Ventilatory Equivalents For Carbon Dioxide Research Articles

Effect of Off-Season Iron Supplementation on Aerobic Capacity of Female Handball Player: A Randomized, Double-Blinded, Placebo-Controlled Study

BackgroundIron supplementation, especially in female athletes, is 1 of the influential factors in aerobic capacity, and its deficiency can lead to significant problems related to reduced aerobic capacity. ObjectivesThis study aimed to investigate the effect of 3 wk of iron supplementation on the aerobic capacity of female handball players. MethodsIn this randomized, double-blinded, and placebo control trial, 14 elite handball players (age: 21.6 ± 5.68 y; height: 169.5 ± 4.9 cm; weight: 62.2 ± 9.25 kg; body mass index (in kg/m2): 21.5 ± 2.9) randomly divided into 2 supplement groups (receiving a 100 mg/d of poly-maltose tri hydroxide iron complex in the form of tablets) and the placebo group (receiving a tablet containing 100 mg/d starch which is the same color and shape as iron tablets). The supplementation protocol was performed for 3 wk during the off-season. Maximal oxygen consumption (VO2max), amounts of carbon dioxide at the first ventilatory threshold, amounts of carbon dioxide at the second ventilatory threshold, time to exhaustion (TTE), pulmonary ventilation (VE), ventilatory equivalents for oxygen, amounts of oxygen at the first ventilatory threshold, amounts of oxygen at the second ventilatory threshold, time to reach first ventilatory threshold, end-tidal partial pressure of oxygen at the first ventilatory threshold, end-tidal partial pressure of carbon dioxide at the first ventilatory threshold and ventilatory equivalents for carbon dioxide were measured using the Bruce test and gas analyzer in 2 pretest and posttest stages. ResultsThere were significant improvements in oxygen at the first ventilatory threshold, time to reach first ventilatory threshold, and end-tidal partial pressure of carbon dioxide at the first ventilatory threshold and a significant decrease in end-tidal partial pressure of oxygen at the first ventilatory threshold (P < 0.05). Also, no significant changes were found in VO2max, carbon dioxide at the first ventilatory threshold, carbon dioxide at the second ventilatory threshold, oxygen at the second ventilatory threshold, TTE, VE, ventilatory equivalents for oxygen, and ventilatory equivalents for carbon dioxide after 3 wk of iron supplementation (P > 0.05). ConclusionsThe study found that 3 wk of off-season iron supplementation positively impacted female handball players’ aerobic capacity; however, it did not significantly improve their VO2max.

Cardiopulmonary Exercise Testing Predicts Postoperative Morbidity after Major Abdominal Cancer Surgeries: A Prospective Observational Study

Background and Aim: Cardiopulmonary exercise testing (CPET) has been shown to predict outcomes after major surgery. However, CPET performance and risk thresholds may vary geographically due to different body composition, nutritional status, anaemia, etc. This study aimed to investigate the relationship between preoperative CPET variables and in-hospital morbidity after abdominal cancer surgeries. Methods: In this prospective observational study, 142 patients aged 18–70 years, American Society of Anesthesiologists Physical Status II–III, underwent CPET preoperatively within 7 days of planned surgery. Oxygen uptake (VO2), ventilatory equivalents for carbon dioxide, heart rate (HR) and oxygen pulse (VO2/HR) were measured at anaerobic threshold (AT) and peak exercise (PE). Morbidity was assessed using the postoperative morbidity survey (POMS) postoperatively on days 3, 5 and 7. Receiver operating characteristic (ROC) curves were constructed to assess the optimal cut-offs for various CPET parameters. A multivariate logistic regression model was applied to test the relationship between CPET and postoperative morbidity. Results: After excluding patients who met the exclusion criteria, data from 109 participants were available for analysis. Forty-two patients (39%) suffered some morbidity postoperatively. VO2@AT (univariate odds ratio (OR) 1.36 [1.11–1.67] P = 0.002), sex (0.40 [0.17–0.99] P = 0.04), HR@AT (0.91 [0.94–0.99] P = 0.01), VO2/HR@AT (2.00 [1.42–2.80] P &lt; 0.001) and VO2/HR@PE (2.04 [1.45–2.87] P &lt; 0.001] were associated with postoperative morbidity. The final multivariate regression model contained VO2@AT (multivariate OR 1.25 [1.00–1.56] P = 0.04) and VO2/HR@PE (1.89 [1.34–11.09] P = 0.001). ROC curves revealed the optimal cut-off for VO2@AT as 11.9 ml/kg/min and VO2/HR@PE at 6.1 ml/beat. Conclusion: CPET parameters of oxygen uptake at AT and oxygen pulse at PE can predict morbidity in patients undergoing major abdominal onco-surgeries.

