Boutou AK; Manika K; Hajimitrova M; Pitsiou G; Giannakopoulou P; Sourla E; Kioumis I;

Advances in respiratory medicine [Adv Respir Med] 2020; Vol. 88 (5), pp. 420-423.

Introduction: Longitudinal data regarding changes in exercise capacity among adult cystic fibrosis (CF) patients are currently scarce. The aim of this brief report was to assess changes in exercise capacity among adult CF patients with stable and mild-to-moderate disease eight years after their initial evaluation.
Material and Methods: Maximum cardiopulmonary exercise testing (CPET) was utilized. Other assessments included Doppler echocardiography, the 6-minute walking test, spirometry, and lung volume evaluation.
Results: Eleven (6 male, 5 female) patients completed both evaluations (initial and after eight years). During follow-up, indices of ventilatory impairment (such as ventilatory reserve; p=0.019, and ventilatory equivalent for carbon dioxide; p = 0.047) deterio-rated significantly following a decline in respiratory function measurements. Peak oxygen uptake (VO2), both as an absolute (26.6 ± 8.46 vs 23.89 ± 6.16 mL/kg/min; p = 0.098) and as a % of predicted value (71.21 ± 16.54 vs 70.60 ± 15.45; p = 0.872), did not deteriorate. This is also true for oxygen pulse (p = 0.743), left heart ejection fraction (p = 0.574), and pulmonary artery systolic pressure (p = 0.441). However, the anaerobic threshold, both as an absolute (p = 0.009) and as a % of predicted value (p = 0.047), was significantly lower during follow-up.
Conclusion: In adult CF patients with stable, mild-to-moderate disease, a peak VO2 may be preserved for several years. However, even in these patients, deconditioning is present.

Puente-Maestú L; Ortega F; Pedro JG; Rodríguez-Nieto MJ; Gómez-Seco J; Gáldiz B; Ojanguren I; Muñoz X; Blanco I; Burgos F; Rodríguez-Chiaradía DA; Gea J; García-Rio F;

Archivos de bronconeumologia [Arch Bronconeumol] 2020 Oct 10. Date of Electronic Publication: 2020 Oct 10.

Background: Frequently used reference values for clinical exercise testing have been derived from non-random samples and some with poorly defined maximal criteria. Our objective was to obtain population based reference values for peak oxygen uptake (V˙O ₂ ) and work rate (WR) for cardiopulmonary exercise testing in a representative sample of Caucasian Spanish men and women.
Methods: 182 men and women, 20-85 years old, were included and exercised on cycle-ergometer to exhaustion. (V˙O ₂ ) and WR were measured. The equations obtained from this sample were validated in an independent cohort of 69 individuals, randomly sampled form the same population. Then a final equation merging the two cohorts (=251) was produced.
Results: Height, sex and age resulted predictive of both V˙O ₂ peak and WR. Weight and physical activity added very little to the accuracy to the equations. The formulas V˙O ₂ peak=0.017⋅height(cm)-0.023⋅age(years)+0.864⋅sex(female=0/male=1)±179lmin ^-1 , and peak WR=1.345 · height (cm) – 2.074 · age (years)+76.54 · sex (female=0/male=1)±21.2W were the best compromise between accuracy and parsimony.
Conclusions: This study provides new and accurate V˙O ₂ peak and WR rate reference values for individuals of European Spanish descent.

Phillips DB; Domnik NJ; Elbehairy AF; Preston ME; Milne KM; James MD; Vincent SG; Ibrahim-Masthan M; Neder JA; O’Donnell DE;

Respiratory physiology & neurobiology [Respir Physiol Neurobiol] 2020 Nov 05, pp. 103571. Date of Electronic Publication: 2020 Nov 05.

