Idiopathic pulmonary fibrosis and diabetes mellitus: a meta-analysis and systematic review

Exploring the Interrelationship Between Diabetes Mellitus and Chronic Lung Diseases: A Comprehensive Review

Diabetes mellitus (DM) is a chronic metabolic disorder that affects millions of individuals worldwide. With an increasing prevalence, understanding its implications for respiratory health is essential. Chronic lung diseases, such as asthma and chronic obstructive pulmonary disease (COPD), significantly impact morbidity and healthcare costs, with COPD alone accounting for substantial economic burdens. This comprehensive review investigates the intricate relationship between DM and chronic lung diseases. A systematic search across multiple databases yielded 1,078 articles, from which 10 studies were selected for detailed examination. The findings reveal a bidirectional relationship: diabetes increases the risk of developing chronic lung conditions, while chronic lung diseases can exacerbate glycemic control. Shared inflammatory pathways and comorbidities complicate patient outcomes, underscoring the urgent need for integrated treatment approaches. By elucidating the mechanisms linking these conditions, this review provides valuable insights for healthcare professionals, emphasizing the importance of interdisciplinary care to enhance the quality of life for individuals affected by both diabetes and chronic lung diseases. The results highlight the necessity for further research to explore targeted therapies and preventive measures addressing these interconnected health issues.

Ameliorating lung fibrosis and pulmonary function in diabetic mice: Therapeutic potential of mesenchymal stem cell

This study aimed to investigate the potential of mesenchymal stem cells (MSCs) in alleviating diabetic lung injury by decreasing inflammation, fibrosis and recovering tissue macrophage homeostasis. To induce pulmonary injuries in an in vivo murine model, we utilized a streptozotocin (STZ), and high-fat diet (HFD) induced diabetic C57 mouse model. Subsequently, human umbilical cord-derived MSCs (hUC-MSCs) were administered through the tail vein on a weekly basis for a duration of 4 weeks. In addition, in vitro experiments involved co-culturing of isolated primary abdominal macrophages from diabetic mice and high glucose-stimulated MLE-12 cells with hUC-MSCs. The objective was to evaluate if hUC-MSCs co-culturing could effectively mitigate cell inflammation and fibrosis. Following hUC-MSCs injection, diabetic mice displayed enhanced pulmonary functional parameters, reduced pulmonary fibrosis, and diminished inflammation. Notably, the dynamic equilibrium of lung macrophages shifted from the M1 phenotype to the M2 phenotype, accompanied by a notable reduction in various indicators associated with inflammation and fibrosis. Results from cell co-culturing experiments further supported this trend, demonstrating a reduction in inflammatory and fibrotic indicators. In conclusion, our findings suggest that hUC-MSCs treatment holds promise in mitigating diabetic pulmonary injury by significantly reducing inflammation, fibrosis and maintain tissue macrophage homeostasis within the lungs. This study sheds light on the therapeutic potential of hUC-MSCs in managing diabetic complications affecting the pulmonary system.

The impact of diabetes mellitus on blood-tissue barrier regulation and vascular complications: Is the lung different from other organs?

Diabetes Mellitus presents a formidable challenge as one of the most prevalent and complex chronic diseases, exerting significant strain on both patients and the world economy. It is recognized as a common comorbidity among severely ill individuals, often leading to a myriad of micro- and macro-vascular complications. Despite extensive research dissecting the pathophysiology and molecular mechanisms underlying vascular complications of diabetes, relatively little attention has been paid to potential lung-related complications. This review aims to illuminate the impact of diabetes on prevalent respiratory diseases, including chronic obstructive pulmonary disease (COPD), acute respiratory distress syndrome (ARDS), idiopathic pulmonary fibrosis (IPF), tuberculosis (TB), pneumonia infections, and asthma, and compare the vascular complications with other vascular beds. Additionally, we explore the primary mechanistic pathways contributing to these complications, such as the expression modulation of blood-tissue-barrier proteins, resulting in increased paracellular and transcellular permeability, and compromised immune responses rendering diabetes patients more susceptible to infections. The activation of inflammatory pathways leading to cellular injury and hastening the onset of these respiratory complications is also discussed.

