Pulmonary hypertension in interstitial lung disease and in chronic obstructive pulmonary disease: different entities?

PURPOSE OF REVIEW: Pulmonary hypertension (PH) is a common complication of both chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD), classified as Group 3 PH. To which extent PH presents and behaves similarly in COPD and ILD is unclear. This review examines the similarities and differences in pathogenesis, clinical presentation, natural history and treatment response of PH in COPD and ILD. RECENT FINDINGS: The latest studies on PH in chronic lung disease have re-evaluated the role of traditionally held etiopathogenetic factors such as tobacco exposure and hypoxia, although new ones such as airborne pollutant and genetic mutations are increasingly recognized. We examine common and diverging factors involved in PH development in COPD and ILD, as well as common and diverging clinical features of presentation, natural history and response to treatment and highlight areas for future research. SUMMARY: The development of PH in lung disease significantly worsens the morbidity and mortality of patients with COPD and ILD. However, recent findings show importance of recognizing distinct patterns and behaviors of pulmonary vascular disease, taking into account the specific underlying lung disease and severity of the hemodynamic involvement. Further studies are needed to build evidence on these aspects, especially in early disease.

Nitrosative and Oxidative Stress, Reduced Antioxidant Capacity, and Fiber Type Switch in Iron-Deficient COPD Patients: Analysis of Muscle and Systemic Compartments.

We hypothesized that a rise in the levels of oxidative/nitrosative stress markers and a decline in antioxidants might take place in systemic and muscle compartments of chronic obstructive pulmonary disease (COPD) patients with non-anemic iron deficiency. In COPD patients with/without iron depletion (n = 20/group), markers of oxidative/nitrosative stress and antioxidants were determined in blood and vastus lateralis (biopsies, muscle fiber phenotype). Iron metabolism, exercise, and limb muscle strength were assessed in all patients. In iron-deficient COPD compared to non-iron deficient patients, oxidative (lipofuscin) and nitrosative stress levels were greater in muscle and blood compartments and proportions of fast-twitch fibers, whereas levels of mitochondrial superoxide dismutase (SOD) and Trolox equivalent antioxidant capacity (TEAC) decreased. In severe COPD, nitrosative stress and reduced antioxidant capacity were demonstrated in vastus lateralis and systemic compartments of iron-deficient patients. The slow- to fast-twitch muscle fiber switch towards a less resistant phenotype was significantly more prominent in muscles of these patients. Iron deficiency is associated with a specific pattern of nitrosative and oxidative stress and reduced antioxidant capacity in severe COPD irrespective of quadriceps muscle function. In clinical settings, parameters of iron metabolism and content should be routinely quantify given its implications in redox balance and exercise tolerance.

Iron Depletion in Systemic and Muscle Compartments Defines a Specific Phenotype of Severe COPD in Female and Male Patients: Implications in Exercise Tolerance.

We hypothesized that iron content and regulatory factors, which may be involved in exercise tolerance, are differentially expressed in systemic and muscle compartments in iron deficient severe chronic obstructive pulmonary disease (COPD) patients. In the vastus lateralis and blood of severe COPD patients with/without iron depletion, iron content and regulators, exercise capacity, and muscle function were evaluated in 40 severe COPD patients: non-iron deficiency (NID) and iron deficiency (ID) (20 patients/group). In ID compared to NID patients, exercise capacity, muscle iron and ferritin content, serum transferrin saturation, hepcidin-25, and hemojuvelin decreased, while serum transferrin and soluble transferrin receptor and muscle IRP-1 and IRP-2 increased. Among all COPD, a significant positive correlation was detected between FEV1 and serum transferrin saturation. In ID patients, significant positive correlations were detected between serum ferritin, hepcidin, and muscle iron content and exercise tolerance and between muscle IRP-2 and serum ferritin and hepcidin levels. In ID severe COPD patients, iron content and its regulators are differentially expressed. A potential crosstalk between systemic and muscle compartments was observed in the ID patients. Lung function and exercise capacity were associated with several markers of iron metabolism regulation. Iron status should be included in the overall assessment of COPD patients given its implications in their exercise performance.

Predictors and changes of physical activity in idiopathic pulmonary fibrosis.

