3) fatty acids are widely investigated for their anti-inflammatory potential, however, there is little evidence regarding their action in the lung parenchyma in the context of obesity. The objective is to investigate the effects of flaxseed oil (FS), rich in α-linolenic (C18:3 - ω3), on the lungs of obese mice. Mice were fed a high-fat diet (HF) for 8 weeks to induce obesity. Subsequently, a part of these animals received HF containing FS oil for another 8 weeks. The HF consumption induced weight gain and hyperglycemia. The lung parenchyma shows a complete fatty acids profile, compared to the control group (CT). In the lung parenchyma, FS increases the ω3 content and, notwithstanding a reduction in the interleukins (IL) IL1β and IL18 contents compared to HF. However, FS promoted increased alveolar spaces, followed by MCP1 (Monocytes Chemoattractant Protein-1) positive cell infiltration and a dramatic reduction in the anti-inflammatory cytokine, IL10. Despite reducing the pulmonary inflammatory response, the consumption of a food source of ω3 was associated with alterations in the lipid profile and histoarchitecture of the lung parenchyma, which can lead to the development of pulmonary complications. This study brings an alert against the indiscriminate use of ω3 supplements, warranting caution.

Relationship between commonly defined metabolic health phenotypes and obesity with lung function in a working population: A cross-sectional study

BACKGROUND

Four phenotypes relate metabolism and obesity: metabolically healthy (MHO) and unhealthy (MUO) people with obesity and metabolically healthy (MHNO) and unhealthy (MUNO) people without obesity. No studies have addressed the association between these categories and lung function in the working population.

OBJECTIVES

The aim was to determine the relationship of phenotypes to lung ageing as measured by lung age and its relationship to lung dysfunction.

METHODS

A descriptive cross-sectional study was conducted in a working population. The outcome variable was lung function assessed by lung age. The four phenotypes of obesity and metabolic health (MHNO, MHO, MUO and MUNO) were determined using NCEP-ATP III criteria. Lung dysfunctions were classified into restrictive, obstructive, and mixed patterns.

RESULTS

The mean age of the participants was 43.7 years, ranging from 18 to 67 years. Of the 1860 workers, 51.3 % were women. The prevalences found were 71.4 %, 12 %, 10.6 % and 6 % for MHNO, MUO, MHO, and MUNO, respectively. MHO (β = 0.66; p = 0.591) was not associated with increased lung ageing compared with MHNO, but MUO (β = 7.1; p < 0.001) and MUNO (β = 6.6; p < 0.001) were. Concerning pulmonary dysfunctions, MUNO (OR = 1.93; p < 0.001) and MUO (OR = 2.91; p < 0.001) were found to be related to the presence of a restrictive pattern, and MUNO (OR = 2.40; p = 0.028) to the mixed pattern.

CONCLUSION

The results show that metabolic abnormalities, not obesity, are responsible for premature lung ageing and, therefore, lung function decline. In our study, having obesity without metabolic abnormality was not significantly associated with the presence of dysfunctional respiratory patterns.

Malnutrition and Obesity in Patients with COPD Exacerbation, Insights from the National Inpatient Sample

Background

The obesity paradox suggests that obese patients with Chronic Obstructive Pulmonary Disease Exacerbation (COPDE) may have better outcomes. COPD patients are at a higher risk of becoming malnourished, which has been linked to poor outcomes.

Objective

This paper aims to study the impact of malnutrition in patients with and without obesity hospitalized with COPDE.

Methods

Our retrospective study analyzed data from the National Inpatient Sample dataset between 2017 and 2020 to observe patients who were hospitalized with COPDE. The patients were divided into two groups: with and without malnutrition. The outcomes included all-cause mortality, invasive mechanical ventilation, length of stay, and total charge. We adjusted for confounders using multivariate regression model analysis.

Results

The study involved 392,920 patients with COPDE, out of which 5720 (1.45%) were diagnosed with malnutrition. Most of the patients in both groups were female, white, and under Medicare coverage. The mean age was higher in patients with malnutrition (67.6 vs. 64 years). In both groups, the rates of admissions were lowest in 2020 compared to three years prior. The rates and adjusted odds ratios of all-cause mortality were higher in patients with malnutrition (3.59% vs. 0.61%, P <0.01; adjusted odds ratio (aOR) 2.36, P<0.01, CI 1.8-3.7). We observed comparable findings when using invasive mechanical ventilation (13.2% vs. 2.82%, P<0.01, aOR 4.9, P<0.01, 3.9-6). Malnourished patients had a lengthier hospital stay and a greater total charge.

Conclusion

Malnutrition was identified as an independent risk factor associated with worse outcomes in obese patients admitted with COPD exacerbation.

Impact of Transplant Body Mass Index and Post-Transplant Weight Changes on the Development of Chronic Lung Allograft Dysfunction Phenotypes

INTRODUCTION

Chronic lung allograft dysfunction (CLAD) is a lung transplant complication for which four phenotypes are recognized: Bronchiolitis obliterans syndrome (BOS), Restrictive allograft syndrome (RAS), mixed and undefined phenotypes. Weight gain is common after transplant and may negatively impact lung function. Study objectives were to describe post-transplant weight trajectories of patients who developed (or did not) CLAD phenotypes and examine the associations between BMI at transplant, post-transplant changes in weight and BMI, and the risk of developing these phenotypes.

METHODS

Adults who underwent a bilateral lung transplant between 2000 and 2020 at our institution were categorized as having (or not) one of the four CLAD phenotypes based on the proposed classification system. Demographic, anthropometric, and clinical data were retrospectively collected from medical records and analyzed.

RESULTS

Study population included 579 recipients (412 [71.1%] CLAD-free, 81 [14.0%] BOS, 20 [3.5%] RAS, 59 [10.2%] mixed, and 7 [1.2%] undefined phenotype). Weight gains of greater amplitude were seen in recipients with restrictive phenotypes than CLAD-free and BOS patients within the first five years post-transplant. While the BMI category at transplant was not statistically associated with the risk of developing CLAD phenotypes, an increase in weight (Hazard ratio [HR]: 1.04, 95% CI [1.01-1.08]; P = .008) and BMI (HR: 1.13, 95% CI [1.03-1.23]; P = .008) over the post-transplant period was associated with a greater risk of RAS.

CONCLUSION

Post-LTx gain in weight and BMI modestly increased the risk of RAS, adding to the list of unfavorable outcomes associated with weight gain following transplant.

Does sex modify the effect of pre-pandemic body mass index on the risk of Long COVID? Evidence from the longitudinal analysis of the Survey of Health, Ageing and Retirement in Europe

BACKGROUND

Research on Long COVID risk factors is ongoing. High body mass index (BMI) may increase Long COVID risk, yet no evidence has been established regarding sex differences in the relationship between BMI and the risk of Long COVID. Investigating the nature of this relationship was the main objective of this study.

METHODS

A population-based prospective study involving a sample of respondents aged 50 years and older (n = 4004) from 27 European countries that participated in the 2020 and 2021 Survey of Health, Ageing and Retirement in Europe's (SHARE) Corona Surveys and in Waves 7 and 8 of the main SHARE survey. Logistic regression models were estimated to produce unadjusted and adjusted estimates of the sex differences in the relationship between BMI and Long COVID.

RESULTS

Linear relationship for females, with probability of Long COVID increasing with BMI (68% at BMI = 18, 93% at BMI = 45). Non-linear relationship for males, with probability of Long COVID of 27% at BMI = 18, 68% at BMI = 33, and 40% at BMI = 45. Relationships remained significant after adjusting for known Long COVID risk factors (age and COVID-19 hospitalization), presence of chronic diseases, and respondents' place of residence.