Immune cells crosstalk Pathways, and metabolic alterations in Idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) presents a challenging progression characterized by lung tissue scarring and abnormal extracellular matrix deposition. This review examines the influence of immune responses, emphasizing their complex role in initiating and perpetuating fibrosis. It highlights how metabolic pathways modulate immune cell function during IPF. Immune cell modulation holds promise in managing pulmonary fibrosis (PF). Inhibiting neutrophil recruitment and monitoring mast cell levels offer insights into PF progression. Low-dose IL-2 therapy and regulation of fibroblast recruitment present potential therapeutic avenues, while the role of innate lymphoid cells (ILC2s) in allergic lung inflammation sheds light on disease mechanisms. The review focuses on metabolic reprogramming's role in shaping immune cell function during IPF progression. While some immune cells use glycolysis for pro-inflammatory responses, others favor fatty acid oxidation for regulatory functions. Targeting specialized pro-resolving lipid mediators (SPMs) presents significant potential for managing fibrotic disorders. Additionally, it highlights the pivotal role of amino acid metabolism in synthesizing serine and glycine as crucial regulators of collagen production and exploring the interconnectedness of lipid metabolism, mitochondrial dysfunction, and adipokines in driving fibrotic processes. Moreover, the review discusses the impact of metabolic disorders such as obesity and diabetes on lung fibrosis. Advocating for a holistic approach, it emphasizes the importance of considering this interplay between immune cell function and metabolic pathways in developing effective and personalized treatments for IPF.

Glycolysis and beyond in glucose metabolism: exploring pulmonary fibrosis at the metabolic crossroads

At present, pulmonary fibrosis (PF) is a prevalent and irreversible lung disease with limited treatment options, and idiopathic pulmonary fibrosis (IPF) is one of its most common forms. Recent research has highlighted PF as a metabolic-related disease, including dysregulated iron, mitochondria, lipid, and glucose homeostasis. Systematic reports on the regulatory roles of glucose metabolism in PF are rare. This study explores the intricate relationships and signaling pathways between glucose metabolic processes and PF, delving into how key factors involved in glucose metabolism regulate PF progression, and the interplay between them. Specifically, we examined various enzymes, such as hexokinase (HK), 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3), pyruvate kinase (PK), and lactate dehydrogenase (LDH), illustrating their regulatory roles in PF. It highlights the significance of lactate, alongside the role of pyruvate dehydrogenase kinase (PDK) and glucose transporters (GLUTs) in modulating pulmonary fibrosis and glucose metabolism. Additionally, critical regulatory factors such as transforming growth factor-beta (TGF-β), interleukin-1 beta (IL-1β), and hypoxia-inducible factor 1 subunit alpha (HIF-1α) were discussed, demonstrating their impact on both PF and glucose metabolic pathways. It underscores the pivotal role of AMP-activated protein kinase (AMPK) in this interplay, drawing connections between diabetes mellitus, insulin, insulin-like growth factors, and peroxisome proliferator-activated receptor gamma (PPARγ) with PF. This study emphasizes the role of key enzymes, regulators, and glucose transporters in fibrogenesis, suggesting the potential of targeting glucose metabolism for the clinical diagnosis and treatment of PF, and proposing new promising avenues for future research and therapeutic development.

Twenty-Four week Taichi training improves pulmonary diffusion capacity and glycemic control in patients with Type 2 diabetes mellitus

This study evaluated the effect of 24-week Taichi training and Taichi plus resistance band training on pulmonary diffusion capacity and glycemic control in patients with Type 2 diabetes mellitus (T2DM). Forty-eight patients with T2DM were randomly divided into three groups: Group A-Taichi training: practiced Taichi 60 min/day, 6 days/week for 24 weeks; Group B-Taichi plus resistance band training: practiced 60-min Taichi 4 days/week plus 60-min resistance band training 2 days/week for 24 weeks; and Group C-controls: maintaining their daily lifestyles. Stepwise multiple regression analysis was applied to predict diffusion capacity of the lungs for carbon monoxide (DLCO) by fasting blood glucose, insulin, glycosylated hemoglobin (HbA1c), tumour necrosis factor alpha (TNF-α), von Willebrand Factor (vWF), interleukin-6 (IL-6), intercellular adhesion molecule 1 (ICAM-1), endothelial nitric oxide synthase (eNOS), nitric oxide (NO), endothelin-1 (ET-1), vascular endothelial growth factor, and prostaglandin I-2. Taichi with or without resistance band training significantly improved DLCO, increased insulin sensitivity, eNOS and NO, and reduced fasting blood glucose, insulin, HbA1c, TNF-α, vWF, IL-6, ICAM-1, and ET-1. There was no change in any of these variables in the control group. DLCO was significantly predicted (R2 = 0.82) by insulin sensitivity (standard-β = 0.415, P<0.001), eNOS (standard-β = 0.128, P = 0.017), TNF-α (standard-β = -0.259, P = 0.001), vWF (standard-β = -0.201, P = 0.007), and IL-6 (standard-β = -0.175, P = 0.032) in patients with T2DM. The impact of insulin sensitivity was the most important predictor for the variation of DLCO based on the multiple regression modeling. This study demonstrates that 24-week Taichi training and Taichi plus resistance band training effectively improve pulmonary diffusion capacity and blood glycemic control in patients with T2DM. Variation of DLCO is explained by improved insulin sensitivity and endothelial function, and reduced inflammatory markers, including TNF-α, vWF, and IL-6.

