Limitation in tidal volume expansion partially determines the intensity of physical activity in COPD

Daily Physical Activity in Asthma and the Effect of Mepolizumab Therapy

For the various asthma-specific beneficial effects of physical activity, daily physical activity (DPA) and the potential of asthma therapies on DPA require better characterization. Hence, we aimed to determine (a) the DPA of asthma patients, and (b) the effect of add-on mepolizumab on the DPA of severe asthma patients. Methods: Adult outpatients with mild-to-moderate or severe asthma had accelerometer assessment of DPA. Severe asthma patients who were commenced on mepolizumab had their DPA reassessed after 12 months. Results: For the total cohort (n = 36), daily step count, time in moderate-to-vigorous physical activity (MVPA), MVPA volume and Movement Intensity (MI) were 7806 ± 3823 steps, 123 (interquartile range, 63) min, 657 ± 255 MET·min and 1.96 (0.45) m/s², respectively. All patients met at least one recommendation for DPA but less than half met recommendations for vigorous DPA. Patients on mepolizumab therapy increased daily step count (646 steps; 9%), time in MVPA (20 min; 21%), MVPA volume (87 MET·min; 17%) and MI (0.11 m/s²; 6%) for the same amount of moving time; lung function, asthma control and health-related quality of life also improved. Conclusions: Analysis of the first national data on DPA in asthma and novel comparison against current applicable guidelines and identified beneficial thresholds showed borderline levels of DPA with room for improvement especially for severe asthma patients. In a non-sedentary cohort of severe asthma patients, mepolizumab conferred significant and meaningful improvements in DPA.

Loss of Neural Automaticity Contributes to Slower Walking in COPD Patients

The physical impairments (e.g., slower walking speed) in patients with chronic obstructive pulmonary disease (COPD) have been attributed to peripheral characteristics (e.g., muscle atrophy). However, cognitive impairment may compromise motor control including walking automaticity. The objective of this study was to investigate PFC neural activity, evaluated using changes in oxygenated hemoglobin (ΔO₂Hb), during preferred paced walking (PPW) in COPD patients and age-matched controls. The ΔO₂Hb from the left and right dorsolateral PFC was measured using functional near-infrared spectroscopy. Fifteen COPD patients (age: 71 ± 8) and twenty age-matched controls (69 ± 7 years) participated. Two-way mixed ANOVA demonstrated that O₂Hb in both groups decreased during PPW from the start (quintile 1; Q1) to the end (quintile 5; Q5) in the left dorsolateral and medial PFC. Q1 was comprised of the data during the first 20% of the task, while Q5 included data collected in the last 20% of the task duration. PPW duration ranged between 30.0 and 61.4 s in the control group and between 28.6 and 73.0 s in COPD patients. COPD patients demonstrated a higher O₂Hb in Q5 compared to the negative O₂Hb in controls in the right medial and dorsolateral PFC during PPW. PPW velocity was lower in COPD patients compared to controls (1.02 ± 0.22 vs. 1.22 ± 0.14 m/s, p = 0.005). Healthy older controls exhibited automaticity during walking unlike patients with COPD. The lesser decrease in O₂Hb in COPD patients may be attributed to increased executive demands or affect-related cues (e.g., pain or dyspnea) during walking.

Isotonic quadriceps endurance is better associated with daily physical activity than quadriceps strength and power in COPD: an international multicentre cross-sectional trial