Preoperative aerobic fitness and perioperative outcomes in patients undergoing cystectomy before and after implementation of a national lockdown

BackgroundLower fitness is a predictor of adverse outcomes after radical cystectomy. Lockdown measures during the COVID-19 pandemic affected daily physical activity. We hypothesised that lockdown during the pandemic was associated with a reduction in preoperative aerobic fitness and an increase in postoperative complications in patients undergoing radical cystectomy. MethodsWe reviewed routine preoperative cardiopulmonary exercise testing (CPET) data collected prior to the pandemic (September 2018 to March 2020) and after lockdown (March 2020 to July 2021) in patients undergoing radical cystectomy. Differences in CPET variables, Postoperative Morbidity Survey (POMS) data, and length of hospital stay were compared. ResultsWe identified 267 patients (85 pre-lockdown and 83 during lockdown) who underwent CPET and radical cystectomy. Patients undergoing radical cystectomy throughout lockdown had lower ventilatory anaerobic threshold (9.0 [7.9–10.9] vs 10.3 [9.1–12.3] ml kg−1 min−1; P=0.0002), peak oxygen uptake (15.5 [12.9–19.1] vs 17.5 [14.4–21.0] ml kg−1 min−1; P=0.015), and higher ventilatory equivalents for carbon dioxide (34.7 [31.4–38.5] vs 33.4 [30.5–36.5]; P=0.030) compared with pre-lockdown. Changes were more pronounced in males and those aged >65 yr. Patients undergoing radical cystectomy throughout lockdown had a higher proportion of day 5 POMS-defined morbidity (89% vs 75%, odds ratio [OR] 2.698, 95% confidence interval [CI] 1.143–6.653; P=0.019), specifically related to pulmonary complications (30% vs 13%, OR 2.900, 95% CI 1.368–6.194; P=0.007) and pain (27% vs 9%, OR 3.471, 95% CI 1.427–7.960; P=0.004), compared with pre-lockdown on univariate analysis. ConclusionsLockdown measures in response to the COVID-19 pandemic were associated with a reduction in fitness and an increase in postoperative morbidity among patients undergoing radical cystectomy.

The effectiveness of high-intensity interval training compared to moderate-intensity continuous training in patients with heart failure: a systematic review and meta-analysis

Abstract Background/Introduction Cardiac rehabilitation including exercise therapy is beneficial for improving exercise tolerance, physical function, quality of life (QOL), and life expectancy in patients with heart failure. High-intensity interval training (HIIT) has attracted attention as a new training modality in heart failure, whereas moderate-intensity continuous aerobic training (MCT) is recommended as the main training modality to improve exercise tolerance. However, the effects of HIIT in patients with heart failure remain controversial. Purpose This systematic review and meta-analysis aimed to examine the effectiveness of HIIT compared to MCT on exercise tolerance in patients with heart failure. Methods We searched for studies published up to 4 March 2022 in EMBASE, MEDLINE via Ovid SP, PubMed, and the Cochrane Library via Wiley Online Library with no limitations on data, language, or publication status. We included randomised controlled trials comparing the effectiveness of HIIT and MCT on peak oxygen uptake (VO2), as a measure of exercise tolerance, aerobic threshold (AT) VO2, ventilatory equivalent of carbon dioxide (VE/VCO2), and QOL. We pooled the data on peak VO2, compared HIIT to MCT, and conducted a sub-analysis if there was heterogeneity in the result. Results We identified 15 randomised controlled trials with 557 patients from a total of 23,272 records. Our meta-analysis showed that participants who underwent HIIT achieved a significantly higher peak VO2 than those who underwent MCT (mean difference 1.46 ml/kg/min, 95% confidence interval 0.39 to 2.53; I2 = 65.7%; very low-quality evidence) (Figure 1). Participants who underwent HIIT had no statistically significant difference in AT VO2, VE/VCO2, and QOL compared to those who underwent MCT. The meta-regression analysis, conducted as a sub-analysis to explore possible causes of heterogeneity, revealed that the effect size of HIIT compared to MCT was inversely associated with body mass index (r = -0.508, p = 0.028, 95% confidence interval -0.95 to -0.07) (Figure 2). Conclusions Our systematic review showed that HIIT achieved a higher peak VO2 than MCT in patients with heart failure. In addition, HIIT may be more effective in improving exercise tolerance in patients with low body mass index.

