Dysregulation in CD39/CD73 Axis May Trigger the Upsurge of the Immune Suppressive Agent Adenosine in OSA Patients

Introduction Although higher incidence of cancer represents a major burden for obstructive sleep apnea (OSA) patients, the molecular pathways driving this association are not completely understood. Interestingly, adenosinergic signaling has emerged as a powerful immune checkpoint driving tumor development and progression. Methods Here, we explored the expression of the adenosinergic ecto-enzymes CD39 and CD73 in T-lymphocytes of OSA patients without any evidence of cancer, as well as their soluble forms in plasma (sCD39 and sCD73), along with adenosine. In addition, we explored the role of intermittent hypoxia (IH) in this context by in vitro models. Results Our results showed that CD39 is upregulated while CD73 is downregulated in OSA T-cells’ membrane. Moreover, our findings suggest that IH, through HIF-1, mediates the upregulation of both CD39 and CD73; and that CD73 downregulation could be mediated by a higher release of sCD73 by OSA T-lymphocytes. Importantly, we found that both sCD39 and sCD73 are upregulated in OSA plasma, suggesting T-lymphocytes as a potential source for plasmatic sCD73. Finally, our data propose the alterations in CD39/CD73 axis could underlie the upsurge of adenosine levels in the plasma of OSA patients. Conclusion Our study reveals a hypoxia-mediated alteration of the CD39/CD73 axis in OSA patients, which could trigger ADO upregulation, thus potentially contributing to the immune suppressive environment and ultimately facilitating tumor development and progression. Therefore, our data highlights the need for new longitudinal studies evaluating CD39 and/or CD73 as potential cancer-risk prognostic biomarkers in OSA patients. (AU)

Dysregulation in CD39/CD73 Axis May Trigger the Upsurge of the Immune Suppressive Agent Adenosine in OSA Patients.

INTRODUCTION: Although higher incidence of cancer represents a major burden for obstructive sleep apnea (OSA) patients, the molecular pathways driving this association are not completely understood. Interestingly, adenosinergic signaling has emerged as a powerful immune checkpoint driving tumor development and progression. METHODS: Here, we explored the expression of the adenosinergic ecto-enzymes CD39 and CD73 in T-lymphocytes of OSA patients without any evidence of cancer, as well as their soluble forms in plasma (sCD39 and sCD73), along with adenosine. In addition, we explored the role of intermittent hypoxia (IH) in this context by in vitro models. RESULTS: Our results showed that CD39 is upregulated while CD73 is downregulated in OSA T-cells' membrane. Moreover, our findings suggest that IH, through HIF-1, mediates the upregulation of both CD39 and CD73; and that CD73 downregulation could be mediated by a higher release of sCD73 by OSA T-lymphocytes. Importantly, we found that both sCD39 and sCD73 are upregulated in OSA plasma, suggesting T-lymphocytes as a potential source for plasmatic sCD73. Finally, our data propose the alterations in CD39/CD73 axis could underlie the upsurge of adenosine levels in the plasma of OSA patients. CONCLUSION: Our study reveals a hypoxia-mediated alteration of the CD39/CD73 axis in OSA patients, which could trigger ADO upregulation, thus potentially contributing to the immune suppressive environment and ultimately facilitating tumor development and progression. Therefore, our data highlights the need for new longitudinal studies evaluating CD39 and/or CD73 as potential cancer-risk prognostic biomarkers in OSA patients.

Dynamic hyperinflation is a risk factor for mortality and severe exacerbations in COPD patients.

OBJECTIVE: To assess if dynamic hyperinflation is an independent risk factor for mortality and severe exacerbations in COPD patients. METHODS: A cohort of 141 patients with stable COPD and moderate to very severe airflow limitation, treated according to conventional guidelines, was followed for a median of 9 years. Clinical characteristics were recorded and arterial blood gases, pulmonary function tests, 6-min walk and incremental exercise test with measurement of respiratory pattern and operative lung volumes were performed. Endpoints were all-cause mortality and hospitalization for COPD exacerbation. RESULTS: 58 patients died during the follow-up period (1228 patients x year). The mortality rate was higher in patients with dynamic hyperinflation (n = 106) than in those without it (n = 35) (14.6; 95% CI, 14.5-14.8 vs. 7.2; 95% CI, 7.1-7.4 per 1000 patients-year). After adjusting for sex, age, body mass index, pack-years and treatment with inhaled corticosteroids, dynamic hyperinflation was associated with a higher mortality risk (adjusted hazard ratio [aHR], 2.725; 95% CI, 1.010-8.161), and in a multivariate model, comorbidity, peak oxygen uptake and dynamic hyperinflation were retained as independent predictors of mortality. The time until first severe exacerbation was shorter for patients with dynamic hyperinflation (aHR, 3.961; 95% CI, 1.385-11.328), and dynamic hyperinflation, FEV1 and diffusing capacity were retained as independent risk factors for severe exacerbation. Moreover, patients with dynamic hyperinflation had a higher hospitalization risk than those without it (adjusted incidence rate ratio, 1.574; 95% CI, 1.087-2.581). CONCLUSION: In stable COPD patients, dynamic hyperinflation is an independent prognostic factor for mortality and severe exacerbations.

