Obesity and acute lung injury

The therapeutic efficacy of resveratrol for acute lung injury—A meta−analysis of preclinical trials

Background: Resveratrol (RES) has a protective effect on acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). Our purpose was to conduct a meta−analysis to investigate the efficacy of RES for ALI/ARDS in animal models.

Methods: PubMed, EMBASE and Web of Science were searched to screen relevant preclinical trials. The standardized mean difference (SMD) was used to compare the lung injury score, lung wet−dry weight ratio (W/D ratio), tumor necrosis factor−α (TNF−α), interleukin−1β (IL−1β), IL−6, IL−10, the number of neutrophils in bronchoalveolar lavage fluid (BALF) and the total protein in BALF between the treatment and control groups. SYRCLE’s risk of bias tool was used for quality assessment.

Results: A total of 17 studies published from 2005 to 2021 were included in our study to calculate the SMD with corresponding confidence interval (CI). As compared with controls, RES significantly decreased the lung injury score (SMD −2.06; 95% CI −2.77, −1.35; p < 0.00001) and W/D ratio (SMD −1.92; 95% CI −2.62, −1.22; p < 0.00001). RES also reduced the number of neutrophils in BALF (SMD −3.03; 95% CI −3.83, −2.24; p < 0.00001) and the total protein in BALF (SMD −5.59; 95% CI −10.10, −1.08; p = 0.02). Furthermore, RES was found to downregulate proinflammatory mediators such as TNF−α (SMD −2.02; 95% CI −3.09, −0.95; p = 0.0002), IL−1β (SMD −2.51; 95% CI −4.00, −1.02; p = 0.001) and IL−6 (SMD −2.26; 95% CI −3.49, −1.04; p = 0.0003). But RES had little effect on the anti−inflammatory mediators such as IL−10 (SMD 2.80; 95% CI −0.04, 5.63; p = 0.05). Sensitivity analysis and stratified analysis were performed for the outcome indicators with heterogeneity.

Conclusion: RES treatment is effective on reducing the severity of ALI. However, more animal studies and human trials are needed for further investigation. Our study may provide a reference for preclinical and clinical studies in the future to some extent.

Detection of SARS-CoV-2 in subcutaneous fat but not visceral fat, and the disruption of fat lymphocyte homeostasis in both fat tissues in the macaque

The well documented association between obesity and the severity of SARS-CoV-2 infection raises the question of whether adipose tissue (AT) is impacted during this infection. Using a model of SARS-CoV-2 infection in cynomolgus macaques, we detected the virus within subcutaneous AT (SCAT) but not in visceral AT (VAT) or epicardial AT on day 7 post-infection. We sought to determine the mechanisms responsible for this selective detection and observed higher levels of angiotensin-converting-enzyme-2 mRNA expression in SCAT than in VAT. Lastly, we evaluated the immunological consequences of SARS-CoV-2 infection on AT: both SCAT and VAT T cells showed a drastic reduction in CD69 expression, a standard marker of resident memory T cell in tissue, that is also involved in the migratory and metabolic properties of T cells. Our results demonstrate that in a model of mild infection, SCAT is selectively infected by SARS-CoV-2 although changes in the immune properties of AT are observed in both SCAT and VAT.

Subcutaneous fat tissue expresses higher angiotensin-converting-enzyme 2 mRNA than visceral fat tissue and is selectively infected by SARS-Cov-2, while both fat tissues show drastic reduction in CD69 expression in T cells.

Stellate Ganglion Block Combined with Dexmedetomidine Protects Obese Rats from Lipopolysaccharide-Induced Acute Lung Injury

Objective

To investigate the effect and mechanism of combined stellate ganglion block (SGB) and dexmedetomidine (Dex) in obesity-related acute lung injury.

Methods

Thirty-six 4-week-old male Wistar rats were randomly divided into 6 groups, each with 6 rats: blank group (Control), high-fat diet group (HFD), high-fat + lipopolysaccharide (LPS)-induced acute lung injury group (HFD + LPS), SGB group, Dex group, and SGB + Dex group. H&E staining detected the pathological structure of rat lung tissue. TUNEL staining was used to examine cell apoptosis in lung tissue. Oxidative factors were accessed by biochemical reagents. ELISA was employed to measure the levels of TNF-α, IL-1β, and MCP1 in rat alveolar lavage fluid. Western blot detected the protein expression of glucose-regulated Protein 78 (GRP78), C/EBP homologous protein (CHOP), protein kinase R-like endoplasmic reticulum kinase (PERK), and p-PERK in lung tissue.

Results

The body weight of rats in the HFD group was higher than that in the control group. The use of SGB or Dex alone could significantly reduce the rate of pulmonary edema and lung cell apoptosis in HFD-induced obese rats and reduce MPO, TNF-α, IL-1β, and MCP1 levels, increasing the activity of SOD and GSH-Px. In addition, using SGB or Dex alone can also significantly reduce the protein expression levels of GRP78, CHOP, and p-PERK. The combined use of SGB and Dex can enhance the above effects.

Conclusion

The combined use of SGB and Dex can protect against obesity-related acute lung injury and is more effective than using SGB or Dex alone.

Predictive Equations for Adult Pulmonary Function in Zhejiang Province, China

Background

Accurate interpretation of lung function tests requires appropriate spirometry reference values derived from large-scale population-specific epidemiological surveys. The aim of this cross-sectional study was to establish normal spirometric values for the population of healthy, nonsmoking Han Chinese adults residing in Zhejiang province, China.

Methods

We measured lung function parameters such as forced expiratory volume in 1 s, forced vital capacity, peak expiratory flow, maximal midexpiratory flow, and diffusion capacity for carbon monoxide and considered age, height, and weight as independent factors that may modify these parameters. The clinical data were divided into the study arm and validation group. The study arms were used to construct predictive equations using stepwise multiple linear regression, and data from the validation group were used to assess the robustness of the equations.

Results

The 3866 participants were randomized into a study arm (n = 1,949) and a validation arm (n = 1,917). Lung function parameters had a negative association with age and a positive association with height. Data from the two groups were similar. Predictive equations were constructed from the study arm, and the validation group was used to test the feasibility of the reference equations.

Conclusions

The reference values we derived can be used to evaluate lung function in this cohort in both epidemiological studies and clinical practice.

The association between body mass index and risk of preoperative oxygenation impairment in patients with the acute aortic syndrome

OBJECTIVE

The study aimed to determine the relationship between body mass index (BMI) and the risk of acute aortic syndrome (AAS) with preoperative oxygenation impairment.

METHODS

A meta-analysis of published observational studies involving BMI and AAS with preoperative oxygenation impairment was conducted. A total of 230 patients with AAS were enrolled for retrospective analysis. All patients were divided into 2 groups (Non-oxygenation impairment group and Oxygenation impairment group). Logistic regression analysis was performed to assess the relation between BMI and the risk of preoperative oxygenation impairment after the onset of AAS. Dose-response relationship curve and subgroup analysis were conducted to test the reliability of BMI as an independent factor of it.

RESULTS

For the meta-analysis, the quantitative synthesis indicated that excessive BMI increased the risk of preoperative oxygenation impairment (OR: 1.30, 95% CI: 1.05-1.60, P _{heterogeneity} = 0.001). For the retrospective analysis, a significant association was observed after adjusting for a series of variables. BMI was significantly related to preoperative oxygenation impairment after the onset of AAS (OR: 1.34, 95% CI: 1.15-1.56, p <0.001), and compared with normal weight group (18.5 kg/m² ≤ BMI < 23.0 kg/m²), the individuals with excessive BMI were at higher risk of preoperative oxygenation impairment for the obese group (BMI ≥ 25 kg/m²) (OR: 17.32, 95% CI: 4.03-74.48, p <0.001). A J-shape curve in dose-response relationship analysis further confirmed their positive correlation. Subgroup analysis showed that diastolic blood pressure (DBP) ≥ 90mmHg carried an excess risk of preoperative oxygenation impairment in obese patients.