Background: The purpose of this study was to determine if altered central chemoreceptor characteristics contributed to the elevated ventilation relative to carbon dioxide production (V̇ _E /V̇CO ₂ ) response during exercise in mild chronic obstructive pulmonary disease (COPD).
Methods: Twenty-nine mild COPD and 19 healthy age-matched control participants undertook lung function testing followed by symptom-limited incremental cardiopulmonary exercise testing (CPET). On a separate day, basal (non-chemoreflex) ventilation (V̇ _EB ), the central chemoreflex ventilatory recruitment threshold for CO ₂ (VRTCO ₂ ), and central chemoreflex sensitivity (V̇ _ES ) were assessed using the modified Duffin’s CO ₂ rebreathing method. Resting arterialized blood gas data were also obtained.
Results: At standardized exercise intensities, absolute V̇ _E and V̇ _E /V̇CO ₂ were consistently elevated and the end-tidal partial pressure of CO ₂ was relatively decreased in mild COPD versus controls (all p < 0.05). There were no between-group differences in resting arterialized blood gas parameters, basal V̇ _E , VRTCO ₂ , or V̇ _ES (all p > 0.05).
Conclusion: These data have established that excessive exercise ventilation in mild COPD is not explained by altered central chemosensitivity.

Guo Q; Zhao Y; Shao J; Cao S; Wang Q; Wu W;

The Science of the total environment [Sci Total Environ] 2020 Oct 19, pp. 143011. Date of Electronic Publication: 2020 Oct 19.

Background: The health effects of air pollution are associated with the concentration of pollutants and ventilation (VE). VE is difficult to measure directly and has been predicted by heart rate (HR). However, it is unclear whether equations between HR and VE obtained from a laboratory cardiopulmonary exercise test (CPET) can be extended to external groups and there is still a gap in their relationship for a Chinese population.
Objective: To establish an association between HR and VE in young Chinese individuals and verify the external validity of the model.
Methods: Eighty non-smoking participants aged 16-21 years underwent incremental tests using a bicycle ergometer, where the HR and minute VE were measured simultaneously. Linear mixed models were constructed with data obtained from a CPET. Ten individuals were chosen randomly as the external validation group. The predictive performance was assessed using an eight-fold cross-validation procedure. Air pollution concentration was monitored during the CPET and the inhaled load was calculated.
Results: The overall estimation of the intercept and slope for all participants was 0.585 ± 0.013 and 0.007 ± 0.00002, respectively. The overall fitted R squared (R ² ) was 0.84. The median difference between the measured VE and the predicted VE was 0.3 L/min, and the difference between the inhaled load based on the fitted VE and the measured VE was 0.0-0.3 μg across all the participants. The eight folds cross-validation R ² value was 0.78, suggesting high predictive accuracy.
Conclusion: This is the first study to derive a novel equation for the relationship between HR and VE in a young Chinese population and verify its external validity. This will be important in the assessment of the inhaled load in future epidemiology studies. However, inter-individual variations should also be considered when VE is estimated at an individual level.

Lewthwaite H; Jensen D;

European journal of applied physiology [Eur J Appl Physiol] 2020 Nov 03. Date of Electronic Publication: 2020 Nov 03.

Purpose: This study explored if healthy adults could discriminate between different breathlessness dimensions when rated immediately one after another (successively) during symptom-limited incremental cardiopulmonary cycle exercise testing (CPET) using multiple single-item rating scales.
Methods: Fifteen apparently healthy adults (60% male) aged 22 ± 2 years performed six incremental cycle CPETs separated by ≥ 48 h. During each CPET (at rest, every 2-min and at end exercise), participants rated different breathlessness sensations using the 0-10 modified Borg scale using one of six assessment protocols, randomized for order: (1) ‘BREATHLESS _ALL ‘ = breathlessness sensory intensity (SI), breathlessness unpleasantness (UN), work/effort of breathing (SQ _W/E ), and unsatisfied inspiration (SQ _UI ) assessed; (2) SI and UN assessed; and (3-6) SI, UN, SQ _W/E , and SQ _UI each assessed alone. Physiological responses to CPET were also evaluated.
Results: Physiological and breathlessness responses to CPET were comparable across the six protocols, with the exception of SI rated lower at the highest submaximal power output (220 ± 56 watts) during the BREATHLESS _ALL protocol (0-10 Borg units 4.2 ± 1.7) compared to SI + UN (5.2 ± 2.1, p = 0.03) and SI alone (5.1 ± 1.9, p = 0.04) protocols. Ratings of SI and SQ _W/E were not significantly different when assessed in the same protocol, and were significantly higher than UN and SQ _UI , which were comparable.
Conclusion: In healthy younger adults, use of two separate single-item rating scales to assess breathlessness during CPET is feasible and enables the distinct sensory intensity and affective dimensions of exertional breathlessness to be assessed.

