Metabolic Syndrome and the Lung

Oxygen in Metabolic Dysfunction and Its Therapeutic Relevance

Significance: In recent years, a number of studies have shown altered oxygen partial pressure at a tissue level in metabolic disorders, and some researchers have considered oxygen to be a (macro) nutrient. Oxygen availability may be compromised in obesity and several other metabolism-related pathological conditions, including sleep apnea-hypopnea syndrome, the metabolic syndrome (which is a set of conditions), type 2 diabetes, cardiovascular disease, and cancer. Recent Advances: Strategies designed to reduce adiposity and its accompanying disorders have been mainly centered on nutritional interventions and physical activity programs. However, novel therapies are needed since these approaches have not been sufficient to counteract the worldwide increasing rates of metabolic disorders. In this regard, intermittent hypoxia training and hyperoxia could be potential treatments through oxygen-related adaptations. Moreover, living at a high altitude may have a protective effect against the development of abnormal metabolic conditions. In addition, oxygen delivery systems may be of therapeutic value for supplying the tissue-specific oxygen requirements. Critical Issues: Precise in vivo methods to measure oxygenation are vital to disentangle some of the controversies related to this research area. Further, it is evident that there is a growing need for novel in vitro models to study the potential pathways involved in metabolic dysfunction to find appropriate therapeutic targets. Future Directions: Based on the existing evidence, it is suggested that oxygen availability has a key role in obesity and its related comorbidities. Oxygen should be considered in relation to potential therapeutic strategies in the treatment and prevention of metabolic disorders. Antioxid. Redox Signal. 35, 642-687.

Pulmonary function changes in older adults with and without metabolic syndrome

The low-grade inflammation associated with metabolic syndrome (MS) triggers functional and structural alterations in several organs. Whereas lung function impairment is well reported for older adult population, the effect of MS on functional and immunological responses in the lungs remains unclear. In this cross-sectional study we determined whether MS alters pulmonary function, and immunological responses in older adults with MS. The study sample consisted of older adults with MS (68 ± 3 years old; n = 77) and without MS (67 ± 3 years old; n = 77). Impulse oscillometry was used to evaluate airway and tissue resistance, and reactance. Biomarkers of inflammation and fibrosis were assessed in the blood and in breath condensate. The total resistance of the respiratory system (R5Hz; p < 0.009), and the resistance of the proximal (R20Hz; p < 0.001) and distal (R5Hz–R20Hz; p < 0.004) airways were higher in MS individuals compared to those without MS. Pro-inflammatory (leptin, IL-1beta, IL-8, p < 0.001; TNF-alpha, p < 0.04) and anti-inflammatory cytokines (adiponectin, IL-1ra, IL-10, p < 0.001), anti-fibrotic (relaxin 1, relaxin 3, Klotho, p < 0.001) and pro-fibrotic (VEGF, p < 0.001) factors were increased in sera and in breath condensate individuals with MS. The results show that MS adversely affect lung mechanics, function, and immunological response in older adults. The data offer a metabolic basis for the inflammaging of the lungs and suggest the lungs as a potential therapeutic target for controlling the immune response and delaying the onset of impaired lung function in older adults with MS.

β-caryophyllene ameliorated obesity-associated airway hyperresponsiveness through some non-conventional targets

BACKGROUND

Obesity worsens airway hyperresponsiveness (AHR) in asthmatic subjects by up-regulating macrophage polarization that leads to excessive secretion of pro-inflammatory adipokines from white adipose tissue followed by generation of oxidative stress in the respiratory system. Treatment through conventional signaling pathways proved to be inadequate in obese asthmatics, so a therapeutical approach through a non-conventional pathway may prove to be effective.

PURPOSE

This study aimed to investigate the efficacy of a FDA-approved food additive, β-caryophyllene (BCP) in obesity-associated AHR.

METHOD

A repertoire of protein expression, cytokine and adiponectin estimation, oxidative stress assays, histopathology, and fluorescence immune-histochemistry were performed to assess the efficacy of BCP in C57BL/6 mice model of obesity-associated AHR. Additionally, human adipocyte was utilized to study the effect of BCP on macrophage polarization in Boyden chamber cell culture inserts.

RESULTS

Obesity-associated AHR is ameliorated by administration of BCP by inhibition of the macrophage polarization by activation of AMPKα, Nrf2/HO-1 and AdipoR1 and AdipoR2 signaling pathway, up-regulation of adiponectin, GLP-1, IFN-γ, SOD, catalase and down-regulation of NF-κB, leptin, IL-4, TNF, and IL-1β. Browning of eWAT by induction of thermogenesis and activation of melanocortin pathway also contributed to the amelioration of obesity-associated AHR. We conclude that BCP ameliorated the obesity-associated AHR via inhibition of macrophage polarization, activation of AMPKα, Nrf2/HO-1, and up-regulation of AdipoR1 and AdipoR2 expression and down-regulation of NFκB expression in lung of animal.

CONCLUSION

Being an FDA-approved food additive, BCP may prove to be a safe and potential agent against obesity-associated AHR.

Diabetes, insulin resistance, and asthma: a review of potential links

PURPOSE OF REVIEW

Disorders of glucose metabolism, including insulin resistance, prediabetes, and diabetes, have been identified as risk factors for worsened asthma. This review summarizes emerging evidence for their role as modifiable risk factors in asthma, including the potential benefit of diabetes medications on asthma outcomes.

RECENT FINDINGS

Experimental studies show that hyperinsulinemia associated with insulin resistance is associated with airway smooth muscle proliferation and promotes contractility. Epidemiologic studies have identified a higher prevalence of glycemic dysfunction among those with severe and uncontrolled asthma, and longitudinal studies have associated prediabetes and diabetes with higher risk of asthma exacerbations. The potential benefits of thiazolidinediones (TZDs), glucagon-like peptide-1 agonists, and metformin being investigated in asthma, but thus far interventional studies of TZDs have reported null results. On the contrary, observational studies have inconsistently controlled for relevant confounders which leaves conclusions vulnerable to misattribution of relationships due to corelated metabolic disorders, including dyslipidemia.

SUMMARY

Developing evidence suggests that disorders of glucose metabolism may be associated with worsening asthma. However, these conditions arise within a network of obesity-related metabolic diseases that may themselves worsen asthma. Few interventional trials have not identified a benefit, but data have been limited. Additional research is needed to define the potential independent impact of disorders of glucose metabolism in asthma.

Cardio-metabolic risk factors during childhood in relation to lung function and asthma

BACKGROUND

Cardio-metabolic risk factors might have an adverse effect on respiratory outcomes, but associations in children are unknown. We aimed to study the longitudinal associations of cardio-metabolic risk factors with lung function and asthma at school age. We also examined whether any association was explained by child's body mass index (BMI).

METHODS

In a population-based cohort study among 4988 children, cardio-metabolic risk factors were measured at 6 and 10 years and included blood pressure, cholesterol, triglycerides, insulin, and C-reactive protein (CRP) concentrations. At age 10 years, lung function was measured by spirometry and current physician-diagnosed asthma was assessed by questionnaire.

RESULTS

After adjustment for confounders, child's BMI, and multiple testing, we observed that a higher diastolic blood pressure at the age of 6 years was associated with a higher forced vital capacity (FVC) at the age of 10 years (Z-score difference (95% CI): 0.05 (0.01, 0.08), per SDS increase in diastolic blood pressure). Also, child's CRP concentrations above the 75th percentile at both ages 6 and 10 years were related to a lower FVC as compared to CRP concentrations below the 75th percentile at both ages (Z-score difference (95% CI) -0.21 (-0.36, -0.06)). No consistent associations of other cardio-metabolic risk factors with respiratory outcomes were observed.

CONCLUSION

Blood pressure and CRP, but not lipids and insulin, were associated with lower lung function but not with asthma. The underlying mechanisms and long-term effects of these associations require further investigation.

Sex, Cells, and Asthma

There are marked sex differences in asthma prevalence and severity. Sex hormones play a central role in these sex biases and directly interact with multiple key cells involved in the pathogenesis of asthma. Here we review the known effects of estrogen, progesterone, and testosterone on airway epithelial cells, airway smooth muscle cells, the mononuclear phagocyte system, innate lymphoid cells, eosinophils, mast cells, T cells, and B cells, all in the context of asthma. Furthermore, we explore unresolved clinical questions, such as the role of sex hormones in the link between asthma and obesity.

A Proteomics-Based Analysis of Blood Biomarkers for the Diagnosis of COPD Acute Exacerbation

Purpose

The identification of blood biomarkers to diagnose acute exacerbation of chronic obstructive pulmonary disease (AECOPD) will have clinical utility. Here, we used a proteomics-based approach to identify biomarkers capable of identifying AECOPD.

Patients and Methods

This prospective, single-center pilot study enrolled 12 patients who came to Asan Medical Center (South Korea) via the outpatient clinic or emergency department with symptoms of AECOPD and were follow-up in the outpatient clinic during convalescence between 2015 and 2017. Paired blood samples collected from each patient during the treatment naïve AECOPD and convalescence stages were analyzed. A sequential window acquisition of all theoretical fragmentation spectra-mass spectrometry (SWATH-MS)-based proteome analysis was performed and a subset of the data were verified by ELISA.