CONCLUSION

Excessive BMI was an independent risk factor for AAS with preoperative oxygenation impairment.

Methylglyoxal Exacerbates Lipopolysaccharide-Induced Acute Lung Injury via RAGE-Induced ROS Generation: Protective Effects of Metformin

Purpose

Methylglyoxal (MGO) is a highly reactive dicarbonyl species implicated in diabetic-associated diseases. Acute lung injury (ALI) symptoms and prognosis are worsened by diabetes and obesity. Here, we hypothesized that elevated MGO levels aggravate ALI, which can be prevented by metformin. Therefore, this study evaluated the lung inflammation in lipopolysaccharide (LPS)-exposed mice pretreated with MGO.

Methods

C57Bl/6 male mice treated or not with MGO for 12 weeks were intranasally instilled with LPS (30 µg) to induce ALI, and metformin (300 mg/kg) was given as gavage in the last two weeks of treatment. After 6 h, bronchoalveolar lavage fluid (BALF) and lung tissues were collected to quantify the cell infiltration, cytokine levels, reactive-oxygen species (ROS) production, and RAGE expression.

Results

LPS exposure markedly increased the neutrophil infiltration in BALF and lung tissue, which was accompanied by higher levels of IFN-γ, TNF-α and IL-1β compared with untreated group. MGO treatment significantly increased the airways neutrophil infiltration and mRNA expressions of TNF-α and IL-1β, whereas COX-2 expression remained unchanged. In lung tissues of LPS-exposed mice, MGO treatment significantly increased the immunostaining and mRNA expression of RAGE, and the ROS levels. Serum MGO concentration achieved after 12-week intake was 9.2-fold higher than control mice, which was normalized by metformin treatment. Metformin also reduced the inflammatory markers in response to MGO.

Conclusion

MGO intake potentiates the LPS-induced ALI, increases RAGE expression and ROS generation, which is normalized by metformin. MGO scavengers may be a good adjuvant therapy to reduce ALI in patients with cardiometabolic diseases.

The Use of Extracorporeal Membrane Oxygenation in COVID-19 Patients with Severe Cardiorespiratory Failure: The Influence of Obesity on Outcomes

Extracorporeal membrane oxygenation (ECMO) in the management of severely ill patients with COVID-19 has been reported in more than 5,827 cases worldwide according to the Extracorporeal Life Support Organization (ELSO). Several pre-existing conditions have been linked to an increase in COVID-19 mortality risk including obesity. The purpose of this research is to review the clinical experience from a cohort of 342 COVID-19 patients treated with ECMO in which 61.7% (211/342) are confirmed obese. Following institutional review board approval, we reviewed all 342 COVID-19 patients supported with ECMO between March 17, 2020 and March 18, 2021, at 40 American institutions from a multi-institutional database. Descriptive statistics comparing survivors to non-survivors were calculated using chi-square, Welch's ANOVA, and Kruskal-Wallis rank sum test as appropriate. Multivariable logistic regression was used to estimate the effect of body mass index (BMI) on the odds of survival while adjusting for age, gender, chronic renal failure, diabetes, asthma, hypertension, and pre-ECMO P/F ratio. Descriptive analysis showed that obese patients were more likely to be hypertensive (58.1% vs. 32%, p < .001), diabetic (42% vs. 30%, p < .05), and female (35% vs. 21%, p < .05), and had longer median days from intubation to cannulation (4.0 vs. 2.0, p < .05). Obese patients appeared to also have a slightly lower median age (47.9 vs. 50.5, p = .07), higher incidence of asthma (17.8% vs. 10.2%, p = .09), and a slightly lower pre-ECMO PaO₂/FiO₂ ratio (67.5 vs. 77.5, p = .08) though these differences were slightly less statistically reliable. Results from the logistic regression model suggest no statistically reliable association between BMI and odds of survival. Age had a moderately large and statistically reliable negative association with survival; the relative odds of survival for a 59-year-old patient were approximately half those of a 41-year-old patient (OR = .53, 95% CI: .36-.77, p < .001). Obesity does not seem to be a major risk factor for poor outcomes in COVID-19 patients supported with ECMO; however, age was moderately negatively associated with survival. The potential influence of other comorbidities on odds of survival among these patients warrant further investigation.

Nuciferine, an active ingredient derived from lotus leaf, lights up the way for the potential treatment of obesity and obesity-related diseases

Obesity, is an increasingly global public health problem associated complications. However, the proven anti-obesity agents are inefficient with adverse side effects; hence attention is being paid to novel drugs from natural resources to manage obesity and obesity-related diseases. Nuciferine (NF) is a high-quality aporphine alkaloid present in lotus leaf. Unlike the chemical drugs, NF elicits anti-obesity, anti-dyslipidemia, anti-hyperglycemic, anti-hypouricemic, anti-inflammatory, and anti-tumor effects, and affinity to neural receptors, and protection against obesity-related diseases. The underlying mechanism of NF includes the regulation of targeted molecules and pathways related to metabolism, inflammation, and cancer and modulation of Ca²⁺ flux, gut microbiota, and ferroptosis. Besides, the clinical application, availability, pharmacokinetics, pharmaceutics, and security of NF have been established, highlighting the potential of developing NF as an anti-obesity agent. Therefore, this review provides a comprehensive summarization, which sheds light on future research in NF.

"Obesity Paradox" in Acute Respiratory Distress Syndrome Among Patients Undergoing Cardiac Surgery: A Retrospective Study

Background

The “obesity paradox” exists in many diseases. It is unclear whether it also exists in acute respiratory distress syndrome (ARDS). The purpose of our study was to clarify the relationship between obesity and the development of and hospital mortality from ARDS among patients who underwent cardiac surgery.

Material/Methods

This retrospective case-control study included 202 patients with ARDS and 808 matching patients without ARDS. We clarified the relationship between obesity and the development of ARDS after adjusting for confounding factors by multiple logistic regression analysis. A total of 202 ARDS patients were divided into survival and mortality groups. After all confounding factors were adjusted by multiple logistic regression analysis, we demonstrated the relationship between obesity and mortality from ARDS.

Results

We found a significant association between body mass index (BMI) and the development of ARDS; the cutoff point of BMI was 24.78 kg/m² by adjusting for confounding factors for the development of ARDS. When the BMI was lower than 24.78 kg/m², the higher BMI was a protective factor (odds ratio [OR] 0.68, P=0.000, 95% confidence interval [CI] 0.55–0.84). When the BMI was higher than 24.78 kg/m², the higher BMI was a risk factor (OR 1.07, P=0.050, 95% CI 1.00–1.14). However, obesity was found to be associated with decreased ARDS mortality by adjusting for confounding factors (OR 0.91, P=0.039, 95% CI 0.83–1.00).

Conclusions

An “obesity paradox” may exist in ARDS among patients with obesity who undergo cardiac surgery.

Changes in children's lung function over two decades in relation to socioeconomic, parental and household factors in Wuhan, China

Background

It is important to identify risk and beneficial factors for children's lung function. This study aims to ascertain potential changes in children's lung function in relation to changes in socioeconomic, parental and household factors, based on a comparison between two periods spanning 25 years in Wuhan, the largest metropolis in central China.

Methods

In two cross-sectional studies, lung function measurements and questionnaire surveys were conducted on school-age children in 1993-1996 (Period I) and in 2018 (Period II). Children of 6-12 years old from elementary schools were selected by a multistage sampling method. Demographic information, socioeconomic status, feeding methods, parental illness and behavior patterns, as well as household characteristics, were collected through a questionnaire survey. Spirometric lung function was measured, including forced vital capacity (FVC), forced expiratory volume in the first second (FEV₁), forced expiratory flow at 25% and 75% of the pulmonary volume (FEF25-75), and peak expiratory flow (PEF). Wilcoxon analysis of variances was used to assess the differences in lung function indexes between Period I and Period II. Multiple linear regression models were used to estimate the association of lung function with regard to socioeconomic, parental and household factors, respectively.