Identification and validation of mutual hub genes in idiopathic pulmonary fibrosis and rheumatoid arthritis-associated usual interstitial pneumonia

Objectives

The study aims at exploring common hub genes and pathways in idiopathic pulmonary fibrosis (IPF) and rheumatoid arthritis-associated usual interstitial pneumonia (RA-UIP) through integrated bioinformatics analyses.

Methods

The GSE199152 dataset containing lung tissue samples from IPF and RA-UIP patients was acquired from the Gene Expression Omnibus (GEO) database. The identification of overlapping differentially expressed genes (DEGs) in IPF and RA-UIP was carried out through R language. Protein-protein interaction (PPI) network analysis and module analysis were applied to filter mutual hub genes in the two diseases. Enrichment analyses were also conducted to analyze the possible biological functions and pathways of the overlapped DEGs and hub genes. The diagnostic value of key genes was assessed with R language, and the expressions of these genes in pulmonary cells of IPF and rheumatoid arthritis-associated interstitial lung disease (RA-ILD) patients were analyzed with single cell RNA-sequencing (scRNA-seq) datasets. The expression levels of hub genes were validated in blood samples from patients, specimens of human lung fibroblasts, lung tissue samples from mice, as well as external GEO datasets.

Results

Four common hub genes (THBS2, TIMP1, POSTN, and CD19) were screened. Enrichment analyses showed that the abnormal expressions of DEGs and hub genes may be connected with the onset of IPF and RA-UIP by regulating the progression of fibrosis. ScRNA-seq analyses illustrated that for both IPF and RA-ILD patients, THBS2, TIMP1, and POSTN were mainly expressed in lung fibroblasts, while CD19 was uniquely high-expressed in B cells. The qRT-PCR and immunohistochemistry (IHC) results verified that the expression levels of hub genes were mostly in accordance with the findings obtained from the bioinformatics analyses.

Conclusion

Though IPF and RA-UIP are distinct diseases, they may to some extent have mutual pathogenesis in the development of fibrosis. THBS2, TIMP1, POSTN, and CD19 may be the potential biomarkers of IPF and RA-UIP, and intervention on related pathways of these genes could offer new strategies for the precision treatment of IPF and RA-UIP.

Association between statin use and the risk for idiopathic pulmonary fibrosis and its prognosis: a nationwide, population-based study

Given the pleiotropic effects of statins beyond their lipid-lowering effects, there have been attempts to evaluate the role of statin therapy in IPF, but they have shown inconclusive results. Data from the National Health Insurance Service (NHIS) database of South Korea were used to investigate the effects of statin therapy on IPF. The IPF cohort consisted of a total of 10,568 patients who were newly diagnosed with IPF between 2010 and 2017. These patients were then matched in a 1:3 ratio to 31,704 subjects from a control cohort without IPF, with matching based on age and sex. A case-control study was performed to evaluate the association between statin use and the risk for IPF, and the multivariable analysis revealed that statin use was associated with a lower risk for IPF (adjusted OR 0.847, 95% CI 0.800-0.898). Using the IPF cohort, we also evaluated whether statin use at the time of diagnosis was associated with future clinical outcomes. The statin use at the time of IPF diagnosis was associated with improved overall survival (adjusted HR 0.779, 95% CI 0.709-0.856). Further prospective studies are needed to clarify the role of statin therapy in IPF.

Transglutaminase 2 in diabetes mellitus: Unraveling its multifaceted role and therapeutic implications for vascular complications

Diabetes, a severe metabolic disease characterized by chronic hypoglycemia, poses debilitating and life-threatening risks of microvascular and macrovascular complications, including blindness, kidney failure, heart attacks, and limb amputation. Addressing these complications is paramount, urging the development of interventions targeting diabetes-associated vascular dysfunctions. To effectively combat diabetes, a comprehensive understanding of the pathological mechanisms underlying complications and identification of precise therapeutic targets are imperative. Transglutaminase 2 (TGase2) is a multifunctional enzyme implicated in the pathogenesis of diverse diseases such as neurodegenerative disorders, fibrosis, and inflammatory conditions. TGase2 has recently emerged as a key player in both the pathogenesis and therapeutic intervention of diabetic complications. This review highlights TGase2 as a therapeutic target for diabetic complications and explores TGase2 inhibition as a promising therapeutic approach in their treatment.