BACKGROUND: Different clinical predictors of physical activity (PA) have been described in idiopathic pulmonary fibrosis (IPF), but studies are lacking evaluating the potential role of muscle strength and anxiety and depression symptoms in PA limitation. Moreover, little is known about the impact of changes in PA in the course of the disease. The aim of the present study was to investigate the relationship between baseline PA and a wide range of variables in IPF, to assess its longitudinal changes at 12 months and its impact on progression free-survival. METHODS: PA was assessed by accelerometer and physiological, clinical, psychological factors and health-related quality of life were evaluated in subjects with IPF at baseline and at 12 month follow-up. Predictors of PA were determined at baseline, evolution of PA parameters was described and the prognostic role of PA evolution was also established. RESULTS: Forty participants with IPF were included and 22 completed the follow-up. At baseline, subjects performed 5765 (3442) daily steps and spent 64 (44) minutes/day in moderate to vigorous PA. Multivariate regression models showed that at baseline, a lower six-minute walked distance, lower quadriceps strength (QMVC), and a higher depression score in the Hospital Anxiety and Depression scale were associated to lower daily step number. In addition, being in (Gender-Age-Physiology) GAP III stage, having a BMI ≥ 25 kg/m2 and lower QMVC or maximum inspiratory pressure were factors associated with sedentary behaviour. Adjusted for age, gender and forced vital capacity (FVC) (%pred.) a lower progression-free survival was evidenced in those subjects that decreased PA compared to those that maintained, or even increased it, at 12 months [HR 12.1 (95% CI, 1.9-78.8); p = 0.009]. CONCLUSION: Among a wide range of variables, muscle strength and depression symptoms have a predominant role in PA in IPF patients. Daily PA behaviour and its evolution should be considered in IPF clinical assessment and as a potential complementary indicator of disease prognosis.

Intravenous Iron Replacement Improves Exercise Tolerance in COPD: A Single-Blind Randomized Trial.

INTRODUCTION: Iron deficiency affects exercise capacity because of the critical role iron plays in the optimal functioning of skeletal muscle metabolism. We hypothesized that intravenous iron may improve exercise tolerance, quality of life (QoL), and daily physical activity (DPA) in patients with chronic obstructive pulmonary disease (COPD). METHODS: This was a placebo-controlled, single-blind, parallel-group, randomized clinical trial. Iron deficiency was defined as a ferritin level<100ng/mL or a ferritin level between 100 and 299ng/mL with a transferrin saturation<20%, with or without mild anaemia. Patients were randomized at a 2:1 ratio to receive intravenous ferric carboxymaltose or placebo. The primary objective was to investigate whether intravenous iron replacement improved endurance time from baseline by at least 33%. The secondary objectives were to evaluate impact on QoL using the COPD Assessment Test (CAT) and on DPA by accelerometry. RESULTS: We included 66 patients, 44 (66.7%) in the intervention group and 22 (33.3%) in the placebo group. Among patients receiving ferric carboxymaltose, 23 (52.3%) achieved the primary endpoint compared to 4 (18.2%) in the placebo group [p=0.009; relative risk 3.12, (95% CI, 1.19-8.12)]. CAT score decreased -3 (-6.0-1.3) points from baseline in the intervention group (p=0.007), in contrast to placebo group [-1 (-4.0-2.3) points, p=0.236] with no differences in DPA and adverse events in both groups. CONCLUSIONS: Iron replacement improved exercise capacity and QoL in stable COPD patients with iron deficiency. The treatment was well tolerated. CLINICAL TRIAL REGISTRATION: EudraCT 2016-001238-89.

Impact of high-flow oxygen therapy during exercise in idiopathic pulmonary fibrosis: a pilot crossover clinical trial.

BACKGROUND: Supplemental oxygen delivered with standard oxygen therapy (SOT) improves exercise capacity in patients with idiopathic pulmonary fibrosis (IPF). Although high-flow nasal cannula oxygen therapy (HFNC) improves oxygenation in other respiratory diseases, its impact on exercise performance has never been evaluated in IPF patients. We hypothesized that HFNC may improve exercise capacity in IPF subjects compared to SOT. METHODS: This was a prospective, crossover, pilot randomized trial that compared both oxygenation methods during a constant submaximal cardiopulmonary exercise test (CPET) in IPF patients with exertional oxygen saturation (SpO2) ≤ 85% in the 6-min walking test. The primary outcome was endurance time (Tlim). Secondary outcomes were muscle oxygen saturation (StO2) and respiratory and leg symptoms. RESULTS: Ten IPF patients [71.7 (6) years old, 90% males] were included. FVC and DLCO were 58 ± 11% and 31 ± 13% pred. respectively. Tlim during CPET was significantly greater using HFNC compared to SOT [494 ± 173 vs. 381 ± 137 s, p = 0.01]. HFNC also associated with a higher increase in inspiratory capacity (IC) [19.4 ± 14.2 vs. 7.1 ± 8.9%, respectively; p = 0.04], and a similar trend was observed in StO2 during exercise. No differences were found in respiratory or leg symptoms between the two oxygen devices. CONCLUSIONS: This is the first study demonstrating that HFNC oxygen therapy improves exercise tolerance better than SOT in IPF patients with exertional desaturation. This might be explained by changes in ventilatory mechanics and muscle oxygenation. Further and larger studies are needed to confirm the benefits of HFNC in IPF patients and its potential usefulness in rehabilitation programs.

Iron Replacement and Redox Balance in Non-Anemic and Mildly Anemic Iron Deficiency COPD Patients: Insights from a Clinical Trial.