Results

The SWATH-MS analysis identified 226 plasma proteins across all samples examined. The median coefficient of variation for triplicate technical replicates of each sample was 1.13 ± 1.38%, indicating high precision of the technique. Fold-change and paired t-test analyses revealed that 14 proteins were present at higher levels in the AECOPD samples than in the convalescence samples. A gene ontology analysis revealed that these proteins are involved in the acute-phase response. A total of 15 proteins were present at higher levels during the recovery (convalescence) stage than during the acute exacerbation phase, and gene ontology analysis revealed that these proteins are related to lipid metabolism and transport. Verification of the SWATH-MS data was performed using ELISAs for three proteins that were up-regulated in AECOPD, namely, LBP, ORM2, and SERPINA3. Among them, SERPINA3 (p = 0.005) was up-regulated significantly in AECOPD compared with the convalescence state.

Conclusion

Potential plasma biomarkers of AECOPD were discovered using the SWATH-MS proteomics method, and functional molecular associations were investigated. SERPINA3 could be a promising diagnostic biomarker for the early identification and tracking of AECOPD.

Comparison of body composition parameters in the study of the association between body composition and pulmonary function

Background

The excess adiposity, even in the absence of diseases, is responsible for a decline in pulmonary function, which is considered a predictor of mortality and a risk factor for diseases in several epidemiological studies. However, studies on the association between obesity and pulmonary function have found only few associations or inconclusive results. The aim of the study is to evaluate the association between body composition and spirometric parameters, comparing simple obesity measures such as body mass index (BMI) and waist circumference with more precise body composition measurements such as dual-energy X-ray absorptiometry (DXA) and air-displacement plethysmography (BOD POD).

Methods

This is an observational, cross-sectional study that used data from the 1978/79 Ribeirão Preto birth cohort (São Paulo, Brazil). The study included 1746 participants from the 5th follow-up of the cohort. Linear regressions were calculated to evaluate the association between BMI, waist circumference, waist–height ratio (WHtR), BOD POD- and DXA-measured fat mass percentage, and spirometric parameters FEV1, and FVC.

Results

For every 1-kg/m² BMI increase, FVC decreased by 13 ml in males and by 6 ml in females and FEV1 decreased by 11 ml and 5 ml, respectively. Regarding body composition measurements, for a 1% increase in fat mass assessed by BOD POD, FVC decreased by 16 ml in males and by 8 ml in females and FEV1 decreased by 13 ml and 7 ml, respectively. Hence, negative associations between body measurements and FEV1 and FVC were observed in both genders, especially when using the fat mass measurement and were more expressive in men.

Conclusion

The anthropometric and body composition parameters were negatively associated with the spirometric variables FVC and FEV1. We have also observed that simple measures such as waist-height ratio were sufficient to detect the association of body composition with pulmonary function reduction.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01543-1.

Evaluation of the obesity influence on the life quality in patients with bronchial asthma

The obese asthma is characterized by a more severe course. The feature of this comorbid condition is the reduced effectiveness of basic therapy with inhaled corticosteroids, which prevents optimal control of symptoms, requires increasing doses and increases the number of exacerbations and hospitalizations. The problem of life quality (LQ) research in patients with asthma and obesity is highly relevant today, which made it the reason for this study. The aim of the study was to determine the effect of obesity on LQ in patients with asthma. Materials and methods. We selected for participating in the study 46 patients with moderate severity asthma. Examination of the patients included: objective examination with an anthropometric evaluation, the test of the LQ with two questionnaires: general one – Medical Outcome Study SF-36 (MOS SF-36) and specialized Asthma Quality of Life Questionnaire (AQLQ). Results. The increase in body mass index (BMI) in patients with asthma according to the questionnaires MOS SF-36 and AQLQ is associated with significant reductions in viability (r=–0.33, p<0.05), physical activity (r=–0.37, p<0.01), social activity (r=–0.36, p <0.01) and the degree of reduction of the patient's tolerance to adverse environmental factors (r=–0.29, p<0.05) Conclusions. The presence of concomitant obesity in patients with asthma is associated with significant reductions in the parameters of physical and social activity, viability and with an increase in the subjective pain assessment (according to the questionnaire MOS SF-36) and characterized by significantly lower rates of activity, tolerance to adverse environmental factors and general life quality (according to the AQLQ questionnaire).

T2-"Low" Asthma: Overview and Management Strategies

Although the term "asthma" has been applied to all patients with airway lability and variable chest symptoms for centuries, phenotypes of asthma with distinct clinical and molecular features that may warrant different treatment approaches are well recognized. Patients with type 2 (T2)-"high" asthma are characterized by upregulation of T2 immune pathways (ie, IL-4 and IL-13 gene sets) and eosinophilic airway inflammation, whereas these features are absent in patients with T2-"low" asthma and may contribute to poor responsiveness to corticosteroid treatment. This review details definitions and clinical features of T2-"low" asthma, potential mechanisms and metabolic aspects, pediatric considerations, and potential treatment approaches. Priority research questions for T2-"low" asthma are also discussed.

Gestational and Postpartum Weight Trajectories Among Women With and Without Asthma

Asthma leads to increased weight gain in nonpregnant populations, but studies have not examined this association within the context of pregnancy. The association between asthma and perinatal weight trajectories was examined in the Breathe-Wellbeing, Environment, Lifestyle, and Lung Function Study (2015-2019). Multilevel linear spline models were adjusted for age, race/ethnicity, income, marital status, education, cigarette smoking, parity, study site, and prepregnancy body mass index were used to examine differences in perinatal weight trajectories between women with (n = 299) and without (n = 101) asthma. Secondary analyses were conducted to assess whether associations differed by asthma phenotypes. At 40 weeks' gestation, women with asthma gained 16.2 kg (95% confidence interval (CI): 14.6, 17.7) and women without asthma gained 13.1 kg (95% CI: 10.9, 15.4). At 3 months postpartum, women with asthma retained 10.4 kg (95% CI: 8.9, 11.9) and women without asthma retained 8.0 kg (95% CI: 5.9, 10.2). Among women with asthma, exercise-induced asthma and step 3 asthma medications were associated with excess gestational weight gain. These study findings suggest women with asthma gain and retain more weight during pregnancy and postpartum than do women without asthma.

Dietary obesity in mice is associated with lipid deposition and metabolic shifts in the lungs sharing features with the liver

Obesity is associated with both chronic and acute respiratory illnesses, such as asthma, chronic obstructive pulmonary disease (COPD) or increased susceptibility to infectious diseases. Anatomical but also systemic and local metabolic alterations are proposed contributors to the pathophysiology of lung diseases in the context of obesity. To bring perspective to this discussion, we used NMR to compare the obesity-associated metabolomic profiles of the lung with those of the liver, heart, skeletal muscles, kidneys, brain and serum from male C57Bl/6J mice fed with a high-fat and high-sucrose (HFHSD) diet vs. standard (SD) chow for 14 weeks. Our results showed that the lung was the second most affected organ after the liver, and that the two organs shared reduced one-carbon (1C) metabolism and increased lipid accumulation. Altered 1C metabolism was found in all organs and in the serum, but serine levels were increased only in the lung of HFHSD compared to SD. Lastly, tricarboxylic acid (TCA)-derived metabolites were specifically and oppositely regulated in the serum and kidneys but not in other organs. Collectively, our data highlighted that HFHSD induced specific metabolic changes in all organs, the lung being the second most affected organ, the main alterations affecting metabolite concentrations of the 1C pathway and, to a minor extend, TCA. The absolute metabolite quantification performed in this study reveals some metabolic specificities affecting both the liver and the lung, that may reveal common metabolic determinants to the ongoing pathological process.

Association of Triglyceride-Glucose Index and Lung Health: A Population-based Study

BACKGROUND

Metabolic syndrome and insulin resistance are associated with worsened outcomes of chronic lung disease. The triglyceride-glucose index (TyG), a measure of metabolic dysfunction, is associated with metabolic syndrome and insulin resistance, but its relationship to lung health is unknown.

RESEARCH QUESTION

What is the relationship of TyG to respiratory symptoms, chronic lung disease, and lung function?

STUDY DESIGN AND METHODS

This study analyzed data from the National Health and Nutrition Examination Survey from 1999 to 2012. Participants included fasting adults age ≥ 40 years (N = 6,893) with lung function measurements in a subset (n = 3,383). Associations of TyG with respiratory symptoms (cough, phlegm production, wheeze, and exertional dyspnea), chronic lung disease (diagnosed asthma, chronic bronchitis, and emphysema), and lung function (FEV₁, FVC, and obstructive or restrictive spirometry pattern) were evaluated, adjusting for sociodemographic variables, comorbidities, and smoking. TyG was compared vs insulin resistance, represented by the homeostatic model assessment of insulin resistance (HOMA-IR), and vs the metabolic syndrome.