Continuous Positive Airway Pressure Effect on Progression of Retinal Disease in Patients with Sleep Apnea and Nonproliferative Diabetic Retinopathy: A Randomized Clinical Trial.

Rationale: Obstructive sleep apnea (OSA) is associated with impaired glycemic control and a higher risk of vascular complications, such as diabetic retinopathy. However, the effect of apnea-hypopnea suppression on retinal disease progression is unclear. Objectives: To evaluate the efficacy and safety of continuous positive airway pressure (CPAP) for the reduction of retinal lesions in patients with non-proliferative diabetic retinopathy (NPDR) and OSA. Methods: This open-label, parallel-group, randomized controlled trial was conducted between October 2016 and February 2020 at a university hospital in Spain. The date of final follow-up was March 2, 2021. Eighty-three patients with OSA and mild to moderate NPDR receiving stable treatment were randomized to receive CPAP and usual care (43 patients with 79 available eyes) or usual care alone (40 patients with 67 available eyes) for 52 weeks. The primary outcomes were the change in the percentage of eyes with retinal exudates and the number of retinal microhemorrhages from baseline to week 52. We also assessed the effects of both interventions on retinal thickness by means of optical coherence tomography, serum concentrations of glycated hemoglobin, blood pressure, lipid concentrations, sleepiness, and quality of life. Results: Fifty-two weeks of CPAP treatment was associated with reductions from baseline in the percentage of eyes with hard exudates (overall difference, -21.7%; P = 0.035) and in optical coherence tomography indices of retinal edema, including central subfield thickness and cube volume. However, in patients who met prespecified criteria for CPAP adherence, treatment was also associated with a higher number of retinal microhemorrhages at 52 weeks (intergroup adjusted difference, 6.0 [95% confidence interval, 0.6-11.5]; P = 0.029), which was directly related to prescribed pressure levels. CPAP treatment also improved glycemic control, sleepiness, and general health-related quality of life. Conclusions: In patients with OSA and NPDR, long-term CPAP treatment in addition to usual care may result in slower progression of retinal disease, although it could also induce an increase in retinal microhemorrhages. Clinical trial registered with www.clinicaltrials.gov (NCT02874313).

SMAD4 Expression in Monocytes as a Potential Biomarker for Atherosclerosis Risk in Patients with Obstructive Sleep Apnea.

Obstructive sleep apnea (OSA) patients are at special risk of suffering atherosclerosis, leading to major cardiovascular diseases. Notably, the transforming growth factor (TGF-ß) plays a crucial role in the development and progression of atherosclerosis. In this context, the central regulator of TGF-ß pathway, SMAD4 (small mother against decapentaplegic homolog 4), has been previously reported to be augmented in OSA patients, which levels were even higher in patients with concomitant cardiometabolic diseases. Here, we analyzed soluble and intracellular SMAD4 levels in plasma and monocytes from OSA patients and non-apneic subjects, with or without early subclinical atherosclerosis (eSA). In addition, we used in vitro and ex vivo models to explore the mechanisms underlying SMAD4 upregulation and release. Our study confirmed elevated sSMAD4 levels in OSA patients and identified that its levels were even higher in those OSA patients with eSA. Moreover, we demonstrated that SMAD4 is overexpressed in OSA monocytes and that intermittent hypoxia contributes to SMAD4 upregulation and release in a process mediated by NLRP3. In conclusion, this study highlights the potential role of sSMAD4 as a biomarker for atherosclerosis risk in OSA patients and provides new insights into the mechanisms underlying its upregulation and release to the extracellular space.

Continuous Positive Airway Pressure Effect on Albuminuria Progression in Patients with Obstructive Sleep Apnea and Diabetic Kidney Disease: A Randomized Clinical Trial.

