Capacity In COPD Patients Research Articles

The effect of singing or playing melodica on disease symptoms, self-efficacy level and exercise capacity in chronic obstructive pulmonary patients: a randomized controlled study.

The aim of this randomized controlled experimental study is to determine the effect of singing or playing melodica activity applied to COPD patients on their symptoms, self-efficacy levels, and exercise capacities. The study was carried out in the chest diseases polyclinics of a hospital in Turkey between September 2020 and August 2021 with 30 patients: 15 in the control group and 15 in the song/melodica group. The data were collected with a patient information form and the scales examining disease symptoms, self-efficacy, and exercise capacity. The physical symptom, anxiety, Borg dyspnea, and fatigue scores of the disease in the post-test were significantly lower in the patients in the song/melodica group than those in the control group. In the post-test, the self-efficacy level, walking distance values were found to be significantly higher in the song/melodica group than in the control group. It is concluded that singing or playing melodica was an effective method in reducing the symptoms of the disease and enhancing the level of self-efficacy and exercise capacity in COPD patients.

Factors limiting exercise capacity in COPD patients

Introduction: Impaired exercise capacity in COPD patients leads to deterioration in their physical activity and quality of life. The aim of our study was to assess the exercise capacity of COPD patients using the 6-minute walk test (6MWT) and to determine the factors limiting their exercise capacity. Methods: Stable COPD patients were included in this study to assess their exercise capacity using the 6-minute walk test (6MWT) and to investigate the relationship between exercise capacity, functional status (FEV1), quadriceps muscle dysfunction (strength and endurance), and fat free mass index (FFMI). Results: 175 COPD patients (166 males and 9 females) aged between 40 and 86 years with a mean age of 67.95 years. The functional stages distribution according to GOLD was GOLDI: 19.43%, GOLDII: 30.29%, GOLDIII: 33.71%, GOLD IV: 16.57%. 25% of patients received long-term oxygen therapy (LTOT). The mean distance covered by COPD patients was 432.26 ± 129.731 meters, corresponding to 64.71 ± 19.04%. 56 (32%) COPD patients had exercise intolerance as assessed by the distance walked over 6 minutes (6MWD). A significant correlation was found between the 6MWD, quadriceps endurance (P<0.000) and FEV1 (p<0.002), whereas no correlation was found with MVC (P<0.039) and (FFMI) (P<0.062). Conclusion: Muscle dysfunction and the severity of bronchial obstruction are the factors most associated with impaired exercise capacity in COPD patients.

DNA damage and antioxidant capacity in COPD patients with and without lung cancer

Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation of the lower airways, and COPD patients show two to five times higher risk of lung cancer than smokers with normal lung function. COPD is associated with increased oxidative stress, which may cause DNA damage and lung carcinogenesis. Our aim was to evaluate DNA damage and oxidative stress (lipid peroxidation and antioxidant status) and their relationship in patients with COPD with and without lung cancer. We evaluated 18 patients with COPD, 18 with COPD with lung cancer, and 18 controls (former or current smokers). DNA damage was evaluated in peripheral blood lymphocytes using a comet assay; the concentration of malondialdehyde (MDA) and hydrophilic antioxidant performance (HAP) were measured in the plasma. DNA damage was higher in patients with COPD with cancer than in the controls (p = 0.003). HAP was significantly lower in patients with COPD with cancer than in those without cancer and controls. The presence of lung cancer and COPD showed a positive association with DNA strand breaks and the concentration of MDA. COPD with lung cancer was associated with elevated DNA damage in peripheral lymphocytes, and cancer and COPD showed a positive correlation with DNA damage. The antioxidant capacity showed a negative association with the interaction COPD and cancer and presence of COPD. The mechanisms underlying the increased incidence of lung cancer in COPD are unknown; DNA damage may be involved. Further research may provide insights into their development and treatment.