CONCLUSION

Sex differences appear to play an important role in the relationship between BMI and risk of Long COVID. Overall, females were more likely to have Long COVID, regardless of their BMI. Males at the higher end of the BMI spectrum had a lower risk of Long COVID as opposed to their female counterparts. Sex-specific research is recommended for better understanding of Long COVID risk factors.

Acod1/itaconate activates Nrf2 in pulmonary microvascular endothelial cells to protect against the obesity-induced pulmonary microvascular endotheliopathy

BACKGROUND

Obesity is the main risk factor leading to the development of various respiratory diseases, such as asthma and pulmonary hypertension. Pulmonary microvascular endothelial cells (PMVECs) play a significant role in the development of lung diseases. Aconitate decarboxylase 1 (Acod1) mediates the production of itaconate, and Acod1/itaconate axis has been reported to play a protective role in multiple diseases. However, the roles of Acod1/itaconate axis in the PMVECs of obese mice are still unclear.

METHODS

mRNA-seq was performed to identify the differentially expressed genes (DEGs) between high-fat diet (HFD)-induced PMVECs and chow-fed PMVECs in mice (|log2 fold change| ≥ 1, p ≤ 0.05). Free fatty acid (FFA) was used to induce cell injury, inflammation and mitochondrial oxidative stress in mouse PMVECs after transfection with the Acod1 overexpressed plasmid or 4-Octyl Itaconate (4-OI) administration. In addition, we investigated whether the nuclear factor erythroid 2-like 2 (Nrf2) pathway was involved in the effects of Acod1/itaconate in FFA-induced PMVECs.

RESULTS

Down-regulated Acod1 was identified in HFD mouse PMVECs by mRNA-seq. Acod1 expression was also reduced in FFA-treated PMVECs. Acod1 overexpression inhibited cell injury, inflammation and mitochondrial oxidative stress induced by FFA in mouse PMVECs. 4-OI administration showed the consistent results in FFA-treated mouse PMVECs. Moreover, silencing Nrf2 reversed the effects of Acod1 overexpression and 4-OI administration in FFA-treated PMVECs, indicating that Nrf2 activation was required for the protective effects of Acod1/itaconate.

CONCLUSION

Our results demonstrated that Acod1/Itaconate axis might protect mouse PMVECs from FFA-induced injury, inflammation and mitochondrial oxidative stress via activating Nrf2 pathway. It was meaningful for the treatment of obesity-caused pulmonary microvascular endotheliopathy.

The microbiome: an integral player in immune homeostasis and inflammation in the respiratory tract

The last decade of microbiome research has highlighted its fundamental role in systemic immune and metabolic homeostasis. The microbiome plays a prominent role during gestation and into early life, when maternal lifestyle factors shape immune development of the newborn. Breast milk further shapes gut colonization, supporting the development of tolerance to commensal bacteria and harmless antigens while preventing outgrowth of pathogens. Environmental microbial and lifestyle factors that disrupt this process can dysregulate immune homeostasis, predisposing infants to atopic disease and childhood asthma. In health, the low-biomass lung microbiome, together with inhaled environmental microbial constituents, establishes the immunological set point that is necessary to maintain pulmonary immune defense. However, in disease perturbations to immunological and physiological processes allow the upper respiratory tract to act as a reservoir of pathogenic bacteria, which can colonize the diseased lung and cause severe inflammation. Studying these host-microbe interactions in respiratory diseases holds great promise to stratify patients for suitable treatment regimens and biomarker discovery to predict disease progression. Preclinical studies show that commensal gut microbes are in a constant flux of cell division and death, releasing microbial constituents, metabolic by-products, and vesicles that shape the immune system and can protect against respiratory diseases. The next major advances may come from testing and utilizing these microbial factors for clinical benefit and exploiting the predictive power of the microbiome by employing multiomics analysis approaches.

Microarray analysis identifies lncFirre as a potential regulator of obesity-related acute lung injury

AIMS

The inflammatory response in acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is heightened in obesity. The aim of this study was to investigate whether lncRNAs are involved in the effects of obesity on acute lung injury and to find possible effector lncRNAs.

MAIN METHODS

Microarray analysis was used to assess the transcriptional profiles of lncRNAs and mRNAs in lung tissues from normal (CON), high-fat diet induced obese (DIO), and obese ALI mice (DIO-ALI). GO and KEGG analyses were employed to explore the biological functions of differentially expressed genes. A lncRNA-mRNA co-expression network was constructed to identify specific lncRNA. Lung tissues and peripheral blood samples from patients with obesity and healthy lean donors were utilized to confirm the expression characteristics of lncFirre through qRT-PCR. lncFirre was knocked down in MH-S macrophages to explore its function. ELISA and Griess reagent kit were used to detect PGE2 and NO. Flow cytometry was used to detect macrophages polarization.

KEY FINDINGS

There were 475 lncRNAs and 404 mRNAs differentially expressed between DIO and CON, while 1348 lncRNAs and 1349 mRNAs between DIO-ALI and DIO. Obesity increased lncFirre expression in both mice and patients, and PA elevated lncFirre in MH-S. PA exacerbated the inflammation and proinflammatory polarization of MH-S induced by LPS. LncFirre knockdown inhibited the secretion of PGE2 and NO, M1 differentiation while promoted the M2 differentiation in PA and LPS co-challenged MH-S.

SIGNIFICANCE

Interfering with lncFirre effectively inhibit inflammation in MH-S, lncFirre can serve as a promising target for treating obesity-related ALI.

Multifaceted roles of T cells in obesity and obesity-related complications: A narrative review

Obesity is characterized by chronic low-grade inflammatory responses in the adipose tissue, accompanied by pronounced insulin resistance and metabolic anomalies. It affects almost all body organs and eventually leads to diseases such as fatty liver disease, type 2 diabetes mellitus, and atherosclerosis. Recently, T cells have emerged as interesting therapeutic targets because the dysfunction of T cells and their cytokines in the adipose tissue is implicated in obesity-induced inflammation and their complicated onset. Although several recent narrative reviews have provided a brief overview of related evidence in this area, they have mainly focused on either obesity-associated T cell metabolism or modulation of T cell activation in obesity. Moreover, at present, no published review has reported on the multifaceted roles of T cells in obesity and obesity-related complications, even though there has been a significant increase in studies on this topic since 2019. Therefore, this narrative review aims to comprehensively summarize current advances in the mechanistic roles of T cells in the development of obesity and its related complications. Further, we aim to discuss relevant drugs for weight loss as well as the contradictory role of T cells in the same disease so as to highlight key findings regarding this topic and provide a valid basis for future treatment strategies.

High-fat diet-induced biogenesis of pulmonary exosomes in an experimental rat model

BACKGROUND

High-fat diets (HFD) have recently become a public health concern. We hypothesize that HFD induces exosomes biogenesis in the lung tissue of rat model.

METHODS AND RESULTS

Sixteen adult male Wistar rats were fed with HFD or a regular chow diet for 3 months. The histopathological changes in lung tissues were measured by hematoxylin and eosin (H&E) staining. Bronchoalveolar lavage (BAL) was performed to assay exosomes by acetylcholinesterase enzyme (AhCE) activity. Real-time PCR (qPCR) was used to evaluate Rab27-b, Alix, and IL-1β expression, while the immunohistochemical examination was performed for CD81 expression in lung tissues. In addition, expression of IL-1β was detected by ELISA. We found pathological alterations in the lung tissue of HFD animals. AhCE activity along with the expression level of Rab27-b, Alix, and IL-1β was increased in HFD animals (p < 0.05). Immunohistochemical staining showed that expression of CD81 was increased in lung tissues of HFD animals compared with the control group (p < 0.05).