Abstract 15275: Cardiac Magnetic Resonance Ventricular Function and Hemodynamic Multivariable Model Predictors of Exercise Performance in Tetralogy of Fallot Using Machine Learning and Multivariable Modelling: A Substudy of the Single Center Cardiac Magnetic Resonance Outcomes Registry-Tetralogy of Fallot

Background: There are no robust predictors of exercise performance in repaired tetralogy of Fallot (rTOF) using both ventricular function and hemodynamics. Aim: To utilize machine learning and multivariable modeling to determine cardiac magnetic resonance (CMR) and other metrics predictive of exercise performance. Methods: We retrospectively reviewed data of all rTOF pts undergoing CMR from 2005-2020. Those who had cardiopulmonary exercising testing (CPET) within 6 months of CMR were analyzed using the machine learning technique LASSO to choose candidate variables for subsequent testing with multivariable modeling. CMR parameters included right (RV) and left ventricular (LV) function and hemodynamics. Significance P&lt;0.05. Results: 266 of 761 pts with rTOF met the inclusion criteria (age at CMR 16.1 + 9.7 years old, age at repair 0.36 years old, 56% male). Higher RV mass, RV global function index and lower pulmonary regurgitant fraction (PR) were independently associated with higher % predicted (%P) maximum oxygen consumption (VO 2 max). In addition, females and non-syndromic pts were also associated with higher %P VO 2 max (table). Those with a higher LV end-diastolic volume (EDV), females and pts without pulmonary atresia performed better at %P work. Those with a higher RV mass/volume demonstrated a worse ventilatory equivalent of carbon dioxide (VE/VCO 2 ). See table. Conclusion: RV ventricular functional parameters, PR (hemodynamics), gender and syndromic status are all independently associated with %P VO 2 max. Those with larger LV volumes were able to perform more work and those with a higher RV mass/volume had a worse VE/VCO 2 . Our findings shed some light into the etiology of poor rTOF exercise performance.

Impaired exercise capacity in individuals with non-obstructive small airway dysfunction.

Whether individuals with non-obstructive spirometry-defined small airway dysfunction (SAD) have impaired exercise capacity is unclear, particularly in never-smokers. This study clarifies the degree of impaired exercise capacity and its potential cause in individuals with non-obstructive SAD. This community-based, multiyear cross-sectional study analyzed data collected in Guangdong, China from 2012-2019 by the National Science and Technology Support Plan Program. Measurements of exercise capacity [peak work rate and peak oxygen uptake ( )] in participants with non-obstructive spirometry-defined SAD (n=157) were compared with those in controls (n=85) and Global Initiative for Chronic Obstructive Lung Disease (GOLD) I patients (n=239). Subgroup analyses were performed by smoking status. The risk of impaired exercise capacity was significantly higher in participants with non-obstructive SAD [ <84%predicted, adjusted odds ratio (aOR) =2.53; 95% confidence interval (CI): 1.42-4.52] than in controls but was not significantly different from that in GOLD I patients. Results were consistent within subgroups of smoking status (ever-smokers: non-obstructive SAD vs. controls, aOR =2.44; 95% CI: 1.08-5.51; never-smokers: non-obstructive SAD vs. controls, aOR =2.38, 95% CI: 1.02-5.58). Participants with non-obstructive SAD had a significantly lower peak work rate (β=-10.5; 95% CI: -16.3 to -4.7) and (%predicted, β=-4.0; 95% CI: -7.7 to -0.2) and tended to have higher ventilatory equivalents for carbon dioxide at the ventilatory threshold ( , β=1.1; 95% CI: -0.1 to 2.3) when compared with controls. Both peak work rate and were negatively correlated with . Although not meeting the current criteria for chronic obstructive pulmonary disease, individuals with non-obstructive SAD have impaired exercise capacity that may be associated with ventilatory inefficiency regardless of smoking status.

The relationship between homocysteine and cardiopulmonary exercise testing in patients with acute coronary syndrome after percutaneous coronary intervention

