Correlates of children’s physical activity during physical education classes

Aim: The aim of this study was to investigate the influence of correlates on physical activity (PA) during physical education (PE). Method: One hundred and ninety children (11.2 ± 0.8 y, 1.5 ± 0.1 m, 37.7 ± 8.3 kg) of 12 classes participated. Children were asked to wear an accelerometer for seven days. Teachers filled in a questionnaire to collect data about correlates of PA during PE (i.e. sex, weight, age of children, daily PA of the children, class size, PA behavior and formation of the teacher and size of gym). Correlates for moderate-to-vigorous PA (MVPA) during PE were determined using multifactor linear regression analysis. Results Fifty-three percent of the variability of MVPA during PE was explained by the investigated correlates. Apart from individual correlates (sex, weight, age), PE taught in small classes and large gyms by a PE specialist and a high overall PA of the child had independent positive effects on MVPA during PE. Conclusion: The results underline the importance of small PE classes taught by specialized PE teachers in large gyms and the increase of overall PA of children for effective future intervention studies and for political discussion focusing on increasing PA during PE

Validation of Noninvasive Assessment of Pulmonary Gas Exchange in Patients with Chronic Obstructive Pulmonary Disease during Initial Exposure to High Altitude

Investigation of pulmonary gas exchange efficacy usually requires arterial blood gas analysis (aBGA) to determine arterial partial pressure of oxygen (mPaO2) and compute the Riley alveolar-to-arterial oxygen difference (A-aDO2); that is a demanding and invasive procedure. A noninvasive approach (AGM100), allowing the calculation of PaO2 (cPaO2) derived from pulse oximetry (SpO2), has been developed, but this has not been validated in a large cohort of chronic obstructive pulmonary disease (COPD) patients. Our aim was to conduct a validation study of the AG100 in hypoxemic moderate-to-severe COPD. Concurrent measurements of cPaO2 (AGM100) and mPaO2 (EPOC, portable aBGA device) were performed in 131 moderate-to-severe COPD patients (mean ±SD FEV1: 60 ± 10% of predicted value) and low-altitude residents, becoming hypoxemic (i.e., SpO2 < 94%) during a short stay at 3100 m (Too-Ashu, Kyrgyzstan). Agreements between cPaO2 (AGM100) and mPaO2 (EPOC) and between the O2-deficit (calculated as the difference between end-tidal pressure of O2 and cPaO2 by the AGM100) and Riley A-aDO2 were assessed. Mean bias (±SD) between cPaO2 and mPaO2 was 2.0 ± 4.6 mmHg (95% Confidence Interval (CI): 1.2 to 2.8 mmHg) with 95% limits of agreement (LoA): −7.1 to 11.1 mmHg. In multivariable analysis, larger body mass index (p = 0.046), an increase in SpO2 (p < 0.001), and an increase in PaCO2-PETCO2 difference (p < 0.001) were associated with imprecision (i.e., the discrepancy between cPaO2 and mPaO2). The positive predictive value of cPaO2 to detect severe hypoxemia (i.e., PaO2 ≤ 55 mmHg) was 0.94 (95% CI: 0.87 to 0.98) with a positive likelihood ratio of 3.77 (95% CI: 1.71 to 8.33). The mean bias between O2-deficit and A-aDO2 was 6.2 ± 5.5 mmHg (95% CI: 5.3 to 7.2 mmHg; 95%LoA: −4.5 to 17.0 mmHg). AGM100 provided an accurate estimate of PaO2 in hypoxemic patients with COPD, but the precision for individual values was modest. This device is promising for noninvasive assessment of pulmonary gas exchange efficacy in COPD patients

Exercise Performance of Lowlanders with Chronic Obstructive Pulmonary Disease Acutely Exposed to 2048 m: A Randomized Cross-Over Trial