CONCLUSION

Hence, HFD induced exosomes biogenesis and histopathological changes with IL-1β expression in rats' lung tissues.

Fructooligosaccharide (FOS) and Galactooligosaccharide (GOS) Improve Neuroinflammation and Cognition By Up-regulating IRS/PI3K/AKT Signaling Pathway in Diet-induced Obese Mice

Increasing evidence has indicated that prebiotics as an alternative treatment for neuropsychiatric diseases. This study evaluated the prebiotics Fructooligosaccharides (FOS) and Galactooligosaccharides (GOS) on the modulation of neuroinflammation and cognition in an experimental model of mice high-fat diet fed. Initially, mice were distributed in the following groups: (A) control standard diet (n = 15) and (B) HFD for 18 weeks (n = 30). In the 13th week, the mice were later divided into the following experimental groups: (A) Control (n = 15); (B) HFD (n = 14); and (C) HFD + Prebiotics (n = 14). From the 13th week, the HFD + Prebiotics group received a high-fat diet and a combination of FOS and GOS. In the 18th week, all animals performed the T-maze and Barnes Maze, and were later euthanized. Biochemical and molecular analyzes were performed to assess neuroinflammation, neurogenesis, synaptic plasticity, and intestinal inflammation. Mice fed HFD had higher blood glucose, triglyceridemia, cholesterolemia, and higher serum IL-1β associated with impaired learning and memory. These obese mice also showed activation of microglia and astrocytes and significant immunoreactivity of neuroinflammatory and apoptosis markers, such as TNF-α, COX-2, and Caspase-3, in addition to lower expression of neurogenesis and synaptic plasticity markers, such as NeuN, KI-67, CREB-p, and BDNF. FOS and GOS treatment significantly improved the biochemistry profile and decreased serum IL-1β levels. Treatment with FOS and GOS also reduced TNF-α, COX-2, Caspase-3, Iba-1, and GFAP-positive cells in the dentate gyrus, decreasing neuroinflammation and neuronal death caused by chronic HFD consumption. In addition, FOS and GOS promoted synaptic plasticity by increasing NeuN, p-CREB, BDNF, and KI-67, restoring spatial learning ability and memory. Moreover, FOS and GOS on HFD modulated the insulin pathway, which was proved by up-regulating IRS/PI3K/AKT signaling pathway, followed by a decreasing Aβ plate and Tau phosphorylation. Furthermore, the prebiotic intervention reshaped the HFD-induced imbalanced gut microbiota by modulating the composition of the bacterial community, markedly increasing Bacteroidetes. In addition, prebiotics decreased intestinal inflammation and leaky gut. In conclusion, FOS and GOS significantly modulated the gut microbiota and IRS/PI3K/AKT signaling pathway, decreased neuroinflammation, and promoted neuroplasticity improving spatial learning and memory. Schematic summarizing of the pathways by FOS and GOS improves memory and learning through the gut-brain axis. FOS and GOS improve the microbial profile, reducing intestinal inflammation and leaky gut in the distal colon. Specifically, the administration of FOS and GOS decreases the expression of TLR4, TNF-α, IL-1β, and MMP9 and increases the expression of occludin and IL-10. Prebiotics inhibit neuroinflammation, neuronal apoptosis, and reactive gliosis in the hippocampus but restore synaptic plasticity, neuronal proliferation, and neurogenesis.

Exploring the Network between Adipocytokines and Inflammatory Response in SARS-CoV-2 Infection: A Scoping Review

Adipose tissue is actually regarded as an endocrine organ, rather than as an organ that merely stores energy. During the COVID-19 pandemic, obesity has undoubtedly emerged as one of the most important risk factors for disease severity and poor outcomes related to SARS-CoV-2 infection. The aberrant production of cytokine-like hormones, called adipokines, may contribute to alterations in metabolism, dysfunction in vascular endothelium and the creation of a state of general chronic inflammation. Moreover, chronic, low-grade inflammation linked to obesity predisposes the host to immunosuppression and excessive cytokine activation. In this respect, understanding the mechanisms that link obesity with the severity of SARS-CoV-2 infection could represent a real game changer in the development of new therapeutic strategies. Our review therefore examines the pathogenic mechanisms of SARS-CoV-2, the implications with visceral adipose tissue and the influences of the adipose tissue and its adipokines on the clinical behavior of COVID-19.

Cognitive behavioural therapy for adults with overweight or obesity

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To assess the effects of cognitive behavioural therapy for weight management in adults with overweight or obesity.

Depressive symptoms predict the incidence of common chronic diseases in women and men in a representative community sample

BACKGROUND

Depression, the most frequent and harmful mental disorder, has been associated with specific somatic diseases as the leading cause of death. The purposes of this prospective study were to predict incident chronic diseases based on baseline depressive symptoms and to test sex-dependent effects.

METHODS

In a representative German community sample of over 12 000 participants, baseline depressive symptoms (assessed using the Patient Health Questionnaire-9) were tested as a predictor of new onset of cardiovascular disease (CVD), chronic obstructive lung disease, diabetes, cancer, and migraine at 5-year follow-up. To study disease incidence, we created subsamples for each chronic disease by excluding participants who already had the respective disease at baseline. Potential confounders were included in logistic regression models and sex-specific analyses were performed.

RESULTS

Controlling for demographic characteristics and loneliness, in men and women, baseline depressive symptoms were predictive of CVD, chronic obstructive lung disease, diabetes, and migraine, but not of cancer. When we additionally adjusted for metabolic and lifestyle risk factors, there was an 8% increase of chronic obstructive lung disease and migraine per point of depressive symptoms. There was a trend for CVD (4%; p = 0.053). Sex-sensitive analyses revealed trends for the relevance of depressive symptoms for CVD in men (p = 0.065), and for diabetes in women (p = 0.077).

CONCLUSIONS

These findings underscore the need to implement screening for depression in the treatment of major somatic illnesses. At the same time, depressed patients should be screened for metabolic and lifestyle risk factors and for somatic diseases and offered lifestyle interventions.

Diabetes and climate change: current evidence and implications for people with diabetes, clinicians and policy stakeholders

Climate change will be a major challenge for the world's health systems in the coming decades. Elevated temperatures and increasing frequencies of heat waves, wildfires, heavy precipitation and other weather extremes can affect health in many ways, especially if chronic diseases are already present. Impaired responses to heat stress, including compromised vasodilation and sweating, diabetes-related comorbidities, insulin resistance and chronic low-grade inflammation make people with diabetes particularly vulnerable to environmental risk factors, such as extreme weather events and air pollution. Additionally, multiple pathogens show an increased rate of transmission under conditions of climate change and people with diabetes have an altered immune system, which increases the risk for a worse course of infectious diseases. In this review, we summarise recent studies on the impact of climate-change-associated risk for people with diabetes and discuss which individuals may be specifically prone to these risk conditions due to their clinical features. Knowledge of such high-risk groups will help to develop and implement tailored prevention and management strategies to mitigate the detrimental effect of climate change on the health of people with diabetes.

Type 1 diabetes and diet-induced obesity predispose C57BL/6J mice to PM2.5-induced lung injury: a comparative study

BACKGROUND

Pre-existing metabolic diseases may predispose individuals to particulate matter (PM)-induced adverse health effects. However, the differences in susceptibility of various metabolic diseases to PM-induced lung injury and their underlying mechanisms have yet to be fully elucidated.