Reduced decline of lung diffusing capacity in COPD patients with diabetes and metformin treatment

We studied whether in patients with COPD the use of metformin for diabetes treatment was linked to a pattern of lung function decline consistent with the hypothesis of anti-aging effects of metformin. Patients of GOLD grades 1–4 of the COSYCONET cohort with follow-up data of up to 4.5 y were included. The annual decline in lung function (FEV1, FVC) and CO diffusing capacity (KCO, TLCO) in %predicted at baseline was evaluated for associations with age, sex, BMI, pack-years, smoking status, baseline lung function, exacerbation risk, respiratory symptoms, cardiac disease, as well as metformin-containing therapy compared to patients without diabetes and metformin. Among 2741 patients, 1541 (mean age 64.4 y, 601 female) fulfilled the inclusion criteria. In the group with metformin treatment vs. non-diabetes the mean annual decline in KCO and TLCO was significantly lower (0.2 vs 2.3, 0.8 vs. 2.8%predicted, respectively; p < 0.05 each), but not the decline of FEV1 and FVC. These results were confirmed using multiple regression and propensity score analyses. Our findings demonstrate an association between the annual decline of lung diffusing capacity and the intake of metformin in patients with COPD consistent with the hypothesis of anti-aging effects of metformin as reflected in a surrogate marker of emphysema.

Effects of Pilates Breathing on Chest Expansion, Dyspnoea and Functional Capacity in COPD Patients - An Experimental Study

COPD is highly prevalent and not fully reversible. Hence there arises need for finding new significant treatment strategies for treating and preventing COPD. Pilates breathing is growing in both the area of fitness and rehabilitation, but there is scarcely any scientific research on Pilates breathing, particularly in the area related to respiration, with no research done in India. Pilates breathing if proved effective can be of great benefit in curing and rehabilitating respiratory conditions like COPD who present diaphragmatic muscle dysfunction, where it can be of maximum utility. Taking into consideration the progressive acceptance of the Pilates breathing and lack of its studies in COPD, the study was undertaken to study its effectiveness and inculcate it in routine rehabilitation of COPD patients if proven effective. Keywords: Pilates breathing, COPD, Chronic obstructive pulmonary disease, chest expansion, dyspnoea, functional capacity, experimental study.

Measurement properties of step tests for exercise capacity in COPD: A systematic review

Objective: To determine the level of evidence of the measurement properties (validity, reliability, and responsiveness) and interpretability of the step tests available for assessing the exercise capacity in patients with chronic obstructive pulmonary disease. Data sources: The data sources Web of Science, MEDLINE, PubMed, PEDro, CENTRAL of Cochrane Library, and Scopus were searched up to June 26, 2020. Review methods: Studies of any design that reported results for any measurement property of the step tests for assessing the exercise capacity in COPD patients were selected. One reviewer extracted the data, and two reviewers independently rated the level of evidence by using the Consensus-Based Standards for the Selection of Health Measurements Instruments recommendations. Results: Thirty-one studies were included in the data synthesis. Chester Step Test, Modified Incremental Step Test, two-, three-, four-, and six-Minute Step Test, Paced Step Test, and six-Minute Stepper Test were identified. A step test protocol was also found. The level of evidence of their results for the measurement properties was mostly determined as “low” to “very low.” The best level of evidence found was for the six-minute stepper test: “high” on construct validity (r = 0.56–0.71); and “moderate” on criterion validity (r = 0.36–0.69), and responsiveness (r = 0.26–0.34). Conclusion: The general level of evidence of the measurement properties of the step tests is “low” to “very low” for assessing exercise capacity in patients with chronic obstructive pulmonary disease, which can limit their application in clinical practice. The six-minute Stepper Test is currently the most appropriate step test available.

NIV Is not Adequate for High Intensity Endurance Exercise in COPD.

