Objective: To establish clinical and functional baseline characteristics related to aerobic improvement (AI) after supervised training, in COPD patients submitted to a comprehensive pulmonary rehabilitation program (PR). Material and methods: Before and after PR was performed in 36 male COPD patients (25 with mild to moderate disease): clinical and anthropometric evaluation, 6-minute walking test, spirometry, arterial blood gas analysis, maximum inspiratory and expiratory pressure measurement, and a symptom-limited incremental cardiopulmonary exercise testing (MGC-CPX System). Supervised training intensity was targeted at the heart rate (HR) corresponding to anaerobic threshold (AT) or at 90% of the maximum HR attained. Results: Initial maximum oxygen consumption (VO2max) was negatively correlated with age and positively with the body mass index (BMI), the maximum inspiratory pressure (MIP) and the forced expiratory volume in one second (FEV1 ) - p < 0.05. After PR, an increment on submaximal exercise tolerance was found in 29 patients (80.5%); however, AI was only found in 15 individuals (41.6%). AI was associated to the following baseline variables: age < 65 years, AT < 40% of VO2max pred, BMI > 18.5, FEV1 > 60% pre and MIP > 60% pred (p < 0.05). Improvement in MIP and BMI and decrease in the maximum dyspnea score were found only in patients with AI (p < 0.05). Conclusion: Supervised pulmonary rehabilitation in a group of COPD patients was able to increase the submaximal exercise tolerance in most of them. Aerobic improvement was more prevalent in the younger, eutrophic, detrained and least obstructed patient; it was associated with an increment in BMI and MIP and decrease in the maximal dyspnea score after training.

Keywords: COPD. Pulmonary rehabilitation. Exercise training. COPD. Pulmonary rehabilitation. Exercise training.

Objective: To study the effects of nocturnal hypoxemia in patients with chronic obstructive pulmonary disease without obstructive sleep apnea syndrome. Methods: We studied 21 patients-10 desaturators and 11 nondesaturators-submitted to arterial blood gas analysis, polysomnography, spirometry, cardiopulmonary exercise testing (cycle ergometer), and hand-grip dynamometry, as well as measurements of maximal inspiratory pressure, maximal expiratory pressure, and C-reactive protein (CRP) levels. Patients with arterial oxygen tension > 60 mmHg were included; those with an apnea-hypopnea index > 5 events/hour of sleep were excluded. Maximal oxygen uptake, maximal power, systolic blood pressure, diastolic blood pressure (DBP), and maximal heart rate were measured during exercise in order to detect hemodynamic alterations. Patients presenting CRP levels above 3 mg/L were considered CRP-positive. Results: Minimal peripheral oxygen saturation during sleep was significantly higher among nondesaturators (p = 0.03). More desaturators presented CRP > 3 mg/L (p < 0.05). No differences were observed in terms of any variables, However, mean peripheral oxygen saturation during sleep correlated with DBP and maximal inspiratory pressure (p < 0.001 and p = 0.001, respectively). Conclusions: Although nocturnal hypoxemia does not reduce exercise capacity or hand-grip strength in patients with mild/moderate COPD, its effect on maximal exercise DBP seems to depend on the degree of hypoxemia. In addition, there is a positive relationship between maximal inspiratory pressure and mean peripheral oxygen saturation during sleep, as well as evidence of pronounced inflammatory activation in patients with nocturnal hypoxemia.

Keywords: Pulmonary disease, chronic obstructive; Exercise test; Anoxia; Respiratory function tests.

Chronic obstructive pulmonary disease is currently considered a systemic disease, presenting structural and metabolic alterations that can lead to skeletal muscle dysfunction. This negatively affects the performance of respiratory and peripheral muscles, functional capacity, health-related quality of life and even survival. The decision to prescribe ergogenic aids for patients with chronic obstructive pulmonary disease is based on the fact that these drugs can avert or minimize catabolism and stimulate protein synthesis, thereby reducing the loss of muscle mass and increasing exercise tolerance. This review summarizes the available data regarding the use of anabolic steroids, creatine, L-carnitine, branched-chain amino acids and growth hormones in patients with chronic obstructive pulmonary disease. The advantage of using these ergogenic aids appears to lie in increasing lean muscle mass and inducing bioenergetic modifications. Within this context, most of the data collected deals with anabolic steroids. However, to date, the clinical benefits in terms of increased exercise tolerance and muscle strength, as well as in terms of the effect on morbidity and mortality, have not been consistently demonstrated. Dietary supplementation with substances of ergogenic potential might prove to be a valid adjuvant therapy for treating patients with advanced chronic obstructive pulmonary disease, especially those presenting loss of muscle mass or peripheral muscle weakness.