ObjectiveThe purpose of this study was to investigate the relationship between homocysteine (Hcy) levels and cardiopulmonary exercise testing (CPET) in patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI). We also explored the relationship between Hcy levels and cardiac ultrasonography.MethodsThis study comprised 261 patients with ACS who underwent coronary angiography and PCI at Yulin First Hospital from January 2020 to June 2021. All subjects completed basic data collection, laboratory examination, CPET and cardiac ultrasonography. The CPET includes the peak oxygen uptake (peak VO2), anaerobic threshold (AT), metabolic equivalents (METs), exercise load (load), oxygen pulse (O2 pulse), end-tidal CO2 partial pressure (PETCO2), ventilatory equivalents for carbon dioxide (VE/VCO2) and Oxygen uptake efficiency (OUES). Cardiac ultrasonography was used to evaluate the left ventricular end diastolic diameter (LVEDD), interventricular septal thickness (IVST), left ventricular posterior wall thickness (LVPWT) and left ventricular ejection fraction (LVEF). A serum Hcy level ≥ 15 µmol/L was defined as hyperhomocysteinemia (HHcy). The patients were divided into the Hcy < 15 µmol/L group (n = 189) and the Hcy ≥ 15 µmol/L group (n = 72).ResultsThe average age of the participating patients was 58.9 ± 10.1 years. The majority of participants were male (86.6%). The CPET indices of METs, load, VO2/kg, and PETCO2 were significantly decreased in the Hcy ≥ 15 µmol/L group compared with the Hcy < 15 µmol/L group. Additionally, the CPET index of the VE/VCO2 slope and the cardiac ultrasonography indices of IVST and LVPWT were significantly increased in the Hcy ≥ 15 µmol/L group compared with the Hcy < 15 µmol/L group. These differences were statistically significant (P < 0.05). Correlation analysis showed that Hcy levels were negatively correlated with METs, VO2/kg and PETCO2 and positively correlated with the VE/VCO2 slope (P < 0.05). Partial correlation analysis showed that Hcy levels were negatively correlated with METs and VO2/kg in the AT state. The correlation coefficients were − 0.172 and − 0.172, respectively (P < 0.05). Hcy levels were negatively correlated with METs, VO2/kg and PETCO2 in the peak state. The correlation coefficients were − 0.177, -0.153 and − 0.129, respectively (P < 0.05). After further adjustment for confounders, multiple linear regression analysis showed that Hcy levels were negatively correlated with METs and VO2/kg in the AT state and peak state. The standardized regression coefficients were − 0.035, -0.122, -0.048 and − 0.128, respectively (P < 0.05). Correlation analysis showed that Hcy levels were positively correlated with the IVST and LVPWT (P < 0.05), but after adjusting for confounding factors, partial correlation analysis showed that there was no correlation between them.ConclusionA high Hcy level is associated with lower METs and VO2/kg and worse cardiopulmonary function in patients with ACS after PCI.

Cardiorespiratory Parameters Do Not Account For Elevated Perceived Exertion In Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Our prior meta-analysis of 37 case-control studies found that people with Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS) perceive aerobic exercise as more effortful than otherwise healthy people (HP). Whether elevated perceived exertion (RPE) is disease specific or a secondary consequence of between-group differences in aerobic fitness or other cardiorespiratory parameters is not well studied. PURPOSE: Determine the influence of cardiorespiratory parameters on elevated RPE in people with ME/CFS. METHODS: We examined peak RPE responses during ramped cycle ergometry in 178 people with ME/CFS (age = 49.3 ± 13.2; BMI = 27.3 ± 6.9; % female = 65) and 169 HP (age = 42.5 ± 13.2; BMI = 26 ± 5.1; % female = 68). Subgroup analyses were conducted for 198 participants (99 ME/CFS; 99 HP) matched for age (±5 years) and peak oxygen consumption (VO2peak) (~1 ml/kg/min-1). Independent samples t-tests and Hedges’ d (d) effect sizes were used to test for between-group differences in RPE at peak exercise. A series of one-way analysis of covariance (ANCOVA) models with group (ME/CFS, HP) as the between-subjects factor tested whether peak cardiorespiratory parameters influenced between-group differences in RPE. These covariates included ventilatory equivalents for carbon dioxide and oxygen, heart rate, power, respiratory rate, and tidal volume. RESULTS: Mean ± SD peak RPE was 19.1(1) and 18.3(1.9) for ME/CFS and HP, respectively. Peak RPE was significantly higher in people with ME/CFS before (p < 0.001, d = 0.53; 95%CI: 0.32, 0.75) and after (p < 0.001, d = 0.56; 95%CI: 0.27, 0.84) matching for aerobic fitness. ANCOVA models revealed that between-group differences in RPE remained significant after including cardiorespiratory parameters as covariates in the model (all p < 0.05). CONCLUSIONS: People with ME/CFS perceive aerobic exercise as more effortful than HP, but these differences are not influenced by aerobic fitness or other cardiorespiratory factors. These findings extend those of our prior meta-analysis and also signify the importance of incorporating physiological measures beyond indirect calorimetry when studying mechanisms of elevated RPE in ME/CFS. Supported by Centers for Disease Control Contract AAD3581 to the University of Wisconsin-Madison.

Dead Space Breathing in Patients with Malignancies: Determination by Cardiopulmonary Exercise Testing