Knowledge about modifiable determinants of daily physical activity (PA) in patients with chronic obstructive pulmonary disease (COPD) is crucial to design effective PA interventions. The present study aimed to determine the contribution of quadriceps strength, power and endurance to daily PA in COPD. Additionally, for quadriceps endurance, we also aimed to determine to what extent the association varies according to the mode of movement (isotonic, isometric, or isokinetic). Using a multicentre cross-sectional trial design we determined the contribution of quadriceps function to daily PA (steps, sedentary time and time spent doing moderate-to-very-vigorous physical activity [MVPA]) using bivariate and partial Pearson correlation analysis (r) and multiple linear regression models (ΔR²). Pre-determined controlling factors were sex, age, body mass index (BMI), COPD-assessment test, forced expiratory volume in one second in percent of the predicted value (FEV_1pred), and distance walked on the 6-minute walk test. Eighty-one patients with COPD (mean ± SD: age 67 ± 8 years, FEV_1pred 57 ± 19%, daily steps 4968 ± 3319, daily sedentary time 1016 ± 305 min, and MVPA time 83 ± 45 min) were included. Small to moderate bivariate correlations (r = .225 to .452, p < .05) were found between quadriceps function and measures of PA. The best multiple linear regression models explained 38–49% of the variance in the data. Isotonic endurance was the only muscle contributor that improved all PA models; daily steps (ΔR² = .04 [relative improvement 13%] p = .026), daily sedentary time (ΔR² = .07 [23%], p = .005) and MVPA-minutes (ΔR² = .08 [20%], p = .001). Isotonic endurance was also independently associated with most PA variables, even when controlling for strength, power or isometric-isokinetic endurance properties of the muscle (r = .246 to .384, p < .05). In contrast, neither strength, power, isometric-or isokinetic endurance properties of the muscle was independently associated with PA measures when controlling for isotonic endurance (r = .037 to .219, p > .05). To conclude, strength, power, and endurance properties of the quadriceps were low to moderately associated with PA in patients with COPD. Isotonic quadriceps endurance was the only quadriceps property that was independently associated with the different measures of PA after controlling for a basic set of known determinants of PA, quadriceps strength or power, or isometric or isokinetic quadriceps endurance. Future longitudinal studies should investigate its potential as a modifiable determinant of PA.

Impact of Exercise Capacity Upon Respiratory Functions, Perception of Dyspnea, and Quality of Life in Patients with Chronic Obstructive Pulmonary Disease

Background

Chronic obstructive pulmonary disease (COPD) is associated with a high prevalence of morbidity and mortality worldwide. We investigated the effects of exercise capacity upon respiratory functions, perception of dyspnea, and quality of life (QoL) in patients with COPD.

Methods

A total of 512 COPD patients formed the study cohort. They were divided into four subgroups according to the distance walked in the 6-minute walking test (6MWT). We compared respiratory functions, perception of dyspnea, and QoL between groups.

Results

Patients who walked >350 m had significantly better disease-specific QoL scores (p < 0.001) than those of other groups. A negative correlation was found between the walking distance and anxiety, depression, and dyspnea scores (p < 0.001).

Conclusions

In patients who walked <350 m, the reduced walking distance adversely affected respiratory functions, psychological symptoms, and QoL.

Ventilatory constraint is more severe in walking than cycling in patients with COPD

Due to its effectivity in assessing functional capacity and adding prognostic information to the staging of chronic obstructive pulmonary disease (COPD) patients, the 6-min walk test (6MWT) is extensively used in clinical evaluation. Currently, there is little information about the physiological response this test elicits in patients, especially when compared to cardiopulmonary exercise test (CPET). The aim of the study was to compare ventilatory and metabolic responses between these tests commonly used for the assessment of clinical outcome. A group of 20 patients with moderate to very severe COPD were tested for their pulmonary function (flow-volume curve, static lung volumes), occlusion mouth pressures and breath-by-breath measurement of flow, volumes, and oxygen (O₂) and carbon dioxide (CO₂) concentration during the 6MWT and CPET. All parameters measured during both exercise tests were assessed over the throughout of the tests and compared between each other at specified time points. Serially measured inspiratory vital capacity (IVC) decreased more rapidly and extensively during the walk-test (p ​< ​0,0001). This was accompanied by a limited increase in tidal volume (V_T) and minute ventilation (V_E), which were significantly lower in the course of the 6MWT (p ​= ​0,0003 and p ​= ​0,0097, respectively). We also noticed a significant decrease in hemoglobin oxygen saturation (SpO₂) during the 6MWT which was correlated to percent decrease in IVC (p ​= ​0,0206). Over the course of the 6MWT, oxygen consumption (VO₂) and V_T reached plateau within 2 ​min, while carbon dioxide production (VCO₂) and V_E within 3 ​min. During CPET, VO₂, VCO₂ and V_E rose continuously, while V_T reached plateau within 4 ​min. The 6MWT seems to be a rather endurance-based test associated with more pronounced dynamic lung hyperinflation and mechanical constraint of ventilation in comparison to cycling.