Pulmonary Fibrosis and Diabetes Mellitus: Two coins with the same face

Idiopathic pulmonary fibrosis (IPF) constitutes a long-term disease with a complex pathophysiology composed of multiple molecular actors that lead to the deposition of extracellular matrix, the loss of pulmonary function and ultimately the patient's death. Despite the approval of pirfenidone and nintedanib for the treatment of the disease, lung transplant is the only long-term solution to fully recover the respiratory capacity and gain quality of life. One of the risk factors for the development of IPF is the pre-existing condition of diabetes mellitus. Both, IPF and diabetes mellitus, share similar pathological damage mechanisms, including inflammation, endoplasmic reticulum stress, mitochondrial failure, oxidative stress, senescence and signaling from glycated proteins through receptors. In this critical review article, we provide information about this interrelationship, examining molecular mediators that play an essential role in both diseases and identify targets of interest for the development of potential drugs. We review the findings of clinical trials examining the progression of IPF and how novel molecules may be used to stop this process. The results highlight the importance of early detection and addressing multiple therapeutic targets simultaneously to achieve better therapeutic efficacy and potentially reverse lung fibrosis.

Chlorogenic Acid Inhibits Progressive Pulmonary Fibrosis in a Diabetic Rat Model

Background

Chlorogenic acid (CGA) is known to have antifibrotic and hypoglycemic effects and may play a role in preventing diabetes-induced pulmonary fibrosis. This study aimed to determine the effect and optimum dose of CGA on diabetes-induced pulmonary fibrosis.

Methods

Thirty Wistar rats (two-month-old, 150-200 grams) were randomly divided into six groups, namely control, six weeks diabetes mellitus (DM1), eight weeks DM (DM2), and three DM2 groups (CGA1, CGA2, and CGA3) who received CGA doses of 12.5, 25, and 50 mg/Kg BW, respectively. After six weeks, CGA was administered intraperitoneally for 14 consecutive days. Lung tissues were taken for TGF-β1, CTGF, SMAD7, Collagen-1, and α-SMA mRNA expression analysis and paraffin embedding. Data were analyzed using one-way ANOVA and the Kruskal-Wallis test. P<0.05 was considered statistically significant.

Results

TGF-β1 expression in the CGA1 group (1.01±0.10) was lower than the DM1 (1.33±0.25, P=0.05) and DM2 (1.33±0.20, P=0.021) groups. α-SMA expression in the CGA1 group (median 0.60, IQR: 0.34-0.64) was lower than the DM1 (median 0.44, IQR: 0.42-0.80) and DM2 (median 0.76, IQR: 0.66-1.10) groups. Collagen-1 expression in the CGA1 group (0.75±0.13) was lower than the DM1 (P=0.24) and DM2 (P=0.26) groups, but not statistically significant. CTGF expression in CGA groups was lower than the DM groups (P=0.088), but not statistically significant. There was an increase in SMAD7 expression in CGA groups (P=0.286). Histological analysis showed fibrosis improvement in the CGA1 group compared to the DM groups.

Conclusion

CGA (12.5 mg/Kg BW) inhibited the expression of profibrotic factors and increased antifibrotic factors in DM-induced rats.

Latent inter-organ mechanism of idiopathic pulmonary fibrosis unveiled by a generative computational approach

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive disease characterized by complex lung pathogenesis affecting approximately three million people worldwide. While the molecular and cellular details of the IPF mechanism is emerging, our current understanding is centered around the lung itself. On the other hand, many human diseases are the products of complex multi-organ interactions. Hence, we postulate that a dysfunctional crosstalk of the lung with other organs plays a causative role in the onset, progression and/or complications of IPF. In this study, we employed a generative computational approach to identify such inter-organ mechanism of IPF. This approach found unexpected molecular relatedness of IPF to neoplasm, diabetes, Alzheimer's disease, obesity, atherosclerosis, and arteriosclerosis. Furthermore, as a potential mechanism underlying this relatedness, we uncovered a putative molecular crosstalk system across the lung and the liver. In this inter-organ system, a secreted protein, kininogen 1, from hepatocytes in the liver interacts with its receptor, bradykinin receptor B1 in the lung. This ligand-receptor interaction across the liver and the lung leads to the activation of calmodulin pathways in the lung, leading to the activation of interleukin 6 and phosphoenolpyruvate carboxykinase 1 pathway across these organs. Importantly, we retrospectively identified several pre-clinical and clinical evidence supporting this inter-organ mechanism of IPF. In conclusion, such feedforward and feedback loop system across the lung and the liver provides a unique opportunity for the development of the treatment and/or diagnosis of IPF. Furthermore, the result illustrates a generative computational framework for machine-mediated synthesis of mechanisms that facilitates and complements the traditional experimental approaches in biomedical sciences.