Rationale: Obstructive sleep apnea (OSA) is associated with impaired glycemic control and a higher risk of vascular complications, such as diabetic kidney disease (DKD). However, the effect of apnea-hypopnea suppression on DKD progression is unclear. Objectives: To assess the effect of continuous positive airway pressure (CPAP) on the urinary albumin-to-creatinine ratio (UACR) in patients with DKD and OSA. Methods: In a 52-week, multicentric, open-label, parallel, and randomized clinical trial, 185 patients with OSA and DKD were randomized to CPAP and usual care (n = 93) or usual care alone (n = 92). Measurements and Main Results: UACR, estimated glomerular filtration rate, serum concentrations of creatinine and glycated hemoglobin, insulin resistance, lipid concentrations, sleepiness, and quality of life. A 52-week change in UACR from baseline did not differ significantly between the CPAP group and the usual-care group. However, in per-protocol analyses that included 125 participants who met prespecified criteria for adherence, CPAP treatment was associated with a great reduction in UACR (mean difference, -10.56% [95% confidence interval, -19.06 to -2.06]; P = 0.015). CPAP effect on UACR was higher in nonsleepy patients with more severe OSA, worse renal function, and a more recent diagnosis of DKD. CPAP treatment also improved glycemic control and insulin resistance, as well as sleepiness and health-related quality of life. Conclusions: In patients with OSA and DKD, the prescription of CPAP did not result in a statistically significant reduction in albuminuria. However, good adherence to CPAP treatment in addition to usual care may result in long-term albuminuria reduction compared with usual care alone. Clinical trial registered with www.clinicaltrials.gov (NCT02816762).

Inflammasome Activation: A Keystone of Proinflammatory Response in Obstructive Sleep Apnea.

Rationale: As the mechanism that links obstructive sleep apnea (OSA) with the regulation of inflammatory response is not well known, it is important to understand the inflammasome activation, mainly of NLRP3 (nucleotide-binding oligomerization domain-like receptor 3). Objectives: To assess the NLRP3 activity in patients with severe OSA and to identify its role in the systemic inflammatory response of patients with OSA. Methods: We analyzed the NLRP3 activity as well as key components of the inflammasome cascade, such as adaptor molecule apoptosis-associated speck-like protein, caspase-1, Gasdermin D, IL-1ß, IL-18, and tissue factor, in monocytes and plasma from patients with severe OSA and control subjects without sleep apnea. We explored the association of the different key markers with inflammatory comorbidities. Measurements and Main Results: Monocytes from patients with severe OSA presented higher NLRP3 activity than those from control subjects, which directly correlated with the apnea-hypopnea index and hypoxemic indices. NLRP3 overactivity triggered inflammatory cytokines (IL-1ß and IL-18) via caspase-1 and increased Gasdermin D, allowing for tissue factor to be released. In vitro models confirmed that monocytes increase NLRP3 signaling under intermittent hypoxia in a hypoxia-inducible factor-1α-dependent manner, and/or in combination with plasma from patients with OSA. Plasma concentrations of tissue factor were higher in patients with OSA with systemic inflammatory comorbidities than in those without them. Conclusions: In patients with severe OSA, NLRP3 activation might be a linking mechanism between intermittent hypoxia and other OSA-induced immediate changes with the development of systemic inflammatory response.

Effect of CPAP treatment on BP in resistant hypertensive patients according to the BP dipping pattern and the presence of nocturnal hypertension.

High heterogeneity in the blood pressure (BP) response to continuous positive airway pressure (CPAP) exists in patients with resistant hypertension (RH). Only nondipper normotensive and hypertensive patients exhibited BP reductions when treated with CPAP; the baseline BP dipping pattern has been proposed as a predictor of BP response to CPAP but has never been explored in patients with RH. This study aimed to assess the effect of CPAP on BP in subjects with RH with respect to BP dipping pattern or nocturnal hypertension. This is an ancillary study of the SARAH study. RH subjects with an apnea/hypopnea index (AHI) ≥ 15/h and who received CPAP treatment for 1 year were included. Subjects underwent a sleep study and ambulatory BP monitoring (ABPM) at baseline and at the 1-year follow-up. Eighty-nine RH subjects were included. The subjects were mainly male (77.5%) and obese, with a mean age of 66 years (25th-75th percentile; 59.0; 70.0) and an AHI of 32.7/h (25th-75th percentile; 25.0; 54.7). A total of 68.5% of participants were nondippers, and 71.9% had nocturnal hypertension. After 1 year of CPAP, no significant differences in ABPM parameters were observed between dippers and nondippers. According to nighttime BP, subjects with nocturnal normotension did not show significant changes in ABPM parameters, while nocturnal hypertensive subjects achieved a significant reduction in mean nighttime BP of -4.38 mmHg (-7.10 to -1.66). The adjusted difference between groups was 3.04 (-2.25 to 8.34), which was not significant. This study shows that the BP response to CPAP in patients with RH does not differ according to the BP dipping pattern (dipper and nondipper) and suggests a differential response according to the presence of nocturnal hypertension (ClinicalTrials.gov: NCT03002558).

