Upper Limb Anaerobic Metabolism Capacity is Reduced in Mild and Moderate COPD Patients.

Limited information is available regarding the role of anaerobic metabolism capacity on GOLD 1 and 2 COPD patients during upper limb exercise. We aimed to compare the upper limb anaerobic power capacity, blood lactate concentration, cardiovascular and respiratory responses, in male COPD patients versus healthy subjects during the 30-s Wingate anaerobic test (WAnT). The rate of fatigue and time constant of the power output decay (τ, tau) were also calculated and a regression analysis model was built to assess the predictors of τ in these patients. Twenty-four male COPD patients (post-bronchodilator FEV1 73.2 ± 15.3% of predicted) and 17 healthy subjects (FEV1 103.5 ± 10.1% of predicted) underwent the WAnT. Measurements were performed at rest, at the end of the WAnT, and during 3' and 5' of recovery time. Peak power (p = 0.04), low power (p = 0.002), and mean power output (p = 0.008) were significantly lower in COPD patients than in healthy subjects. Power output decreased exponentially in both groups, but at a significantly faster rate (p = 0.007) in COPD patients. The time constant of power decay was associated with resistance (in ohms) and fat-free mass (r2 = 0.604, adjusted r2 = 0.555, and p = 0.002). Blood lactate concentration was significantly higher in healthy subjects at the end of the test, as well as during 3' and 5' of recovery time (p < 0.01). Compared with healthy subjects, COPD patients with GOLD 1 and 2 presented lower upper limb anaerobic capacity and a faster rate of power output decrease during a maximal intensity exercise. Also, the WAnT proved to be a valid tool to measure the upper limb anaerobic capacity in these patients.

The Glittre ADL-Test Differentiates COPD Patients with and without Self-Reported Functional Limitation.

The Glittre ADL-test is based on important and common activities of daily living (ADLs), and it is an useful test to objectively distinguish patients with and without self-reported functional limitations. This study aims to analyze if difficulty to perform ADLs, as self-reported by patients with COPD, would reflect a worse Glittre ADL-test performance. In the first visit, patients were evaluated for clinical and nutritional status, spirometry, maximal cardiopulmonary exercise test on a treadmill. One week later, the patients performed two Glittre ADL-tests. Maximal voluntary ventilation (MVV) and the VEGlittre/MVV, VO2Glittre/VO2peak, and HRGlittre/HRpeak ratios were calculated to analyze the ventilatory, metabolic, and cardiac reserves. The London Chest Activity of Daily Living (LCADL) scale was only answered after the two Glittre ADL-test were performed. Patients were splited into two subgroups based on the anchor question of the LCADL: those with and those without self-reported ADL limitation. Sixty-two COPD patients were included (65.3 ± 8.6 years, FEV1 62 ± 22%pred). Those with ADL limitation (39 patients) completed the Glittre ADL-test with a significantly longer time (p = 0.002), as well as higher VEGlittre/MVV (p = 0.005) and lower oxygen pulse (p = 0.021) than those without ADL limitation. The time spent to perform the Glittre ADL-test was significantly associated with total LCADL score (ρ = 0.327, p < 0.05). A cutoff of 253 s was able to distinguish those patients without and with ADL limitation. COPD patients who self-reported ADL limitation according to the LCADL scale took a longer time to perform the Glittre ADL-test with higher VEGlittre/MVV and lower oxygen pulse than those without ADL limitation.

Lactic acid levels in patients with chronic obstructive pulmonary disease accomplishing unsupported arm exercises.

Patients with chronic obstructive pulmonary disease (COPD) may suffer dyspnea when performing unsupported arm exercises (UAE). However, some factors related to the tolerance of the upper limbs during these exercises are not well understood. Our investigation was to determine if an unsupported arm exercise test in patients with COPD accomplishing diagonal movements increases lactic acid levels; also, we assessed the metabolic, ventilatory and cardiovascular responses obtained from the unsupported arm exercise test. The study used results of maximal symptom limited tests with unsupported arms and legs performed on 16 patients with COPD. In order to do the test, some metabolic, respiratory and cardiovascular parameters such as oxygen uptake (VO(2)), carbon dioxide production (VCO(2)), respiratory rate (RR), pulmonary ventilation (VE), heart rate (HR) and blood pressure (BP) were measured during the exercise tests. Furthermore, blood lactate concentration was measured during the arm test. We detected a significant increase in the mean blood lactate concentration, VO(2), VCO(2), VE and RR from the resting to the peak phase of the UAE test. The mean values of VO(2), VCO(2) and VE obtained at the peak of the UAE test corresponded to 52.5%, 50.0% and 61.2%, respectively, of the maximal values obtained at the peak of the leg exercise test. In comparison, the mean heart rate and systolic arterial blood pressure were significantly lower at the peak of the UAE test than at the peak leg exercise test and corresponded to 76.2% and 83.0%, respectively. Unsupported incremental arm exercises in patients with COPD increases blood lactic acid levels.

Variability in Quality of Life Outcomes Following a Pulmonary Rehabilitation Program in Patients With COPD.

