The exercise tolerance and ventilatory efficiency of lung cancer patients with type 2 diabetes / 中华物理医学与康复杂志

Objective:To explore the aerobic exercise tolerance and ventilatory efficiency during cardiopulmonary exercise testing (CPET) of persons with non-small cell lung cancer (NSCLC) complicated by type 2 diabetes mellitus (T2DM).Methods:Forty-eight persons with NSCLC and T2DM formed an NSCLC-T2DM group while another 48 persons with NSCLC but not T2DM formed an NSCLC-non T2DM group. Another 24 healthy counterparts were enrolled into the control group. All completed CPET before pneumonectomies were performed on those with NSCLC. Indexes of static pulmonary function, exercise tolerance, heart rate recovery, ventilation efficiency and gas exchange were computed.Results:Compared with the control group, both NSCLC groups had, on average, lower peak oxygen uptake (VO 2peak), lower anaerobic thresholds (ATs) and lower peak O 2 pulse rates. They also had higher average VE/VCO 2 slopes and VE/VCO 2 nadirs. Compared with the NSCLC-non T2DM group, those with T2DM had a significantly lower average VO 2peak and WRpeak, as well as significantly higher average VE/VCO 2 slope and VE/VCO 2 nadir. Compared with the control group, the average VO 2 and VCO 2 of both NSCLC groups was lower at the AT and during peak exercise, with the NSCLC-T2DM group′s averages significantly lower than those of the NSCLC-non T2DM group during peak exercise. During warm-up and at the AT, the NSCLC groups had a significantly higher average heart rate than the control group. Then, compared with the control group and the NSCLC-non T2DM group, the average heart rate in the NSCLC-T2DM group decreased significantly more slowly during the first three minutes of the recovery period. Compared with the control group, the VE/VCO 2 values of the NSCLC groups were significantly higher at the AT and during peak exercise. During the warm-up and at the AT, the average partial pressures of end-tidal carbon dioxide in the NSCLC groups were significantly lower than among control group, and during peak exercise the NSCLC-T2DM group′s average value was significantly lower than the control group′s. Compared with the control group and the NSCLC-non T2DM group, the NSCLC-T2DM group′s average forced expiratory volume in one second, forced vital capacity, peak expiratory flow rate and maximum voluntary ventilation were all significantly lower. Conclusions:Diabetes impairs the exercise tolerance and ventilation efficiency of persons with NSCLC. Without diabetes their exercise tolerance and ventilation efficiency would be impaired only slightly. CPET can provide a basis for risk assessment before pneumonectomy.

Relationship of Ventilatory Efficiency to Cardiac Function after Exercise in Patients with Chronic Obstructive Pulmonary Disease / 中国康复理论与实践

Objective:To observe the relationship of ventilatory efficiency to cardiac function, especially heart rate recovery after exercise for patients with chronic obstructive pulmonary disease (COPD). Methods:From January, 2019 to December, 2020, 190 patients with COPD were recruited for Cardiopulmonary Exercise Testing. The general condition, medical history and medication history, lung function test and parameters of Cardiopulmonary Exercise Testing were recorded. They were divided into normal group and delay group according to whether the heart rate decline more than twelve beats within a minute after Cardiopulmonary Exercise Testing. Results:There were 89 patients (46.84%) in the delay group. Compared with the normal group, the delay group were older (Z = 2.282, P < 0.05), with less ratio of force exiratory volume in the first second in prediction (FEV1.0%) (Z = 3.626, P < 0.001), maximum power (t = 5.547, P < 0.001), breath reserve (BR) (t = 2.122, P < 0.05) and higher minimum ventilation equivalent of carbon dioxide (VE/VCO2nadir) (Z = 3.296, P = 0.001). Logistic regression showed that the COPD severity, VE/VCO2nadir and BR correlated with heart rate recovery. After adjusting for gender, age, body mass index and COPD severity, VE/VCO2nadir was an independent risk factor for delayed heart rate recovery (OR = 1.203, 95%CI 1.032 to 1.873, P = 0.004), and the best cut-off point was 33.15 (AUC = 0.6387, 95%CI 0.5595 to 0.7178, P = 0.001). Conclusion:The ventilatory inefficiency may increase the risk of abnormal heart rate recovery after exercise in COPD patients.