RESULTS

TyG was moderately correlated with HOMA-IR (Spearman ρ = 0.51) and had good discrimination for metabolic syndrome (area under the receiver-operating characteristic curve, 0.80). A one-unit increase in TyG was associated with higher odds of cough (adjusted OR [aOR], 1.28; 95% CI, 1.06-1.54), phlegm production (aOR, 1.20; 95% CI, 1.01-1.43), wheeze (aOR, 1.18; 95% CI, 1.03-1.35), exertional dyspnea (aOR, 1.21; 95% CI, 1.07-1.38), and a diagnosis of chronic bronchitis (aOR, 1.21; 95% CI, 1.02-1.43). TyG was associated with higher relative risk of a restrictive spirometry pattern (adjusted relative risk ratio, 1.45; 95% CI, 1.11-1.90). Many associations were maintained with additional adjustment for HOMA-IR or metabolic syndrome.

INTERPRETATION

TyG was associated with respiratory symptoms, chronic bronchitis, and a restrictive spirometry pattern. Associations were not fully explained by insulin resistance or metabolic syndrome. TyG is a satisfactory measure of metabolic dysfunction with relevance to pulmonary outcomes. Prospective study to define TyG as a biomarker for impaired lung health is warranted.

Asthma Exacerbations in Patients with Type 2 Diabetes and Asthma on Glucagon-like Peptide-1 Receptor Agonists

Rationale: GLP-1R (glucagon-like peptide-1 receptor) agonists are approved to treat type 2 diabetes mellitus and obesity. GLP-1R agonists reduce airway inflammation and hyperresponsiveness in preclinical models.Objectives: To compare rates of asthma exacerbations and symptoms between adults with type 2 diabetes and asthma prescribed GLP-1R agonists and those prescribed SGLT-2 (sodium-glucose cotransporter-2) inhibitors, DPP-4 (dipeptidyl peptidase-4) inhibitors, sulfonylureas, or basal insulin for diabetes treatment intensification.Methods: This study was an electronic health records-based new-user, active-comparator, retrospective cohort study of patients with type 2 diabetes and asthma newly prescribed GLP-1R agonists or comparator drugs at an academic healthcare system from January 2000 to March 2018. The primary outcome was asthma exacerbations; the secondary outcome was encounters for asthma symptoms. Propensity scores were calculated for GLP-1R agonist and non-GLP-1R agonist use. Zero-inflated Poisson regression models included adjustment for multiple covariates.Measurements and Main Results: Patients initiating GLP-1R agonists (n = 448), SGLT-2 inhibitors (n = 112), DPP-4 inhibitors (n = 435), sulfonylureas (n = 2,253), or basal insulin (n = 2,692) were identified. At 6 months, asthma exacerbation counts were lower in persons initiating GLP-1R agonists (reference) compared with SGLT-2 inhibitors (incidence rate ratio [IRR], 2.98; 95% confidence interval [CI], 1.30-6.80), DPP-4 inhibitors (IRR, 2.45; 95% CI, 1.54-3.89), sulfonylureas (IRR, 1.83; 95% CI, 1.20-2.77), and basal insulin (IRR, 2.58; 95% CI, 1.72-3.88). Healthcare encounters for asthma symptoms were also lower among GLP-1R agonist users.Conclusions: Adult patients with asthma prescribed GLP-1R agonists for type 2 diabetes had lower counts of asthma exacerbations compared with other drugs initiated for treatment intensification. GLP-1R agonists may represent a novel treatment for asthma associated with metabolic dysfunction.

Diabetes Mellitus Is Associated with Worse Outcome in Patients Hospitalized for Asthma

BACKGROUND

Asthma is a prevalent disease with a high economic cost. More than 50% of its direct cost relates to asthma hospitalizations. Diabetes mellitus (DM) is a significant comorbidity in asthmatic patients, yet its impact on asthma-related hospitalizations is unknown.

OBJECTIVE

To compare the outcome of asthma-related hospitalizations in patients with and without DM.

METHODS

Using Healthcare Cost and Utilization Project Nationwide Readmissions Database, we analyzed data of all adults with index admission for asthma and with no other chronic pulmonary conditions, and compared outcomes between patients with and without DM. Weighted regression analysis was used to determine the impact of DM on hospitalization outcomes. All multivariate regression models were adjusted for patient demographics, socioeconomic status, and chronic medical comorbidities.

RESULTS

A total of 717,200 asthmatic patients were included, with 202,489 (28.3%) having DM. Diabetic patients were older and had more comorbidities. When hospitalized for asthma, diabetic patients had increased hospital length of stay, cost, and risk for 30-day all-cause and asthma-related readmission. They also had a higher risk for developing nonrespiratory complications during their hospital stay compared with nondiabetic patients. The risk of mortality was similar between the 2 groups.

CONCLUSIONS

Patients hospitalized for asthma with coexisting DM had increased hospital length of stay, cost, and risk for readmission. Interventions are urgently needed to reduce the risk for hospital admission and readmission in patients with coexisting DM and asthma. These interventions would have profound economic and societal impact.

Role of dietary calcium and its possible mechanism against metabolic disorders: A concise review

The global prevalence of metabolic disorders including hypertension, dyslipidemia, insulin resistance, nonalcoholic fatty liver, and cardiovascular diseases seemed to affect people of all ages cutting across the national, economic, and demographic barrier. Therefore, the prevention of metabolic disorders is considered of paramount importance. The dietary role of nutrients including vitamins and minerals is one of the recommended preventive measures against metabolic disorders in modern society. Recently, dietary calcium, a common nutrient not only showed a beneficial effect against obesity through weight management, but also gained great attention against the risk of metabolic disorders. Though dietary calcium shows several beneficial effects against metabolic disorders but some inconsistent results were also reported. So, the present review aims to extract recent knowledge as well as their possible underlying mechanisms regarding the role of dietary calcium against metabolic disorders. The present review also discusses the negative impact as well as prospect of calcium intake on health issues. In summary, high calcium diet prevents the harmful consequences of metabolic disorders by regulating hormonal actions, alteration in intracellular calcium level, renin-angiotensin system, intestinal fat absorption, fecal fat excretion, lipid metabolism, carbohydrate metabolism, inflammation, and oxidative stress which together improve the metabolic health of an individual. PRACTICAL APPLICATIONS: Metabolic disorder is a global health issue across all sections of society and is growing rapidly in spite of several attempts by the scientific community to prevent it. Recently dietary calcium gained great attention in the last few years for its role in the management and treatment of metabolic disorders. The current review highlights the beneficial role of dietary calcium against several metabolic complications by exploring their underlying mechanisms at cellular level. This study will provide valuable information regarding the recommendation of dietary calcium in health policy as well as its inclusion in the dietary chart through calcium-rich foods and/or taking calcium supplements which can be a useful approach in preventing the risk of metabolic disorder depending on the health status of an individual.

Dietary Carbohydrates and Fat Induce Distinct Surfactant Alterations in Mice

Obesity and type 2 diabetes are nutrition-related conditions associated with lung function impairment and pulmonary diseases; however, the underlying pathomechanisms are incompletely understood. Pulmonary surfactant is essential for lung function, and surfactant synthesis by AT2 (alveolar epithelial type 2) cells relies on nutrient uptake. We hypothesized that dietary amounts of carbohydrates or fat affect surfactant homeostasis and composition. Feeding mice a starch-rich diet (StD), sucrose-rich diet (SuD), or fat-rich diet (FaD) for 30 weeks resulted in hypercholesterolemia and hyperinsulinemia compared with a fiber-rich control diet. In SuD and FaD groups, lung mechanic measurements revealed viscoelastic changes during inspiration, indicating surfactant alterations, and interfacial adsorption of isolated surfactant at the air-liquid interface was decreased under FaD. The composition of characteristic phospholipid species was modified, including a shift from dipalmitoyl-phosphatidylcholine (PC16:0/16:0) to palmitoyl-palmitoleoyl-phosphatidylcholine (PC16:0/16:1) in response to carbohydrates and decreased myristic acid-containing phosphatidylcholine species (PC14:0/14:0; PC16:0/14:0) on excess fat intake, as well as higher palmitoyl-oleoyl-phosphatidylglycerol (PG16:0/18:1) and palmitoyl-linoleoyl-phosphatidylglycerol (PG16:0/18:2) fractions in StD, SuD, and FaD groups than in the control diet. Moreover, mRNA expression levels of surfactant synthesis-related proteins within AT2 cells were altered. Under the StD regimen, AT2 cells showed prominent lipid accumulations and smaller lamellar bodies. Thus, in an established mouse model, distinct diet-related surfactant alterations were subtle, yet detectable, and may become challenging under conditions of reduced respiratory capacity. Dietary fat was the only macronutrient significantly affecting surfactant function. This warrants future studies examining alimentary effects on lung surfactant, with special regard to pulmonary complications in obesity and type 2 diabetes.