Procoagulant State of Sleep Apnea Depends on Systemic Inflammation and Endothelial Damage.

INTRODUCTION: Growing evidence shows a hypercoagulable state in obstructive sleep apnea (OSA) that could be a risk factor for thromboembolic disease. OBJECTIVES: We aimed to elucidate mechanisms involved in the procoagulant profile observed in patients with OSA and to investigate the potential utility of global tests in its characterization. METHODS: Thirty-eight patients with severe OSA without previous history of thrombosis and nineteen healthy age- and sex-matched controls were included. Kinetic of clot formation was determined using rotational thromboelastometry. Haemostatic capacity of plasma and microparticles was determined by Calibrated Automated Thrombinography. Platelet surface receptors, activation markers and formation of platelet/leukocytes aggregates were analyzed by flow cytometry. RESULTS: Thromboelastometry showed a procoagulant state in patients with OSA that did not seem to be related to a basal activation of platelets but by the increased existence of platelet/leukocyte aggregates. Patients with OSA presented many signs of endothelial damage such as increased plasma levels of E-selectin and cfDNA and enhanced thrombin generation due to the presence of microparticles rich in tissue-factor, which is related to OSA severity. CONCLUSIONS: OSA induces an enhancement in the dynamics of clot formation which appears to be caused by at least two pathological mechanisms. First, a greater formation of platelet-leukocyte aggregates; secondly, endothelial damage which provokes a greater procoagulant potential due to the increase in tissue factor-rich microparticles. Moreover, this study has identified thromboelastometry and thrombin generation assay as useful tools to evaluate the prothrombotic state in these patients.

Intermittent Hypoxia Mediates Paraspeckle Protein-1 Upregulation in Sleep Apnea.

As some evidence suggests that hypoxia might be an inducer of nuclear paraspeckle formation, we explore whether intermittent hypoxia (IH)-mediated paraspeckle protein-1 (PSPC1) overexpression might contribute to the activation of tumor growth factor (TGF)ß-SMAD pathway in patients with obstructive sleep apnea (OSA). This activation would promote changes in intracellular signaling that would explain the increased cancer aggressiveness reported in these patients. Here, we show that patients with OSA exhibit elevated PSPC1 levels both in plasma and in monocytes. Our data suggest that PSPC1 is ultimately delivered to the plasma through its cleavage from OSA monocytes by matrix metalloproteinase-2 (MMP2). In addition, IH promotes PSPC1, TGFß, and MMP2 expression in monocytes through the hypoxia-inducible factor. Lastly, both PSPC1 and TGFß induce increased expression of genes that drive the epithelial-to-mesenchymal transition. Our study details the mechanism by which hypoxemia upmodulates the extracellular release of PSPC1 by means of MMP2, such that plasma PSPC1 together with TGFß activation signaling further promotes tumor metastasis and supports cancer aggressiveness in patients with OSA.

Contribution of sleep characteristics to the association between obstructive sleep apnea and dyslipidemia.