Rationale: Patients with cancer commonly experience dyspnea originating from ventilatory, circulatory and musculoskeletal sources, and dyspnea is best determined by cardiopulmonary exercise testing (CPET). Objectives: In this retrospective pilot study, we evaluated patients with hematologic and solid malignancies by CPET to determine the primary source of their dyspnea. Methods: Subjects were exercised on a cycle ergometer with increasing workloads. Minute ventilation, heart rate, breathing reserve, oxygen uptake (V’O2), O2-pulse, ventilatory equivalents for carbon dioxide and oxygen (V’E/V’CO2 and V’E/V’O2, respectively) were measured at baseline and peak exercise. The slope and intercept for V’E/V’CO2 was computed for all subjects. Peak V’O2 4% predicted indicated a circulatory or ventilatory limitation. Results: Complete clinical and physiological data were available for 36 patients (M/F 20/16); 32 (89%) exhibited ventilatory or circulatory limitation as shown by a reduced peak V’O2 and 10 subjects with normal physiologic data. The largest cohort comprised the pulmonary vascular group (n = 18) whose mean ± SD peak V’O2 was 61% ± 17% predicted. There were close associations between V’O2 and spirometric values. Peak V’E/V’O2 and V’E/V’CO2 were highest in the circulatory and ventilatory cohorts, consistent with increase in dead space breathing. The intercept of the V’E-V’CO2 relationship was lowest in patients with cardiovascular impairment. Conclusion: Dyspneic patients with malignancies exhibit dead space breathing, many exhibiting a circulatory source for exercise limitation with a prominent pulmonary vascular component. Potential factors include effects of chemo- and radiation therapy on cardiac function and pulmonary vascular endothelium.

Heart Rate Recovery at 1 Min after Exercise Is a Marker of Disease Severity and Prognosis in Chronic Thromboembolic Pulmonary Hypertension

Background: Attenuated heart rate recovery at 1 min (HRR1) was demonstrated to correlate with poor prognosis in patients with pulmonary arterial hypertension, whereas its role in patients with chronic thromboembolic pulmonary hypertension (CTEPH) remains unclear. Objectives: The aim of this study was to investigate the correlations between HRR1 and functional status, echocardiography, hemodynamics, and prognosis of CTEPH. Methods: We retrospectively enrolled patients with CTEPH who underwent right heart catheterization and cardiopulmonary exercise test between June 2014 to October 2020 in Fuwai hospital. The primary outcome was clinical worsening. Linear regression was performed to assess the association between HRR1 and established markers of CTEPH severity. Receiver operating characteristic curve analysis was performed to determine the optimal cutoff of HRR1. Cox regression models were used to assess the association between HRR1 and clinical worsening. Results: A total of 211 patients with CTEPH were included in the study. After adjusting for confounders, HRR1 positively correlated with 6-min walk distance, mixed venous oxygen saturation, and peak oxygen consumption, and negatively correlated with NT-proBNP, pulmonary vascular resistance, and ventilatory equivalent of carbon dioxide. Compared with patients with HRR1 ≥16 beats, patients with HRR1 <16 beats had approximately a 3-fold risk of experiencing clinical worsening and the risk escalated with time. Conclusion: HRR1 could reflect disease severity and was independently associated with prognosis in patients with CTEPH.

Validity of the ESC Risk Assessment in Idiopathic Pulmonary Arterial Hypertension in China.

Background: The 2015 European pulmonary hypertension (PH) guidelines recommend a risk stratification strategy for pulmonary arterial hypertension (PAH). We aimed to investigate the validation and potential prognostic information in Chinese patients.Methods: The risk assessment variables proposed by the PH guidelines were performed by using the WHO function class, 6-min walking distance, brain natriuretic peptide or its N-terminal fragment, right arterial pressure, cardiac index, mixed venous saturation, right atrium area, pericardial effusion, peak oxygen consumption, and ventilatory equivalents for carbon dioxide. An abbreviated version also was applied.Results: A total of 392 patients with idiopathic PAH (IPAH) were enrolled between 2009 and 2018. After a median interval of 13 months, re-evaluation assessments were available for 386 subjects. The PAH guidelines risk tool may effectively discriminate three risk groups and mortality (p < 0.001) both at the baseline and re-evaluation. Meanwhile, its simplified risk version was valid for baseline and accurately predicted the risk of death in all the risk groups (p < 0.001). At the time of re-evaluation, the percentage of low-risk group has an increase, but a greater proportion achieved the high-risk group and a lesser proportion maintained in the intermediate-risk group.Conclusion: The 2015 European PH guidelines and its simplified version risk stratification assessment present an effective discrimination of different risk groups and accurate mortality estimates in Chinese patients with IPAH. Changes of risk proportion at re-evaluation implicated that natural treatment decisions may not be consistently with goal-oriented treatment strategy.

First Evidence of Cardiopulmonary Adaptation to Physical Effort in Transgender Women After Long-Term Hormone Therapy: A Cross-Sectional Study