Results

Significant prevalence reductions were observed for household coal use, paternal smoking and maternal asthma, while the prevalence increased significantly for children sleeping in their own rooms or own beds and breastfeeding, ventilation use during cooking, and parental education level from Period I to Period II. When adjusted for age, height, weight, sex and other factors assessed in the study, children had significant lower values of FVC, FEV₁, and PEF in Period II than in Period I. Enclosed kitchen was significantly associated with lower lung function in children in Period I. Urban living condition and higher maternal education level were each associated with a higher FVC, while father having no fixed income was associated with a lower FVC and a lower FEV₁, respectively, in Period II. In comparison with Period I, the beneficial impact of urban living and that of breastfeeding were enhanced and the detrimental effect of poor household condition was weakened in Period II.

Conclusions

Lung function was lower in 2018 than in 1993-1996 in school-age children living in Wuhan. Although improvements in urban living and household environmental conditions as well as increased breastfeeding in Period II could have contributed to increased lung function, other unmeasured risk factors may have played a more dominant role in leading to a net decrease in lung function from Period I to Period II. Future studies are needed to identify these risk factors.

Obesity and Critical Illness in COVID-19: Respiratory Pathophysiology

OBJECTIVE

Recent cohort studies have identified obesity as a risk factor for poor outcomes in coronavirus disease 2019 (COVID-19). To further explore the relationship between obesity and critical illness in COVID-19, the association of BMI with baseline demographic and intensive care unit (ICU) parameters, laboratory values, and outcomes in a critically ill patient cohort was examined.

METHODS

In this retrospective study, the first 277 consecutive patients admitted to Massachusetts General Hospital ICUs with laboratory-confirmed COVID-19 were examined. BMI class, initial ICU laboratory values, physiologic characteristics including gas exchange and ventilatory mechanics, and ICU interventions as clinically available were measured. Mortality, length of ICU admission, and duration of mechanical ventilation were also measured.

RESULTS

There was no difference found in respiratory system compliance or oxygenation between patients with and without obesity. Patients without obesity had higher initial ferritin and D-dimer levels than patients with obesity. Standard acute respiratory distress syndrome management, including prone ventilation, was equally distributed between BMI groups. There was no difference found in outcomes between BMI groups, including 30- and 60-day mortality and duration of mechanical ventilation.

CONCLUSIONS

In this cohort of critically ill patients with COVID-19, obesity was not associated with meaningful differences in respiratory physiology, inflammatory profile, or clinical outcomes.

Coronavirus Disease 2019 Hospitalizations Attributable to Cardiometabolic Conditions in the United States: A Comparative Risk Assessment Analysis

BACKGROUND Risk of coronavirus disease 2019 (COVID-19) hospitalization is robustly linked to cardiometabolic health. We estimated the absolute and proportional COVID-19 hospitalizations in US adults attributable to 4 major US cardiometabolic conditions, separately and jointly, and by race/ethnicity, age, and sex. METHODS AND RESULTS We used the best available estimates of independent associations of cardiometabolic conditions with a risk of COVID-19 hospitalization; nationally representative data on cardiometabolic conditions from the National Health and Nutrition Examination Survey 2015 to 2018; and US COVID-19 hospitalizations stratified by age, sex, and race/ethnicity from the Centers for Disease Control and Prevention's Coronavirus Disease 2019-Associated Hospitalization Surveillance Network database and from the COVID Tracking Project to estimate the numbers and proportions of COVID-19 hospitalizations attributable to diabetes mellitus, obesity, hypertension, and heart failure. Inputs were combined in a comparative risk assessment framework, with probabilistic sensitivity analyses and 1000 Monte Carlo simulations to jointly incorporate stratum-specific uncertainties in data inputs. As of November 18, 2020, an estimated 906 849 COVID-19 hospitalizations occurred in US adults. Of these, an estimated 20.5% (95% uncertainty interval [UIs], 18.9-22.1) of COVID-19 hospitalizations were attributable to diabetes mellitus, 30.2% (UI, 28.2-32.3) to total obesity (body mass index ≥30 kg/m²), 26.2% (UI, 24.3-28.3) to hypertension, and 11.7% (UI, 9.5-14.1) to heart failure. Considered jointly, 63.5% (UI, 61.6-65.4) or 575 419 (UI, 559 072-593 412) of COVID-19 hospitalizations were attributable to these 4 conditions. Large differences were seen in proportions of cardiometabolic risk-attributable COVID-19 hospitalizations by age and race/ethnicity, with smaller differences by sex. CONCLUSIONS A substantial proportion of US COVID-19 hospitalizations appear attributable to major cardiometabolic conditions. These results can help inform public health prevention strategies to reduce COVID-19 healthcare burdens.

Influence of obesity on remodeling of lung tissue and organization of extracellular matrix after blunt thorax trauma

Background

Previously, it has been shown that obesity is a risk factor for recovery, regeneration, and tissue repair after blunt trauma and can affect the rate of muscle recovery and collagen deposition after trauma. To date, lung tissue regeneration and extracellular matrix regulation in obese mice after injury has not been investigated in detail yet.

Methods

This study uses an established blunt thorax trauma model to analyze morphological changes and alterations on gene and protein level in lean or obese (diet-induced obesity for 16 ± 1 week) male C57BL/6 J mice at various time-points after trauma induction (1 h, 6 h, 24 h, 72 h and 192 h).

Results

Morphological analysis after injury showed lung parenchyma damage at early time-points in both lean and obese mice. At later time-points a better regenerative capacity of lean mice was observed, since obese animals still exhibited alveoli collapse, wall thickness as well as remaining filled alveoli structures. Although lean mice showed significantly increased collagen and fibronectin gene levels, analysis of collagen deposition showed no difference based on colorimetric quantification of collagen and visual assessment of Sirius red staining. When investigating the organization of the ECM on gene level, a decreased response of obese mice after trauma regarding extracellular matrix composition and organization was detectable. Differences in the lung tissue between the diets regarding early responding MMPs (MMP8/9) and late responding MMPs (MMP2) could be observed on gene and protein level. Obese mice show differences in regulation of extracellular matrix components compared to normal weight mice, which results in a decreased total MMP activity in obese animals during the whole regeneration phase. Starting at 6 h post traumatic injury, lean mice show a 50% increase in total MMP activity compared to control animals, while MMP activity in obese mice drops to 50%.

Conclusions

In conclusion, abnormal regulation of the levels of extracellular matrix genes in the lung may contribute to an aberrant regeneration after trauma induction with a delay of repair and pathological changes of the lung tissue in obese mice.

Should patients with obesity be more afraid of COVID-19?

COVID-19 crisis has lasted since the late 2019 to the present day. The severity of the disease is positively correlated with several factors, such as age and coexisting diseases. Furthermore, obesity is increasingly considered as a yet another risk factor, particularly, because it has been observed that people suffering from excessive body weight may experience a more severe course of COVID-19 infection. On the basis of current research, in our nonsystematic review, we have investigated the extent to which obesity can affect the SARS-CoV-2 course and identify the potential mechanisms of the disease. We have also described the role of proper nutrition, physical activity and other aspects relevant to the management of obesity.

Correlation between levels of adipokines and inflammatory mediators with spirometric parameters in individuals with obesity and symptoms of asthma: Cross-sectional study

INTRODUCTION

The adipose tissue secretes adipokines and influences the release of inflammatory mediators contributing to a state of low-grade systemic inflammation that may change lung function.

OBJECTIVE

To correlate levels of adipokines and inflammatory mediators with lung function in individuals with obesity and bronchial asthma symptoms.