Keywords: Lung diseases, obstructive; Respiratory muscle; Dietary supplements; Anabolic agents/therapeutic use; Exercício; Energy metabolism

In order to assess the relationship between the physical fitness of asthmatics and the clinical expression of the underlying disease, the authors studied 39 physically active children with moderate to severe but stable asthma. The patients (25 boys and 14 girls, aged between 9 and 16 years) were submitted to clinical evaluation; spirometry before and after bronchodilator (BD); maximal cardiopulmonary exercise test in cycle ergometer with breath-by-breath analysis of ventilatory and gas exchange variables; and, on a separate day, an exercise challenge test. As expected by the clinical stability, FEV1 post-BD was in the normal range in most of the children (mean ± SD = 93.8 ± 13.7% predicted). Maximal oxygen uptake (VO2max) was higher than the lower 95% confidence interval in 31/39 children; and in 29/39, the oxygen uptake at the anaerobic threshold (VO2AT) showed values above the lower limit of normality. Seven patients with low tolerance to exercise (reduced VO2max) presented suggestions of circulatory limitation (cardiovascular and/or peripheral) and only 1 had ventilatory limitation. There was no association or correlation between the lower ventilatory reserve (VEmax/MVV% ratio > 80%) and the decreased VO2max. Reduction in VO2AT, but not VO2max, was associated with some clinical indicators of asthma severity, e.g. (i) higher daily inhaled beclomethasone and frequent courses of oral steroids (p < 0.05) and (ii) higher exercise-induced bronchospasm occurrence (p < 0.01). The results show that (i) most patients with moderate to severe asthma, when clinically stable and physically active, present an adequate level of exercise tolerance; (ii) in estimation of the clinical severity of bronchial asthma in children, VO2AT is a better aerobic index than VO2max.

Keywords: Asthma in children. Exercise tolerance. Maximal oxygen uptake. Anaerobic threshold. Physical fitness. Exercise-induced

Objective: To characterize the presence, extent, and patterns of dynamic hyperinflation (DH) during treadmill exercise testing in patients with moderate to severe COPD. Methods: This was a cross-sectional study involving 30 non-hypoxemic patients (FEV1= 43 ± 14% of predicted) who were submitted to a cardiopulmonary exercise test on a treadmill at a constant speed (70-80% of maximum speed) to the tolerance limit (Tlim). Serial inspiratory capacity (IC) maneuvers were used in order to assess DH. Results: Of the 30 patients studied, 19 (63.3%) presented with DH (DH+ group), having greater pulmonary function impairment at rest than did those without DH (DH− group). None of the variables studied correlated with exercise tolerance in the DH− group, whereas Tlim, IC, and perception of dyspnea during exercise did so correlate in the DH+ group (p < 0.05). In the DH+ group, 7 and 12 patients, respectively, presented with a progressive and a stable pattern of DH (ΔICTlim,2min = −0.28 ± 0.11 L vs. 0.04 ± 0.10 L; p < 0.01). Patients with a progressive pattern of DH presented with higher perception of dyspnea/Tlim rate and lower exercise tolerance than did those with a stable pattern (354 ± 118 s and 465 ± 178 s, respectively; p < 0.05). Conclusions: The presence of DH is not a universal phenomenon during walking in COPD patients, even in those with moderate to severe airflow limitation. In the patients who presented DH, a progressive pattern of DH had a greater impact on exercise tolerance than did a stable pattern of DH.

Keywords: Pulmonary disease, chronic obstructive; Exercise; Exercise test; Inspiratory capacity.