Nitrogen single-breath washout test for evaluating exercise tolerance and quality of life in patients with chronic obstructive pulmonary disease

Pulmonary function tests (PFTs) traditionally used in clinical practice do not accurately predict exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). The aim of this study was to assess whether the nitrogen single-breath washout (N2SBW) test explains exercise intolerance and poor quality of life in stable COPD patients. This cross-sectional study included 31 patients with COPD subjected to PFTs (including the N2SBW test) and a cardiopulmonary exercise test (CPET). Patients were also evaluated using the following questionnaires: the COPD assessment test (CAT), the 36-Item Short Form Health Survey (SF36) and St. George's Respiratory Questionnaire (SGRQ). Peak oxygen uptake (peak VO2) was negatively correlated with the phase III slope of the N2SBW (SIIIN2) (r=-0.681, P<0.0001) and positively correlated with forced expiratory volume in one second (FEV1; r=0.441, P=0.013). Breathing reserve was negatively correlated with SIIIN2, closing volume/vital capacity, and residual volume (RV) (r=-0.799, P<0.0001; r=-0.471, P=0.007; r=-0.401, P=0.025, respectively) and positively correlated with FEV1, forced vital capacity (FVC) and FEV1/FVC (r=0.721; P<0.0001; r=0.592, P=0.0004; r=0.670, P<0.0001, respectively). SIIIN2 and CAT were independently predictive of VO2 and breathing reserve at peak exercise. RV, FVC, and FEV1 were independently predictive of the SF36-physical component summary, SF36-mental component summary, and breathing reserve, respectively. The SGRQ did not present any independent variables that could explain the model. In stable COPD patients, inhomogeneity of ventilation explains a large degree of exercise intolerance assessed by CPETs and, to a lesser extent, poor quality of life.

Effect of exercise training on ventilatory efficiency in patients with heart disease: a review

The analysis of ventilatory efficiency in cardiopulmonary exercise testing has proven useful for assessing the presence and severity of cardiorespiratory diseases. During exercise, efficient pulmonary gas exchange is characterized by uniform matching of lung ventilation with perfusion. By contrast, mismatching is marked by inefficient pulmonary gas exchange, requiring increased ventilation for a given CO2 production. The etiology of increased and inefficient ventilatory response to exercise in heart disease is multifactorial, involving both peripheral and central mechanisms. Exercise training has been recommended as non-pharmacological treatment for patients with different chronic cardiopulmonary diseases. In this respect, previous studies have reported improvements in ventilatory efficiency after aerobic exercise training in patients with heart disease. Against this background, the primary objective of the present review was to discuss the pathophysiological mechanisms involved in abnormal ventilatory response to exercise, with an emphasis on both patients with heart failure syndrome and coronary artery disease. Secondly, special focus was dedicated to the role of aerobic exercise training in improving indices of ventilatory efficiency among these patients, as well as to the underlying mechanisms involved.

Effects of continuous vs interval exercise training on oxygen uptake efficiency slope in patients with coronary artery disease

The oxygen uptake efficiency slope (OUES) is a submaximal index incorporating cardiovascular, peripheral, and pulmonary factors that determine the ventilatory response to exercise. The purpose of this study was to evaluate the effects of continuous exercise training and interval exercise training on the OUES in patients with coronary artery disease. Thirty-five patients (59.3±1.8 years old; 28 men, 7 women) with coronary artery disease were randomly divided into two groups: continuous exercise training (n=18) and interval exercise training (n=17). All patients performed graded exercise tests with respiratory gas analysis before and 3 months after the exercise-training program to determine ventilatory anaerobic threshold (VAT), respiratory compensation point, and peak oxygen consumption (peak VO2). The OUES was assessed based on data from the second minute of exercise until exhaustion by calculating the slope of the linear relation between oxygen uptake and the logarithm of total ventilation. After the interventions, both groups showed increased aerobic fitness (P<0.05). In addition, both the continuous exercise and interval exercise training groups demonstrated an increase in OUES (P<0.05). Significant associations were observed in both groups: 1) continuous exercise training (OUES and peak VO2 r=0.57; OUES and VO2 VAT r=0.57); 2) interval exercise training (OUES and peak VO2 r=0.80; OUES and VO2 VAT r=0.67). Continuous and interval exercise training resulted in a similar increase in OUES among patients with coronary artery disease. These findings suggest that improvements in OUES among CAD patients after aerobic exercise training may be dependent on peripheral and central mechanisms.