Noninvasive ventilation (NIV) during exercise has been suggested to sustain higher training intensity but the type of NIV interface, patient-ventilator asynchronies (PVA) or technological limitation of the ventilator may interfere with exercise. We assessed whether these parameters affect endurance exercise capacity in severe COPD patients. In total, 21 patients with severe COPD not eligible to home NIV performed three constant workload tests. The first test was carried out on spontaneous breathing (SB) and the following ones with NIV and a nasal or oronasal mask in a randomized order. PVA and indicators of ventilator performance were assessed through a comprehensive analysis of the flow pressure tracing raw data from the ventilator. The time limit was significantly reduced with both masks (406 s (197–666), 240 s (131–385) and 189 s (115–545), p < 0.01 for tests in SB, with oronasal and nasal mask, respectively). There were few PVA with an oronasal mask (median: 3.4% (1.7–5.2)) but the ventilator reached its maximal generating capacity (median flowmax: 208.0 L/s (189.5–224.8) while inspiratory pressure dropped throughout exercise (from 10.1 (9.4–11.4) to 8.8 cmH2O (8.6–10.8), p < 0.01). PVA were more frequent with nasal mask (median: 12.8% (3.2–31.6), p < 0.01). Particularly, the proportion of patients with ineffective efforts > 10% was significantly higher with nasal interface (0% versus 33.3%, p < 0.01). NIV did not effectively improve endurance capacity in COPD patients not acclimated to home NIV. This was due to a technological limitation of the ventilator for the oronasal mask and the consequence either of an insufficient pressure support or a technological limitation for the nasal mask.

Acute effects of photobiomodulation therapy applied to respiratory muscles of chronic obstructive pulmonary disease patients: a double-blind, randomized, placebo-controlled crossover trial.

To investigate the effects of photobiomodulation applied to respiratory muscles on lung function, thoracoabdominal mobility, respiratory muscle strength, and functional capacity in COPD patients. This is a randomized double-blind crossover clinical trial. Twelve male COPD patients participated in the study. Participants were randomly allocated to receive two photobiomodulation sessions, 1week apart: (1) an effective photobiomodulation session applied at the main respiratory muscles by means of a cluster with 69 light-emitting diodes (LEDs), containing 35 red (630 ± 10nm; 10mW; 0.2cm2) and 34 near-infrared (830 ± 20nm; 10mW; 0.2cm2) LEDs and (2) a sham photobiomodulation session, following the same procedures without emitting light. The primary outcomes were pulmonary function (spirometric indexes); thoracoabdominal mobility (cirtometry); respiratory muscle strength (maximal respiratory pressures), assessed at three moments: (1) baseline, (2) 1h after intervention, and (3) 24h after intervention; and the functional capacity, assessed by the 6-min walk test (6MWT) at baseline and 24h after intervention. No significant interactions were found for spirometric variables, maximal respiratory pressures, and cirtometry. However, there was a Time × Condition interaction (F = 18.63; p = 0.001; η2p = 0.62) in the walked distance on the 6MWT, with a significant increase after photobiomodulation intervention (p < 0.01) compared with the baseline. Photobiomodulation applied to respiratory muscles was effective in improving acute functional capacity in COPD patients. To the best of our knowledge, this is the first study assessing the effects of photobiomodulation applied to respiratory muscles in patients with COPD.

Role of Selexipag in COPD Patients with out of Proportion Pulmonary Hypertension

Background Pulmonary hypertension (PH) in patients with COPD is associated with an increase in the risk of COPD exacerbation, increased hospitalization and worse survival in this patient population. The majority of patients with COPD have a mild degree of pulmonary hypertension (with mean pulmonary artery pressure, mPAP Hypothesis Selexipag improves functional capacity in COPD patients with out of proportion pulmonary hypertension. Methods We reviewed the medical records of COPD patients who were started on selexipag for out of proportion pulmonary hypertension. The patients were diagnosed with COPD according to their history, pulmonary function tests and chest imaging. All patients had a right heart catheterization done at baseline that showed pulmonary hypertension with mPAP ≥ 35 mmHg at rest. Six-minute walk test was done at baseline and repeated at 6 months (+/- 2 months) after starting selexipag. Results Out of the six patients included in this study, five patients showed improvement of 6-minute walk distance (from 512 feet to 681 feet, mean change 169 feet) while 1 patient worsened (from 1177 feet to 913 feet). Conclusions In this case series of COPD patients with out of proportion pulmonary hypertension, the use of selexipag was associated with an improvement in functional status at 6 months. Larger size prospective studies are needed to confirm the findings.