Multimorbidity clusters in patients with chronic obstructive airway diseases in the EpiChron Cohort

Chronic obstructive airway diseases such as chronic obstructive pulmonary disease (COPD), asthma, rhinitis, and obstructive sleep apnea (OSA) are amongst the most common treatable and preventable chronic conditions with high morbidity burden and mortality risk. We aimed to explore the existence of multimorbidity clusters in patients with such diseases and to estimate their prevalence and impact on mortality. We conducted an observational retrospective study in the EpiChron Cohort (Aragon, Spain), selecting all patients with a diagnosis of allergic rhinitis, asthma, COPD, and/or OSA. The study population was stratified by age (i.e., 15-44, 45-64, and ≥ 65 years) and gender. We performed cluster analysis, including all chronic conditions recorded in primary care electronic health records and hospital discharge reports. More than 75% of the patients had multimorbidity (co-existence of two or more chronic conditions). We identified associations of dermatologic diseases with musculoskeletal disorders and anxiety, cardiometabolic diseases with mental health problems, and substance use disorders with neurologic diseases and neoplasms, amongst others. The number and complexity of the multimorbidity clusters increased with age in both genders. The cluster with the highest likelihood of mortality was identified in men aged 45 to 64 years and included associations between substance use disorder, neurologic conditions, and cancer. Large-scale epidemiological studies like ours could be useful when planning healthcare interventions targeting patients with chronic obstructive airway diseases and multimorbidity.

Metabolomics: small molecules that matter more

Metabolomics, an analytical study with high-throughput profiling, helps to understand interactions within a biological system. Small molecules, called metabolites or metabolomes with the size of <1500 Da, depict the status of a biological system in a different manner. Currently, we are in need to globally analyze the metabolome and the pathways involved in healthy, as well as diseased conditions, for possible therapeutic applications. Metabolome analysis has revealed high-abundance molecules during different conditions such as diet, environmental stress, microbiota, and disease and treatment states. As a result, it is hard to understand the complete and stable network of metabolites of a biological system. This review helps readers know the available techniques to study metabolomics in addition to other major omics such as genomics, transcriptomics, and proteomics. This review also discusses the metabolomics in various pathological conditions and the importance of metabolomics in therapeutic applications.

Particulate matter inhalation and the exacerbation of cardiopulmonary toxicity due to metabolic disease

Particulate matter is a significant public health issue in the United States and globally. Inhalation of particulate matter is associated with a number of systemic and organ-specific adverse health outcomes, with the pulmonary and cardiovascular systems being particularly vulnerable. Certain subpopulations are well-recognized as being more susceptible to inhalation exposures, such as the elderly and those with pre-existing respiratory disease. Metabolic syndrome is becoming increasingly prevalent in our society and has known adverse effects on the heart, lungs, and vascular systems. The limited evaluations of individuals with metabolic syndromehave demonstrated that theymay compose a sensitive subpopulation to particulate exposures. However, the toxicological mechanisms responsible for this increased vulnerability are not fully understood. This review evaluates the currently available literature regarding how the response of an individual's pulmonary and cardiovascular systems is influenced by metabolic syndrome and metabolic syndrome-associated conditions such as hypertension, dyslipidemia, and diabetes. Further, we will discuss potential therapeutic agents and targets for the alleviation and treatment of particulate-matter induced metabolic illness. The information reviewed here may contribute to the understanding of metabolic illness as a risk factor for particulate matter exposure and further the development of therapeutic approaches to treat vulnerable subpopulations, such as those with metabolic diseases.

Comorbidities in psoriatic arthritis: a systematic review and meta-analysis

The aims of this systematic review and meta-analysis were to: (1) describe the prevalence of commonly reported comorbidities in psoriatic arthritis (PsA), (2) compare the incidence and/or prevalence of comorbidities between PsA and control populations; and (3) examine the impact of comorbidities on PsA outcomes. We systematically searched Medline, PubMed, Scopus, and Web of Science using a predefined protocol in accordance with PRISMA guidelines. Studies reporting only one comorbidity, or a few closely related diseases within one organ system, were excluded. Where possible, meta-analysis was performed using random-effects models. We included 39 studies amounting to over 152 thousand PsA patients. We performed meta-analysis for the prevalence of 21 commonly reported comorbidities. The most prevalent comorbidities were hypertension (pooled prevalence 34%), metabolic syndrome (29%), obesity (27%), hyperlipidaemia (24%) and any cardiovascular diseases (19%). Eleven studies consistently showed higher prevalence of comorbidities in PsA than controls. Five studies showed that comorbid patients had more severe disease, poorer quality of life, and increased discontinuation of treatment. Comorbidities, particularly cardiometabolic disorders, were highly prevalent in PsA and more common than in healthy controls. Comorbidities were associated with adverse disease features, but more research is needed on their impact on longitudinal outcomes such as treatment response, work productivity and mortality.

Metabolic associated fatty liver disease increases coronavirus disease 2019 disease severity in nondiabetic patients

BACKGROUND AND AIM

Coronavirus disease 2019 (COVID-19) has attracted increasing worldwide attention. While diabetes is known to aggravate COVID-19 severity, it is not known whether nondiabetic patients with metabolic dysfunction are also more prone to more severe disease. The association of metabolic associated fatty liver disease (MAFLD) with COVID-19 severity in nondiabetic patients was investigated here.

METHODS

The study cohort comprised 65 patients with (i.e. cases) and 65 patients without MAFLD (i.e. controls). Each case was randomly matched with one control by sex (1:1) and age (±5 years). The association between the presence of MAFLD (as exposure) and COVID-19 severity (as the outcome) was assessed by binary logistic regression analysis.

RESULTS

In nondiabetic patients with COVID-19, the presence of MAFLD was associated with a four-fold increased risk of severe COVID-19; the risk increased with increasing numbers of metabolic risk factors. The association with COVID-19 severity persisted after adjusting for age, sex, and coexisting morbid conditions.

CONCLUSION

Health-care professionals caring for nondiabetic patients with COVID-19 should be cognizant of the increased likelihood of severe COVID-19 in patients with MAFLD.

Relationships between body composition and pulmonary function in a community-dwelling population in Japan

Pulmonary diseases, including chronic obstructive pulmonary disease (COPD), are major chronic diseases that result in decreased pulmonary function. Relationships between body composition and pulmonary function have been reported. However, few epidemiological studies have used the visceral fat area (VFA) to measure body composition. This study aimed to examine the relationship between body composition and pulmonary function. A cross-sectional study was conducted between 2015 and 2016, using data obtained from 1,287 residents aged between 19 and 91 years living in the Iwaki area of Hirosaki City, a rural region in Aomori Prefecture, Japan. Pulmonary function was evaluated using the forced vital capacity (FVC) as a percentage of the predicted value (predicted FVC%) and the ratio of forced expiratory volume in one second (FEV1) to FVC. The measurements for evaluating body composition included the body fat percentage (BFP) of the whole body and trunk, skeletal muscle index (SMI), body mass index (BMI), VFA, waist circumference (WC) at the navel level, and waist-to-hip ratio (WHR). To adjust for potential confounders, Spearman's partial correlation analysis was used to examine the relationship between the measurements of body composition and pulmonary function. There were significant correlations between the predicted FVC% and the following parameters: BFP (whole body and trunk) in younger males; SMI in older males; WC, VFA, BMI, and SMI in younger females; and BFP (whole body and trunk) and VFA in older females. Contrastingly, WC and VFA in younger males and WC in younger females were correlated with the FEV1/FVC ratio. VFA was correlated with the FEV1/FVC ratio in younger males and predicted FVC% in older females. These findings suggest that visceral fat accumulation may increase the development of obstructive pulmonary disease in young males and accelerate the decline of pulmonary function (predicted FVC%) in older females.

Metabolic Syndrome and Incident Asthma in Chinese Adults: An Open Cohort Study

BACKGROUND

Although metabolic syndrome is awell-known risk factor for many non-communicable diseases, its contribution to asthma remains controversial.

OBJECTIVE

The aim of this study was to explore the associations of metabolic syndrome and its components with incident asthma in Chinese adults.

METHODS

We conducted an open cohort study of participants who were asthma-free at baseline (n=42,304) in the Shandong multi-center health check-up longitudinal study from 2004 to 2015. Participants aged ≥20 years and had regular physical examination (once ayear) more than three times during follow-up.

RESULTS

Ninety subjects (38 women and 52 men) developed incident asthma over 12 years of follow-up. Our study suggested that metabolic syndrome itself was not significantly associated with incident asthma in either women or men (P>0.050). Interestingly, we found that overweight and/or obesity was arisk factor for incident asthma among women but not men in the Cox proportional hazards model after adjusting covariates (adjusted incidence rate ratio (IRR)= 2.940, 95% confidence interval (CI): 1.467-5.894, P=0.002). The result was consistent with the Poisson regression model (hazard ratio (HR)= 2.241, 95% CI: 1.135-4.988, P=0.026). After stratifying according to overweight and/or obesity, we found that female subjects with overweight and obesity were associated with the occurrence of incident asthma (P<0.050). However, we did not find this result among men.

CONCLUSION

Metabolic syndrome was not significantly associated with incident asthma in both women and men; however, overweight and/or obesity was shown to be asignificant risk factor for incident asthma but only in women, not in men.