RESULTS

Type 1 diabetes (T1D) murine models were constructed by streptozotocin injection, while diet-induced obesity (DIO) models were generated by feeding 45% high-fat diet 6 weeks prior to and throughout the experiment. Mice were subjected to real-ambient PM exposure in Shijiazhuang City, China for 4 weeks at a mean PM2.5 concentration of 95.77 µg/m3. Lung and systemic injury were assessed, and the underlying mechanisms were explored through transcriptomics analysis. Compared with normal diet (ND)-fed mice, T1D mice exhibited severe hyperglycemia with a blood glucose of 350 mg/dL, while DIO mice displayed moderate obesity and marked dyslipidemia with a slightly elevated blood glucose of 180 mg/dL. T1D and DIO mice were susceptible to PM-induced lung injury, manifested by inflammatory changes such as interstitial neutrophil infiltration and alveolar septal thickening. Notably, the acute lung injury scores of T1D and DIO mice were higher by 79.57% and 48.47%, respectively, than that of ND-fed mice. Lung transcriptome analysis revealed that increased susceptibility to PM exposure was associated with perturbations in multiple pathways including glucose and lipid metabolism, inflammatory responses, oxidative stress, cellular senescence, and tissue remodeling. Functional experiments confirmed that changes in biomarkers of macrophage (F4/80), lipid peroxidation (4-HNE), cellular senescence (SA-β-gal), and airway repair (CCSP) were most pronounced in the lungs of PM-exposed T1D mice. Furthermore, pathways associated with xenobiotic metabolism showed metabolic state- and tissue-specific perturbation patterns. Upon PM exposure, activation of nuclear receptor (NR) pathways and inhibition of the glutathione (GSH)-mediated detoxification pathway were evident in the lungs of T1D mice, and a significant upregulation of NR pathways was present in the livers of T1D mice.

CONCLUSIONS

These differences might contribute to differential susceptibility to PM exposure between T1D and DIO mice. These findings provide new insights into the health risk assessment of PM exposure in populations with metabolic diseases.

The impact of insulin resistance on the association between metabolic syndrome and lung function: the Kangbuk Samsung Health Study

BACKGROUND/OBJECTIVE

Metabolic syndrome (MS) is related to lung dysfunction. However, its impact according to insulin resistance (IR) remains unknown. Therefore, we evaluated whether the relation of MS with lung dysfunction differs by IR.

SUBJECT/METHODS

This cross-sectional study included 114,143 Korean adults (mean age, 39.6 years) with health examinations who were divided into three groups: metabolically healthy (MH), MS without IR, and MS with IR. MS was defined as presence of any MS component, including IR estimated by HOMA-IR ≥ 2.5. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for lung dysfunction were obtained in MS, MS without IR, and MS with IR groups compared with the MH (reference) group.

RESULTS

The prevalence of MS was 50.7%. The percent predicted forced expiratory volume in 1 s (FEV1%) and forced vital capacity (FVC%) showed statistically significant differences between MS with IR and MH and between MS with IR and MS without IR (all P < 0.001). However, those measures did not vary between MH and MS without IR (P = 1.000 and P = 0.711, respectively). Compared to MH, MS was not at risk for FEV1% < 80% (1.103 (0.993-1.224), P = 0.067) or FVC% < 80% (1.011 (0.901-1.136), P = 0.849). However, MS with IR was clearly associated with FEV1% < 80% (1.374 (1.205-1.566) and FVC% < 80% (1.428 (1.237-1.647) (all p < 0.001), though there was no evident association for MS without IR (FEV1%: 1.078 (0.975-1.192, P = 0.142) and FVC%: 1.000 (0.896-1.116, p = 0.998)).

CONCLUSION

The association of MS with lung function can be affected by IR. However, longitudinal follow-up studies are required to validate our findings.

A role of STING signaling in obesity-induced lung inflammation

BACKGROUND

It is established that pulmonary disorders are comorbid with metabolic disorders such as obesity. Previous studies show that the stimulator of interferon genes (STING) signaling plays crucial roles in obesity-induced chronic inflammation via TANK-binding kinase 1 (TBK1) pathways. However, it remains unknown whether and how the STING signaling is implicated in the inflammatory processes in the lung in obesity.

METHODS

Human lung tissues were obtained from obese patients (n = 3) and controls (n = 3). Mice were fed with the high-fat diet or regular control diet to establish the diet-induced obese (DIO) and lean mice, and were treated with C-176 (a specific STING inhibitor) or vehicle respectively. The lung macrophages were exposed to palmitic acid (PA) in vitro. The levels of STING singaling and metabolic inflammation factors were detected and anlyzed.

RESULTS

We find that STING+/CD68+ macrophages are increased in lung tissues in patients with obesity. Our data also show that the expressions of STING and the levels of proinflammatory cytokines are increased both in lung tissues and bronchoalveolar lavage fluid (BALF) in obesity compared to controls, and inhibition of the STING blunted the obesity-induced lung inflammation. Mechanistically, our data demonstrate that the STING signaling pathway is involved in the PA-induced inflammation through the STING-TBK1-IRF3 (interferon regulatory factor 3)/NF-κB (nuclear factor kappa B) pathways in the lung macrophages.

CONCLUSIONS

Our results collectively suggest that the STING signaling contributes to obesity-associated inflammation by stimulating proinflammatory processes in lung macrophages, one that may serve as a therapeutic target in ameliorating obesity-related lung dysfunctions.

High-Fat Diet Related Lung Fibrosis-Epigenetic Regulation Matters

Pulmonary fibrosis (PF) is an interstitial lung disease characterized by the destruction of the pulmonary parenchyma caused by excessive extracellular matrix deposition. Despite the well-known etiological factors such as senescence, aberrant epithelial cell and fibroblast activation, and chronic inflammation, PF has recently been recognized as a metabolic disease and abnormal lipid signature was observed both in serum and bronchoalveolar lavage fluid (BALF) of PF patients and mice PF model. Clinically, observational studies suggest a significant link between high-fat diet (HFD) and PF as manifested by high intake of saturated fatty acids (SFAs) and meat increases the risk of PF and mice lung fibrosis. However, the possible mechanisms between HFD and PF remain unclear. In the current review we emphasize the diversity effects of the epigenetic dysregulation induced by HFD on the fibrotic factors such as epithelial cell injury, abnormal fibroblast activation and chronic inflammation. Finally, we discuss the potential ways for patients to improve their conditions and emphasize the prospect of targeted therapy based on epigenetic regulation for scientific researchers or drug developers.

Mediterranean Diet and Lung Function in Adults Current Smokers: A Cross-Sectional Analysis in the MEDISTAR Project

BACKGROUND

Previous studies have shown that adherence to the Mediterranean Diet (MeDi) has a positive impact on lung function in subjects with lung disease. In subjects free of respiratory diseases, but at risk, this association is not yet well established.

METHODS

Based on the reference data from the MEDISTAR clinical trial (Mediterranean Diet and Smoking in Tarragona and Reus; ISRCTN 03.362.372), an observational study was conducted with 403 middle-aged smokers without lung disease, treated at 20 centres of primary care in Tarragona (Catalonia, Spain). The degree of MeDi adherence was evaluated according to a 14-item questionnaire, and adherence was defined in three groups (low, medium, and high). Lung function were assessed by forced spirometry. Logistic regression and linear regression models were used to analyse the association between adherence to the MeDi and the presence of ventilatory defects.