Ectopic and visceral fat deposition in aging, obesity, and idiopathic pulmonary fibrosis: an interconnected role

Idiopathic pulmonary fibrosis (IPF) is considered an age-related disease. Age-related changes, along with other factors such as obesity, hormonal imbalances, and various metabolic disorders, lead to ectopic fat deposition (EFD). This accumulation of fat outside of its normal storage sites is associated with detrimental effects such as lipotoxicity, oxidative stress, inflammation, and insulin resistance. This narrative review provides an overview of the connection between ectopic and visceral fat deposition in aging, obesity, and IPF. It also elucidates the mechanism by which ectopic fat deposition in the airways and lungs, pericardium, skeletal muscles, and pancreas contributes to lung injury and fibrosis in patients with IPF, directly or indirectly. Moreover, the review discusses the impact of EFD on the severity of the disease, quality of life, presence of comorbidities, and overall prognosis in IPF patients. The review provides detailed information on recent research regarding representative lipid-lowering drugs, hypoglycemic drugs, and lipid-targeting drugs in animal experiments and clinical studies. This may offer new therapeutic directions for patients with IPF.

Study on Potential Differentially Expressed Genes in Idiopathic Pulmonary Fibrosis by Bioinformatics and Next-Generation Sequencing Data Analysis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease with reduced quality of life and earlier mortality, but its pathogenesis and key genes are still unclear. In this investigation, bioinformatics was used to deeply analyze the pathogenesis of IPF and related key genes, so as to investigate the potential molecular pathogenesis of IPF and provide guidance for clinical treatment. Next-generation sequencing dataset GSE213001 was obtained from Gene Expression Omnibus (GEO), and the differentially expressed genes (DEGs) were identified between IPF and normal control group. The DEGs between IPF and normal control group were screened with the DESeq2 package of R language. The Gene Ontology (GO) and REACTOME pathway enrichment analyses of the DEGs were performed. Using the g:Profiler, the function and pathway enrichment analyses of DEGs were performed. Then, a protein-protein interaction (PPI) network was constructed via the Integrated Interactions Database (IID) database. Cytoscape with Network Analyzer was used to identify the hub genes. miRNet and NetworkAnalyst databaseswereused to construct the targeted microRNAs (miRNAs), transcription factors (TFs), and small drug molecules. Finally, receiver operating characteristic (ROC) curve analysis was used to validate the hub genes. A total of 958 DEGs were screened out in this study, including 479 up regulated genes and 479 down regulated genes. Most of the DEGs were significantly enriched in response to stimulus, GPCR ligand binding, microtubule-based process, and defective GALNT3 causes HFTC. In combination with the results of the PPI network, miRNA-hub gene regulatory network and TF-hub gene regulatory network, hub genes including LRRK2, BMI1, EBP, MNDA, KBTBD7, KRT15, OTX1, TEKT4, SPAG8, and EFHC2 were selected. Cyclothiazide and rotigotinethe are predicted small drug molecules for IPF treatment. Our findings will contribute to identification of potential biomarkers and novel strategies for the treatment of IPF, and provide a novel strategy for clinical therapy.

The causal relationship between physical activity, sedentary time and idiopathic pulmonary fibrosis risk: a Mendelian randomization study

BACKGROUND

Several observational studies have found that physical inactivity and sedentary time are associated with idiopathic pulmonary fibrosis (IPF) risk. However, the causality between them still requires further investigation. Therefore, our study aimed to investigate the causal effect of physical activity (PA) and sedentary time on the risk of IPF via two-sample Mendelian randomization (MR) analysis.

METHODS

Multiple genome-wide association study (GWAS) data involving individuals of European ancestry were analyzed. The datasets encompassed published UK Biobank data (91,105-377,234 participants) and IPF data (2018 cases and 373,064 controls) from FinnGen Biobank. The inverse variance weighting (IVW) method was the primary approach for our analysis. Sensitivity analyses were implemented with Cochran's Q test, MR-Egger regression, MR-PRESSO global test, and leave-one-out analysis.