Introduction: Cisgender men (CM) and women (CM) present different acute cardiopulmonary (CP) adaptation to effort. The smallest arteriovenous difference in oxygen (O2) and cardiac output (CO) in CW determine a lower maximum VO2 (VO2max) than CM. CP capacity adaptation to effort of TW undergoing gender-affirming hormone therapy (GAHT) was not yet reported. Objective: To evaluate CP capacity of TW in long-term GAHT. Methods: A cross-sectional study was carried out with 8 TW (average age of 34.0 ±4.8 yo), 8 CM and 8 CW matched on age, body mass index and activity level. All TW were non-gonadectomized subjects and were in estrogen [transdermal estradiol (n=2), oral estradiol (n=3) and conjugated estrogen (n=3)], plus cyproterone acetate (n=8) therapy in an average time of 15.6 ±8.7 years. Body composition was assessed by InBody 720, and participants’ level of physical activity by IPAQ (International Physical Activity Questionnaire) short form. Total testosterone (ng/dL) levels of TW, CW and CM were 83,5 (12,0;637,0), 20,5 (12,0;41,0) and 480,5 (264,0;843,0), respectively. Hemoglobin levels of TW, CW and CM were 14,2 (13,5;14,9), 14,35 (12,8;14,7) and 15,35 (14,0;18,2), respectively. Everyone performed a CP exercise testing on a treadmill with an incremental effort. Results: Mean VO2max (L/min) in the group of TW was 2648±575.5, of CW 2128±394.0 and of CM 3235±554.0 (TWvsCW p=0.1311; TWvsCM p=0.0806; CWvsCM p=0.009). Free fat mass (FFM) of TW was 55.56±6.88 kg, CW 38.98±4,09 kg, and CM 64,98±6,29 kg (TWvsCW p<0,0001; TWvsCM p=0,024; CWvsCM p<0,0001). Analysis of VO2max/FFM (L/min/kg), TW′s rate was 46.6±6.2, CW′s was 54.6±8.4 and CM′s was 49.4±6.1 (TWvsCW p=0.0770;TWvsCM p=0.6942; CWvsCM p=0.3185). O2 pulse, VE/VO2 (ventilatory equivalents for O2) and VE/VCO2 (ventilatory equivalents for carbon dioxide) were similar in all groups. There was high correlation of O2pulse and free fat mass/height2 (FFM/Hgt2) of TW (r 0,925;p 0,008), not observed in CW (r 0.614;p0.105) or CM (r 0.737; p 0.037).% predicted Heart Rate (%HR) at effort was higher in TW (104) than in CW (95.8)(p=0.0221) and CM (100.3)(p=0.3334). Discussion: Aerobic capacity of TW was intermediate between CM and CW. Regards VO2 / FFM ratio, TW had a lower index than other groups. Since changes in pulmonary O2 diffusion, CO and blood circulation were ruled out as causing such data, it could be related to O2 uptake drops by the muscle. Increased sympathetic activity and %HR in TW and high correlation of O2pulse and FFM/Hgt2 make up compatible framework with exacerbation of ergoreflex. Conclusion: Our results support the finding of a VO2max similar between TW undergoing long-term GAHT and CW groups, despite the previous expose of TWs to testosterone during puberty. We hypothesized the presence of an increased ergoreflex sensitivity in TW individuals. These preliminary results should be confirmed by increasing the number of individuals studied.

Are Smartphones Better in Guiding Physical Activity Among Sedentary Young Adults? A Randomised Controlled Trial

Background. Physical activity promotion in young adults is found to be associated with improved psychosocial well-being and academic performance. Recently smartphones are found to be a potent means for promoting physical activity. So far no study has compared smartphones and traditional walking prescriptions in improving functional capacity and compliance in college adults.Methods. Of 77 participants recruited, only 26 adult sedentary undergraduates with step count less than 7500 steps/ day were completed one of the two interventions:American College of Sports Medicine (ACSM) guided walking (n = 14) and smartphone application (SMART) guided walking (n = 12). The pre and post-intervention oxygen uptake (VO2), anaerobic threshold (AT at VO2), heart rate (HR) and ventilatory equivalents of carbondioxide (VE/VCO2) were measured by metabolimeter (K5,Cosmed, Italy). After normalization, continous variables of VO2, AT at VO2, VE/ VCO2, HR were analysed by two way analysis of variance (2 X 2 ANOVA) at a level of significance of 0.05.Results. Twenty six participants completed the study. Except treadmill distance and time, all exercise test variables including aerobic capacity (3.20 ml/kg/min, d = 0.492) ,anaerobic threshold (- 11.03, d = 0.769), ventilatory equivalent of carbon dioxide (2.32 ml/kg/min, d = 0.801), heart rate (- 10.50 b/min, d = 0.0792) improved significantly.Compliance was found to be 17.65% greater in the SMART than ACSM group.Conclusions. Physical activity promotion is efficient with SMART group than routinely administered traditional exercise prescription in improving the functional capacity of sedentary adults. Long- erm compliance may be better with smartphone guided exercise prescription

Ventilatory compensation during the incremental exercise test is inversely correlated with air trapping in COPD.