OBJECTIVES/BACKGROUND: Little information is available about the association of obstructive sleep apnea (OSA) with atherogenic dyslipidemia and the contribution of sleep characteristics to lipid alterations. We compare dyslipidemia prevalence among non-apneic subjects and mild-severe OSA patients to identify the sleep characteristics that are independently associated with dyslipidemia and serum lipid levels in OSA patients. PATIENTS/METHODS: We recruited 809 consecutive patients who had been referred for polysomnography study by OSA suspicion. Anthropometric characteristics, body composition and comorbidities were recorded. Spirometry and 24-h ambulatory blood pressure monitoring were performed the same day of the sleep study. The day after attended polysomnography, fasting blood samples were drawn to measure the lipid profile. RESULTS: Dyslipidemia prevalence increased with the presence of OSA, from non-OSA subjects to mild, moderate and severe OSA patients (31%, 33%, 42% and 51%, respectively; p < 0.001). After adjusting for sex, age, body mass index and smoking habit, only severe OSA had an independent association with dyslipidemia when compared to non-OSA subjects (adjusted odds ratio 1.71, 95%CI 1.09 to 2.69, p = 0.019). In OSA patients, multivariate logistic regression identified active smoking, apnea-hypopnea index (AHI) and mean nocturnal saturation as variables independently associated with dyslipidemia. However, in these patients, arousal index, slow wave sleep duration and REM latency were also independently associated with cholesterol and low-density lipoprotein levels. CONCLUSIONS: The association between dyslipidemia and OSA is limited to severe patients, with high AHI and nocturnal hypoxemia. However, sleep fragmentation and increased sympathetic activity could also contribute to OSA-related lipid dysregulation.

Effect of Dynamic Hyperinflation on Cardiac Response to Exercise of Patients With Chronic Obstructive Pulmonary Disease.

INTRODUCTION: Although the major limitation to exercise performance in patients with COPD is dynamic hyperinflation (DH), little is known about its relation with cardiac response to exercise. Our objectives were to compare the exercise response of stroke volume (SV) and cardiac output (CO) between COPD patients with or without DH and control subjects, and to assess the main determinants. METHODS: Fifty-seven stable COPD patients without cardiac comorbidity and 25 healthy subjects were recruited. Clinical evaluation, baseline function tests, computed tomography and echocardiography were conducted in all subjects. Patients performed consecutive incremental exercise tests with measurement of operating lung volumes and non-invasive measurement of SV, CO and oxygen uptake (VO2) by an inert gas rebreathing method. Biomarkers of systemic inflammation and oxidative stress, tissue damage/repair, cardiac involvement and airway inflammation were measured. RESULTS: COPD patients showed a lower SV/VO2 slope than control subjects, while CO response was compensated by a higher heart rate increase. COPD patients with DH experienced a reduction of SV/VO2 and CO/VO2 compared to those without DH. In COPD patients, the end-expiratory lung volume (EELV) increase was related to SV/VO2 and CO/VO2 slopes, and it was the only independent predictor of cardiac response to exercise. However, in the regression models without EELV, plasma IL-1ß and high-sensitivity cardiac troponin T were also retained as independent predictors of SV/VO2 slope. CONCLUSION: Dynamic hyperinflation decreases the cardiac response to exercise of COPD patients. This effect is related to systemic inflammation and myocardial stress but not with left ventricle diastolic dysfunction.

Effect of Dynamic Hyperinflation on Cardiac Response to Exercise of Patients With Chronic Obstructive Pulmonary Disease / Efecto de la hiperinsuflación dinámica en la respuesta cardíaca al ejercicio de pacientes con enfermedad pulmonar obstructiva crónica

Introduction: Although the major limitation to exercise performance in patients with COPD is dynamic hyperinflation (DH), little is known about its relation with cardiac response to exercise. Our objectives were to compare the exercise response of stroke volume (SV) and cardiac output (CO) between COPD patients with or without DH and control subjects, and to assess the main determinants.Methods: Fifty-seven stable COPD patients without cardiac comorbidity and 25 healthy subjects were recruited. Clinical evaluation, baseline function tests, computed tomography and echocardiography were conducted in all subjects. Patients performed consecutive incremental exercise tests with measurement of operating lung volumes and non-invasive measurement of SV, CO and oxygen uptake (VO2) by an inert gas rebreathing method. Biomarkers of systemic inflammation and oxidative stress, tissue damage/repair, cardiac involvement and airway inflammation were measured.Results: COPD patients showed a lower SV/VO2 slope than control subjects, while CO response was compensated by a higher heart rate increase. COPD patients with DH experienced a reduction of SV/VO2 and CO/VO2 compared to those without DH. In COPD patients, the end-expiratory lung volume (EELV) increase was related to SV/VO2 and CO/VO2 slopes, and it was the only independent predictor of cardiac response to exercise. However, in the regression models without EELV, plasma IL-1β and high-sensitivity cardiac troponin T were also retained as independent predictors of SV/VO2 slope.(AU)