RESULTS

Genetically predicted self-reported PA was associated with lower IPF risk [OR = 0.27; 95% CI 0.09-0.82; P = 0.02]. No causal effects of accelerometry-based PA or sedentary time on the risk of IPF were observed.

CONCLUSIONS

Our findings supported a protective relationship between self-reported PA and the risk for IPF. The results suggested that enhancing PA may be an effective preventive strategy for IPF.

Emerging opportunities to treat idiopathic pulmonary fibrosis: Design, discovery, and optimizations of small-molecule drugs targeting fibrogenic pathways

Idiopathic pulmonary fibrosis (IPF) is the most common fibrotic form of idiopathic diffuse lung disease. Due to limited treatment options, IPF patients suffer from poor survival. About ten years ago, Pirfenidone (Shionogi, 2008; InterMune, 2011) and Nintedanib (Boehringer Ingelheim, 2014) were approved, greatly changing the direction of IPF drug design. However, limited efficacy and side effects indicate that neither can reverse the process of IPF. With insights into the occurrence of IPF, novel targets and agents have been proposed, which have fundamentally changed the treatment of IPF. With the next-generation agents, targeting pro-fibrotic pathways in the epithelial-injury model offers a promising approach. Besides, several next-generation IPF drugs have entered phase II/III clinical trials with encouraging results. Due to the rising IPF treatment requirements, there is an urgent need to completely summarize the mechanisms, targets, problems, and drug design strategies over the past ten years. In this review, we summarize known mechanisms, target types, drug design, and novel technologies of IPF drug discovery, aiming to provide insights into the future development and clinical application of next-generation IPF drugs.

Non-apoptotic programmed cell deaths in diabetic pulmonary dysfunction: the new side of advanced glycation end products

Diabetes mellitus (DM) is a chronic metabolic disorder that affects multiple organs and systems, including the pulmonary system. Pulmonary dysfunction in DM patients has been observed and studied for years, but the underlying mechanisms have not been fully understood. In addition to traditional mechanisms such as the production and accumulation of advanced glycation end products (AGEs), angiopathy, tissue glycation, oxidative stress, and systemic inflammation, recent studies have focused on programmed cell deaths (PCDs), especially the non-apoptotic ones, in diabetic pulmonary dysfunction. Non-apoptotic PCDs (NAPCDs) including autophagic cell death, necroptosis, pyroptosis, ferroptosis, and copper-induced cell death have been found to have certain correlations with diabetes and relevant complications. The AGE-AGE receptor (RAGE) axis not only plays an important role in the traditional pathogenesis of diabetes lung disease but also plays an important role in non-apoptotic cell death. In this review, we summarize novel studies about the roles of non-apoptotic PCDs in diabetic pulmonary dysfunction and focus on their interactions with the AGE-RAGE axis.

Assessing feasibility of targeted primary care referrals for patients with clinical suspicion of interstitial lung disease using lung ultrasound: a prospective case finding study. The potential benefits of LUS utilization

BACKGROUND

In Primary Health Care (PHC) many interstitial lung disease (ILD) cases may remain at diagnostic delay, due to their challenging presentation and the limited experience of general practitioners (GPs) in recognizing their early symptoms.

OBJECTIVE

We have designed a feasibility study to investigate early ILD case-finding competency between PHC and tertiary care.

METHODS

A cross-sectional prospective case-finding study was launched at two private health care centers of Heraklion, Crete, Greece, during nine months (2021-2022). After clinical assessment by GP, PHC attenders, who agreed to participate in the study, were referred to the Respiratory Medicine Department, University Hospital of Heraklion, Crete, underwent Lung Ultrasound (LUS) and those with an overall suspicion for ILDs underwent high resolution computed tomography (HRCT) scan. Descriptive statistics and chi-square tests were used. Multiple Poisson regression analysis was performed to explain positive LUS and HRCT decision with selected variables.

RESULTS

One hundred and nine patients out of 183 were finally included (54.1% females; mean age 61, SD: 8.3 years). Thirty-five (32.1%) were current smokers. Overall, two out of ten cases were assessed to need HRCT due to a moderate or high suspicion (19.3%; 95%CI 12.7, 27.4). However, in those who had dyspnea in relation to counterparts, a significantly higher percentage of patients with LUS findings (57.9% vs. 34.0%, p=0.013) was found, as in those who had crackles (100.0% vs. 44.2%, p= 0.005). Detected possible ILD provisional labelling cases were 6, and most importantly, 5 of those cases were considered highly suspicious for further evaluation based on LUS findings.