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Various types of exercise are tolerated differently.

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The 6MWT is, as opposed to ergometry, accompanied by a quicker increase in dynamic lung hyperinflation and desaturation.

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It seems that pedaling, as compared to walking, is the superior way of training movement for rehabilitation purposes.

Pain Prevalence, Localization, and Intensity in Adults with and without COPD: Results from the Danish Health and Morbidity Survey (a Self-reported Survey)

Introduction

Pain is a clinical complication to chronic obstructive pulmonary disease (COPD) that interferes negatively with physical activity level (PAL), quality of life (QOL) and pulmonary interventions. Yet, research in pain characteristics including prevalence, localization, and intensity in people with COPD are sparsely researched.

Aim

To investigate self-reported pain prevalence, localization and intensity of pain in people with and without COPD, and to investigate the association between pain intensity and PAL among participants with COPD.

Methods

Data were derived from the Danish Health and Morbidity Survey in 2017. The study population was restricted to individuals aged ≥35 years. Data included pain intensity assessed on the Numeric Rating Scale (NRS) and localization, PAL, QoL, sleep disturbance, comorbidities, sociodemographic and behavioral factors.

Results

In all, 528 participants with COPD and 8184 participants without COPD (51% females, mean ±SD age 67.1±11.4 years) were analyzed. Pain prevalence within the past 14 days was significantly higher in participants with COPD vs nonCOPD (72.7% vs 57.7%, p<0.001) and mainly located in the limbs, thorax, and lower back. COPD was associated with the prevalence of chronic pain (≥6 months) (OR: 2.78, 95%CI: 2.32; 3.34, p<0.001). Participants with COPD reported a higher pain intensity compared to those with nonCOPD with a mean difference of 1.04 points (95%CI: 0.75; 1.32, p<0.001) on the NRS. In the adjusted multiple logistic regression analysis, pain intensity was negatively associated with odds of being physical active (OR: 0.72, 95%CI: 0.61; 0.85, p<0.001).

Conclusion

Pain is more prevalent in people with self-reported COPD. After adjustment for age and gender, COPD was associated with an elevated pain intensity. Sleep disturbance and multimorbidity had the most pronounced impacts on pain intensity in the multiple linear regression model. In participants with COPD, increased pain intensity was negatively associated with being physically active.

Evaluating the Benefits of Exercise Training in HFrEF or COPD Patients: ISO-LEVEL COMPARISON CAN ADD VALUABLE INFORMATION TO V˙o2peak

BACKGROUND

Heart failure with reduced ejection fraction (HFrEF) and chronic obstructive pulmonary disease (COPD) are relatively common conditions with similar symptoms of exercise intolerance and dyspnea. The aim of this study was to compare exercise capacity, ventilatory response, and breathing pattern in patient groups with either advanced HFrEF or COPD before and after exercise training.

METHODS

An observational study was conducted with parallel groups of 25 HFrEF and 25 COPD patients who took part in 6 wk of inpatient rehabilitation with exercise training. All patients underwent cardiopulmonary exercise tests at the start and end of the training, with resting arterial blood gas measurements.