Poor Sleep Quality Decreases Concurrent Training Benefits in Markers of Metabolic Syndrome and Quality of Life of Morbidly Obese Patients

Background: Sleep quality (SQ) plays a role in multiple activities of daily living, but little is known about its role in concurrent training [CT, high-intensity interval (HIIT) plus resistance training (RT)] adaptations for metabolic syndrome (MetS) and health-related quality of life (HRQoL) markers. The aim of the present study was to determine the effects of a 20-week CT programme on MetS and HRQoL markers according to the SQ of morbidly obese patients. Methods: Twenty-nine morbidly obese patients were allocated to one of two groups: good sleep quality (GSQ, n = 15, 38.07 ± 12.26 years) and poor sleep quality (PSQ, n = 14, 40.79 ± 11.62 years). HRQoL, body mass index, waist circumference (WC), systolic and diastolic blood pressure (SBP and DBP, respectively), and plasma outcomes were measured. Results: The GSQ group reported significant changes (pre- vs. post-intervention) in WC (114.0 ± 3.1 vs. 110.4 ± 3.4 cm, p = 0.012), SBP (137.0 ± 4.3 vs. 125.6 ± 1.8 mmHg, p = 0.006), and HRQoL general health (51.33 ± 21.08 vs. 64.33 ± 16.24, p = 0.020). By contrast, the PSQ group showed significant changes only in SQ (9.00 ± 2.42 vs. 5.36 ± 2.84, p = 0.004). Conclusions: Morbidly obese PSQ patients showed a lower response for improving MetS and HRQoL markers after a 20-week CT programme than GSQ peers. However, there was a greater effect size for decreasing WC and SBP in favour of the GSQ compared with the PSQ group, suggesting that there are limitations to CT benefits on these outcomes in the PSQ group. These results call for more complex future studies.

Effects of peripheral and different inspiratory muscle training methods in coronary artery disease patients with metabolic syndrome: A randomized-controlled trial

Background OBJECTIVE: To investigate the effects of peripheral muscle training (PMT) and different inspiratory muscle training (IMT) methods on respiratory functions, exercise capacity, and biochemistry parameters in coronary artery disease patients with metabolic syndrome.

METHODS

This prospective, single-blind, randomized-controlled study included 60 patients of stable coronary artery disease with metabolic syndrome (New York Heart Association [NYHA] Class I-II, left ventricular ejection fraction >40%). Patients were randomly divided into three groups: neuromuscular electrical stimulation (NMES) plus PMT group (NMES + PMT group, n = 20), IMT plus PMT group (IMT + PMT group, n = 20) and PMT group (PMT group, n = 20). Treatment continued for six weeks for all groups. The NMES was applied to rectus abdominis, IMT was applied with 30% of maximal inspiratory pressures, and PMT was applied at home. Spirometry, maximal inspiratory and expiratory pressure, dyspnea scores, exercise stress test, and biochemistry parameters were measured before and after training.

RESULTS

There were significant improvements in spirometric tests, respiratory muscle strength, dyspnea scores, exercise capacity, fasting blood glucose, and antistreptolysin O after treatment in all groups (p < 0.05). Significant improvements in C-reactive protein and erythrocyte sedimentation rate were observed in NMES + PMT and IMT + PMT groups (p < 0.05). Among the groups, there was a significant difference in maximal inspiratory pressure (p = 0.02) and erythrocyte sedimentation rate (p = 0.037) in favor of NMES + PMT group (p < 0.05).

CONCLUSION

Our study results showed significant improvements in respiratory functions, exercise capacity, and biochemistry markers in all groups. Different IMT methods can be used in cardiopulmonary rehabilitation to improve exercise intolerance in coronary artery disease patients with metabolic syndrome.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03523026.

Exploring New Therapeutic Pathways in Pulmonary Hypertension. Metabolism, Proliferation, and Personalized Medicine

In this review, we explore the main themes from the 62nd Annual Aspen Lung Conference (hypoxia, cellular metabolism, inflammatory pathways, aberrant proliferation, and personalized medicine) and highlight challenges and opportunities in the coming decade of pulmonary vascular disease.

Association of Metformin Use with Asthma Exacerbation in Patients with Concurrent Asthma and Diabetes: A Systematic Review and Meta-Analysis of Observational Studies

Background

Asthma and diabetes are both diseases that affect a wide range of people worldwide. As a common treatment for diabetes, metformin has also been reported to be effective in improving asthma outcomes. We conducted a combined analysis to examine the efficacy of metformin in reducing asthma exacerbation in patients with concurrent asthma and diabetes.

Methods

We searched the PubMed, Embase, and CENTRAL databases for articles published prior to April 2020 to find observational studies of individuals with concurrent asthma and diabetes that compared the risk of asthma exacerbation between metformin users and nonusers. Two researchers separately screened the studies, extracted data, and evaluated the risk of bias. The primary outcome was the adjusted risk of asthma exacerbation. The secondary outcomes were the adjusted risk of asthma-related hospitalization and emergency room visits. Review Manager was used for data analysis and plotting. I² and χ² tests were used to estimate heterogeneity. A random effects or fixed effects model was used depending on the heterogeneity. Odds ratios were calculated for dichotomous variables.

Results

We included two studies with a total of 25252 patients. The pooled effect size showed that metformin was inversely associated with a risk of asthma exacerbation (OR = 0.65, 95% CI 0.28–1.48; χ² = 5.42, P=0.02; I² = 82%), asthma-related emergency department visits (OR = 0.81, 95% CI 0.74–0.89; χ² = 0.36, P=0.55; I² = 0%), and hospitalizations (OR = 0.43, 95% CI 0.14–1.29; χ² = 4.01, P=0.05; I² = 75%).

Conclusion

This meta-analysis suggested that metformin decreased the risk of asthma-related emergency room visits for patients with concurrent asthma and diabetes. Metformin reduced the risk of asthma-related hospitalization and exacerbation but was not statistically significant. More randomized trials involving larger samples should be considered, and the mechanisms of these effects need to be fully elucidated.

Indicators of metabolic syndrome in normotensive normoglycemic asthmatic patients

BACKGROUND

Pathophysiology of hypertension and bronchial asthma (BA) shares many similarities, especially those related to the metabolic syndrome (MS).

AIM

In this study, the indicators of the MS were evaluated in normoglycemic normotensive asthmatic patients to clarify if the components of the MS can still interact to increase the risk of BA, provided that blood pressure and glucose level are kept within the normal physiological ranges.

METHODS

Body mass index (BMI), waist circumference (WC), mean arterial blood pressure (MABP), fasting blood glucose (FBG) and fasting blood insulin (FBI) levels, the quantitative insulin sensitivity check index (QUICKI), serum lipid profile, and spirometric measurements were all compared between 120 asthmatic patients and 59 non-asthmatic subjects. Cigarette smoking, pregnancy, age below 20 years or above 40 years, diabetes mellitus and hypertension, and other chronic diseases were excluded from all studied groups.

RESULTS

Asthmatic patients demonstrated higher WC (median [25th-75th interquartile]=88.50 [78.00-101.75], FBI [19.98 (11.12-40.14)], and triglyceride (TG) level [109.5 (76.50-134.0)]) compared with non-asthmatic subjects (81.00 [72.00-92.00], 13.78 [8.84-30.24], and 89.00 [64.25-104], P<0.05). QUICKI and MABP were lower in asthmatic patients (0.310 [0.283-0.338] and 86.66 [83.33-93.33]) compared with non-asthmatic subjects (0.320 [0.297-0.353] and 93.33 [83.33-93.33]), (P<0.05). BMI, FBG, low-density lipoprotein, high-density lipoprotein, and total cholesterol levels were comparable in the studied groups.

CONCLUSIONS

The present finding gives further evidence for higher WC, FBI, TG level, and insulin resistance in normotensive, normoglycemic asthmatic patients compared to healthy controls.

RELEVANCE FOR PATIENTS

The findings of this study suggested that abdominal obesity, hypertriglyceridemia, hyperinsulinemia, and insulin resistance may still be interacting and hence increase the risk of BA in normotensive, normoglycemic subjects.

Role of DNA methylation in the association of lung function with body mass index: a two-step epigenetic Mendelian randomisation study

BACKGROUND

Low lung function has been associated with increased body mass index (BMI). The aim of this study was to investigate whether the effect of BMI on lung function is mediated by DNA methylation.

METHODS

We used individual data from 285,495 participants in four population-based cohorts: the European Community Respiratory Health Survey, the Northern Finland Birth Cohort 1966, the Swiss Study on Air Pollution and Lung Disease in Adults, and the UK Biobank. We carried out Mendelian randomisation (MR) analyses in two steps using a two-sample approach with SNPs as instrumental variables (IVs) in each step. In step 1 MR, we estimated the causal effect of BMI on peripheral blood DNA methylation (measured at genome-wide level) using 95 BMI-associated SNPs as IVs. In step 2 MR, we estimated the causal effect of DNA methylation on FEV1, FVC, and FEV1/FVC using two SNPs acting as methQTLs occurring close (in cis) to CpGs identified in the first step. These analyses were conducted after exclusion of weak IVs (F statistic < 10) and MR estimates were derived using the Wald ratio, with standard error from the delta method. Individuals whose data were used in step 1 were not included in step 2.