MATERIALS AND METHODS

A cross-sectional study, including women with obesity (grade II and III) with symptoms and clinical diagnosis of asthma. Anthropometric measurements (weight, height, BMI), pulmonary function test (spirometry), asthma control test questionnaire, collection of systemic inflammatory markers (blood collection) and pulmonary markers (sputum collection) were collected and were analyzed: IL-6, IL-8, TNF-α, adiponectin, resistin, leptin and C-reactive protein (CRP). The patients were stratified into two groups according to asthma control.

RESULTS

80 women were analyzed and 40% had an ACT score greater than or equal to 18 and were classified as "controlled asthma". More than half of the patients of ACT<18 score obtaining measures of FEV1, PEF and FEF25-75% below and 80% of predicted. There was a significant and negative correlation between IL-6 in the sputum with FVC and FEF25-75% in the group ACT<18 and with FVC and FEV1 in the group ACT≥18.

CONCLUSIONS

Therefore, we concluded that the increase of interleukin-6 in the sputum is related to worse pulmonary function even in patients with controlled asthma, especially in the translate airway permeability measures.

Hepatic histopathology and apoptosis in diet-induced-obese mice under Escherichia coli pneumonia

This research was to investigate the difference of hepatic histopathology and apoptosis between the diet-induced obesity (DIO) and normal (lean) mice after Escherichia coli (E. coli) pneumonia. A total of 128 ICR mice were selected to be challenged intranasally with phosphate-buffered saline (PBS) or 4×10⁹CFUs/mL of E. coli, and the liver histopathology and apoptosis were examined pre- and post-infection. Results showed that the liver index, levels of lipid droplets, cytokines, adipocytokines, oxidative stress, apoptotic percentage, and apoptotic related factors in the E. coli-infected mice were generally higher than those in the uninfected mice, whereas the hepatic glycogen and Bcl-2 were the opposite. Interestingly, after E. coli infection, the DIO-E. coli mice exhibited decreased liver index and apoptotic percentages, and reduced levels of TNF-α, IL-6, resistin, MDA, GSH, CAT, Caspase-3, Caspase-9, Bax as well as Bax/Bcl-2 ratio in comparison to the lean-E. coli mice. Our results indicated that E. coli-induced pneumonia caused hepatic histopathological damage, increased hepatic apoptosis, oxidative damages, and higher levels of cytokines and adipocytokines. However, such changes showed less severely in the DIO mice than in the lean mice following E. coli pneumonia.

Adiponectin Protects Obese Rats from Aggravated Acute Lung Injury via Suppression of Endoplasmic Reticulum Stress

INTRODUCTION

Endoplasmic reticulum (ER) stress seems to mediate the obesity-induced susceptibility to acute lung injury (ALI). The present study was designed to evaluate the role of ER stress in adiponectin (APN)-induced lung protection in an obese rat model treated with lipopolysaccharide (LPS).

METHODS

Four-week-old male Sprague-Dawley rats fed either a normal chow diet or a high-fat diet for 12 weeks were randomly assigned to one of the following groups: lean rats, diet-induced obesity rats, lean rats with ALI, obese rats with ALI, obese rats pretreated with 4-phenylbutyric acid (4-PBA) before ALI or obese rats pretreated with APN before ALI. At 24 h after instillation of LPS into the lungs, cell counts in the bronchoalveolar lavage fluid (BALF) were determined. Lung tissues were separated to assess the degree of inflammation, pulmonary oedema, epithelial apoptosis and the expression of ER stress marker proteins.

RESULTS

The 78-kDa glucose-regulated protein (GRP78) and C/EBP homologous protein (CHOP) expression in the lung tissues of obese rats was upregulated before ALI, as well as the elevated apoptosis in epithelial cells. During ALI, the expression of ER stress marker proteins was similarly increased in both lean and obese rats, while significant downregulation of Mitofusin 2 (MFN2) was detected in obese epithelial cells. The lung tissues of obese rats showed higher concentrations of tumor necrosis factor-alpha (TNF-α), Interleukin 6 (IL-6) and IL-10, enhanced neutrophil counts and elevated wet/dry weight ratios. APN and 4-PBA decreased the degree of ER stress and suppressed LPS-induced lung inflammation, pulmonary oedema and epithelial apoptosis.

CONCLUSION

APN may exert protective effects against the exacerbated lung injuries in obese rats by attenuating ER stress, which operates as a key molecular pathway in the progression of ALI.

Histopathological Changes Caused by Inflammation and Oxidative Stress in Diet-Induced-Obese Mouse following Experimental Lung Injury

Obesity has been identified as a risk factor for adverse outcomes of various diseases. However, information regarding the difference between the response of obese and normal subjects to pulmonary inflammation is limited. Mice were fed with the control or high-fat diet to establish the lean and diet-induced obese (DIO) mice. Escherichia coli was intranasally instilled to reproduce non-fatal acute pneumonia model. After infection, serum samples and lung tissues were obtained at 0, 12, 24, and 72 h. DIO mice exhibited increased serum triglyceride (TG) and total cholesterol (TC) contents as well as pulmonary resistin, IL-6, and leptin levels compared with lean mice. E. coli infection caused an acute suppurative inflammation in the lung with increased lung index and serum TG and TC contents; elevated pulmonary tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-8, and leptin levels; and oxidative stress in mice. Interestingly, almost all the above-mentioned parameters peaked at 12 h after infection in the lean-E. coli group but after 12 h in the DIO-E. coli group. These results indicated that the DIO mice presented a delayed inflammatory response and oxidative stress in non-fatal acute pneumonia induced by E. coli infection.

Pulmonary Effects of Adjusting Tidal Volume to Actual or Ideal Body Weight in Ventilated Obese Mice

Obese patients could be more susceptible to mechanical ventilation (MV)-induced lung injury than non-obese patients due to weight-dependent changes in lung properties. The aim of this study was therefore to evaluate the pulmonary effects of 2 hours low V_T MV in a diet-induced obese mice model, with V_T calculated on either the actual body weight (V_Taw) or the ideal body weight (V_Tiw) . First, we hypothesized that a MV with V_Taw would be associated with altered lung mechanics and an increased lung inflammation. Second, we hypothesised that a MV with a V_Tiw would preserve lung mechanics and limit lung inflammation. We analyzed lung mechanics and inflammation using bronchoalveolar lavage (BAL) cell counts, flow cytometry tissue analysis and histology. Lung mechanics and inflammation were comparable in control and obese mice receiving V_Tiw. By contrast, obese mice receiving V_Taw had significantly more alterations in lung mechanics, BAL cellularity and lung influx of monocytes as compared to control mice. Their monocyte expression of Gr1 and CD62L was also increased. Alveolar neutrophil infiltration was significantly increased in all obese mice as compared to controls. In conclusion, our findings suggest that protective MV with a V_Taw is deleterious, with a marked alteration in lung mechanics and associated lung inflammation as compared to lean mice. With V_Tiw, lung mechanics and inflammation were close to that of control mice, except for an increased alveolar infiltrate of polymorphonuclear neutrophils. This inflammation might be attenuated by a blunted recruitment of inflammatory cells associated with obesity.

Factors Affecting Lung Function: A Review of the Literature

Lung function reference values are traditionally based on anthropometric factors, such as weight, height, sex, and age. FVC and FEV₁ decline with age, while volumes and capacities, such as RV and FRC, increase. TLC, VC, RV, FVC and FEV₁ are affected by height, since they are proportional to body size. This means that a tall individual will experience greater decrease in lung volumes as they get older. Some variables, such as FRC and ERV, decline exponentially with an increase in weight, to the extent that tidal volume in morbidly obese patients can be close to that of RV. Men have longer airways than women, causing greater specific resistance in the respiratory tract. The increased work of breathing to increase ventilation among women means that their consumption of oxygen is higher than men under similar conditions of physical intensity. Lung volumes are higher when the subject is standing than in other positions. DLCO is significantly higher in supine positions than in sitting or standing positions, but the difference between sitting and standing positions is not significant. Anthropometric characteristics are insufficient to explain differences in lung function between different ethnic groups, underlining the importance of considering other factors in addition to the conventional anthropometric measurements.