Neunhäuserer D; Reich B; Mayr B; Kaiser B; Lamprecht B; Ermolao A; Studnicka M; Niebauer J;

Scandinavian journal of medicine & science in sports [Scand J Med Sci Sports] 2020 Nov 05. Date of Electronic Publication: 2020 Nov 05.

Functional impairment caused by chronic obstructive pulmonary disease (COPD) impacts on activities of daily living and quality of life. Indeed, patients’ submaximal exercise capacity is of crucial importance. It was the aim of this study to investigate the effects of an exercise training intervention with and without supplemental oxygen on submaximal exercise performance. This is a secondary analysis of a randomized, controlled, double-blind, crossover trial. 29 COPD patients (63.5±5.9 years; FEV ₁ 46.4±8.6%) completed two consecutive 6-week periods of high intensity interval cycling and strength training, which was performed three times/week with either supplemental oxygen or medical air (10 L/min). Submaximal exercise capacity as well as the cardiocirculatory, ventilatory and metabolic response were evaluated at isotime (point of termination in the shortest cardiopulmonary exercise test), at physical work capacity at 110 bpm of heart rate (PWC 110), at the anaerobic threshold (AT), and at the lactate-2 mmol/L threshold. After 12 weeks of exercise training, patients improved in exercise tolerance, shown by decreased cardiocirculatory (heart rate, blood pressure) and metabolic (respiratory exchange ratio, lactate) effort at isotime; ventilatory response was not affected. Submaximal exercise capacity was improved at PWC 110, AT and the lactate-2 mmol/L threshold, respectively. Although supplemental oxygen seems to affect patients’ work rate at AT and the lactate-2 mmol/L threshold, no other significant effects were found. The improved submaximal exercise capacity and tolerance might counteract patients’ functional impairment. Although cardiovascular and metabolic training adaptations were shown, ventilatory efficiency remained essentially unchanged. The impact of supplemental oxygen seems less important on submaximal training effects.

Sovová M; Sovová E; Nakládalová M; Pokorná T; Štégnerová L; Masný O; Moravcová K; Štěpánek L;

Central European journal of public health [Cent Eur J Public Health] 2020 Oct; Vol. 28 Suppl, pp. S53-S56.

Objectives: Low cardiorespiratory fitness (CRF) is related to higher risk of cardiovascular diseases, increase in all-cause mortality and higher risk of different tumors. The reverse is also true; improvement in CRF is related to decrease in mortality. Cardiopulmonary exercise testing (CPET) is a standard and also the most precise test for determination of CRF – the best possibility is the maximal test measuring different parameters including maximal oxygen consumption. Healthcare professionals throughout the developed world have markedly high rates of sickness absence, burnout, and distress compared to other sectors and this leads to higher risk factors. The study aimed to assess CRF in a group of nurses in a big hospital and compare it with population norms and available published results.
Methods: Nurses over 50 years of age working in one faculty hospital were gradually included in the study from the beginning of 2018. These nurses work in physically demanding positions. A CPET was carried out following the Bruce protocol.
Results: 90 nurses (84 females and 6 males), mean age 55.7 years, were evaluated by CPET. The resting blood pressure was within the norm in 58 persons (64.44%), maximal oxygen consumption in 61 persons (67.8%), W/kg in 25 persons (46.2%). We detected a hypertension reaction in 28 persons (31.1%), some types of arrhythmia in 17 persons (18.9%) and signs of ischaemia in 8 persons (8.9%). The result of CPET led to further examination in 42 persons (46.6%). Detailed examination resulted in change of medication in 21 nurses (23.3%). New diseases were diagnosed in 15 nurses (hypertension, atrial fibrillation, mitral valve prolapse indicated for cardiac surgery, coronary artery stenosis, and lipid disorders).
Conclusions: It was concluded that the usage of CPET during the regular medical check-ups significantly increases detection of hidden diseases and thus improves the care for nurses.