Background: Air trapping and gas exchange abnormalities are major causes of exercise limitation in chronic obstructive pulmonary disease (COPD). During incremental cardiopulmonary exercise testing, actual nadir values of ventilatory equivalents for carbon dioxide (V E/VCO 2) and oxygen (V E/VO 2) may be difficult to identify in COPD patients because of limited ventilatory compensation capacity. Therefore, we aimed in this exploratory study to detect a possible correlation between the magnitude of ventilation augmentation, as manifested by increments in ventilatory equivalents from nadir to peak exercise values and air trapping, detected with static testing. Methods: In this observational study, we studied data obtained previously from 20 COPD patients who, during routine follow-up, underwent a symptom-limited incremental exercise test and in whom a plethysmography was obtained concurrently. Air trapping at rest was assessed by measurement of the residual volume (RV) to total lung capacity (TLC) ratio (RV/TLC). Gas exchange data collected during the symptom-limited incremental cardiopulmonary exercise test allowed determination of the nadir and peak exercise values of V E/VCO 2 and V E/VO 2, thus enabling calculation of the difference between peak exrcise value and nadir values of V E/VCO 2 and V E/VO 2, designated ΔV E/VCO 2 and ΔV E/VO 2, respectively. Results: We found a statistically significant inverse correlation between both ΔV E/VCO 2 (r = -0. 5058, 95% CI -0.7750 to -0.08149, p = 0.0234) and ΔV E/VO 2 (r = -0.5588, 95% CI -0.8029 to -0.1545, p = 0.0104) and the degree of air trapping (RV/TLC). There was no correlation between ΔV E/VCO 2 and forced expiratory volume in the first second, or body mass index. Conclusions: The ventilatory equivalents increment to compensate for acidosis during incremental exercise testing was inversely correlated with air trapping (RV/TLC).

Ventilatory compensation during the incremental exercise test is inversely correlated with air trapping in COPD

Background: Air trapping and gas exchange abnormalities are major causes of exercise limitation in chronic obstructive pulmonary disease (COPD). During incremental cardiopulmonary exercise testing, actual nadir values of ventilatory equivalents for carbon dioxide (V E/VCO 2) and oxygen (V E/VO 2) may be difficult to identify in COPD patients because of limited ventilatory compensation capacity. Therefore, we aimed in this exploratory study to detect a possible correlation between the magnitude of ventilation augmentation, as manifested by increments in ventilatory equivalents from nadir to peak exercise values and air trapping, detected with static testing. Methods: In this observational study, we studied data obtained previously from 20 COPD patients who, during routine follow-up, underwent a symptom-limited incremental exercise test and in whom a plethysmography was obtained concurrently. Air trapping at rest was assessed by measurement of the residual volume (RV) to total lung capacity (TLC) ratio (RV/TLC). Gas exchange data collected during the symptom-limited incremental cardiopulmonary exercise test allowed determination of the nadir and peak exercise values of V E/VCO 2 and V E/VO 2, thus enabling calculation of the difference between peak exrcise value and nadir values of V E/VCO 2 and V E/VO 2, designated ΔV E/VCO 2 and ΔV E/VO 2, respectively. Results: We found a statistically significant inverse correlation between both ΔV E/VCO 2 (r = -0. 5058, 95% CI -0.7750 to -0.08149, p = 0.0234) and ΔV E/VO 2 (r = -0.5588, 95% CI -0.8029 to -0.1545, p = 0.0104) and the degree of air trapping (RV/TLC). There was no correlation between ΔV E/VCO 2 and forced expiratory volume in the first second, or body mass index. Conclusions: The ventilatory equivalents increment to compensate for acidosis during incremental exercise testing was inversely correlated with air trapping (RV/TLC).

Ventilatory compensation during the incremental exercise test is inversely correlated with air trapping in COPD

Background: Air trapping and gas exchange abnormalities are major causes of exercise limitation in chronic obstructive pulmonary disease (COPD). During incremental cardiopulmonary exercise testing, ventilatory equivalents for carbon dioxide (VE/VCO2) and oxygen (VE/VO2) may be difficult to identify in COPD patients because of limited ventilatory compensation capacity. Therefore, we aimed to detect a possible correlation between the magnitude of ventilation augmentation, as manifested by increments in ventilatory equivalents from nadir to peak effort values and air trapping, detected with static testing. Methods: In this observational study, we studied data obtained previously from 20 COPD patients who, during routine follow-up, underwent a symptom-limited incremental exercise test and in whom a plethysmography was obtained concurrently. Air trapping at rest was assessed by measurement of the residual volume (RV) to total lung capacity (TLC) ratio (RV/TLC). Gas exchange data collected during the symptom-limited incremental cardiopulmonary exercise test allowed determination of the nadir and peak effort values of VE/VCO2 and VE/VO2, thus enabling calculation of the difference between peak effort value and nadir values of VE/VCO2 and VE/VO2, designated ΔVE/VCO2 and ΔVE/VO2, respectively. Results: We found a statistically significant inverse correlation between both ΔVE/VCO2 (r = -0. 5058, 95% CI -0.7750 to -0.08149, p = 0.0234) and ΔVE/VO2 (r = -0.5588, 95% CI -0.8029 to -0.1545, p = 0.0104) and the degree of air trapping (RV/TLC). There was no correlation between ΔVE/VCO2 and peak oxygen consumption, forced expiratory volume in the first second, or body mass index. Conclusions: The ventilatory equivalents increment to compensate for acidosis during incremental exercise testing was inversely correlated with air trapping (RV/TLC) and may be a candidate prognostic biomarker.