Fifty Years of Research in ARDS. The Epidemiology of Acute Respiratory Distress Syndrome. A 50th Birthday Review

Since its first description 50 years ago, no other intensive care syndrome has been as extensively studied as acute respiratory distress syndrome (ARDS). Despite this extensive body of research, many basic epidemiologic questions remain unsolved. The lack of gold standard tests jeopardizes accurate diagnosis and translational research. Wide variation in the population incidence has been reported, making even simple estimates of the burden of disease problematic. Despite these limitations, there has been an increase in the understanding of pathophysiology and important risk factors both for the development of ARDS and for important patient-centered outcomes like mortality. In this Critical Care Perspective, we discuss the historical context of ARDS description and attempts at its definition. We highlight the epidemiologic challenges of studying ARDS, as well as other intensive care syndromes, and propose solutions to address them. We update the current knowledge of ARDS trends in incidence and mortality, risk factors, and recently described endotypes.

Definition and epidemiology of acute respiratory distress syndrome

Fifty years ago, Ashbaugh and colleagues defined for the first time the acute respiratory distress syndrome (ARDS), one among the most challenging clinical condition of the critical care medicine. The scientific community worked over the years to generate a unified definition of ARDS, which saw its revisited version in the Berlin definition, in 2014. Epidemiologic information about ARDS is limited in the era of the new Berlin definition, and wide differences are reported among countries all over the world. Despite decades of study in the field of lung injury, ARDS is still so far under-recognized, with 2 out of 5 cases missed by clinicians. Furthermore, although advances of ventilator strategies in the management of ARDS associated with outcome improvements-such as protective mechanical ventilation, lower driving pressure, higher PEEP levels and prone positioning-ARDS appears to be undertreated and mortality remains elevated up to 40%. In this review, we cover the history that led to the current worldwide accepted Berlin definition of ARDS and we summarize the recent data regarding ARDS epidemiology.

Analysis of quality of life among asthmatic individuals with obesity and its relationship with pulmonary function: cross-sectional study

CONTEXT AND OBJECTIVE:

The combined effect of obesity and asthma may lead to significant impairment of quality of life (QOL). The aim here was to evaluate the prevalence of asthma among obese individuals, characterize the severity of impairment of quality of life and measure its relationship with pulmonary function.

DESIGN AND SETTING:

Observational cross-sectional study in public university hospital.

METHODS:

Morbidly obese individuals (body mass index &gt; 40 kg/m2) seen in a bariatric surgery outpatient clinic and diagnosed with asthma, were included. Anthropometric data were collected, the Standardized Asthma Quality of Life Questionnaire (AQLQ(S)) was applied and spirometry was performed. The subjects were divided into two groups based on the median of the score in the questionnaire (worse &lt; 4 and better &gt; 4) and were compared regarding anthropometric data and pulmonary function.

RESULTS:

Among the 4791 individuals evaluated, 219 were asthmatic; the prevalence of asthma was 4.57%. Of these, 91 individuals were called to start multidisciplinary follow-up during the study period, of whom 82 answered the questionnaire. The median score in the AQLQ(S) was 3.96 points and, thus, the individuals were classified as having moderate impairment of their overall QOL. When divided according to better or worse QOL, there was a statistically difference in forced expiratory flow (FEF) 25-75%, with higher values in the better QOL group.

CONCLUSION:

The prevalence of asthma was 4.57% and QOL was impaired among the asthmatic obese individuals. The worst QOL domain related to environmental stimuli and the best QOL domain to limitations of the activities. Worse QOL was correlated with poorer values for FEF 25-75%.

Effect of High-Fat Diet on the Formation of Pulmonary Neutrophil Extracellular Traps during Influenza Pneumonia in BALB/c Mice

Obesity is an independent risk factor for severe outcome of influenza infection. Higher dietary fat consumption has been linked to greater morbidity and severe influenza in mouse models. However, the extent of generation of neutrophil extracellular traps (NETs or NETosis) in obese individuals during influenza pneumonia is hitherto unknown. This study investigated pulmonary NETs generation in BALB/c mice fed with high-fat diet (HFD) and low-fat diet (LFD), during the course of influenza pneumonia. Clinical disease progression, histopathology, lung reactive oxygen species, and myeloperoxidase activity were also compared. Consumption of HFD over 18 weeks led to significantly higher body weight, body mass index, and adiposity in BALB/c mice compared with LFD. Lethal challenge of mice (on HFD and LFD) with influenza A/PR/8/34 (H1N1) virus led to similar body weight loss and histopathologic severity. However, NETs were formed at relatively higher levels in mice fed with HFD, despite the absence of significant difference in disease progression between HFD- and LFD-fed mice.

Autophagy and Obesity-Related Lung Disease

Obesity-related disease is a significant source of premature death and economic burden globally. It is also a common comorbidity in patients suffering from lung disease, affecting both severity and treatment success. However, this complex association between obesity and the lung is poorly understood. Autophagy is a self-recycling homeostatic process that has been linked to beneficial or deleterious effects, depending on the specific lung disease. Obesity affects autophagy in a tissue-specific manner, activating autophagy in adipocytes and impairing autophagy in hepatocytes, immune cells, and pancreatic β-cells, among others. Obesity is also characterized by chronic low-grade inflammation that can be modulated by the pro- and antiinflammatory effects of the autophagic machinery. Scant evidence exists regarding the impact of autophagy in obesity-related lung diseases, but there are communal pathways that could be related to disease pathogenesis. Important signaling molecules in obesity, including IL-17, leptin, adiponectin, NLRP3 inflammasome, and TLR-4, have been implicated in the pathogenesis of lung disease. These mediators are known to be modulated by autophagy activity. In this perspective, we highlight the recent advances in the understanding of autophagy in obesity-related conditions, as well as the potential mechanisms that can link autophagy and obesity in the pathogenesis of lung disease.

Analysis of the prevalence of atelectasis in patients undergoing bariatric surgery

BACKGROUND AND OBJECTIVE

To observe the prevalence of atelectasis in patients undergoing bariatric surgery and the influence of the body mass index (BMI), gender and age on the prevalence of atelectasis.

METHOD

Retrospective study of 407 patients and reports on chest X-rays carried out before and after bariatric surgery over a period of 14 months. Only patients who underwent bariatric surgery by laparotomy were included.

RESULTS

There was an overall prevalence of 37.84% of atelectasis, with the highest prevalence in the lung bases and with greater prevalence in women (RR=1.48). There was a ratio of 30% for the influence of age for individuals under the age of 36, and of 45% for those older than 36 (RR=0.68). There was no significant influence of BMI on the prevalence of atelectasis.

CONCLUSION

The prevalence of atelectasis in bariatric surgery is 37% and the main risk factors are being female and aged over 36 years.

Impact of obesity on sepsis mortality: A systematic review

PURPOSE

Sepsis and severe sepsis are the most common cause of death among critically ill patients admitted in medical intensive care units. As more than one-third of the adult population of the United States is obese; we undertook a systematic review of the association between obesity and mortality among patients admitted with sepsis, severe sepsis, or septic shock.

MATERIALS AND METHODS

A systematic review was conducted to identify pertinent studies using a comprehensive search strategy. Studies reporting mortality in obese patients admitted with sepsis were identified.

RESULTS

Our initial search identified 183 studies of which 7 studies met our inclusion criteria. Three studies reported no significant association between obesity and mortality, 1 study observed increased mortality among obese patients, whereas 3 studies found lower mortality among obese patients.

CONCLUSION

Our review of the current clinical evidence of association of obesity with sepsis mortality revealed mixed results. Clinicians are faced with a number of challenges while managing obese patients with sepsis and should be mindful of the impact of obesity on antibiotics administration, fluid resuscitation, and ventilator management. Further studies are needed to elicit the impact of obesity on mortality in patients with sepsis.