Suter B; Kay WA; Kuhlenhoelter AM; Ebenroth ES;

Cardiology in the young [Cardiol Young] 2020 Oct 21, pp. 1-7. Date of Electronic Publication: 2020 Oct 21.

Background: Cardiopulmonary exercise testing performance has been shown to be a predictor of morbidity, mortality, and quality of life in patients with Fontan physiology; however, the role of exercise performance along with other diagnostics is not fully understood. We evaluated the hypothesis that reduced exercise performance correlates with poorer quality of life in Fontan patients as they continue to age.
Methods: Chart review was performed on patients 12 years and older with Fontan who had completed cardiopulmonary exercise testing and age-appropriate quality of life surveys. Quality of life outcomes were analysed against exercise performance and other descriptive data.
Results: For the younger cohort (n = 22), exercise performance predicted quality of life with different measures across domains and had a stronger correlation than echocardiographic parameters. For the older cohort (n = 34), exercise performance did not predict quality of life.
Conclusions: Objective exercise performance was a useful marker for general, physical, emotional, social, and school quality of life in a younger cohort but less helpful in older adults. This is perhaps due to older patients accommodating to their conditions over time. The role of exercise performance and objective data in predicting quality of life in patients with Fontan physiology is incompletely understood and additional prospective evaluation should be undertaken.

Strozza D; ; Wilhite DP; Babb TG; Bhammar DM

Medicine and science in sports and exercise [Med Sci Sports Exerc] 2020 Nov; Vol. 52 (11), pp. 2310-2319.

Purpose: Thoracic gas compression and exercise-induced bronchodilation can influence the assessment of expiratory flow limitation (EFL) during cardiopulmonary exercise tests. The purpose of this study was to examine the effect of thoracic gas compression and exercise-induced bronchodilation on the assessment of EFL in children with and without obesity.
Methods: Forty children (10.7 ± 1.0 yr; 27 obese; 15 with EFL) completed pulmonary function tests and incremental exercise tests. Inspiratory capacity maneuvers were performed during the incremental exercise test for the placement of tidal flow volume loops within the maximal expiratory flow volume (MEFV) loops, and EFL was calculated as the overlap between the tidal and the MEFV loops. MEFV loops were plotted with volume measured at the lung using plethysmography (MEFVp), with volume measured at the mouth using spirometry concurrent with measurements in the plethysmograph (MEFVm), and from spirometry before (MEFVpre) and after (MEFVpost) the incremental exercise test. Only the MEFVp loops were corrected for thoracic gas compression.
Results: Not correcting for thoracic gas compression resulted in incorrect diagnosis of EFL in 23% of children at peak exercise. EFL was 26% ± 15% VT higher for MEFVm compared with MEFVp (P < 0.001), with no differences between children with and without obesity (P = 0.833). The difference in EFL estimation using MEFVpre (37% ± 30% VT) and MEFVpost (31% ± 26% VT) did not reach statistical significance (P = 0.346).
Conclusions: Not correcting the MEFV loops for thoracic gas compression leads to the overdiagnosis and overestimation of EFL. Because most commercially available metabolic measurement systems do not correct for thoracic gas compression during spirometry, there may be a significant overdiagnosis of EFL in cardiopulmonary exercise testing. Therefore, clinicians must exercise caution while interpreting EFL when the MEFV loop is derived through spirometry.