Introducción: Aunque la principal limitación para el rendimiento durante el ejercicio en pacientes con EPOC es la hiperinsuflación dinámica (HD), se sabe poco sobre su relación con la respuesta cardíaca al ejercicio. Nuestros objetivos fueron comparar la respuesta al ejercicio del volumen sistólico (VS) y el gasto cardíaco (GC) entre los pacientes con EPOC con o sin HD y sujetos control, y evaluar los principales determinantes.Métodos: Se reclutaron 57 pacientes con EPOC estable sin comorbilidad cardíaca y 25 sujetos sanos. En todos los sujetos se realizó una evaluación clínica, pruebas de función basal, una tomografía computarizada y una ecocardiografía. Los pacientes realizaron pruebas de esfuerzo incrementales consecutivas con medición de los volúmenes pulmonares operativos y medición no invasiva del VS, el GC y el consumo de oxígeno (VO2) mediante un método de reinhalación de gas inerte. Se midieron los biomarcadores de inflamación sistémica y estrés oxidativo, daño/reparación tisular, afectación cardíaca e inflamación de las vías respiratorias.Resultados:Los pacientes con EPOC presentaron una curva más baja de VS/VO2 que los controles, mientras que la respuesta del GC se compensó con un mayor aumento del ritmo cardíaco. Los pacientes con EPOC e HD experimentaron una reducción de VS/VO2 y de GC/VO2 en comparación con aquellos sin HD. En los pacientes con EPOC, el aumento del volumen pulmonar teleespiratorio (EELV, por sus siglas en inglés) se relacionó con las curvas de VS/VO2 y GC/VO2, y fue el único factor predictivo independiente de la respuesta cardíaca al ejercicio. Sin embargo, en los modelos de regresión sin EELV, la IL-1β plasmática y la troponina T cardíaca ultrasensible también se mantuvieron como factores predictivos independientes de la curva de VS/VO2. (AU)

[Palliative Sedation at the End of Life: A Comparative Study of Chronic Obstructive Pulmonary Disease and Lung Cancer Patients].

BACKGROUND: Although patients with chronic obstructive pulmonary disease (COPD) receive poor-quality palliative care, information about the use of palliative sedation (PS) in the last days of life is very scarce. OBJECTIVES: To compare the use of PS in hospitalized patients who died from COPD or lung cancer and identify factors correlating with PS application. METHODS: In a retrospective observational cohort study, from 1,675 patients died at a teaching hospital between 2013 and 2015, 109 patients who died from COPD and 85 from lung cancer were compared. Sociodemographic data, clinical characteristics, health care resource utilization, application of PS and prescribed drugs were recorded. RESULTS: In the last 6 months of life, patients who died from COPD had more hospital admissions due to respiratory causes and less frequent support by a palliative home care team (PHCT). Meanwhile, during their last hospitalization, patients who died from COPD had fewer do-not-resuscitate orders and were subjected to more intensive care unit admissions and cardiopulmonary resuscitation maneuvers. PS was applied less frequently in patients who died from COPD than in those who died from lung cancer (31 vs. 53%, p = 0.002). Overall, previous use of opioid drugs, support by a PHCT, and a diagnosis of COPD (adjusted odds ratio 0.48, 95% CI: 0.26-0.89, p = 0.020) were retained as factors independently related to PS. In COPD patients, only previous use of opioid drugs was identified as a PS-related factor. CONCLUSION: During their last days of life, hospitalized COPD patients receive PS less frequently than patients with lung cancer.

Hypermethylation of Anti-oncogenic MicroRNA 7 is Increased in Emphysema Patients / La hipermetilación del microrna antioncogénico 7 se encuentra aumentada en pacientes con enfisema

INTRODUCTION: MicroRNA-7 (miR-7) has a suppressive role in lung cancer and alterations in its DNA methylation may contribute to tumorigenesis. As COPD patients with emphysema have a higher risk of lung cancer than other COPD phenotypes, we compared the miR-7 methylation status among smoker subjects and patients with various COPD phenotypes to identify its main determinants. METHODS: 30 smoker subjects without airflow limitation and 136 COPD patients without evidence of cancer were recruited in a prospective study. Clinical and functional characteristics were assessed and patients were classified into: frequent exacerbator, emphysema, chronic bronchitis and asthma COPD overlap (ACO). DNA collected from buccal epithelial samples was isolated and bisulfite modified. miR-7 methylation status was evaluated by quantitative methylation-specific polymerase chain reaction (qMSP). RESULTS: miR-7 Methylated levels were higher in COPD patients than in smokers without airflow limitation (23.7 ± 12.4 vs. 18.5 ± 8.8 %, p = 0.018). Among COPD patients, those with emphysema had higher values of methylated miR-7 (27.1 ± 10.2 %) than those with exacerbator (19.4 ± 9.9 %, p = 0.004), chronic bronchitis (17.3 ± 9.0 %, p = 0.002) or ACO phenotypes (16.0 ± 7.2 %, p = 0.010). After adjusting for clinical parameters, differences between emphysematous patients and those with other phenotypes were retained. In COPD patients, advanced age, mild-moderate airflow limitation, reduced diffusing capacity and increased functional residual capacity were identified as independent predictors of methylated miR-7 levels. CONCLUSION: The increase of miR-7 methylation levels experienced by COPD patients occurs mainly at the expense of the emphysema phenotype, which might contribute to explain the higher incidence of lung cancer in these patients