RESULTS

Globally, the pulmonary alteration prevalence (impaired FEV1 and/or FVC) was 28.8%, although it was lower in participants with medium and high adherence to the MeDi, compared to those with a low score (24.2% and 27.4% vs. 38.5%, p = 0.004). Logistic regression models showed a significant and independent association between medium and high adherence to the MeDi and the presence of altered lung patterns (OR 0.467 [95%CI 0.266, 0.820] and 0.552 [95%CI 0.313, 0.973], respectively).

CONCLUSIONS

MeDi adherence is inversely associated with the risk impaired lung function. These results indicate that healthy diet behaviours can be modifiable risk factors to protect lung function and reinforce the possibility of a nutritional intervention to increase adherence to MeDi, in addition to promoting smoking cessation.

The intersection of obesity and (long) COVID-19: Hypoxia, thrombotic inflammation, and vascular endothelial injury

The role of hypoxia, vascular endothelial injury, and thrombotic inflammation in worsening COVID-19 symptoms has been generally recognized. Damaged vascular endothelium plays a crucial role in forming in situ thrombosis, pulmonary dysfunction, and hypoxemia. Thrombotic inflammation can further aggravate local vascular endothelial injury and affect ventilation and blood flow ratio. According to the results of many studies, obesity is an independent risk factor for a variety of severe respiratory diseases and contributes to high mechanical ventilation rate, high mortality, and slow recovery in COVID-19 patients. This review will explore the mechanisms by which obesity may aggravate the acute phase of COVID-19 and delay long COVID recovery by affecting hypoxia, vascular endothelial injury, and thrombotic inflammation. A systematic search of PubMed database was conducted for papers published since January 2020, using the medical subject headings of "COVID-19" and "long COVID" combined with the following keywords: "obesity," "thrombosis," "endothelial injury," "inflammation," "hypoxia," "treatment," and "anticoagulation." In patients with obesity, the accumulation of central fat restricts the expansion of alveoli, exacerbating the pulmonary dysfunction caused by SARS-CoV-2 invasion, inflammatory damage, and lung edema. Abnormal fat secretion and immune impairment further aggravate the original tissue damage and inflammation diffusion. Obesity weakens baseline vascular endothelium function leading to an early injury and pre-thrombotic state after infection. Enhanced procoagulant activity and microthrombi promote early obstruction of the vascular. Obesity also prolongs the duration of symptoms and increases the risk of sequelae after hospital discharge. Persistent viral presence, long-term inflammation, microclots, and hypoxia may contribute to the development of persistent symptoms, suggesting that patients with obesity are uniquely susceptible to long COVID. Early interventions, including supplemental oxygen, comprehensive antithrombotic therapy, and anti-inflammatory drugs, show effectiveness in many studies in the prevention of serious hypoxia, thromboembolic events, and systemic inflammation, and are therefore recommended to reduce intensive care unit admission, mortality, and sequelae.

Short-term complications and post-acute sequelae in hospitalized paediatric patients with COVID-19 and obesity: A multicenter cohort study

BACKGROUND

Obesity increases the severity of coronavirus disease 2019 illness in adults. The role of obesity in short-term complications and post-acute sequelae in children is not well defined.

OBJECTIVE

To evaluate the relationship between obesity and short-term complications and post-acute sequelae of SARS-CoV-2 infection in hospitalized paediatric patients.

METHODS

An observational study was conducted in three tertiary hospitals, including paediatric hospitalized patients with a confirmatory SARS-CoV-2 RT-PCR from March 2020 to December 2021. Obesity was defined according to WHO 2006 (0-2 years) and CDC 2000 (2-20 years) growth references. Short-term outcomes were intensive care unit admission, ventilatory support, superinfections, acute kidney injury, and mortality. Neurological, respiratory, and cardiological symptoms and/or delayed or long-term complications beyond 4 weeks from the onset of symptoms were considered as post-acute sequalae. Adjusted linear, logistic regression and generalized estimating equations models were performed.

RESULTS

A total of 216 individuals were included, and 67 (31.02%) of them had obesity. Obesity was associated with intensive care unit admission (aOR = 5.63, CI95% 2.90-10.94), oxygen requirement (aOR = 2.77, CI95% 1.36-5.63), non-invasive ventilatory support (aOR = 6.81, CI95% 2.11-22.04), overall superinfections (aOR = 3.02 CI95% 1.45-6.31), and suspected bacterial pneumonia (aOR = 3.00 CI95% 1.44-6.23). For post-acute sequalae, obesity was associated with dyspnea (aOR = 9.91 CI95% 1.92-51.10) and muscle weakness (aOR = 20.04 CI95% 2.50-160.65).

CONCLUSIONS

In paediatric hospitalized patients with COVID-19, severe short-term outcomes and post-acute sequelae are associated with obesity. Recognizing obesity as a key comorbidity is essential to develop targeted strategies for prevention of COVID-19 complications in children.

Pediatric obesity and severe asthma: Targeting pathways driving inflammation

Asthma affects more than 300 million people of all ages worldwide, including about 10-15% of school-aged children, and its prevalence is increasing. Severe asthma (SA) is a particular and rare phenotype requiring treatment with high-dose inhaled corticosteroids plus a second controller and/or systemic glucocorticoid courses to achieve symptom control or remaining "uncontrolled" despite this therapy. In SA, other diagnoses have been excluded, and potential exacerbating factors have been addressed. Notably, obese asthmatics are at higher risk of developing SA. Obesity is both a major risk factor and a disease modifier of asthma in children and adults: two main "obese asthma" phenotypes have been described in childhood with high or low levels of Type 2 inflammation biomarkers, respectively, the former characterized by early onset and eosinophilic inflammation and the latter by neutrophilic inflammation and late-onset. Nevertheless, the interplay between obesity and asthma is far more complex and includes obese tissue-driven inflammatory pathways, mechanical factors, comorbidities, and poor response to corticosteroids. This review outlines the most recent findings on SA in obese children, particularly focusing on inflammatory pathways, which are becoming of pivotal importance in order to identify selective targets for specific treatments, such as biological agents.

Asthma, obesity, and microbiota: A complex immunological interaction

Obesity and allergic asthma are inflammatory chronic diseases mediated by distinct immunological features, obesity presents a Th1/Th17 profile, asthma is commonly associated with Th2 response. However, when combined, they result in more severe asthma symptoms, greater frequency of exacerbation episodes, and lower therapy responsiveness. These features lead to decreased life quality, associated with higher morbidity/mortality rates.  In addition, obesity prompts specific asthma phenotypes, which can be dependent on atopic status, age, and gender. In adults, obesity is associated with neutrophilic/Th17 profile, while in children, the outcome is diverse, in some cases children with obesity present aggravation of atopy, and Th2 inflammation, and in others an association with a Th1 profile, with reduced IgE levels and eosinophilia. These alterations occur due to a complex group of factors among which the microbiome has been recently explored. Particularly, evidence shows its important role in susceptibility or resistance to asthma development, via gut-lung-axis, and demonstrates its relevance to the immune pathogenesis of the syndrome. Few studies address the relevance of the lung microbiome in shaping the immune response, locally. However, specific bacteria, like Moraxella catarrhalis, Haemophilus influenza, and Streptococcus pneumoniae, correlate with important features of the obese-asthmatic phenotype. Although maternal obesity is known to increase asthma risk in offspring, the impact on lung colonization is unknown. This review details the main key immune mechanisms involved in obesity-aggravated asthma, featuring the effect of maternal obesity in the establishment of gut and lung microbiota of the offspring, acting as potential childhood asthma inducer.