Konstantinos Bitos,1 Tobias Kuehne,1 Tsogyal D Latshang,1 Sayaka S Aeschbacher,1 Fabienne Huber,1 Deborah Flueck,1 Elisabeth D Hasler,1 Philipp M Scheiwiller,1 Mona Lichtblau,1 Silvia Ulrich,1 Konrad E Bloch,1 Michael Furian1,2 1University Hospital Zurich, Department of Respiratory Medicine, Zurich, Switzerland; 2Swiss University of Traditional Chinese Medicine, Research Department, Bad Zurzach, SwitzerlandCorrespondence: Michael Furian, University Hospital Zurich, Department of Pulmonology, Raemistrasse 100, Zurich, 8092, Switzerland, Email [email protected]: Amongst the millions of travelers to high altitude worldwide are many with chronic obstructive pulmonary disease (COPD), but data regarding the effects of acute exposure to altitude on exercise performance are limited. The current study investigated how acute exposure to moderate altitude influences exercise performance in COPD patients, providing novel insights to the underlying physiological mechanisms.Methods: Twenty-nine COPD patients, GOLD grade 2– 3, median (quartile) forced expiratory volume in 1 second (FEV1) of 60% predicted (46; 69) performed cycling incremental ramp exercise test (IET) at 490 m and after acute exposure of 2– 6 hours to 2048 m or vice versa, according to a randomized cross-over design. Exercise performance and breath-by-breath analyses of the last 30 seconds of each IET were compared between locations.Results: At 2048 m compared to 490 m, the maximum power output (Wmax) was 77 watts (62;104) vs 88 watts (75;112), median reduction 5 watts (95% CI, 2 to 8, P< 0.05), corresponding to a median reduction of 6% (95% CI, 2 to 11, P< 0.05) compared to 490 m. The peak oxygen uptake (V’O2peak) was 70% predicted (56;86) at 2048 m vs 79% predicted (63;90) at 490 m, median reduction of 6% (95% CI, 3 to 9, P< 0.05). The oxygen saturation by pulse oximetry (SpO2) at 2048 m was reduced by 8% (95% CI, 4 to 9, P< 0.05) compared to 490 m. The minute ventilation (V’E) increased by 2.8L/min (95% CI, 0.9 to 4.2, P< 0.05) at 2048 m. The maximum heart rate and the subjective sense of dyspnea and leg fatigue did not change.Conclusion: Lowlanders with moderate-to-severe COPD acutely exposed to 2048 m reveal small but significant reduction in cycling IET along with a reduced V’O2peak. As dyspnea perception and maximal heart rate were unchanged, the lower blood oxygenation and exaggerated ventilatory response were culprit factors for the reduced performance.Keywords: COPD, exercise, high altitude, hypoxia, hypoxemia, cardiopulmonary exercise testin

Validation of Noninvasive Assessment of Pulmonary Gas Exchange in Patients with Chronic Obstructive Pulmonary Disease during Initial Exposure to High Altitude

Investigation of pulmonary gas exchange efficacy usually requires arterial blood gas analysis (aBGA) to determine arterial partial pressure of oxygen (mPaO2) and compute the Riley alveolar-to-arterial oxygen difference (A-aDO2); that is a demanding and invasive procedure. A noninvasive approach (AGM100), allowing the calculation of PaO2 (cPaO2) derived from pulse oximetry (SpO2), has been developed, but this has not been validated in a large cohort of chronic obstructive pulmonary disease (COPD) patients. Our aim was to conduct a validation study of the AG100 in hypoxemic moderate-to-severe COPD. Concurrent measurements of cPaO2 (AGM100) and mPaO2 (EPOC, portable aBGA device) were performed in 131 moderate-to-severe COPD patients (mean &plusmn;SD FEV1: 60 &plusmn; 10% of predicted value) and low-altitude residents, becoming hypoxemic (i.e., SpO2 &lt; 94%) during a short stay at 3100 m (Too-Ashu, Kyrgyzstan). Agreements between cPaO2 (AGM100) and mPaO2 (EPOC) and between the O2-deficit (calculated as the difference between end-tidal pressure of O2 and cPaO2 by the AGM100) and Riley A-aDO2 were assessed. Mean bias (&plusmn;SD) between cPaO2 and mPaO2 was 2.0 &plusmn; 4.6 mmHg (95% Confidence Interval (CI): 1.2 to 2.8 mmHg) with 95% limits of agreement (LoA): &minus;7.1 to 11.1 mmHg. In multivariable analysis, larger body mass index (p = 0.046), an increase in SpO2 (p &lt; 0.001), and an increase in PaCO2-PETCO2 difference (p &lt; 0.001) were associated with imprecision (i.e., the discrepancy between cPaO2 and mPaO2). The positive predictive value of cPaO2 to detect severe hypoxemia (i.e., PaO2 &le; 55 mmHg) was 0.94 (95% CI: 0.87 to 0.98) with a positive likelihood ratio of 3.77 (95% CI: 1.71 to 8.33). The mean bias between O2-deficit and A-aDO2 was 6.2 &plusmn; 5.5 mmHg (95% CI: 5.3 to 7.2 mmHg; 95%LoA: &minus;4.5 to 17.0 mmHg). AGM100 provided an accurate estimate of PaO2 in hypoxemic patients with COPD, but the precision for individual values was modest. This device is promising for noninvasive assessment of pulmonary gas exchange efficacy in COPD patients