CONCLUSIONS

This is a feasibility study exploring potentials by combining data of medical history, basic auscultation skills, as crackles detection, and inexpensive and radiation-free imaging technique, such as LUS. Cases of ILD labeling may be hidden within PHC, sometimes, much before any clinical manifestation.

Diabetes-related perturbations in the integrity of physiologic barriers

One of the hallmarks of health is the integrity of barriers at the cellular and tissue levels. The two cardinal functions of barriers include preventing access of deleterious elements of the environment (barrier function) while facilitating the transport of essential ions, signaling molecules and nutrients needed to maintain the internal milieu (transport function). There are several cellular and subcellular barriers and some of these barriers can be interrelated. The principal physiologic barriers include blood-retinal barrier, blood-brain barrier, blood-testis barrier, renal glomerular/tubular barrier, intestinal barrier, pulmonary blood-alveolar barrier, blood-placental barrier and skin barrier. Tissue specific barriers are the result of the vasculature, cellular composition of the tissue and extracellular matrix within the tissue. Uncontrolled diabetes and acute hyperglycemia may disrupt the integrity of physiologic barriers, primarily through altering the vascular integrity of the tissues and may well contribute to the clinically recognized complications of diabetes. Although diabetes is a systemic disease, some of the organs display clinically significant deterioration in function while others undergo subclinical changes. The pathophysiology of the disruption of these barriers is not entirely clear but it may be related to diabetes-related cellular stress. Understanding the mechanisms of diabetes related dysfunction of various physiologic barriers might help identifying novel therapeutic targets for reducing clinically significant complications of diabetes.

Effects of Ultrasound-Guided Transversus Thoracic Muscle Plane Block on Postoperative Pain and Side Effects: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The effects of the transversus thoracic muscle plane (TTP) block on postoperative pain have become increasingly controversial. This meta-analysis compared the effects of the TTP block versus no block on postoperative analgesia and side effects to determine whether this new technique is a reliable alternative for pain management. PubMed, Cochrane Library, Embase, Web of Science, ClinicalTrials.gov, China National Knowledge Infrastructure, Chongqing VIP information, and Wanfang Data were searched for clinical studies investigating the analgesic effect of the TTP block compared to controls. The primary outcomes included the postoperative pain scores at rest and during movement, morphine consumption in 24 hours, and the rate of postoperative nausea and vomiting (PONV). Eleven randomized controlled trials (RCTs), including 682 patients, were reviewed. The meta-analysis showed that the TTP block significantly could reduce the pain scores at 0 (at rest: mean difference [MD], -2.28; 95% CI: -2.67 to -1.90) (during movement: MD: -2.09, 95% CI: -2.62 to -1.56) and 12 hours (at rest: -1.42, 95% CI: -2.03 to -0.82) (during movement: MD: -2.13, 95% CI: -2.80 to -1.46) after surgery, 24-hour postoperative analgesic consumption (MD: -23.18, 95% CI: -33.71 to -12.66), and the incidence of PONV (odds ratio, 0.36, 95% CI: 0.15-0.88). Furthermore, the trial sequence analysis confirmed the result of less 24-hour postoperative analgesic consumption in the TTP block group. As a novel technique, the TTP block exhibited a superior postoperative analgesic effect during the early postoperative period. Nevertheless, additional well-designed RCTs are needed.

Usual interstitial pneumonia as a stand-alone diagnostic entity: the case for a paradigm shift?

Usual interstitial pneumonia (UIP) is characterised by a distinctive morphological and radiological appearance that was considered the pathognomonic hallmark of idiopathic pulmonary fibrosis (IPF). However, this peculiar lung remodelling pattern is also seen in other fibrotic interstitial lung diseases, including hypersensitivity pneumonitis, and connective tissue diseases. In this Personal View, we advocate the designation of a UIP pattern as a single, discrete diagnostic entity, amalgamating its primary form and secondary processes in disorders such as hypersensitivity pneumonitis (hypersensitivity pneumonitis with UIP), rheumatoid arthritis (rheumatoid arthritis with UIP), and others. The current separation between primary and secondary UIP is in keeping with the view that every individual interstitial lung disease must be viewed as a separate entity but does not reflect striking similarities between primary and secondary UIP in the morphological or radiological appearance, clinical behaviour, pathogenic pathways, and the efficacy of anti-fibrotic therapy. We believe that the unification of UIP as a single diagnostic entity has undeniable advantages.

Effectiveness and mechanism of metformin in animal models of pulmonary fibrosis: A preclinical systematic review and meta-analysis

Background: Pulmonary fibrosis (PF) is a lung disease with no curative drug, characterized by a progressive decrease in lung function. Metformin (MET) is a hypoglycemic agent with the advantages of high safety and low cost and has been used in several in vivo trials to treat fibrotic diseases.