Relationship between overweight and obesity and insufficient micronutrient intake: a nationwide study in Taiwan

The aim of the present study is to examine whether overweight or obese people in Taiwan have an inadequate intake of selected micronutrients. A population-based study was conducted using data from the Nutrition and Health Survey in Taiwan (NAHSIT) 2013-2016. We evaluated fourteen nutrient intakes using the 24 h dietary recall method. The dietary reference intake (DRI) adherence was estimated by the prevalence of participants whose intake was lower than the recommended dietary allowance (RDA) or adequate intakes (AIs) for selected micronutrients. Body mass index (BMI) ≥ 27 kg/m² and waist circumference (WC), with men having WC ≥ 90 cm or women having WC ≥ 80 cm, were defined as obesity. A total of 3075 participants aged 19 years and above were included. After adjusting for confounders, we found that obese women have a lower DRI adherence of vitamin C (odds ratio (OR) 0⋅73, 95 % confidence interval (CI) 0⋅56, 0⋅95) and magnesium (OR 0⋅72, 95 % CI 0⋅54, 0⋅95), compared with normal-weight women. Obese men have a higher DRI adherence of vitamin B3 (OR 1⋅70, 95 % CI 1⋅29, 2⋅23), iron (OR 1⋅46, 95 % CI 1⋅06, 2⋅00) and zinc (OR 1⋅41, 95 % CI 1⋅07, 1⋅85), compared with normal-weight men. Similar findings were found using WC to define obesity. We conclude that obese women may have insufficient intakes of vitamin A, vitamin C and magnesium.

Targeting of G-protein coupled receptor 40 alleviates airway hyperresponsiveness through RhoA/ROCK1 signaling pathway in obese asthmatic mice

Obesity increases the severity of airway hyperresponsiveness (AHR) in individuals with asthma, but the mechanism is not well elucidated. G-protein coupled receptor 40 (GPR40) has been found to induce airway smooth muscle contraction after activated by long-chain fatty acids (LC-FFAs), suggesting a close correlation between GPR40 and AHR in obese. In this study, C57BL/6 mice were fed a high-fat diet (HFD) to induce obesity with or without ovalbumin (OVA) sensitization, the regulatory effects of GPR40 on AHR, inflammatory cells infiltration, and the expression of Th1/Th2 cytokines were evaluated by using a small-molecule antagonist of GPR40, DC260126. We found that the free fatty acids (FFAs) level and GPR40 expression were greatly elevated in the pulmonary tissues of obese asthmatic mice. DC260126 greatly reduced methacholine-induced AHR, ameliorated pulmonary pathological changes and decreased inflammatory cell infiltration in the airways in obese asthma. In addition, DC260126 could down-regulate the levels of Th2 cytokines (IL-4, IL-5, and IL-13) and pro-inflammatory cytokines (IL-1β, TNF-α), but elevated Th1 cytokine (IFN-γ) expression. In vitro, DC260126 could remarkedly reduce oleic acid (OA)-induced cell proliferation and migration in HASM cells. Mechanistically, the effects that DC260126 alleviated obese asthma was correlated with the down-regulation of GTP-RhoA and Rho-associated coiled-coil-forming protein kinase 1 (ROCK1). Herein, we proved that targeting of GPR40 with its antagonist helped to mitigate multiple parameters of obese asthma effectively.

The Relationship Between BMI and Lung Function in Populations with Different Characteristics: A Cross-Sectional Study Based on the Enjoying Breathing Program in China

Purpose

To analyze the relationship between body mass index (BMI) and lung function, which may help optimize the screening and management process for chronic obstructive pulmonary disease (COPD) in the early stages.

Patients and Methods

In this cross-sectional study using data from the Enjoying Breathing Program in China, participants were divided into two groups according to COPD Screening Questionnaire (COPD-SQ) scores (at risk and not at risk of COPD) and three groups based on lung function (normal lung function, preserved ratio impaired spirometry [PRISm], and obstructive lung function).

Results

A total of 32,033 subjects were enrolled in the current analysis. First, in people at risk of COPD, overweight and obese participants had better forced expiratory volume in one second (FEV1; overweight: 0.33 liters (l), 95% confidence interval [CI]: 0.27 to 0.38; obesity: 0.31 L, 95% CI: 0.22 to 0.39) values than the normal BMI group. Second, among people with PRISm, underweight participants had a lower FEV1 (−0.56 L, 95% CI: −0.86 to −0.26) and forced vital capacity (FVC; −0.33 L, 95% CI: −0.55 to −0.11) than participants with a normal weight, and obese participants had a higher FEV1 (0.22 L, 95% CI: 0.02 to 0.42) and FVC (0.16 L, 95% CI: 0.02 to 0.30) than participants with a normal weight. Taking normal BMI as the reference group, lower FEV1 (−0.80 L, 95% CI: −0.97 to −0.63) and FVC (−0.53 L, 95% CI: −0.64 to −0.42) were found in underweight participants with obstructive spirometry, and better FEV1 (obesity: 0.26 L, 95% CI: 0.12 to 0.40) was found in obese participants with obstructive spirometry.

Conclusion

Being underweight and severely obese are associated with reduced lung function. Slight obesity was shown to be a protective factor for lung function in people at risk of COPD and those with PRISm.

Analysis of a State Police Academy Menu Cycle for Dietary Quality and Performance Nutrition Adequacy

Law enforcement officers have high rates of overweight and obesity. With diet as a leading risk factor, training academies present an opportunity for early-career nutrition intervention. Our purpose was to determine the dietary quality (DQ) and performance nutrition adequacy of a state police academy's cafeteria menu. This cross-sectional content analysis included six weeks (three daily meals, Monday-Friday) of a police academy menu. Nutrient content was determined by portioning menus, gathering food specifications, and performing nutrient analysis. DQ was assessed using the Healthy Eating Index (HEI) 2015. Statistical analyses included independent t-tests and Cohen's d. The total HEI score was 54/100. Subcomponent scores indicating adequacy included added sugar (5/5), total protein (4.97/5) and whole fruits (4.77/5). Seafood/plant proteins (0.33/5), fatty acid ratio (1.31/5), and dairy scores (1.59/10) needed significant improvement. The menu met the recommended intake for 13 of 19 nutrients investigated. Nutrients that did not meet adequacy were calories (% mean difference, needs-menu = 36.7%), carbohydrates (52.3%), vitamins D (82.5%) and E (66.7%), magnesium (44.1%), and potassium (41.8%). The academy menu leaves room for improvement in DQ and shortfall nutrients. By increasing low scores, the overall DQ of the menu will increase and supplement missing nutrients.

Activation of PPARγ Protects Obese Mice from Acute Lung Injury by Inhibiting Endoplasmic Reticulum Stress and Promoting Mitochondrial Biogenesis

Objective

Obesity-induced endoplasmic reticulum (ER) stress plays a role in increased susceptibility to acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). The activation of peroxisome proliferator-activated receptor-γ (PPARγ) is associated with lung protection and is effective in ameliorating ER stress and mitochondrial dysfunction. The aim of this study was to investigate the expression of PPARγ in the lung tissues of obese mice and explore whether the PPARγ-dependent pathway could mediate decreased ALI/ARDS by regulating ER stress and mitochondrial biogenesis.

Methods

We determined PPARγ expression in the lung tissues of normal and obese mice. ALI models of alveolar epithelial cells and of obese mice were used and treated with either PPARγ activator rosiglitazone (RSG) or PPARγ inhibitor GW9662. Lung tissue and cell samples were collected to assess lung inflammation and apoptosis, and ER stress and mitochondrial biogenesis were detected.