Objective: To investigate the modulatory effects that dynamic hyperinflation (DH), defined as a reduction in inspiratory capacity (IC), has on exercise tolerance after bronchodilator in patients with COPD. Methods: An experimental, randomized study involving 30 COPD patients without severe hypoxemia. At baseline, the patients underwent clinical assessment, spirometry, and incremental cardiopulmonary exercise testing (CPET). On two subsequent visits, the patients were randomized to receive a combination of inhaled fenoterol/ipratropium or placebo. All patients then underwent spirometry and submaximal CPET at constant speed up to the limit of tolerance (Tlim). The patients who showed ΔIC(peak-rest) < 0 were considered to present with DH (DH+). Results: In this sample, 21 patients (70%) had DH. The DH+ patients had higher airflow obstruction and lower Tlim than did the patients without DH (DH−). Despite equivalent improvement in FEV1 after bronchodilator, the DH− group showed higher ΔIC(bronchodilator-placebo) at rest in relation to the DH+ group (p < 0.05). However, this was not found in relation to ΔIC at peak exercise between DH+ and DH− groups (0.19 ± 0.17 L vs. 0.17 ± 0.15 L, p > 0.05). In addition, both groups showed similar improvements in Tlim after bronchodilator (median [interquartile range]: 22% [3-60%] vs. 10% [3-53%]; p > 0.05). Conclusions: Improvement in TLim was associated with an increase in IC at rest after bronchodilator in HD− patients with COPD. However, even without that improvement, COPD patients can present with greater exercise tolerance after bronchodilator provided that they develop DH during exercise.

Keywords: Pulmonary disease, chronic obstructive; Bronchodilator agents; Exercise test; Exercise tolerance; Inspiratory capacity.

Background: Dyspnea is a symptom that is difficult to evaluate, especially in occupational diseases. Objective: To evaluate the relationship between chronic dyspnea, in its varying degrees of severity, and the functional repercussions for dysfunction or incapacitation in former workers with asbestosis. Method: A total of 40 former workers diagnosed with asbestosis were evaluated. Dyspnea scores were determined using the modified Medical Research Council scale, the 1984 and 1993 American Medical Association scales, and the Baseline Dyspnea Index. Spirometry, measurement of diffusion capacity for carbon monoxide and cardiopulmonary exercise tests (incremental and submaximal) were also performed. Results: Based on scores obtained using the Medical Research Council and 1984 American Medical Association scales, respectively, 72.5% and 67.5% of the subjects were classified as dyspneic, compared with 37.5% and 31.6%, respectively, using the 1993 American Medical Association and Baseline Dyspnea Index scales. There was greater concordance between the Medical Research Council and 1993 American Medical Association scales, as well as between the 1984 and 1993 American Medical Association scales, when the categories of "absent" and "mild" were grouped. No significant relation was found between dyspnea, as determined by each of the scales, and functional abnormalities - either at rest or during exercise. Conclusion: In individuals with asbestosis, the degree of concordance among the available dyspnea scales varies significantly. There is a real need for dyspnea indices that evaluate respiratory dysfunction at rest and during exercise.

Keywords: Asbestosis/diagnosis. Dyspnea/physiopathology. Spirometry/methods.

Objective: To evaluate the influence of chronic heart failure (CHF) on resting lung volumes in patients with COPD, i.e., inspiratory fraction-inspiratory capacity (IC)/TLC-and relative inspiratory reserve-[1 − (end-inspiratory lung volume/TLC)]. Methods: This was a prospective study involving 56 patients with COPD-24 (23 males/1 female) with COPD+CHF and 32 (28 males/4 females) with COPD only-who, after careful clinical stabilization, underwent spirometry (with forced and slow maneuvers) and whole-body plethysmography. Results: Although FEV1, as well as the FEV1/FVC and FEV1/slow vital capacity ratios, were higher in the COPD+CHF group than in the COPD group, all major "static" volumes-RV, functional residual capacity (FRC), and TLC-were lower in the former group (p < 0.05). There was a greater reduction in FRC than in RV, resulting in the expiratory reserve volume being lower in the COPD+CHF group than in the COPD group. There were relatively proportional reductions in FRC and TLC in the two groups; therefore, IC was also comparable. Consequently, the inspiratory fraction was higher in the COPD+CHF group than in the COPD group (0.42 ± 0.10 vs. 0.36 ± 0.10; p < 0.05). Although the tidal volume/IC ratio was higher in the COPD+CHF group, the relative inspiratory reserve was remarkably similar between the two groups (0.35 ± 0.09 vs. 0.44 ± 0.14; p < 0.05). Conclusions: Despite the restrictive effects of CHF, patients with COPD+CHF have relatively higher inspiratory limits (a greater inspiratory fraction). However, those patients use only a part of those limits, probably in order to avoid critical reductions in inspiratory reserve and increases in elastic recoil.

Keywords: Respiratory function tests; Pulmonary disease, chronic obstructive; Heart failure; Spirometry.