INTRODUCCIÓN: El microRNA-7 (miR-7) tiene un papel supresor en el cáncer de pulmón, y las alteraciones en la metilación de su DNA podrían contribuir a la tumorogénesis. Como los pacientes con EPOC y enfisema presentan un mayor riesgo de sufrir cáncer de pulmón frente a otros fenotipos de EPOC, comparamos la metilación de miR-7 entre los pacientes fumadores y los pacientes con varios fenotipos de EPOC para identificar sus factores determinantes principales. MÉTODOS: Se reclutaron para un estudio prospectivo 30 sujetos fumadores sin restricciones en el flujo aéreo y 136 pacientes con EPOC sin evidencia de cáncer. Se valoraron las características clínicas y funcionales y se clasificaron a los pacientes en: exacerbaciones frecuentes, enfisema, bronquitis crónica y solapamiento de asma y EPOC (ACO, por sus siglas en inglés). Se recogió ADN a partir de muestras de epitelio bucal, se aisló y se modificó con bisulfito. El estado de metilación del miR-7 se evaluó mediante la reacción cuantitativa en cadena de la polimerasa específica de la metilación (qMPS por sus siglas en inglés). RESULTADOS: Los niveles de metilación del miR-7 fueron más altos en los pacientes con EPOC que en los fumadores sin restricciones en el flujo aéreo (23,7 ± 12,4 frente a 18,5 ± 8,8%, p = 0,018). Entre los pacientes con EPOC, aquellos con enfisema presentaban valores más altos de miR-7 metilado (27,1 ± 10,2%) que aquellos con exacerbaciones (19,4 ± 9,9%, p = 0,004), bronquitis crónica (17,3 ± 9,0%, p = 0,002) o los fenotipos ACO (16,0 ± 7,2%, p = 0,010). Tras ajustar los resultados a los parámetros clínicos, las diferencias entre los pacientes enfisematosos y aquellos con otros fenotipos permanecieron. En los pacientes con EPOC, se identificaron como predictores independientes de los niveles de metilación del miR-7 a: la edad avanzada, limitación al flujo aéreo leve-moderada, capacidad de difusión reducida y capacidad residual funcional aumentada. CONCLUSIÓN: El aumento de los niveles de metilación del miR-7 que experimentan los pacientes con EPOC ocurre principalmente a expensas del fenotipo con enfisema, lo que podría contribuir a explicar la mayor incidencia de cáncer de pulmón en estos pacientes

SMAD4 Overexpression in Patients with Sleep Apnoea May Be Associated with Cardiometabolic Comorbidities.

Obstructive sleep apnoea (OSA) is associated with several diseases related to metabolic and cardiovascular risk. Although the mechanisms involved in the development of these disorders may vary, OSA patients frequently present an increase in transforming growth factor beta (TGFß), the activity of which is higher still in patients with hypertension, diabetes or cardiovascular morbidity. Smad4 is a member of the small mother against decapentaplegic homologue (Smad) family of signal transducers and acts as a central mediator of TGFß signalling pathways. In this study, we evaluate Smad4 protein and mRNA expression from 52 newly diagnosed OSA patients, with an apnoea-hypopnoea index (AHI) ≥30 and 26 healthy volunteers. These analyses reveal that OSA patients exhibit high levels of SMAD4 which correlates with variation in HIF1α, mTOR and circadian genes. Moreover, we associated high concentrations of Smad4 plasma protein with the presence of diabetes, dyslipidaemia and hypertension in these patients. Results suggest that increased levels of SMAD4, mediated by intermittent hypoxaemia and circadian rhythm deregulation, may be associated with cardiometabolic comorbidities in patients with sleep apnoea.