Correlation of forced expiratory volume in first second with 6-minute walk work in COPD patients

Background: 6 minute walk test (6MWT) is a simple routine exercise test. This test provides information about functional capacity of COPD patients. Though 6 minute walk distance (6MWD) is most commonly used outcome measure, it is influenced by various physical factors like body weight. So, we tried to assess the correlation between 6 minute walk work (6MWW) and forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC). Methodology: A cross sectional study done at a tertiary care hospital in Nellore. Institutional ethical committee approved the study. All patients with COPD attending Respiratory medicine OPD were recruited. Detailed history was taken and physical examination was done after taking informed consent. Patients underwent chest x-ray, Arterial blood gas analysis, Electrocardiogram, Transthoracic 2-D Echo, Spirometry and 6 MWT. Data was analysed using MS Excel 2007. Results: Total of 154 subjects were included.122 were males and 32 were females. 49(31.81%) walked a distance of ? 350 meters, 91(59.09%) walked ? 250 to 349 meters, and 14(9.09%) walked 22000kg.m, 32(20.77%) had ?15000kg.m, 90(58.44%) had 15001-22000kg.m. 6MWW correlated better with FEV1 and FVC. Conclusions: 6MWW is a better outcome measure of 6MWT and can be used to assess functional capacity of COPD patients and monitoring where spirometry cannot be done. Keywords: Six minute walk work, Six minute walk distance, Forced expiratory volume in 1 second, Forced vital capacity, Chronic obstructive pulmonary disease.

Efficacy of yoga, tai chi and qi gong on the main symptoms of chronic obstructive pulmonary disease: A systematic review

IntroductionThe aim of this systematic review was to summarize the effects of yoga, qi gong or tai chi in COPD patients. MethodsStudies evaluating effects of the selected complementary therapies on lung function, dyspnea, quality of life or functional exercise capacity in COPD patients were identified and reviewed from three databases. ResultsEighteen studies were included. Six studies evaluated the effects of yoga and the others focused on tai chi or qi gong separately or combined. The duration of the programs ranged from 6 weeks to 6 months and the frequency from 2 to 7 times a week. Each session reached 30 to 90 minutes. Benefits were observed on lung function and functional exercise capacity but benefit was clearly stated neither on quality of life nor on dyspnea. ConclusionThis systematic review highlights the potential of these therapies as complementary therapeutic approach in COPD patients.

Exercise capacity in COPD patients with exercise-induced pulmonary hypertension

BackgroundPulmonary hypertension (PH) in patients with COPD is associated with reduced exercise capacity. A subgroup of COPD patients has normal mean pulmonary artery pressure (mPAP) at rest, but develops high mPAP relative to cardiac output (CO) during exercise, a condition we refer to as exercise-induced pulmonary hypertension (EIPH). We hypothesized that COPD patients with EIPH could be identified by cardiopulmonary exercise test (CPET) and that these patients have lower exercise capacity and more abnormal CPET parameters compared to COPD patients with normal hemodynamic exercise response.MethodsNinety-three stable outpatients with COPD underwent right heart catheterization with the measurement of mPAP, CO, and capillary wedge pressure at rest and during supine exercise. Resting mPAP <25 mmHg with ΔmPAP/ΔCO slope above or below 3 mmHg/L/min were defined as COPD-EIPH and COPD-normal, respectively. Pulmonary function tests and CPET with arterial blood gases were performed. Linear mixed models were fitted to estimate differences between the groups with adjustment for gender, age, and airflow obstruction.ResultsEIPH was observed in 45% of the study population. Maximal workload was lower in COPD-EIPH compared to COPD-normal, whereas other CPET measurements at peak exercise in % predicted values were similar between the two groups. After adjustment for gender, age, and airflow obstruction, patients with COPD-EIPH showed significantly greater increase in oxygen uptake, ventilation, respiratory frequency, heart rate, and lactate with increasing work load, as well as more reduction in pH compared to those with normal hemodynamic responses.ConclusionCOPD-EIPH could not be discriminated from COPD-normal by CPET. However, COPD-EIPH experienced a higher cost of exercise in terms of higher oxygen uptake, ventilation, respiratory frequency, heart rate, and lactate for a given increase in workload compared to COPD-normal.