RESULTS

The average peak oxygen uptake (V˙o2) was low at the start of the study but increased significantly after training in both groups, or by 2.2 ± 2.1 mL/kg/min in HFrEF patients and 1.2 ± 2.2 mL/kg/min in COPD patients. At ISO-V˙o2 (ie, same level of V˙o2 in pre- and post-exercise tests), carbon dioxide production (V˙co2) decreased after exercise training in both groups. Similarly, at ISO-V˙E (ie, same level of ventilation), breathing frequency (f) decreased and tidal volume (VT) increased, resulting in an improved breathing pattern (lower f/VT ratio) after training.

CONCLUSION

The findings of this study show that exercise training in severely affected patient groups with HFrEF or COPD led to an increase in maximal exercise capacity, a more favorable breathing pattern, and a diminished V˙co2 during exercise. Therefore, comparisons of V˙co2 and breathing pattern at ISO-levels of V˙o2 or V˙E before and after training are valuable and underutilized outcome measures in treatment studies.

Verification of a Motion Sensor for Evaluating Physical Activity in COPD Patients

Background

Objective evaluation of the physical activity (PA) in patients with chronic obstructive pulmonary disease (COPD) is important. We validated a triaxial accelerometer, Active Style Pro HJA-750C® (HJA), and evaluated the necessary conditions for obtaining reproducible data.

Methods

The PA measured by HJA was compared with that measured by two already validated accelerometers in 11 patients with COPD (age: 76.6 ± 6.9, FEV1% predicted: 57.6 ± 18.6). Then, the influence of weather and holidays on the PA and the required number of days to obtain repeatability were examined in 21 patients with COPD (age: 73.0 ± 8.0, FEV1% predicted: 58.7 ± 19.0).

Results

The PA values measured by HJA and those by DynaPort Move Monitor® (DMM) or Actimarker® (AM) were significantly correlated at all intensities (p=0.024 at ≥4.0 METs by DMM and p < 0.0001 at the rest) except at ≥4.0 METs by AM, though the values measured by HJA were higher than those by AM which was reported to underestimate PA. The durations of PA on rainy days were significantly shorter than those on nonrainy days, but those on holidays were not different from those on weekdays. The values of ICC for 3, 4, or 5 days were higher than 0.8 at all intensities. The PA measured by HJA was correlated with the dyspnea scale FVC and age and tended to correlate with FEV1.

Conclusions

The HJA was validated for evaluating the PA in patients with COPD. This trial is registered with UMIN000016363.

Transcutaneous carbon-dioxide partial pressure trends during six-minute walk test in patients with very severe COPD

BACKGROUND

Transcutaneous carbon-dioxide partial-pressure (T_CPCO₂) can be reliably measured and may be of clinical relevance in COPD. Changes in T_CPCO₂ and exercise-induced hypercapnia (EIH) during six-minute walk test (6MWT) need further investigation. We aimed (1) to define patterns of T_CPCO₂ trends during 6MWT and (2) to study determinants of CO2-retention and EIH.

METHODS

Sixty-two COPD patients (age: 63±8years, FEV1: 33±10%pred.) were recruited and T_CPCO2 was recorded by SenTec digital-monitoring-system during 6MWT.

RESULTS

Half of patients (50%) exhibited CO₂-retention (T_CPCO₂[Δ]>4mmHg); 26% preserved and 24% reduced T_CPCO₂. Nineteen (31%) patients presented EIH (T_CPCO₂>45mmHg). EIH was associated to higher baseline-P_CCO₂, worse FEV1, lower inspiratory-pressures, underweight/normal BMI, and pre-walk dyspnea. Stronger determinants of CO₂-retention were FEV1 and pre-walk dyspnea, whereas baseline-P_CCO₂ and pre-walk dyspnea better predict EIH.

CONCLUSIONS

PCO₂ response to 6MWT is highly heterogeneous; however, very low FEV1 and elevated baseline-P_CCO₂ together with pre-walk dyspnea increase the risk for CO₂-retention and EIH. Overweight-BMI seems to carry a protective effect against EIH in very severe COPD.