La disfunción de las pequeñas vías aéreas deteriora la calidad de vida de fumadores sin limitación al flujo aéreo / Small Airway Dysfunction Impairs Quality of Life Among Smokers With No Airflow Limitation

Introducción: La disfunción de las pequeñas vías aéreas (DPV) inducida por el tabaco contribuye precozmente a la patogenia de la limitación al flujo aéreo (LFA), aunque resulta poco conocida su repercusión en la percepción de salud. Se pretende evaluar la frecuencia de DPV en fumadores activos sin LFA y comparar la calidad de vida relacionada con la salud (CVRS) de no fumadores, fumadores sin DPV, fumadores con DPV y fumadores con LFA. Métodos: En 53 fumadores activos sin LFA, 20 fumadores con LFA y 20 no fumadores, se utilizaron los cuestionarios SF-36 y EuroQoL y se realizó oscilometría de impulsos, espirometría y determinación de las densidades de atenuación del parénquima pulmonar en inspiración y espiración máximas. Se consideró que existía DPV cuando la resistencia a 5 Hz (R5), la diferencia R5-R20 y el área de reactancia (AX) excedían su límite superior de la normalidad. Resultados: El 35,8% de los fumadores sin LFA tenía DPV. No se detectaron diferencias en los parámetros espirométricos ni la atenuación pulmonar entre los fumadores con o sin DPV y los no fumadores. Sin embargo, los fumadores con DPV presentaban una peor puntuación en los cuestionarios de CVRS que los fumadores sin DPV o los no fumadores, e intermedia a los fumadores con LFA. R5 y X5 fueron identificados como determinantes independientes de la CVRS en los fumadores sin LFA. Conclusiones: La DPV es frecuente en fumadores sin LFA, afectando a un tercio de los mismos, y condicionando de forma independiente su percepción de salud

Introduction: Small airway dysfunction (SAD) caused by smoking contributes to the early onset of airflow limitation (AFL), although its impact on patients’ perception of health is largely unknown. We aimed to evaluate the frequency of SAD in active smokers without AFL, and to compare health-related quality of life (HRQoL) of non-smokers, smokers without SAD, smokers with SAD, and smokers with AFL. Methods: A total of 53 active smokers without AFL, 20 smokers with AFL, and 20 non-smokers completed the SF-36 and EuroQoL questionnaires and performed impulse oscillometry and spirometry. Pulmonary parenchymal attenuation was determined in inspiration and expiration. SAD was determined to exist when resistance at 5Hz (R5), the difference between R5 and R20, and reactance area (AX) exceeded the upper limit of normal. Results: In total, 35.8% of smokers without AFL had SAD. No differences were detected in spirometric parameters or pulmonary attenuation between smokers with or without AFL and non-smokers. However, smokers with SAD had worse scores on HRQoL questionnaires than smokers without SAD or non-smokers, and scores compared to smokers with AFL were intermediate. R5 and X5 were identified as independent determinants of HRQoL in smokers without AFL. Conclusions: SAD is common in smokers without AFL, affecting one third of this population, and independently affecting their perception of health

Small Airway Dysfunction Impairs Quality of Life Among Smokers With No Airflow Limitation. / La disfunción de las pequeñas vías aéreas deteriora la calidad de vida de fumadores sin limitación al flujo aéreo.

INTRODUCTION: Small airway dysfunction (SAD) caused by smoking contributes to the early onset of airflow limitation (AFL), although its impact on patients' perception of health is largely unknown. We aimed to evaluate the frequency of SAD in active smokers without AFL, and to compare health-related quality of life (HRQoL) of non-smokers, smokers without SAD, smokers with SAD, and smokers with AFL. METHODS: A total of 53 active smokers without AFL, 20 smokers with AFL, and 20 non-smokers completed the SF-36 and EuroQoL questionnaires and performed impulse oscillometry and spirometry. Pulmonary parenchymal attenuation was determined in inspiration and expiration. SAD was determined to exist when resistance at 5Hz (R5), the difference between R5 and R20, and reactance area (AX) exceeded the upper limit of normal. RESULTS: In total, 35.8% of smokers without AFL had SAD. No differences were detected in spirometric parameters or pulmonary attenuation between smokers with or without AFL and non-smokers. However, smokers with SAD had worse scores on HRQoL questionnaires than smokers without SAD or non-smokers, and scores compared to smokers with AFL were intermediate. R5 and X5 were identified as independent determinants of HRQoL in smokers without AFL. CONCLUSIONS: SAD is common in smokers without AFL, affecting one third of this population, and independently affecting their perception of health.