PURPOSE: Pulmonary rehabilitation (PR) improves exercise tolerance in patients with chronic obstructive pulmonary disease. However, it is unclear why some patients do not improve quality of life during a training program. Our objective was to evaluate the differences between patients with chronic obstructive pulmonary disease who improve and those who do not improve quality of life during a pulmonary rehabilitation program. METHODS: Seventy-three patients underwent a PR program. All patients trained at 80% (legs) and 50% (arms) of their maximum load. Incremental and endurance tests, 6-min walk test, and health-related quality of life with the St George Respiratory Questionnaire (SGRQ) were measured. We subdivided the groups based on a decrease ≥4 points in the pre- and post-PR SGRQ total score (G1); <4-point change in the SGRQ total score (G2); and an increase in scores ≥4 points (G3). RESULTS: Exacerbation frequency (P = .004) and SGRQ total scores (P < .001) were lower in G1 and G2 than in G3. G1 (P = .0007) and G2 (P = .0005) significantly improved 6-min walk test distance. Before PR, G1 and G2 walked greater distances than G3 (P = .003); however, the difference was no longer significant after PR (P = .34). A significant load increase was seen after PR for the 3 groups (P < .05). We found a significant correlation between the SGRQ and the Charlson index (r = 0.78, P < .0001), exacerbation frequency (r = 0.72, P < .0001), and basal dyspnea index (r = -0.48, P < .0001). CONCLUSION: Patients whose quality of life did not improve after comprehensive PR presented a higher number of disease-related exacerbations with comorbidities.

Physiological Requirements to Perform the Glittre Activities of Daily Living Test by Subjects With Mild-to-Severe COPD.

BACKGROUND: The Glittre activities of daily living (ADL) test is supposed to evaluate the functional capacity of COPD patients. The physiological requirements of the test and the time taken to perform it by COPD patients in different disease stages are not well known. The objective of this work was to compare the metabolic, ventilatory, and cardiac requirements and the time taken to carry out the Glittre ADL test by COPD subjects with mild, moderate, and severe disease. METHODS: Spirometry, Medical Research Council questionnaire, cardiopulmonary exercise test, and 2 Glittre ADL tests were evaluated in 62 COPD subjects. Oxygen uptake (V̇O2 ), carbon dioxide production, pulmonary ventilation, breathing frequency, heart rate, SpO2 , and dyspnea were analyzed before and at the end of the tests. Maximum voluntary ventilation, Glittre peak V̇O2 /cardiopulmonary exercise test (CPET) peak V̇O2 , Glittre V̇E/maximum voluntary ventilation, and Glittre peak heart rate/CPET peak heart rate ratios were calculated to analyze their reserves. RESULTS: Subjects carried out the Glittre ADL test with similar absolute metabolic, ventilatory, and cardiac requirements. Ventilatory reserve decreased progressively from mild to severe COPD subjects (P < .001 for Global Initiative for Chronic Obstructive Lung Disease [GOLD] 1 vs GOLD 2, P < .001 for GOLD 1 vs GOLD 3, and P < .001 for GOLD 2 vs GOLD 3). Severe subjects with COPD presented a significantly lower metabolic reserve than the mild and moderate subjects (P = .006 and P = .043, respectively) and significantly lower Glittre peak heart rate/CPET peak heart rate than mild subjects (P = .01). Time taken to carry out the Glittre ADL test was similar among the groups (P = .82 for GOLD 1 vs GOLD 2, P = .19 for GOLD 1 vs GOLD 3, and P = .45 for GOLD 2 vs GOLD 3). CONCLUSIONS: As the degree of air-flow obstruction progresses, the COPD subjects present significant lower ventilatory reserve to perform the Glittre ADL test. In addition, metabolic and cardiac reserves may differentiate the severe subjects. These variables may be better measures to differentiate functional performance than Glittre ADL time.

Oxygen and ventilatory output during several activities of daily living performed by COPD patients stratified according to disease severity.

OBJECTIVES: To measure the oxygen and ventilatory output across all COPD stages performing 18 common ADL and identify the activities that present the highest metabolic and ventilatory output as well as to compare the energy expenditure within each disease severity. MATERIALS AND METHODS: Metabolic (VO2 and VCO2), ventilatory (f and VE), cardiovascular (HR) and dyspnea (Borg score) variables were assessed in one hundred COPD patients during the completion of eighteen ADL grouped into four activities domains: rest, personal care, labor activities and efforts. RESULTS: The activities with the highest proportional metabolic and ventilatory output (VO2/VO2max and VE/MVV) were walking with 2.5 Kg in each hand and walking with 5.0 Kg in one hand. Very severe patients presented the highest metabolic, ventilatory output and dyspnea than mild patients (p<0.05). CONCLUSIONS: COPD patients present an increased proportion of energy expenditure while performing activities of daily living. The activities that developed the highest metabolic and ventilatory output are the ones associated to upper and lower limbs movements combined. Very severe patients present the highest proportional estimated metabolic and ventilatory output and dyspnea. Activities of daily living are mainly limited by COPD's reduced ventilatory reserve.