Physical Inactivity, Functional Status and Exercise Capacity in COPD Patients Receiving Home-Based Oxygen Therapy

ABSTRACTChronic obstructive pulmonary disease (COPD) has systemic consequences that lead to reduced physical activity in daily life (PADL). Little is known about PADL and its associations in individuals with COPD on home-based long-term oxygen therapy (LTOT). The objective of the study was to determine whether there is an association between severe physical inactivity and pulmonary function, fatigue, dyspnea, functional status and exercise capacity in individuals with COPD on home-based LTOT using electric oxygen concentrators and to investigate which of these variables could influence inactivity in these individuals. The population sample included 39 individuals with COPD who were on LTOT (69 ± 8 years, FEV1: 32 ± 14% predicted). They were assessed in terms of PADL (number of steps/day), fatigue (Fatigue Severity Scale – FSS), dyspnea (Medical Research Council – MRC scale), functional status (London Chest ADL scale [LCADL] and Timed Up and Go [TUG] test) and functional exercise capacity (Six-Minute Step test [6MST] and Sit-to-Stand test [STST]). PADL was markedly low (1444 ± 1203 steps/day) and associated with daily duration of LTOT (r = –0.50), fatigue (r = –0.36), LCADL (r = –0.41), 6MST (r = 0.48), and STST (r = 0.53) (p < .05 for all). Multiple linear regression revealed that daily duration of LTOT and STST explained 39% of the variability of PADL. Longer daily duration of LTOT, fatigue, worse functional status and exercise capacity were all associated with physical inactivity in individuals with COPD on LTOT, whereas daily duration of LTOT and the STST were determinants of reduced physical activity.

Long-acting bronchodilators improve exercise capacity in COPD patients: a systematic review and meta-analysis

We carried out a systematic review and meta-analysis with the aim to evaluate the efficacy of longacting bronchodilators on exercise capacity in COPD patients. The endpoints were the efficacy of long-acting bronchodilators (altogether, and by single classes) vs. placebo in modifying endurance time (ET), inspiratory capacity (IC) and dyspnea during exercise, taking into consideration the outcomes according to different patients’ inclusion criteria and exercise methodology. Twenty-two studies were deemed eligible for analysis. Weighted mean increase in ET resulted of 67 s (95% CI ranges from 55 to 79). For isotime IC and dyspnea during exercise, weighted improvements were 195 ml (162–229), and − 0.41 units (− 0.56 to − 0.27), respectively. The increase in trough IC was 157 ml (138–175). We found a trend in favour of LAMA compared to LABA in terms of ET. In the 11 studies which reported a value of functional residual capacity > 120% as inclusion criterion, weighted mean increase in endurance time was 94 s (65 to 123); however we did not find any significant correlation between ET and mean trough IC (P: 0.593). The improvement of ET in the 5 studies using walking as exercise methodology resulted of 58 s (− 4 to 121). Long-acting bronchodilators improve exercise capacity in COPD. The main effect of long-acting bronchodilators seems to be a increase of basal IC rather than a modification of dynamic hyperinflation during exercise. The efficacy in terms of endurance time seems higher in studies which enrolled patients with hyperinflation, with a similar efficacy on walking or cycling.