Lard-based high-fat diet increases secretory leukocyte protease inhibitor expression and attenuates the inflammatory response of acute lung injury in endotoxemic rats

BACKGROUND & AIMS

Acute lung injury (ALI) is less severe in obese than in nonobese patients, but the mechanism is unclear. Secretory leukocyte protease inhibitor (SLPI) is the key anti-inflammatory protein in various lung diseases. We have previously reported changes of the surgical stress in obese rats using lard-based high-fat diet (HFD). The purpose of this study was to elucidate the effect of lard-based HFD on the pathophysiology of lipopolysaccharide (LPS)-induced ALI, and the role of SLPI expression.

METHODS

Male Wistar rats were fed lard-based HFD (60 kcal% fat) or control diet (CD) for either 4 or 12 weeks and were killed after intraperitoneal LPS injection. Analyses included messenger RNA expression of TNF-α, macrophage inflammatory protein (MIP)-2, inducible nitric oxide synthase (iNOS), IL-10 and SLPI in the lung tissue and bronchoalveolar lavage fluid, and histology of the lungs.

RESULTS

Rats fed HFD for 12 weeks showed suppression of the lung injury and oxidative stress after LPS injection, as indicated by reduction of pulmonary TNF-α, MIP-2 and iNOS mRNA expression and 8-hydroxy-2'-deoxyguanosine immunostaining. The increased pulmonary SLPI caused by lard was associated with decreased pro-inflammatory cytokines and oxidative stress, which eventually resulted in the prevention of ALI. Those effects of lard on LPS-induced ALI were greater after 12 weeks than after 4 weeks feeding, as indicated by the reduction of TNF-α, MIP-2 and iNOS levels.

CONCLUSIONS

Feeding lard-based HFD for 12 weeks attenuated LPS-induced ALI with increased pulmonary SLPI expression in rats.

Obesity and nutrition in acute respiratory distress syndrome

This article discusses obesity, its contribution to clinical outcomes, and the current literature on nutrition. More than one third of Americans are obese. Literature suggests that, among critically ill patients, the relationship between obesity and outcomes is complex. Obese patients may be at greater risk of developing acute respiratory distress syndrome (ARDS) than normal weight patients. Although obesity may confer greater morbidity in intensive care, it seems to decrease mortality. ARDS is a catabolic state; patients demonstrate a profound inflammatory response, multiple organ dysfunction, and hypermetabolism, often with malnutrition. The concept of pharmaconutrition has emerged.

Therapeutic potential of intermittent hypoxia: a matter of dose

Intermittent hypoxia (IH) has been the subject of considerable research in recent years, and triggers a bewildering array of both detrimental and beneficial effects in multiple physiological systems. Here, we review the extensive literature concerning IH and its impact on the respiratory, cardiovascular, immune, metabolic, bone, and nervous systems. One major goal is to define relevant IH characteristics leading to safe, protective, and/or therapeutic effects vs. pathogenesis. To understand the impact of IH, it is essential to define critical characteristics of the IH protocol under investigation, including potentially the severity of hypoxia within episodes, the duration of hypoxic episodes, the number of hypoxic episodes per day, the pattern of presentation across time (e.g., within vs. consecutive vs. alternating days), and the cumulative time of exposure. Not surprisingly, severe/chronic IH protocols tend to be pathogenic, whereas any beneficial effects are more likely to arise from modest/acute IH exposures. Features of the IH protocol most highly associated with beneficial vs. pathogenic outcomes include the level of hypoxemia within episodes and the number of episodes per day. Modest hypoxia (9-16% inspired O2) and low cycle numbers (3-15 episodes per day) most often lead to beneficial effects without pathology, whereas severe hypoxia (2-8% inspired O2) and more episodes per day (48-2,400 episodes/day) elicit progressively greater pathology. Accumulating evidence suggests that "low dose" IH (modest hypoxia, few episodes) may be a simple, safe, and effective treatment with considerable therapeutic potential for multiple clinical disorders.

The impact of cardiac dysfunction on acute respiratory distress syndrome and mortality in mechanically ventilated patients with severe sepsis and septic shock: an observational study

PURPOSE

Acute respiratory distress syndrome (ARDS) is associated with significant mortality and morbidity in survivors. Treatment is only supportive, therefore elucidating modifiable factors that could prevent ARDS could have a profound impact on outcome. The impact that sepsis-associated cardiac dysfunction has on ARDS is not known.

MATERIALS AND METHODS

In this retrospective observational cohort study of mechanically ventilated patients with severe sepsis and septic shock, 122 patients were assessed for the impact of sepsis-associated cardiac dysfunction on incidence of ARDS (primary outcome) and mortality.

RESULTS

Sepsis-associated cardiac dysfunction occurred in 44 patients (36.1%). There was no association of sepsis-associated cardiac dysfunction with ARDS incidence (p= 0.59) or mortality, and no association with outcomes in patients that did progress to ARDS after admission. Multivariable logistic regression demonstrated that higher BMI was associated with progression to ARDS (adjusted OR 11.84, 95% CI 1.24 to 113.0, p= 0.02).

CONCLUSIONS

Cardiac dysfunction in mechanically ventilated patients with sepsis did not impact ARDS incidence, clinical outcome in ARDS patients, or mortality. This contrasts against previous investigations demonstrating an influence of nonpulmonary organ dysfunction on outcome in ARDS. Given the frequency of ARDS as a sequela of sepsis, the impact of cardiac dysfunction on outcome should be further studied.

Effect of type II diabetes mellitus on outcomes in patients with acute respiratory distress syndrome

PURPOSE

The acute respiratory distress syndrome (ARDS) is a life-threatening condition, whereas the presence of diabetes has been shown to be protective in its development. We undertook this study to assess the association of type II diabetes mellitus with clinical outcomes in patients with ARDS.

MATERIALS AND METHODS

We retrospectively examined the medical records of consecutive series of patients with ARDS requiring mechanical ventilation from January 2008 to March 2011. Patients with type I diabetes were excluded from the study. Clinical outcomes such as ventilator-free days, mortality, length of stay in the hospital and intensive care unit (ICU), and reintubations were compared based on the presence of diabetes. Multivariate regression model was used to find if the presence of type II diabetes mellitus predicts ventilator-free days at day 28.

RESULTS

Two hundred forty-nine patients with ARDS were admitted to the ICU during the study period. Fifty (20%) subjects had type II diabetes mellitus. Differences in ventilator-free days, in-hospital mortality, reintubation rate, and length of stay in the hospital or ICU were not statistically significant between diabetic and nondiabetic patients with ARDS. Acute Physiologic and Chronic Health Evaluation II, ICU specialty, use of vasopressors, and the need for reintubation were predictors of ventilator-free days at day 28. The presence of type II diabetes mellitus and its adjustment by body mass index did not show association with ventilator-free days at day 28.

CONCLUSIONS

The presence of type II diabetes mellitus is not associated with clinical outcomes in ARDS, even when its presence is adjusted by body mass index.

Effect of adenovirus and influenza virus infection on obesity

The purpose of this review is to provide an overview of the effects of adenovirus and influenza virus infections on obesity in various experimental models. We reviewed studies that were conducted within the past 10 years and were related to virus infection and obesity prevalence. Here, we discuss a different causal relationship between adenovirus and influenza infections with obesity. Adenovirus infection can cause obesity, whereas obesity can be a risk factor for increasing influenza virus infection and increases the risk of morbidity and mortality. The prevalence of obesity due to adenovirus infections may be due to an increase in glucose uptake and reduction in lipolysis caused by an increase in corticosterone secretion. Adenovirus infections may lead to increases in appetite by decreasing norepinephrine and leptin levels and also cause immune dysfunction. The relationship between obesity and influenza virus infection could be summarized by the following features: decreases in memory T-cell functionality and interferon (IFN)-α, IFN-β, and IFN-γ mRNA expression, increases in viral titer and infiltration, and impaired dendritic cell function in obese individuals. Moreover, leptin resistance may play an important role in increasing influenza virus infections in obese individuals. In conclusion, prevention of adenovirus infections could be a good approach for reducing obesity prevalence, and prevention of obesity could reduce influenza virus infections from the point of view of viral infections and obesity.