In COPD patients, non-anemic iron deficiency (NAID) is a common systemic manifestation. We hypothesized that in COPD patients with NAID, iron therapy may improve systemic oxidative stress. The FACE (Ferinject assessment in patients with COPD and iron deficiency to improve exercise tolerance) study was a single-blind, unicentric, parallel-group, placebo-controlled clinical trial (trial registry: 2016-001238-89). Sixty-six patients were enrolled (randomization 2:1): iron arm, n = 44 and placebo arm, n = 22, with similar clinical characteristics. Serum levels of 3-nitrotyrosine, MDA-protein adducts, and reactive carbonyls, catalase, superoxide dismutase (SOD), glutathione, Trolox equivalent antioxidant capacity (TEAC), and iron metabolism biomarkers were quantified in both groups. In the iron-treated patients compared to placebo, MDA-protein adducts and 3-nitrotyrosine serum levels significantly declined, while those of GSH increased and iron metabolism parameters significantly improved. Hepcidin was associated with iron status parameters. This randomized clinical trial evidenced that iron replacement elicited a decline in serum oxidative stress markers along with an improvement in GSH levels in patients with stable severe COPD. Hepcidin may be a surrogate biomarker of iron status and metabolism in patients with chronic respiratory diseases. These findings have potential clinical implications in the management of patients with severe COPD.

Feasibility, tolerability, and effects of exercise-based prehabilitation after neoadjuvant therapy in esophagogastric cancer patients undergoing surgery: an interventional pilot study.

Patients requiring surgery for locally advanced esophagogastric cancer often require neoadjuvant therapy (NAT), which may have a detrimental impact on cardiorespiratory reserve. The aims of this study were to investigate the feasibility and tolerability of a 5-week preoperative high-intensity interval training program after NAT, and to assess the potential effects of the training protocol on exercise capacity, muscle function, and health-related quality of life (HRQL). We prospectively studied consecutive patients with resectable locally advanced esophageal and gastric cancer in whom NAT was planned (chemo- or chemoradiotherapy). Feasibility was assessed with the TELOS (Technological, Economics, Legal, Operational, and Scheduling) components, and data on exercise tolerability (attendance and occurrence of adverse or unexpected events). Exercise capacity was assessed with peak oxygen uptake (VO2peak) in a cardiopulmonary exercise test at baseline, post-NAT, and following completion of a high-intensity interval exercise training (25 sessions). Changes in muscle strength and HRQL were also assessed. Of 33 recruited subjects (mean age 65 years), 17 received chemoradiotherapy and 16 chemotherapy. All the TELOS components were addressed before starting the intervention; from a total of 17 questions considered as relevant for a successful implementation, seven required specific actions to prevent potential concerns. Patients attended a mean of 19.4 (6.4) exercise sessions. The predefined level of attendance (≥15 sessions of scheduled sessions) was achieved in 27 out of 33 (81.8%) patients. Workload progression was adequate in 24 patients (72.7%). No major adverse events occurred. VO2peak decreased significantly between baseline and post-NAT (19.3 vs. 15.5 mL/Kg/min, P < 0.05). Exercise led to a significant improvement of VO2peak (15.5 vs. 19.6 mL/kg/min, P < 0.05). Exercise training was associated with clinically relevant improvements in some domains of HRQL, with the social and role function increasing by 10.5 and 11.6 points, respectively, and appetite loss and fatigue declining by 16 and 10.5, respectively. We conclude that a structured exercise training intervention is feasible and safe following NAT in patients with esophagogastric cancer, and it has positive effects to restore exercise capacity to baseline levels within 5 weeks with some improvements in HRQL.

Determinants of the Appearance and Progression of Early-Onset Chronic Obstructive Pulmonary Disease in Young Adults. A Case-Control Study with Follow-up. / EARLY COPD: determinantes de la aparición y progresión de la enfermedad pulmonar obstructiva crónica en adultos jóvenes. Protocolo de un estudio caso-control con seguimiento.

INTRODUCTION AND OBJECTIVES: Determinants of chronic obstructive pulmonary disease (COPD) in the early stages of its natural history are not well known. Improving our knowledge of these factors will help to design interventions that can modify prognosis. Study objectives are: a) to characterize a COPD population of young adults aged 35-50 years from a multidimensional point of view; b) to compare these patients with smokers with normal lung function; and c) to create a cohort of young adults aged 35-50 years (smokers or former smokers), with and without COPD, who will be followed in the future to improve understanding of the natural history of the disease. PARTICIPANTS AND METHOD: This is a case-control multicenter study aimed at establishing a well-characterized cohort of young adults, smokers or former-smokers, with and without COPD, for subsequent follow-up. A total of 311 participants (101 cases and 210 controls) were selected from approximately 30 primary care settings and 12 hospitals in 8 Spanish regions. Subjects were smokers or former smokers (>10 pack-years) aged 35-50 years. Diagnosis of COPD was based on a post-bronchodilator result of FEV1/FVC<70%. The main study variables were: questionnaires on health, symptoms, exacerbations and daily physical activity, lung function tests, blood and sputum samples, and low-dose computed tomography. In the statistical analysis, COPD patient characteristics will be described and compared with control subjects using a logistic regression analysis.