RESULTS

In step 1, we found that BMI might have a small causal effect on DNA methylation levels (less than 1% change in methylation per 1 kg/m2 increase in BMI) at two CpGs (cg09046979 and cg12580248). In step 2, we found no evidence of a causal effect of DNA methylation at cg09046979 on lung function. We could not estimate the causal effect of DNA methylation at cg12580248 on lung function as we could not find publicly available data on the association of this CpG with SNPs.

CONCLUSIONS

To our knowledge, this is the first paper to report the use of a two-step MR approach to assess the role of DNA methylation in mediating the effect of a non-genetic factor on lung function. Our findings do not support a mediating effect of DNA methylation in the association of lung function with BMI.

Spermidine supplementation and voluntary activity differentially affect obesity-related structural changes in the mouse lung

Obesity is associated with lung function impairment and respiratory diseases; however, the underlying pathophysiological mechanisms are still elusive, and therapeutic options are limited. This study examined the effects of prolonged excess fat intake on lung mechanics and microstructure and tested spermidine supplementation and physical activity as intervention strategies. C57BL/6N mice fed control diet (10% fat) or high-fat diet (HFD; 60% fat) were left untreated or were supplemented with 3 mM spermidine, had access to running wheels for voluntary activity, or a combination of both. After 30 wk, lung mechanics was assessed, and left lungs were analyzed by design-based stereology. HFD exerted minor effects on lung mechanics and resulted in higher body weight and elevated lung, air, and septal volumes. The number of alveoli was higher in HFD-fed animals. This was accompanied by an increase in epithelial, but not endothelial, surface area. Moreover, air-blood barrier and endothelium were significantly thicker. Neither treatment affected HFD-related body weights. Spermidine lowered lung volumes as well as endothelial and air-blood barrier thicknesses toward control levels and substantially increased the endothelial surface area under HFD. Activity resulted in decreased volumes of lung, septa, and septal compartments but did not affect vascular changes in HFD-fed mice. The combination treatment showed no additive effect. In conclusion, excess fat consumption induced alveolar capillary remodeling indicative of impaired perfusion and gas diffusion. Spermidine alleviated obesity-related endothelial alterations, indicating a beneficial effect, whereas physical activity reduced lung volumes apparently by other, possibly systemic effects.

Coronavirus Disease (COVID-19-SARS-CoV-2) and Nutrition: Is Infection in Italy Suggesting a Connection?

Novel coronavirus disease (COVID-19) was declared a global pandemic on March 11, 2020. The outbreak first occurred in Wuhan, Hubei, China, in December 2019 and hit Italy heavily in February 2020. Several countries are adopting complete or partial lockdown to contain the growth of COVID-19 infection. These measures may affect people's mental health and well-being but are necessary to avoid spreading the pandemic. There has been a gradual increase in studies exploring prevention and control measures, and we recommend paying close attention to nutrition, which may contribute to modulating some important consequences of COVID-19 infection, as such pro-inflammatory cytokine storm.

Waist to Height Ratio and Metabolic Syndrome as lung dysfunction predictors

Metabolic Syndrome (MetS) has been related to pulmonary diseases but its relationship with lung age has not been sufficiently studied. In addition, anthropometric variables have been associated with pulmonary dysfunction, highlighting the waist-to-height ratio (WHtR). The aim was to evaluate the relationship between MetS and: lung age, anthropometric variables and the alteration of lung function. A cross-sectional study was carried out in 1901 workers, evaluating lung function through lung age (Morris & Temple equation) and spirometric values. The diagnosis of MetS was based on the harmonized criteria. We measured anthropometric variables (WHtR, waist circumference, body mass index, waist to hip ratio), blood pressure and biochemical variables (glucose, cholesterol total, HDL, triglycerides). Workers suffering from MetS showed an accelerated lung aging (59.4 ± 18.7 years vs 49 ± 18.4 years). The WHtR ≥ 0.55 was significantly related to an increase in lung age (β = 6.393, p < 0.001). In addition, a significant linear trend was found between clinical categories of WHtR and lung dysfunction, restrictive and mixed pattern. MetS caused an accelerated lung aging and favored the presence of restrictive lung impairment. In addition, WHtR ≥ 0.55 has been shown as the best predictor for pulmonary health.

Metabolic profiles among COPD and controls in the CanCOLD population-based cohort

A high prevalence of intermediate cardiometabolic risk factors and obesity in chronic obstructive pulmonary disease (COPD) has suggested the existence of pathophysiological links between hypertriglyceridemia, insulin resistance, visceral adiposity, and hypoxia or impaired pulmonary function. However, whether COPD contributes independently to the development of these cardiometabolic risk factors remains unclear. Our objective was to compare ectopic fat and metabolic profiles among representative individuals with COPD and control subjects and to evaluate whether the presence of COPD alters the metabolic risk profile. Study participants were randomly selected from the general population and prospectively classified as non-COPD controls and COPD, according to the Global Initiative for Chronic Obstructive Lung Disease classification. The metabolic phenotype, which consisted of visceral adipose tissue area, metabolic markers including homeostasis model assessment of insulin resistance (HOMA-IR), and blood lipid profile, was obtained in 144 subjects with COPD and 119 non-COPD controls. The metabolic phenotype was similar in COPD and controls. The odds ratios for having pathologic values for HOMA-IR, lipids and visceral adipose tissue area were similar in individuals with COPD and control subjects in multivariate analyses that took into account age, sex, body mass index, tobacco status and current medications. In a population-based cohort, no difference was found in the metabolic phenotype, including visceral adipose tissue accumulation, between COPD and controls. Discrepancies between the present and previous studies as to whether or not COPD is a risk factor for metabolic abnormalities could be related to differences in COPD phenotype or disease severity of the study populations.

Body mass index and weight change are associated with adult lung function trajectories: the prospective ECRHS study

BACKGROUND

Previous studies have reported an association between weight increase and excess lung function decline in young adults followed for short periods. We aimed to estimate lung function trajectories during adulthood from 20-year weight change profiles using data from the population-based European Community Respiratory Health Survey (ECRHS).

METHODS

We included 3673 participants recruited at age 20-44 years with repeated measurements of weight and lung function (forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1)) in three study waves (1991-93, 1999-2003, 2010-14) until they were 39-67 years of age. We classified subjects into weight change profiles according to baseline body mass index (BMI) categories and weight change over 20 years. We estimated trajectories of lung function over time as a function of weight change profiles using population-averaged generalised estimating equations.

RESULTS

In individuals with normal BMI, overweight and obesity at baseline, moderate (0.25-1 kg/year) and high weight gain (>1 kg/year) during follow-up were associated with accelerated FVC and FEV1 declines. Compared with participants with baseline normal BMI and stable weight (±0.25 kg/year), obese individuals with high weight gain during follow-up had -1011 mL (95% CI -1.259 to -763) lower estimated FVC at 65 years despite similar estimated FVC levels at 25 years. Obese individuals at baseline who lost weight (<-0.25 kg/year) exhibited an attenuation of FVC and FEV1 declines. We found no association between weight change profiles and FEV1/FVC decline.

CONCLUSION

Moderate and high weight gain over 20 years was associated with accelerated lung function decline, while weight loss was related to its attenuation. Control of weight gain is important for maintaining good lung function in adult life.

Metabolic syndrome is associated with better quality of sleep in the oldest old: results from the "Mugello Study"

BACKGROUND AND AIMS

Reduced sleep quality is common in advanced age. Poor sleep quality is associated with adverse outcomes, chiefly cardiovascular, in young and middle-aged subjects, possibly because of its association with metabolic syndrome (MetS). However, the correlates of sleep quality in oldest populations are unknown. We evaluated the association of sleep quality with MetS in a cohort of subjects aged 90+.

METHODS AND RESULTS

We analysed data of 343 subjects aged 90+ living in the Mugello area (Tuscany, Italy). Quality of sleep was assessed using the Pittsburgh Sleep Quality Assessment Index (PSQI). Good quality of sleep was defined by a PSQI score < 5. MetS was diagnosed according to the National Cholesterol Education Program's ATP-III criteria; 83 (24%) participants reported good quality of sleep. MetS was diagnosed in 110 (24%) participants. In linear and logistic models, MetS was inversely associated with PSQI score ((B = - 1.04; 95% CI - 2.06 to - .03; P = .044), with increased probability of good sleep quality (OR = 2.52; 95% CI 1.26-5.02; P = .009), and with a PSQI below the median (OR = 2.11; 95% CI 1.11-3.40, P = .022), after adjusting. None of the single components of MetS were associated with PSQI (all P values > .050). However, an increasing number of MetS components was associated with increasing probability of good quality of sleep (P for trend = .002), and of PSQI below the median (P for trend = .007). Generalized Additive Model analysis documented no smoothing function suggestive of nonlinear association between PSQI and MetS.