Objective: This study aimed to explore the efficacy and safety of MET in treating PF and elaborate on its mechanism.

Methods: Eight databases were searched for in vivo animal trials of MET for PF from the time of database creation until 1 March 2022. The risk of bias quality assessment of the included studies was conducted using SYRCLE’s risk of bias assessment. Pulmonary inflammation and fibrosis scores were the primary outcomes of this study. Hydroxyproline (HYP), type I collagen (collagen I), α-smooth muscle actin (α-SMA), transforming growth factor-β (TGF-β), Smad, AMP-activated protein kinase (AMPK), and extracellular signal–regulated kinase (ERK) protein expression in lung tissues and animal mortality were secondary outcomes. Effect magnitudes were combined and calculated using Revman 5.3 and Stata 16.0 to assess the efficacy and safety of MET in animal models of PF. Inter-study heterogeneity was examined using the I² or Q test, and publication bias was assessed using funnel plots and Egger’s test.

Results: A total of 19 studies involving 368 animals were included, with a mean risk of bias of 5.9. The meta-analysis showed that MET significantly suppressed the level of inflammation and degree of PF in the lung tissue of the PF animal model. MET also reduced the content of HYP, collagen I, α-SMA, and TGF-β and phosphorylation levels of Smad2, Smad3, p-smad2/3/smad2/3, ERK1/2, and p-ERK1/2/ERK1/2 in lung tissues. MET also elevated AMPK/p-AMPK levels in lung tissues and significantly reduced animal mortality.

Conclusion: The results of this study suggest that MET has a protective effect on lung tissues in PF animal models and may be a potential therapeutic candidate for PF treatment.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=327285, identifier CRD42022327285.

Why is UIP peripheral?

INTRODUCTION

The radiology pattern associated with IPF is called UIP. It is unique because unlike any other form of fibrosis it is peripheral in its distribution. We investigated the peripheral nature of UIP and why it was a key feature of IPF the deadliest of the ILDS.

AREAS COVERED

It is not enough to say that UIP is peripheral but instead as scientists we must ask ourselves why it is peripheral. This review dives into the published hypothesis that includes vascular insult, tensile forces, microaspiration, and inflammation and looks at the pros and cons for each argument, and ultimately comes to its own conclusion. PubMed searches using the below keywords were used to identify papers that described pathogenesis of IPF with regard to a particular theory.

EXPERT OPINION

In this paper, we will review four ideas that support why UIP is peripheral and propose the most likely explanation given what is currently known about the pathophysiology of IPF.

Analysis of risk factors of mortality in rheumatoid arthritis patients with interstitial lung disease: a nationwide, population-based cohort study in Taiwan

Objective

To examine the risk and risk factors of mortality in patients with rheumatoid arthritis (RA) with interstitial lung disease (ILD).

Methods

Using the 1997–2013 Taiwanese National Health Insurance Research Database, we identified 32 289 incident patients with RA by using International Classification of Diseases, Ninth Revision codes from 2001 to 2013, and 214 patients developed ILD subsequently. We matched (1:10) RA-ILD with controls for sex, age, time of ILD diagnosis and disease duration. In addition, we conducted propensity score matching (PSM) (1:1) for selected comorbidities to choose RA-ILD patients and controls. Using the Cox proportional hazard model, we estimated the association of mortality with ILD for the two matched populations and assessed factors associated with mortality among 214 RA-ILD patients, shown as adjusted HRs (aHRs) with 95% CIs.

Results

In the populations selected before and after PSM, we included 164 and 155 patients with RA-ILD and 1640 and 155 controls, respectively. ILD was associated with mortality in the population before PSM (aHR, 1.73; 95% CI 1.19 to 2.52) and in the PSM population (HR 4.38; 95% CI 2.03 to 9.43). Among 214 patients with RA-ILD, age (aHR 1.04; 95% CI 1.03 to 1.08), chronic obstructive pulmonary disease (COPD) (aHR 2.12; 95% CI 1.25 to 3.58), diabetes mellitus (DM) with end-organ damage and corticosteroid dose (prednisolone equivalent, mg/day) (aHR 1.09; 95% CI 1.07 to 1.11) were associated with mortality in RA-ILD.

Conclusion

This population-based cohort study showed that ILD was associated with risk of mortality in patients with RA, and risk factors associated with mortality in patients with RA-ILD included age, COPD, DM with end-organ damage and average daily prednisolone dose.