Effect of Once-Daily Tiotropium and Olodaterol, Alone and Combined With Exercise Training, on Two Measures of Walking Capacity in Patients With COPD

SESSION TITLE: Airways 3 SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, October 26, 2016 at 01:30 PM - 02:30 PM PURPOSE: PHYSACTO® (NCT02085161) tested effects of bronchodilators alone or with exercise training (ExT), combined with a physical activity behavior-modification (BM) program, on walking capacity in COPD patients. We assessed effects on two walking tests; the endurance shuttle-walk test (ESWT), where walking speed is externally paced, and the 6 minute walk test (6MWT), a self-paced test. METHODS: In this 12-week (wk), randomized, partially double-blind, placebo (P)-controlled, parallel-group trial, interventions (all + 12-wk BM) were P, tiotropium (T) 5 µg, T + olodaterol (T+O) 5/5 µg, and T+O 5/5 µg with 8-wk ExT (T+O 5/5 µg + ExT). Primary endpoint was exercise endurance time (EET) to symptom limitation during ESWT after 8 wks. A further endpoint was 6MWT distance after 8 wks. For both ESWT and 6MWT, intensity of breathing discomfort (BrD) and leg discomfort (LeD) were measured pre-exercise, every 2 min during, and at end-exercise (modified Borg scale). RESULTS: 304 patients were randomized, 303 treated [full analysis set (FAS) n=274]. Baseline geometric mean (SE) EET during ESWT (FAS) was 242.7 (9.4) seconds (s), with a mean (SE) end-exercise BrD of 5.1 (0.1) Borg units (B) (“severe”) and mean (SE) end-exercise LeD of 3.7 (0.2) B (“moderate” / “somewhat severe”); baseline mean (SE) 6MWT distance was 456.9 (5.9) m, with a mean (SE) end-exercise BrD of 3.1 (0.1) B (“moderate”) and mean (SE) end-exercise LeD of 2.4 (0.1) B (“slight” / “moderate”). Adjusted geometric mean (SE) EET during ESWT at 8 wks was 244.1 (17.7) s for P, 254.2 (18.1) s for T 5 µg, 315.3 (21.7) s for T+O 5/5 µg, and 355.7 (24.8) s for T+O 5/5 µg + ExT. EET significantly increased with T+O 5/5 µg (29%; p=0.0109) and T+O 5/5 µg + ExT (46%; p=0.0002) versus P. Adjusted mean (SE) distance during 6MWT after 8 wks was 463.6 (7.4) m for P, 459.0 (7.1) m for T 5 µg, 484.6 (6.6) m for T+O 5/5 µg, and 490.9 (6.9) m for T+O 5/5 µg + ExT. Distance was improved with T+O 5/5 µg [21.0 m (5%); p=0.0344] and T+O 5/5 µg + ExT [27.3 m (6%); p=0.0070] versus P. CONCLUSIONS: After 8 wks, T+O 5/5 µg, alone and combined with ExT, improved EET during ESWT and 6MWT distance compared to P in moderate to severe COPD. The magnitude of improvement was greater for the ESWT than for the 6MWT. CLINICAL IMPLICATIONS: The externally paced ESWT is more responsive to pharmacological and non-pharmacological treatment than the self-paced 6MWT. Funding: Boehringer Ingelheim. Editorial assistance: Complete HealthVizion. DISCLOSURE: François Maltais: Consultant fee, speaker bureau, advisory committee, etc.: Boehringer-Ingelheim, GlaxoSmithKline, AstraZeneca, Novartis, Other: Boehringer-Ingelheim, GlaxoSmithKline, AstraZeneca, Nycomed, Novartis Alan Hamilton: Employee: Boehringer-Ingelheim Matthias Trampisch: Employee: Boehringer-Ingelheim Carlos Tafur: Employee: Boehringer-Ingelheim Thierry Troosters: Grant monies (from industry related sources): IMI-JU Grant number #115011, Consultant fee, speaker bureau, advisory committee, etc.: Boehringer Ingelheim, GSK, Fees paid to Institution No Product/Research Disclosure Information

Heterogeneity of Systemic Oxidative Stress Profiles in COPD: A Potential Role of Gender.