CONCLUSION

Our results confirm a high prevalence of poor sleep quality in oldest age; however, in these subjects, MetS seems to be associated with better sleep quality. Additional larger, dedicated studies are required to confirm our results, and, if so, to identify the subsystems involved and the potential therapeutic implications of such an association.

Contemporary management techniques of asthma in obese patients

Introduction: Obesity-associated asthma represents a heterogeneous group of clinical phenotypes, including an adult-onset phenotype. These patients often have difficult to control symptoms and often are less likely to respond to conventional asthma therapies.Areas covered: This review covers the effects of lifestyle interventions, including diet and weight loss, effect asthma outcomes and how obesity-associated asthma responds to conventional approaches to asthma management.Expert opinion: Management of obesity-associated asthma should include lifestyle modifications aimed at weight reduction, management of other co-morbidities, and limiting systemic steroids. As many of these patients have non-Th2 asthma, long-acting muscarinic antagonists and macrolides may be potentially helpful. Medications to treat metabolic syndrome.

Metabolic Syndrome in Early Chronic Obstructive Pulmonary Disease: Gender Differences and Impact on Exacerbation and Medical Costs

Background

Metabolic syndrome (MetS) is a well-known comorbidity of chronic obstructive pulmonary disease (COPD). However, their interrelationship, particularly in early COPD, remains unclear. Therefore, we aimed to assess the prevalence and clinical characteristics of MetS in patients with early COPD, and to explore the impact of MetS on the frequency of COPD exacerbations and associated medical costs.

Patients and methods

We retrospectively enrolled 43,874 subjects from the KNHANES, including 2164 patients with early COPD (≥40 years old), recorded smoking history, and Global Initiative for Chronic Obstructive Lung Disease spirometric grade I or II, with data linked to the NHI database. We extracted and analyzed data regarding health-care utilization and medical costs for 5 years (2007 to 2012).

Results

Among 2164 patients with early COPD, the prevalence of MetS was 31.2%, and it was higher in women than in men (35.1% vs. 26.6%; P<0.001). Patients with MetS were older and had lower pulmonary function and greater number of comorbidities. The frequency of moderate-to-severe COPD exacerbations for 5 years was significantly higher in women with MetS than in those without MetS (5.8/year vs. 4.9/year; P=0.02). After adjusting for confounding factors, the risk for moderate-to-severe exacerbation was significantly greater in women with MetS (IRR, 1.17; 95% CI, 1.01 to 1.36; P=0.03). COPD exacerbations leading to hospitalization and medical expenses were also higher in women with MetS than in those without MetS.

Conclusion

MetS is more prevalent in women with early COPD. MetS increased the frequency of exacerbations and the medical costs in women with early COPD.

Preventing metabolic syndrome in morbid obesity with resistance training: Reporting interindividual variability

BACKGROUND AND AIMS

Resistant training (RT) improves health markers in obesity, but its effects in morbid obesity are unknown. We aimed to determine the effects of a RT-program in preventing/attenuating the metabolic syndrome (MetS) in patients with morbid obesity. A second aim was to report the interindividual variability in terms of improvements in MetS markers and other related co-variables.

METHODS AND RESULTS

Twenty-one adults with obesity or morbid obesity were divided into two groups based on body mass index (BMI): a control obesity (CO, n = 7, BMI ≥35 < 40.0 kg/m²) and a morbid obese group (MO, n = 14, BMI ≥40 kg/m²). Participants completed a 20-week RT-program (3 sessions/week, 4-8 exercise) using free weights. Participants were assessed for MetS markers (waist circumference, systolic and diastolic blood pressure [BP], fasting glucose, high-density lipoproteins, and triglycerides) and other co-variables (total cholesterol, low-density lipoprotein, one-maximum repetition of biceps curl, and handgrip strength, 6 min walking test). Significant reductions in MetS markers were observed in both CO and MO groups (P < 0.05 to P < 0.0001), but significant reductions in diastolic BP and increases in HDL-C were noted only in the MO group (P < 0.0001). Changes in waist circumference, and systolic and diastolic BP were significantly greater only in the MO group (P < 0.001), but the CO group presented a greater fasting glucose decreases (P < 0.0001). The prevalence of non-responders between CO and MO groups was similar in the MetS outcomes.

CONCLUSIONS

RT promotes greater improvements in overall MetS outcomes waist circumference, BP, and plasma triglycerides in patients with morbid obesity than in obese peers, with no overall differences in the prevalence of non-responders.

CLINICAL TRIAL NUMBER

NCT03921853 at www.clinicaltrials.gov.

Validation of Predictive Metabolic Syndrome Biomarkers of World Trade Center Lung Injury: A 16-Year Longitudinal Study

BACKGROUND

Metabolic syndrome (MetSyn) predicted future development of World Trade Center lung injury (WTC-LI) in a subgroup of firefighters who never smoked and were male. An intracohort validation of MetSyn as a predictor of WTC-LI is examined in the cohort exposed to the World Trade Center (WTC) that has been followed longitudinally for 16 years.

METHODS

Results of pulmonary function tests (n = 98,221) in workers exposed to the WTC (n = 9,566) were evaluated. A baseline cohort of firefighters who had normal FEV1 before 9/11 and who had had serum drawn before site closure on July 24, 2002 (n = 7,487) was investigated. Case subjects with WTC-LI (n = 1,208) were identified if they had at least two measured instances of FEV1 less than the lower limit of normal (LLN). Cox proportional hazards modeled early MetSyn biomarker ability to predict development of FEV1 less than the LLN.

RESULTS

Case subjects were more likely to smoke, be highly exposed, and have MetSyn. There was a significant exposure dose response; the individuals most highly exposed had a 30.1% increased risk of developing WTC-LI, having MetSyn increased risk of developing WTC-LI by 55.7%, and smoking increased risk by 15.2%. There was significant interaction between smoking and exposure.

CONCLUSIONS

We validated the usefulness of MetSyn to predict future WTC-LI in a larger population of individuals who were exposed. MetSyn defined by dyslipidemia, insulin resistance, and cardiovascular disease suggests that systemic inflammation can contribute to future lung function loss.

MIF signaling blocking alleviates airway inflammation and airway epithelial barrier disruption in a HDM-induced asthma model

Recent studies have indicated that Macrophage migration inhibitory factor (MIF) plays an important role in the prevention and treatment of asthma. However the role of MIF in airway inflammation and airway epithelial barrier disruption in house dust mite (HDM)-induced asthma has not been addressed. We hypothesized that MIF contributed to HDM-induced the production of Th2-associated cytokines and E-cadherin dysfunction in asthmatic mice and 16HBE cells. In vivo, a HDM-induced asthma mouse model was set up and mice treated with MIF antagonist ISO-1 after HDM. The mice treated with the ISO-1 ameliorated airway hyper-reactivity, airway inflammation, increased serum IgE levels, the aberrant arrangement of E-cadherin as well as the release of Th2 cytokines induced by HDM. In vitro, the exposure of 16HBE cells to HDM and rhMIF resulted in airway epithelial barrier disruption, inflammatory cytokine production and enhanced glycolytic flux. While these changes were attenuated by MIF siRNA treatment. Sequentially, treatment of 16HBE cells with PFKFB3 antagonist PFK15 significantly lowered rhMIF-induced these changes in 16HBE cells. Therefore, these results indicate that MIF may be an important contributor in airway inflammation and airway epithelial barrier disruption of HDM-induced asthma. Moreover, HDM specifically induces airway inflammation and airway epithelial barrier disruption of 16HBE cells through MIF-mediated enhancement of aerobic glycolysis.

Association Between Prediabetes/Diabetes and Asthma Exacerbations in a Claims-Based Obese Asthma Cohort

BACKGROUND

Metabolic dysfunction may contribute to worsened asthma in obesity. The relationship between prediabetes and diabetes, metabolic conditions more common in obesity, and asthma outcomes is not well characterized.

OBJECTIVE

We sought to determine the association between prediabetes/diabetes and asthma exacerbations in an obese asthma cohort.

METHODS

A retrospective cohort of US obese adults with asthma, aged 18-64, was created from a claims-based health services database spanning 2010 to 2015. Individuals with a hemoglobin A1c (HbA1c) measurement were identified, categorized as within normal (<5.6%), prediabetes (5.7% to 6.4%), and diabetes (≥6.5%) ranges. Exacerbations, defined as asthma-related hospitalization, emergency department visit, or corticosteroid prescription ±14 days of an asthma-related outpatient visit, were ascertained. Associations were fit with zero-inflated negative binomial models, adjusted for age, sex, region, smoking, medication use, and comorbidities.

RESULTS

A total of 5722 individuals were identified. Higher HgbA1c was associated with higher asthma exacerbation rates. In the fully adjusted model, compared with individuals with normal HbA1c, those in the prediabetes range had a 27% higher rate (95% confidence interval [CI], 5% to 52%), and those in the diabetes range had a 33% higher rate (95% CI, 2% to 73%).

CONCLUSIONS

Prediabetes and diabetes were associated with higher rates of asthma exacerbation among obese adults with asthma. Results support evidence that insulin resistance and metabolic syndrome, metabolic features common in prediabetes/diabetes, can influence asthma morbidity.