Results

PPARγ expression was significantly decreased in the lung tissue of obese mice compared with that in normal mice. Both in vivo and in vitro studies have shown that activation of PPARγ leads to reduced expression of the ER stress marker proteins 78-kDa glucose-regulated protein (GRP78), C/EBP homologous protein (CHOP), and Caspase12. Conversely, expression of the mitochondrial biogenesis-related proteins peroxisome proliferator-activated receptor γ coactivator 1 (PGC-1α), nuclear respiratory factor-1 (NRF-1), and mitochondrial transcription factor A (TFAM) increased. Furthermore, activation of PPARγ is associated with decreased levels of lung inflammation and epithelial apoptosis and increased expression of adiponectin (APN) and mitofusin2 (MFN2). GW9662 bound to PPARγ and blocked its transcriptional activity and then diminished the protective effect of PPARγ on lung tissues.

Conclusions

PPARγ activation exerts anti-inflammation effects in alveolar epithelia by alleviating ER stress and promoting mitochondrial biogenesis. Therefore, lower levels of PPARγ in the lung tissues of obese mice may lead to an increased susceptibility to ALI.

Correlation of Body Mass Index and Proinflammatory Cytokine Levels with Hematopoietic Stem Cell Mobilization

This study investigated the correlation of body mass index (BMI) and proinflammatory cytokine levels with hematopoietic stem cell (HSC) mobilization triggered by granulocyte colony-stimulating factor (G-CSF). Stem cell donors (n = 309) were recruited between August 2015 and January 2018 and grouped into four groups according to their BMI: underweight (BMI < 18.5 kg/m2, n = 10), normal (18.5 kg/m2 ≦ BMI < 25 kg/m2, n = 156), overweight (25 kg/m2 ≦ BMI < 30 kg/m2, n = 102), and obese (BMI ≧ 30 kg/m2, n = 41). The participants were then administered with five doses of G-CSF and categorized as good mobilizers (CD34 ≧ 180/μL, n = 15, 4.85%) and poor mobilizers (CD34 ≦ 25/μL, n = 14, 4.53%) according to the number of CD34+ cells in their peripheral blood after G-CSF administration. The correlation between BMI and HSC mobilization was then analyzed, and the levels of proinflammatory cytokines in the plasma from good and poor mobilizers were examined by ProcartaPlex Immunoassay. Results showed that BMI was highly correlated with G-CSF-triggered HSC mobilization (R2 = 0.056, p < 0.0001). Compared with poor mobilizers, good mobilizers exhibited higher BMI (p < 0.001) and proinflammatory cytokine [interferon gamma (IFN-γ) (p < 0.05), interleukin-22 (IL-22) (p < 0.05), and tumor necrosis factor alpha (TNF-α) levels (p < 0.05)]. This study indicated that BMI and proinflammatory cytokine levels are positively correlated with G-CSF-triggered HSC mobilization.

Association of Growth Trajectory Profiles with Asthma Development in Infants Hospitalized with Bronchiolitis

BACKGROUND

Little is known about the relationship of longitudinal growth trajectory in early life with asthma development, particularly in infants with bronchiolitis (a high-risk population).

OBJECTIVE

Among infants with bronchiolitis, we aimed to identify growth trajectory profiles and determine their longitudinal relationship with the risk for developing childhood asthma.

METHODS

A multicenter prospective study enrolled infants (aged <1 year) hospitalized for bronchiolitis. We identified growth trajectory profiles-derived from body mass index-for-age at ages 0, 6, 12, 15, 18, 24, and 36 months by using a longitudinal clustering method. We examined associations between growth trajectory profiles and asthma development by age 5 years.

RESULTS

The analytic cohort consists of 880 infants hospitalized for bronchiolitis (median age, 3 months). Overall, 26% developed asthma by age 5 years. The longitudinal clustering identified 5 distinct profiles: persistent low growth (27%), normative growth (33%), transient overweight (21%), late-onset overweight (16%), and persistent obesity (3%) profiles. In multivariable model, compared with children with a normative profile, those with a persistent obesity profile had significantly higher risks of developing asthma (24% vs 38%, odds ratio [OR]: 2.55, 95% confidence interval [CI]: 1.07-6.09, P = .03). Among children with a persistent obesity profile, those without allergic predisposition had significantly higher risks of asthma (OR: 3.02, 95% CI: 1.05-8.64, P = .04 in the nonparental allergic history group; OR: 3.18, 95% CI: 1.02-9.92, P = .047 in the non-IgE sensitization group), whereas those with allergic predisposition were not at increased risk.

CONCLUSIONS

This multicenter cohort study of infants with bronchiolitis demonstrated distinct growth trajectory profiles that have differential risks for developing asthma.

Chronic Inflammation as the Underlying Mechanism of the Development of Lung Diseases in Psoriasis: A Systematic Review

Psoriasis is a systemic inflammatory disease caused by dysfunctional interactions between the innate and adaptive immune responses. The systemic inflammation in psoriasis may be associated with the development of comorbidities, including lung diseases. In this review, we aimed to provide a summary of the evidence regarding the prevalence of lung diseases in patients with psoriasis and the potential underlying mechanisms. Twenty-three articles published between March 2010 and June 2021 were selected from 195 initially identified records. The findings are discussed in terms of the prevalence of asthma, chronic obstructive pulmonary disease, interstitial lung disease, obstructive sleep apnea, pulmonary hypertension, and sarcoidosis in psoriasis. A higher prevalence of lung diseases in psoriasis has been confirmed in asthma, chronic obstructive pulmonary disease, obstructive sleep apnea, and pulmonary hypertension. These conditions are important as they are previously unrecognized causes of morbidity and mortality in psoriasis. The development of lung diseases in patients with psoriasis can be explained by several mechanisms, including common risk factors, shared immune and molecular characteristics associated with chronic inflammation, as well as other mechanisms. Understanding the prevalence of lung diseases in psoriasis and their underlying mechanisms can help implement appropriate preventative and therapeutic strategies to address respiratory diseases in patients with psoriasis.

Dedicator of Cytokinesis 2 (DOCK2) Deficiency Attenuates Lung Injury Associated with Chronic High-Fat and High-Fructose Diet-Induced Obesity

Obesity is a major risk factor for lung disease development. However, little is known about the impact of chronic high-fat and high-fructose (HFHF) diet-induced obesity on lung inflammation and subsequent pulmonary fibrosis. Herein we hypothesized that dedicator of cytokinesis 2 (DOCK2) promotes a proinflammatory phenotype of lung fibroblasts (LFs) to elicit lung injury and fibrosis in chronic HFHF diet-induced obesity. An HFHF diet for 20 weeks induced lung inflammation and profibrotic changes in wild-type C57BL/6 mice. CD68 and monocyte chemoattractant protein-1 (MCP-1) expression were notably increased in the lungs of wild-type mice fed an HFHF diet. An HFHF diet further increased lung DOCK2 expression that co-localized with fibroblast-specific protein 1, suggesting a role of DOCK2 in regulating proinflammatory phenotype of LFs. Importantly, DOCK2 knockout protected mice from lung inflammation and fibrosis induced by a HFHF diet. In primary human LFs, tumor necrosis factor-α (TNF-α) and IL-1β induced DOCK2 expression concurrent with MCP-1, IL-6, and matrix metallopeptidase 2. DOCK2 knockdown suppressed TNF-α-induced expression of these molecules and activation of phosphatidylinositol 3-kinase/AKT and NF-κB signaling pathways, suggesting a mechanism of DOCK2-mediated proinflammatory and profibrotic changes in human LFs. Taken together, these findings reveal a previously unrecognized role of DOCK2 in regulating proinflammatory phenotype of LFs, potentiation of lung inflammation, and pulmonary fibrosis in chronic HFHF diet-caused obesity.