Mechanical ventilation and acute lung injury in emergency department patients with severe sepsis and septic shock: an observational study

OBJECTIVES

The objectives were to characterize the use of mechanical ventilation in the emergency department (ED), with respect to ventilator settings, monitoring, and titration and to determine the incidence of progression to acute lung injury (ALI) after admission, examining the influence of factors present in the ED on ALI progression.

METHODS

This was a retrospective, observational cohort study of mechanically ventilated patients with severe sepsis and septic shock (June 2005 to May 2010), presenting to an academic ED with an annual census of >95,000 patients. All patients in the study (n = 251) were analyzed for characterization of mechanical ventilation use in the ED. The primary outcome variable of interest was the incidence of ALI progression after intensive care unit (ICU) admission from the ED and risk factors present in the ED associated with this outcome. Secondary analyses included ALI present in the ED and clinical outcomes comparing all patients progressing to ALI versus no ALI. To assess predictors of progression to ALI, significant variables in univariable analyses at a p ≤ 0.10 level were candidates for inclusion in a bidirectional, stepwise, multivariable logistic regression analysis.

RESULTS

Lung-protective ventilation was used in 68 patients (27.1%) and did not differ based on ALI status. Delivered tidal volume was highly variable, with a median tidal volume delivered of 8.8 mL/kg ideal body weight (IBW; interquartile range [IQR] = 7.8 to 10.0) and a range of 5.2 to 14.6 mL/kg IBW. Sixty-nine patients (27.5%) in the entire cohort progressed to ALI after admission to the hospital, with a mean (±SD) onset of 2.1 (±1) days. Multivariable logistic regression analysis demonstrated that a higher body mass index (BMI), higher Sequential Organ Failure Assessment (SOFA) score, and ED vasopressor use were associated with progression to ALI. There was no association between ED ventilator settings and progression to ALI. Compared to patients who did not progress to ALI, patients progressing to ALI after admission from the ED had an increase in mechanical ventilator duration, vasopressor dependence, and hospital length of stay (LOS).

CONCLUSIONS

Lung-protective ventilation is uncommon in the ED, regardless of ALI status. Given the frequency of ALI in the ED, the progression shortly after ICU admission, and the clinical consequences of this syndrome, the effect of ED-based interventions aimed at reducing the sequelae of ALI should be investigated further.

Review on the impact of pregnancy and obesity on influenza virus infection

A myriad of risk factors have been linked to an increase in the severity of the pandemic H1N1 2009 influenza A virus [A(H1N1)pdm09] including pregnancy and obesity where death rates can be elevated as compared to the general population. The goal of this review is to provide an overview of the influence of pregnancy and obesity on the reported cases of A(H1N1)pdm09 virus infection and of how the concurrent presence of these factors may have an exacerbating effect on infection outcome. Also, the hypothesized immunologic mechanisms that contribute to A(H1N1)pdm09 virus severity during pregnant or obese states are outlined. Identifying the mechanisms underlying the increased disease severity in these populations may result in improved therapeutic approaches and future pandemic preparedness.

Obesity is associated with neutrophil dysfunction and attenuation of murine acute lung injury

Although obesity is implicated in numerous health complications leading to increased mortality, the relationship between obesity and outcomes for critically ill patients appears paradoxical. Recent studies have reported better outcomes and lower levels of inflammatory cytokines in obese patients with acute lung injury (ALI)/acute respiratory distress syndrome, suggesting that obesity may ameliorate the effects of this disease. We investigated the effects of obesity in leptin-resistant db/db obese and diet-induced obese mice using an inhaled LPS model of ALI. Obesity-associated effects on neutrophil chemoattractant response were examined in bone marrow neutrophils using chemotaxis and adoptive transfer; neutrophil surface levels of chemokine receptor CXCR2 were determined by flow cytometry. Airspace neutrophilia, capillary leak, and plasma IL-6 were all decreased in obese relative to lean mice in established lung injury (24 h). No difference in airspace inflammatory cytokine levels was found between obese and lean mice in both obesity models during the early phase of neutrophil recruitment (2-6 h), but early airspace neutrophilia was reduced in db/db obese mice. Neutrophils from uninjured obese mice demonstrated diminished chemotaxis to the chemokine keratinocyte cytokine compared with lean control mice, and adoptive transfer of obese mouse neutrophils into injured lean mice revealed a defect in airspace migration of these cells. Possibly contributing to this defect, neutrophil CXCR2 expression was significantly lower in obese db/db mice, and a similar but nonsignificant decrease was seen in diet-induced obese mice. ALI is attenuated in obese mice, and this blunted response is in part attributable to an obesity-associated abnormal neutrophil chemoattractant response.

The impact of comorbid [corrected] conditions on critical illness

OBJECTIVE

To review the current knowledge of common comorbidities in the intensive care unit, including diabetes mellitus, chronic obstructive pulmonary disease, cancer, end-stage renal disease, end-stage liver disease, HIV infection, and obesity, with specific attention to epidemiology, contribution to diseases and outcomes, and the impact on treatments in these patients.

DATA SOURCE

Review of the relevant medical literature for specific common comorbidities in the critically ill.

RESULTS

Critically ill patients are admitted to the intensive care unit for various reasons, and often the admission diagnosis is accompanied by a chronic comorbidity. Chronic comorbid conditions commonly seen in critically ill patients may influence the decision to provide intensive care unit care, decisions regarding types and intensity of intensive care unit treatment options, and outcomes. The presence of comorbid conditions may predispose patients to specific complications or forms of organ dysfunction. The impact of specific comorbidities varies among critically ill medical, surgical, and other populations, and outcomes associated with certain comorbidities have changed over time. Specifically, outcomes for patients with cancer and HIV have improved, likely related to advances in therapy. Overall, the negative impact of chronic comorbidity on survival in critical illness may be primarily influenced by the degree of organ dysfunction or the cumulative severity of multiple comorbidities.

CONCLUSION

Chronic comorbid conditions are common in critically ill patients. Both the acute illness and the chronic conditions influence prognosis and optimal care delivery for these patients, particularly for adverse outcomes and complications influenced by comorbidities. Further work is needed to fully determine the individual and combined impact of chronic comorbidities on intensive care unit outcomes.

Usefulness of combining intermittent hypoxia and physical exercise in the treatment of obesity

Obesity is an important public health problem worldwide and is a major risk factor for a number of chronic diseases such as type II diabetes, adverse cardiovascular events and metabolic syndrome-related features. Different treatments have been applied to tackle body fat accumulation and its associated clinical manifestations. Often, relevant weight loss is achieved during the first 6 months under different dietary treatments. From this point, a plateau is reached, and a gradual recovery of the lost weight may occur. Therefore, new research approaches are being investigated to assure weight maintenance. Pioneering investigations have reported that oxygen variations in organic systems may produce changes in body composition. Possible applications of intermittent hypoxia to promote health and in various pathophysiological states have been reported. The hypoxic stimulus in addition to diet and exercise can be an interesting approach to lose weight, by inducing higher basal noradrenalin levels and other metabolic changes whose mechanisms are still unclear. Indeed, hypoxic situations increase the diameter of arterioles, produce peripheral vasodilatation and decrease arterial blood pressure. Furthermore, hypoxic training increases the activity of glycolytic enzymes, enhancing the number of mitochondria and glucose transporter GLUT-4 levels as well as improving insulin sensitivity. Moreover, hypoxia increases blood serotonin and decreases leptin levels while appetite is suppressed. These observations allow consideration of the hypothesis that intermittent hypoxia induces fat loss and may ameliorate cardiovascular health, which might be of interest for the treatment of obesity. This new strategy may be useful and practical for clinical applications in obese patients.