Oxidative stress (OS) plays a key role in the muscle impairment and exercise capacity of COPD patients. However, the literature reveals that systemic OS markers show great heterogeneity, which may hinder the prescription of effective antioxidant supplementation. This study therefore aimed to identify OS markers imbalance of COPD patients, relative to validated normal reference values, and to investigate the possibility of systemic OS profiles. We measured systemic enzymatic/nonenzymatic antioxidant and lipid peroxidation (LP) levels in 54 stable COPD patients referred for a rehabilitation program. The main systemic antioxidant deficits in these patients concerned vitamins and trace elements. Fully 89% of the COPD patients showed a systemic antioxidant imbalance which may have caused the elevated systemic LP levels in 69% of them. Interestingly, two patient profiles (clusters 3 and 4) had a more elevated increase in LP combined with increased copper and/or decreased vitamin C, GSH, and GPx. Further analysis revealed that the systemic LP level was higher in COPD women and associated with exercise capacity. Our present data therefore support future supplementations with antioxidant vitamins and trace elements to improve exercise capacity, but COPD patients will probably show different positive responses.

Dietary nitrate supplementation in COPD: An acute, double-blind, randomized, placebo-controlled, crossover trial☆

BackgroundThe acute consumption of dietary nitrate has been shown to improve exercise capacity in athletes, healthy adults and subjects with peripheral vascular disease. Many COPD patients have reduced exercise capacity. We hypothesized that acute nitrate consumption might increase incremental shuttle walk test (ISWT) distance in COPD subjects. MethodsEleven COPD subjects were randomly assigned to consume either a high nitrate or a matched, low nitrate beverage in a double-blind, randomized, placebo-controlled, crossover design. ISWT distance was measured both before and 3 h after the beverage and change was recorded. After a 7-day washout, ISWT distances were re-measured before and 3 h after the alternate beverage and changes were recorded. ResultsWe observed an increase in ISWT distance after consuming the high nitrate juice (25 m) compared with a reduction after the low nitrate juice (14 m) (p < 0.01). This improvement in exercise capacity was associated with significant increases in serum nitrate (p < 0.000005) and nitrite (p < 0.01) levels and a significant lowering of resting blood pressure (<0.05). ConclusionsIn patients with stable COPD, the acute consumption of dietary nitrate increased serum nitrate/nitrite levels and exercise capacity and was associated with a decrease in resting blood pressure. Nitrate consumption might alter exercise capacity in COPD patients.

Impaired Carbon Monoxide Diffusing Capacity is the strongest lung function predictor of decline in 12 minute-walking distance in COPD; a 5-year follow-up study

Background: The purpose of this study was to evaluate the longitudinal relationship between functional exercise capacity, assessed through standardized 12-minute walk test (12MWT), and various lung function parameters obtained using spirometry, body plethysmography and diffusing capacity (DLco) measurements in patients with COPD. Methods: Spirometry, body plethysmography and DLco-measurements were performed at baseline in 84 subjects with moderate to very severe COPD and at follow-up visit (n = 34) after 5 years. Functional exercise capacity was determined using standardized 12MWT. Results: Patients were characterized at baseline by FEV1 of 1.2 ± 0.4 L (41 ± 13% predicted), RV of 3.4 ± 1.0 L (187 ± 58% predicted) and DLco of 3.8 ± 1.2 mmol/min/kPa (51 ± 16% predicted). A decrease of 12MWD was found between baseline and follow-up (928 ± 193 m vs. 789 ± 273 m, p < 0.001). DLco and 12MWD at baseline were the only independent predictors of 12MWD at follow-up in a multiple logistic regression model that also included all other lung function parameters, gender, age and BMI. Decline in 12MWD was mainly explained by deterioration in DLco. Furthermore, DLco value at baseline had the highest explanatory value for the loss in 12MWD after 5 years (R2 = 0.18, p = 0.009). Conclusions: In a 5-year longitudinal study, DLco-measurements at baseline were the most important predictors of declining exercise capacity in COPD patients. These results suggest that integration of DLco in the clinical workup provides a more comprehensive assessment in patients with COPD.