Emerging Therapeutic Targets for Metabolic Syndrome: Lessons from Animal Models

Background:

Metabolic syndrome is a cluster of medical conditions that synergistically increase the risk of heart diseases and diabetes. The current treatment strategy for metabolic syndrome focuses on treating its individual components. A highly effective agent for metabolic syndrome has yet to be developed. To develop a target for metabolic syndrome, the mechanism encompassing different organs - nervous system, pancreas, skeletal muscle, liver and adipose tissue - needs to be understood. Many animal models have been developed to understand the pathophysiology of metabolic syndrome. Promising molecular targets have emerged while characterizing these animals. Modulating these targets is expected to treat some components of metabolic syndrome.

Objective:

o discuss the emerging molecular targets in an animal model of metabolic syndrome.

Methods:

A literature search was performed for the retrieval of relevant articles.

Conclusion:

Multiple genes/pathways that play important role in the development of Metabolic Syndrome are discussed.

Voluntary Activity Modulates Sugar-Induced Elastic Fiber Remodeling in the Alveolar Region of the Mouse Lung

Diabetes and respiratory diseases are frequently comorbid conditions. However, the mechanistic links between hyperglycemia and lung dysfunction are not entirely understood. This study examined the effects of high sucrose intake on lung mechanics and alveolar septal composition and tested voluntary activity as an intervention strategy. C57BL/6N mice were fed a control diet (CD, 7% sucrose) or a high sucrose diet (HSD, 35% sucrose). Some animals had access to running wheels (voluntary active; CD-A, HSD-A). After 30 weeks, lung mechanics were assessed, left lungs were used for stereological analysis and right lungs for protein expression measurement. HSD resulted in hyperglycemia and higher static compliance compared to CD. Lung and septal volumes were increased and the septal ratio of elastic-to-collagen fibers was decreased despite normal alveolar epithelial volumes. Elastic fibers appeared more loosely arranged accompanied by an increase in elastin protein expression. Voluntary activity prevented hyperglycemia in HSD-fed mice. The parenchymal airspace volume, but not the septal volume, was increased. The septal extracellular matrix (ECM) composition together with the protein expression of ECM components was similar to control levels in the HSD-A-group. In conclusion, HSD was associated with elastic fiber remodeling and reduced pulmonary elasticity. Voluntary activity alleviated HSD-induced ECM alterations, possibly by preventing hyperglycemia.

Diffuse Idiopathic Skeletal Hyperostosis in Smokers and Restrictive Spirometry Pattern: An Analysis of the COPDGene Cohort

OBJECTIVE

Diffuse idiopathic skeletal hyperostosis (DISH) is a condition characterized by bony proliferation at sites of tendinous and ligamentous insertions in the spine. Spinal mobility is reduced in DISH and may affect movement in the thorax, potentially leading to restrictive pulmonary function. This study investigated whether DISH is associated with restrictive spirometric pattern (RSP) in former and current smokers.

METHODS

Participants (n = 1784) with complete postbronchodilator spirometry who did not meet spirometric criteria for chronic obstructive pulmonary disease (COPD) at time of enrollment in the COPDGene study were included in this study. Subjects were classified as RSP if they had forced expiratory volume in 1 s(FEV1) to forced vital capacity (FVC) ratio > 0.7 with an FVC < 80%. Computed tomography (CT) scans were scored for the presence of DISH in accordance with the Resnick criteria. Chest CT measures of interstitial and alveolar lung disease, clinical symptoms, health surveys, and 6-min walking distance were recorded. Uni- and multivariable analyses were performed to test the association of DISH with RSP.

RESULTS

DISH was present in 236 subjects (13.2%). RSP was twice as common in participants with DISH (n = 90/236, 38.1%) compared to those without DISH (n = 301/1548, 19.4%; p < 0.001). In multivariable analysis, DISH was significantly associated with RSP (OR 1.78; 95% CI 1.22-2.60; p = 0.003) after adjusting for potential confounders. The RSP group with and without DISH had significantly worse spirometry, dyspnea, St. George's Respiratory Questionnaire score, BODE index (Body mass index, airflow Obstruction, Dyspnea and Exercise capacity), and Medical Outcomes Study Short Form-36 questionnaire score.

CONCLUSION

In heavy smokers with an FEV1/FVC ratio > 0.70, DISH is associated with RSP after adjustment for intrinsic and extrinsic causes of restrictive lung function. (Clinical trial registration number: NCT00608764.).

Metabolic Syndrome Biomarkers of World Trade Center Airway Hyperreactivity: A 16-Year Prospective Cohort Study

Airway hyperreactivity (AHR) related to environmental exposure is a significant public health risk worldwide. Similarly, metabolic syndrome (MetSyn), a risk factor for obstructive airway disease (OAD) and systemic inflammation, is a significant contributor to global adverse health. This prospective cohort study followed N = 7486 World Trade Center (WTC)-exposed male firefighters from 11 September 2001 (9/11) until 1 August 2017 and investigated N = 539 with newly developed AHR for clinical biomarkers of MetSyn and compared them to the non-AHR group. Male firefighters with normal lung function and no AHR pre-9/11 who had blood drawn from 9 September 2001–24 July 2002 were assessed. World Trade Center-Airway Hyperreactivity (WTC-AHR) was defined as either a positive bronchodilator response (BDR) or methacholine challenge test (MCT). The electronic medical record (EMR) was queried for their MetSyn characteristics (lipid profile, body mass index (BMI), glucose), and routine clinical biomarkers (such as complete blood counts). We modeled the association of MetSyn characteristics at the first post-9/11 exam with AHR. Those with AHR were significantly more likely to be older, have higher BMIs, have high intensity exposure, and have MetSyn. Smoking history was not associated with WTC-AHR. Those present on the morning of 9/11 had 224% increased risk of developing AHR, and those who arrived in the afternoon of 9/11 had a 75.9% increased risk. Having ≥3 MetSyn parameters increased the risk of WTC-AHR by 65.4%. Co-existing MetSyn and high WTC exposure are predictive of future AHR and suggest that systemic inflammation may be a contributor.

The impact of bariatric surgery on asthma control differs among obese individuals with reported prior or current asthma, with or without metabolic syndrome

BACKGROUND

Both obesity and the metabolic syndrome have been independently associated with increased asthma morbidity. However, it is unclear whether metabolic syndrome limits the beneficial effects of weight loss on asthma.

OBJECTIVES

To evaluate whether bariatric weight loss is associated with improved asthma control, and whether this association varies by metabolic syndrome status.

METHODS

We determined the changes in asthma control, defined by the Asthma Control Test (ACT), before and after bariatric surgery among participants with asthma in the multi-center Longitudinal Assessment of Bariatric Surgery (LABS) study, stratifying our analysis by the presence or absence of metabolic syndrome.

RESULTS

Among 2,458 LABS participants, 555 participants had an asthma diagnosis and were included in our analysis. Of these, 78% (n = 433) met criteria for metabolic syndrome (MetSyn) at baseline. In patients without MetSyn, mean ACT increased from 20.4 at baseline to 22.1 by 12-24 months, ending at 21.3 at 60 months. In contrast, among those with MetSyn there was no significant improvement in ACT scores. The proportion of patients without MetSyn with adequate asthma control (ACT >19) increased from 58% at baseline to 78% and 82% at 12 and 60 months, respectively, whereas among those with MetSyn, it was 73.8% at baseline, 77.1% at 12 months, dropping to 47.1% at 60 months (p = 0.004 for interaction between metabolic syndrome and time). Having MetSyn also increased the likelihood of losing asthma control during follow-up (HR = 1.92, 95% confidence interval [CI] 1.24-2.97, p = 0.003).

CONCLUSIONS

Metabolic syndrome may negatively modify the effect of bariatric surgery-induced weight loss on asthma control.

The role of modifiable health-related behaviors in the association between PTSD and respiratory illness

BACKGROUND

Posttraumatic stress disorder (PTSD) increases risk of future respiratory illness. However, mechanisms that underpin the association between these common and debilitating conditions remain unknown. The aim of this study was to identify modifiable, health-related behaviors they may explain the link between PTSD and respiratory problems.

METHODS

World Trade Center responders (N = 452, 89% male, mean age = 55 years) completed baseline PTSD and sleep questionnaires, followed by 2-weeks of daily diaries, actigraphy and ambulatory spirometry to monitor lower respiratory symptoms, pulmonary function, activity levels, stressors, and sleep. Lipid levels were obtained from electronic medical records.

RESULTS

Cross-sectional mediation analyses revealed that the association between PTSD and self-reported respiratory symptoms was explained by poor sleep, low activity, and daily stressors. The association between PTSD symptoms and pulmonary function was explained by insomnia and low activity.

CONCLUSIONS

A range of health-related daily behaviors and experiences, especially sleep disturbances and inactivity, may explain excess respiratory illness morbidity in PTSD. The findings were generally consistent across daily self-report and spirometry measures of respiratory problems. Targeting these behaviors might enhance prevention of and intervention in respiratory problems in traumatized populations.