Intensive care in the obese

Nearly 20% of all patients admitted to an intensive-care unit are obese. Their excess weight puts them at risk for several problems and complications during their intensive-care unit stay. Especially, pulmonary problems need particular attention, and comprehensive knowledge of the specific pathophysiologic changes of the respiratory system is important. Lung protective ventilation strategies, supplemented by lung-recruiting manoeuvres, may be feasible in critically ill obese patients with lung injury. Careful positioning of the obese is essential to optimise ventilation and facilitate weaning from mechanical ventilation. Optimal hypocaloric nutrition with a high proportion of proteins is advised to control hyperglycaemia. Because mortality in obese patients is similar to or lower than in non-obese ones, it is conceivable that obesity has a protective effect in the critically ill.

The STRATOB study: design of a randomized controlled clinical trial of Cognitive Behavioral Therapy and Brief Strategic Therapy with telecare in patients with obesity and binge-eating disorder referred to residential nutritional rehabilitation

BACKGROUND

Overweight and obesity are linked with binge eating disorder (BED). Effective interventions to significantly reduce weight, maintain weight loss and manage associated pathologies like BED are typically combined treatment options (dietetic, nutritional, physical, behavioral, cognitive-behavioral, pharmacological, surgical). Significant difficulties with regard to availability, costs, treatment adherence and long-term efficacy are present. Particularly Cognitive Behavioral Therapy (CBT) is the therapeutic approach indicated both in in-patient and in out-patient settings for BED. In recent years systemic and systemic-strategic psychotherapies have been implemented to treat patients with obesity and BED involved in familiar problems. Particularly a brief protocol for the systemic-strategic treatment of BED, using overall the strategic dialogue, has been recently developed. Moreover telemedicine, a new promising low cost method, has been used for obesity with BED in out-patient settings in order to avoid relapse after the in-patient step of treatment and to keep on a continuity of care with the involvement of the same clinical in-patient team.

METHODS

The comparison between CBT and Brief Strategic Therapy (BST) will be assessed in a two-arm randomized controlled clinical trial. Due to the novelty of the application of BST in BED treatment (no other RCTs including BST have been carried out), a pilot study will be carried out before conducting a large scale randomized controlled clinical trial (RCT). Both CBT and BST group will follow an in-hospital treatment (diet, physical activity, dietitian counseling, 8 psychological sessions) plus 8 out-patient telephone-based sessions of psychological support and monitoring with the same in-patient psychotherapists. Primary outcome measure of the randomized trial will be the change in the Global Index of the Outcome Questionnaire (OQ-45.2). Secondary outcome measures will be the percentage of BED patients remitted considering the number of weekly binge episodes and the weight loss. Data will be collected at baseline, at discharge from the hospital (c.a. 1 month after) and after 6-12-24 months from the end of the in-hospital treatment. Data at follow-up time points will be collected through tele-sessions.

DISCUSSION

The STRATOB (Systemic and STRATegic psychotherapy for OBesity), a comprehensive two-phase stepped down program enhanced by telepsychology for the medium-term treatment of obese people with BED seeking intervention for weight loss, will shed light about the comparison of the effectiveness of the BST with the gold standard CBT and about the continuity of care at home using a low-level of telecare (mobile phones).

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01096251

2009 H1N1 influenza and experience in three critical care units

AIM

We describe futures of ICU admission, demographic characteristics, treatment and outcome for critically ill patients with laboratory-confirmed and suspected infection with the H1N1 virus admitted to the three different critical care departments in Turkey.

METHODS

Retrospective study of critically ill patients with 2009 influenza A(H1N1) at ICU. Demographic data, symptoms, comorbid conditions, and clinical outcomes were collected using a case report form.

RESULTS

Critical illness occurred in 61 patients admitted to an ICU with confirmed (n=45) or probable and suspected 2009 influenza A(H1N1). Patients were young (mean, 41.5 years), were female (54%). Fifty-six patients, required mechanical ventilation (14 invasive, 27 noninvasive, 15 both) during the course of ICU. On admission, mean APACHE II score was 18.7±6.3 and median PaO(2)/FIO(2) was 127.9±70.4. 31 patients (50.8%) was die. There were no significant differences in baseline PaO(2)/FIO(2 )and ventilation strategies between survivors and nonsurvivors. Patients who survived were more likely to have NIMV use at the time of admission to the ICU.

CONCLUSION

Critical illness from 2009 influenza A(H1N1) in ICU predominantly affects young patients with little major comorbidity and had a high case-fatality rate. NIMV could be used in 2009 influenza A (H1N1) infection-related hypoxemic respiratory failure.

An assessment of H1N1 influenza-associated acute respiratory distress syndrome severity after adjustment for treatment characteristics

Pandemic influenza caused significant increases in healthcare utilization across several continents including the use of high-intensity rescue therapies like extracorporeal membrane oxygenation (ECMO) or high-frequency oscillatory ventilation (HFOV). The severity of illness observed with pandemic influenza in 2009 strained healthcare resources. Because lung injury in ARDS can be influenced by daily management and multiple organ failure, we performed a retrospective cohort study to understand the severity of H1N1 associated ARDS after adjustment for treatment. Sixty subjects were identified in our hospital with ARDS from “direct injury” within 24 hours of ICU admission over a three month period. Twenty-three subjects (38.3%) were positive for H1N1 within 72 hours of hospitalization. These cases of H1N1-associated ARDS were compared to non-H1N1 associated ARDS patients. Subjects with H1N1-associated ARDS were younger and more likely to have a higher body mass index (BMI), present more rapidly and have worse oxygenation. Severity of illness (SOFA score) was directly related to worse oxygenation. Management was similar between the two groups on the day of admission and subsequent five days with respect to tidal volumes used, fluid balance and transfusion practices. There was, however, more frequent use of “rescue” therapy like prone ventilation, HFOV or ECMO in H1N1 patients. First morning set tidal volumes and BMI were significantly associated with increased severity of lung injury (Lung injury score, LIS) at presentation and over time while prior prescription of statins was protective. After assessment of the effect of these co-interventions LIS was significantly higher in H1N1 patients. Patients with pandemic influenza-associated ARDS had higher LIS both at presentation and over the course of the first six days of treatment when compared to non-H1N1 associated ARDS controls. The difference in LIS persisted over the duration of observation in patients with H1N1 possibly explaining the increased duration of mechanical ventilation.

Brief Strategic Therapy vs Cognitive Behavioral Therapy for the Inpatient and Telephone-Based Outpatient Treatment of Binge Eating Disorder: The STRATOB Randomized Controlled Clinical Trial

This paper describes the results of the STRATOB (Systemic and STRATegic psychotherapy for OBesity) study, a two-arm randomized controlled clinical trial (RCT) comparing Brief Strategic Therapy (BST, Nardone or Arezzo model) with the gold standard CBT (Cognitive Behavioral Therapy) for the inpatient and telephone-based outpatient treatment of obese people with Binge Eating Disorder (BED) seeking treatment for weight reduction. Primary outcome measure of the randomized trial was change in the Global Index of the Outcome Questionnaire (OQ 45.2). Secondary outcome measures were BED remission (weekly binge episodes < 2) and weight loss. Data were collected at baseline, at discharge from the hospital (c.a. 1 month after) and after 6 months from discharge.. No significant difference between groups (BST vs CBT) was found in the primary outcome at discharge. However, a greater improvement was seen in the BST vs the CBT group (P<.01) in the primary outcome at 6 months. About secondary outcomes, no significant difference between groups were found in weight change both at discharge and at 6 months. Notably, a significant association emerged between treatment groups and BED remission at 6 months in favor of BST (only 20% of patients in BST group reported a number of weekly binge episodes > 2 vs 63.3% in CBT group).