Association of oxygen uptake efficiency in exercise test with exercise capacity in patients of obstructive sleep apnea hypopnea syndrome / 中华全科医师杂志

Objective To explore the characteristics of oxygen uptake efficiency (OUES) in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and analyze the relationship between OUE and severity of disease.Methods Pulmonary function test,polysomnogram and cardiopulmonary exercise testing were performed in 35 patients with OSAHS and 25 age-matched healthy volunteers.Their successive breathing respiratory exchange parameters were collected and analyzed.And t and x2 tests were used for 2 sample comparison.Correlation analysis was performed by Pearson correlation test.Results Significant differences in peak VO2 and peak VO2 ％ pred existed between OSAHS and normal control groups [(18±4) vs.(28 ±6) L/min,P＜0.01;(68±14) vs.(84±16) ％,P＜0.01].Compared with normal control group [(2.3 ±0.5) L · min-1 · lg-1 ; (36 ±4) ml/L; (36 ±4) ml/L],OUES,OUEP and OUE@AT of OSAHS group [(1.8 ± 0.4) L · min-1 · lg-1 ; (31 ± 5) ml/L; (30 ± 5) ml/L] were significantly lower (t =3.78-4.49,all P ＜0.01).And OUES,OUEP and OUE@AT in OSAHS patients were correlated (r =0.53-0.67,all P ＜0.01) positively with exercise tolerance (peak VO2％ pred) while negatively with apnea hypopnea index (AHI) (r=-0.67--0.54,all P ＜0.01).Conclusion The oxygen uptake efficiency of patients with OSAHS is significantly reduced compared to that of normal subjects.And it is correlated negatively with severity of disease.

Effect of continuous and interval exercise training on the PETCO2 response during a graded exercise test in patients with coronary artery disease

OBJECTIVE: The purpose of this study was to evaluate the following: 1) the effects of continuous exercise training and interval exercise training on the end-tidal carbon dioxide pressure (PETCO2) response during a graded exercise test in patients with coronary artery disease; and 2) the effects of exercise training modalities on the association between PETCO2 at the ventilatory anaerobic threshold (VAT) and indicators of ventilatory efficiency and cardiorespiratory fitness in patients with coronary artery disease. METHODS: Thirty-seven patients (59.7 + 1.7 years) with coronary artery disease were randomly divided into two groups: continuous exercise training (n = 20) and interval exercise training (n = 17). All patients performed a graded exercise test with respiratory gas analysis before and after three months of the exercise training program to determine the VAT, respiratory compensation point (RCP) and peak oxygen consumption. RESULTS: After the interventions, both groups exhibited increased cardiorespiratory fitness. Indeed, the continuous exercise and interval exercise training groups demonstrated increases in both ventilatory efficiency and PETCO2 values at VAT, RCP, and peak of exercise. Significant associations were observed in both groups: 1) continuous exercise training (PETCO2VAT and cardiorespiratory fitness r = 0.49; PETCO2VAT and ventilatory efficiency r = -0.80) and 2) interval exercise training (PETCO2VAT and cardiorespiratory fitness r = 0.39; PETCO2VAT and ventilatory efficiency r = -0.45). CONCLUSIONS: Both exercise training modalities showed similar increases in PETCO2 levels during a graded exercise test in patients with coronary artery disease, which may be associated with an improvement in ventilatory efficiency and cardiorespiratory fitness.