The effectiveness of short-term pulmonary rehabilitation program in patients with comorbid asthma, chronic obstructive pulmonary disease and obesity

The effectiveness of pulmonary rehabilitation (PR) has not yet been established in patients with asthma – chronic obstructive pulmonary disease overlap (ACO) depending on their nutritional status. We aimed to evaluate the effectiveness of a short-term PR program in patients with comorbid asthma, chronic obstructive pulmonary disease (COPD), and obesity. We included 40 ACO patients and divided them into 3 groups according to body mass index (BMI) and then subdivided them into PR (n=21) and control (n=19) groups. The COPD Assessment Test (CAT), the Asthma Control Test (ACT), and the modified Medical Research Council dyspnea scale (mMRS) were used to evaluate symptoms levels. BODE index (body mass index, forced expiratory volume in one second, dyspnoea, and 6-min walk distance) was used to evaluate the effectiveness of pulmonary rehabilitation. In addition, spirometry and bioimpedansometry were performed. All measurements were done before and after a 6-month PR program. A significantly lower decline in the BODE index was observed in overweight patients (decreased by 43.6% compared to baseline and lower by 40.7% compared to the control group). The six-minute walking test (6MWT) significantly increased in all groups (p<0.001). There was a decrease in total CAT score by 25.4% and by 31.2% in the overweight group (p<0.001). The BMI decreased more in the obese group (by 9.4% compared to baseline). Our study result showed that early use of PR program significantly improves functional capacity and BODE index, leads to dyspnea and CAT scores reduction and improvement in pulmonary function, cause a decrease in BMI, body fat percentage, and visceral fat level, and an increase in muscle mass in overweight and obese patients with ACO.

Obesity-Related Indices Are Associated with Longitudinal Changes in Lung Function: A Large Taiwanese Population Follow-Up Study

The global pandemic of obesity and the increasing incidence of chronic respiratory diseases are growing health concerns. The association between obesity and pulmonary function is uncertain. Therefore, this study aimed to explore associations between changes in lung function and obesity-related indices in a large longitudinal study. A total of 9059 participants with no personal histories of asthma, smoking, bronchitis, or emphysema were enrolled from the Taiwan Biobank and followed for 4 years. Lung function was assessed using spirometry measurements including forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC). Changes in FEV1/FVC (∆FEV1/FVC) between baseline and follow-up were calculated. The following obesity-related indices were studied: lipid accumulation product (LAP), body roundness index (BRI), conicity index (CI), body adiposity index (BAI), abdominal volume index (AVI), body mass index (BMI), waist–hip ratio (WHR), and waist-to-height ratio (WHtR). In multivariable analysis, the subjects with high BMI (p < 0.001), WHR (p < 0.001), WHtR (p < 0.001), LAP (p = 0.002), BRI (p < 0.001), CI (p = 0.005), BAI (p < 0.001), and AVI (p < 0.001) were significantly associated with a high baseline FEV1/FVC. After 4 years of follow-up, the subjects with high BMI (p < 0.001), WHR (p < 0.001), WHtR (p < 0.001), LAP (p = 0.001), BRI (p < 0.001), CI (p = 0.002), BAI (p < 0.001), and AVI (p < 0.001) were significantly associated with a low △FEV1/FVC. High obesity-related index values were associated with better baseline lung function and a rapid decrease in lung function at follow-up.

Dynamic Metabolic Risk Profiling of World Trade Center Lung Disease: A Longitudinal Cohort Study

Rationale: Metabolic syndrome (MetSyn) increases the risk of World Trade Center (WTC) lung injury (LI). However, the temporal relationship of MetSyn, exposure intensity, and lung dysfunction is not well understood. Objective: To model the association of longitudinal MetSyn characteristics with WTC lung disease to define modifiable risk. Methods: Firefighters, for whom consent was obtained (N = 5,738), were active duty on September 11, 2001 (9/11). WTC-LI (n = 1,475; FEV1% predicted Collapse

Key Words

• World Trade Center
• World Trade Center lung disease
• World Trade Center lung injury
• dynamic risk model
• metabolic syndrome

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MESH Headings

• Adult
• Case-Control Studies
• Cohort Studies
• Female
• Firefighters/statistics & numerical data
• Humans
• Longitudinal Studies
• Lung Injury/physiopathology
• Male
• Metabolome
• Middle Aged
• Models, Theoretical
• Occupational Exposure/adverse effects
• Occupational Exposure/statistics & numerical data
• Risk Assessment/methods
• September 11 Terrorist Attacks/statistics & numerical data

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Grants

• U01 OH012069 NIOSH CDC HHS
• U01 OH011300 NIOSH CDC HHS
• U01 OH011855 NIOSH CDC HHS
• U01OH011300 ACL HHS
• U01 OH012637 NIOSH CDC HHS
• R01 ES032808 NIEHS NIH HHS
• R01 HL119326 NHLBI NIH HHS

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Affiliation(s)

Sophia Kwon Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine
Myeonggyun Lee Division of Biostatistics, Department of Population Health, and
George Crowley Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine
Theresa Schwartz Bureau of Health Services and Office of Medical Affairs, Fire Department of New York, Brooklyn, New York; and
Rachel Zeig-Owens Bureau of Health Services and Office of Medical Affairs, Fire Department of New York, Brooklyn, New York; and Department of Epidemiology and Population Health and
David J. Prezant Bureau of Health Services and Office of Medical Affairs, Fire Department of New York, Brooklyn, New York; and Pulmonary Medicine Division, Department of Medicine, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York
Mengling Liu Division of Biostatistics, Department of Population Health, and Department of Environmental Medicine, New York University School of Medicine, New York, New York
Anna Nolan Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine Department of Environmental Medicine, New York University School of Medicine, New York, New York Bureau of Health Services and Office of Medical Affairs, Fire Department of New York, Brooklyn, New York; and

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Storage conditions of high-fat diets affect pulmonary inflammation

Obesity alters the risks and outcomes of inflammatory lung diseases. It is important to accurately recapitulate the obese state in animal models to understand these effects on the pathogenesis of disease. Diet-induced obesity is a commonly used model of obesity, but when applied to other disease models like acute respiratory distress syndrome, pneumonia, and asthma, it yields widely divergent. We hypothesized high-fat chow storage conditions would affect lipid oxidation and inflammatory response in the lungs of lipopolysaccharide (LPS)-challenged mice. For 6 weeks, C57BL/6crl mice were fed either a 10% (low-fat diet, LFD) or 60% (high-fat diet, HFD) stored at room temperature (RT, 23°C) for up to 7, 14, 21, or 42 days. Mice were treated with nebulized LPS to induce lung inflammation, and neutrophil levels in bronchoalveolar lavage were determined 24 h later. Lipid oxidation (malondialdehyde, MDA) was assayed by thiobarbituric acid reactive substances in chow and mouse plasma. Concentrations of MDA in chow and plasma rose in proportion to the duration of RT chow storage. Mice fed a HFD stored <2 weeks at RT had an attenuated response 24 h after LPS compared with mice fed an LFD. This effect was reversed after 2 weeks of chow storage at RT. Chow stored above freezing underwent lipid oxidation associated with significant alterations in the LPS-induced pulmonary inflammatory response. Our data show that storage conditions affect lipid peroxidation, which in turn affects pulmonary inflammatory responses in a mouse model of disease. It also suggests changes in the microbiome, although not significantly different suggests decreased variety and richness of bacteria in the gut, a large aspect of the immune system. Dietary composition and storage of chow may also affect pulmonary inflammation and the gut microbiome in humans.