Correlations between small airway function, ventilation distribution, and functional exercise capacity in COPD patients.

Interest in using the nitrogen single-breath washout (N2SBW) test to measure ventilation inhomogeneity and small airway function in COPD patients has grown in recent years. Our aim was to assess the correlation of the measures obtained by the N2SBW test and other pulmonary function parameters with the six-minute walk distance (6MWD), the degree of dyspnea score, and health status in COPD patients. In this cross-sectional study, 31 patients with COPD were subjected to the N2SBW test, spirometry, whole-body plethysmography, carbon monoxide diffusing capacity measurement, the six-minute walk test, the modified Medical Research Council (mMRC) scale, and the COPD Assessment Test (CAT). We found a strong correlation between the 6MWD and the phase III slope of the nitrogen single-breath washout (Phase III slopeN2SBW) (r = -0.796; p = 0.0001). We found moderate correlations between the 6MWD and the residual volume (RV) (r = -0.651; p = 0.0001) and RV/total lung capacity (RV/TLC) (r = -0.600; p = 0.0004). We also found moderate correlations between the CAT score and Phase III slopeN2SBW(r = 0.728; p = 0.0001), RV (r = 0.646; p = 0.0001) and RV/TLC (r = 0.603; p = 0.0003). There was a significant difference between the mMRC grades for the following variables: Phase III slopeN2SBW (p = 0.0001), RV (p = 0.0001), and smoking history (p = 0.008). Multivariate analysis showed that Phase III slopeN2SBW was the only independent predictor of the 6MWD (R2 = 0.703; p = 0.0001), CAT score (R2 = 0.586; p = 0.0001), and mMRC scale (relative risk = 1.14; p = 0.0001). In patients with COPD, our findings suggest that the ventilation inhomogeneity impacts the functional exercise capacity, the degree of dyspnea, and health status.

Lifetime occupational exposure to dusts, gases and fumes is associated with bronchitis symptoms and higher diffusion capacity in COPD patients.

BackgroundOccupational exposure to dusts, gases and fumes has been associated with reduced FEV1 and sputum production in COPD patients. The effect of occupational exposure on other characteristics of COPD, especially those reflecting emphysema, has not been studied in these patients.MethodsWe studied 338 patients hospitalized for a first exacerbation of COPD in 9 Spanish hospitals, obtaining full occupational history in a face-to-face interview; job codes were linked to a job exposure matrix for semi-quantitative estimation of exposure to mineral/biological dust, and gases/fumes for each job held. Patients underwent spirometry, diffusing capacity testing and analysis of gases in stable conditions. Quality of life, dyspnea and chronic bronchitis symptoms were determined with a questionnaire interview. A high- resolution CT scan was available in 133 patients.Results94% of the patients included were men, with a mean age of 68(8.5) years and a mean FEV1% predicted 52 (16). High exposure to gases or fumes was associated with chronic bronchitis, and exposure to mineral dust and gases/fumes was associated with higher scores for symptom perception in the St. George’s questionnaire. No occupational agent was associated with a lower FEV1. High exposure to all occupational agents was associated with better lung diffusion capacity, in long-term quitters. In the subgroup with CT data, patients with emphysema had 18% lower DLCO compared to those without emphysema.ConclusionsIn our cohort of COPD patients, high exposure to gases or fumes was associated with chronic bronchitis, and high exposure to all occupational agents was consistently associated with better diffusion capacity in long-term quitters.