RESPUESTAS CARDIORRESPIRATORIAS A INTENSIDAD UMBRAL. ESTUDIO COMPARATIVO ENTRE MEDIA SENTADILLA Y CICLOERGÓMETRO // CARDIORRESPIRATORY RESPONSES AT THRESHOLD INTENSITY. COMPARATIVE BETWEEN HALF SQUAT VS CYCLE ERGOMETER

Objective: To compare respiratory responses, heart rate (HR) and lactate at the intensity of the lactate threshold (LT) between half squat (HS) and cycloergometer. Methods: 24 men (21.5±1.8 years, 180.1 ± 5.2 cm, 81.9±8.7 kg) with experience in resitance performed a progressive incremental test in HS and cycloergometer to determine LT. During such test, the following parameters were measured: blood lactate concentrations, HR, oxygen consumption (VO2), carbon dioxide production (VCO2), pulmonary ventilation (PV), ventilatory equivalent of oxygen (PV·VO2-1) and ventilatory equivalent of carbon dioxide (PV·VCO2-1). A t student evaluated the variables analysed among the two exercise modalities. Results: blood lactate concentrations, HR, PV, and PV·VO2-1 and PV·VCO2-1 were higher in HS than in cycloergometer (p <0.05). Conclusions: LT can be detected in HS exercise. Furthermore, the resistance training sessions to the intensity of LT might be used in training sessions which seek to improve cardiovascular endurance and muscle strength.

Exercise right heart catheterisation before and after pulmonary endarterectomy in patients with chronic thromboembolic disease.

Symptomatic patients with chronic thromboembolic disease (CTED) without pulmonary hypertension often show an excessive increase in mean pulmonary arterial pressure (MPAP) during exercise.We report on the impact of pulmonary endarterectomy (PEA) on pulmonary haemodynamics in a prospective series of 32 consecutive CTED patients who underwent PEA. All patients had a comprehensive diagnostic work-up including right heart catheterisation at baseline and 12 months after PEA. Furthermore, in 12 patients exercise right heart catheterisation was performed before and after PEA.After PEA, MPAP was lower at rest (20±3 versus 17±3 mmHg; p=0.008) and during maximal exercise (39±8 versus 31±6 mmHg; p=0.016). The mean total pulmonary resistance (TPR) decreased from 3.6±0.8 Wood Units (WU) pre-operatively to 2.7±0.7 WU 1 year after PEA (p=0.004) and the mean slope of the MPAP/cardiac output (CO) relationship decreased from 3.6±1.0 to 2.3±0.8 WU (p=0.002). Peak oxygen uptake increased from 1.2±0.4 to 1.5±0.3 L·min-1 (p=0.014) and ventilatory equivalents of carbon dioxide decreased from 39±2 to 30±2 (p=0.002). There was a significant improvement in quality of life assessed by the Cambridge Pulmonary Hypertension Outcome Review questionnaire.In CTED patients, PEA resulted in haemodynamic and clinical improvements. The means of TPR and MPAP/CO slopes decreased to <3.0 WU.

Pre-operative variables including fitness associated with complications after oesophagectomy.

Oesophagectomy is a technically-demanding operation associated with a high level of morbidity. We analysed the association of pre-operative variables, including those from cardiopulmonary exercise testing, with complications (logistic regression) and survival and length of stay (Cox regression) after scheduled transthoracic oesophagectomy in 273 adults, in isolation and on multivariate testing (maximum Akaike information criterion). On multivariate analysis, any postoperative complication was associated with ventilatory equivalents for carbon dioxide, odds ratio (95%CI) 1.088 (1.02-1.17), p = 0.018. Cardiorespiratory complications were associated with FEV1 and pre-operative background survival (in an analogous group without cancer), odds ratios (95%CI) 0.55 (0.37-0.80), p = 0.002 and 0.89 (0.82-0.96), p = 0.004, respectively. Survival was associated with the ratio of expected-to-observed ventilatory equivalents for carbon dioxide and predicted postoperative survival, hazard ratios (95%CI) 0.17 (0.03-0.91), p = 0.039 and 0.96 (0.90-1.01), p = 0.076. Length of hospital stay was associated with FVC, hazard ratio (95%CI) 1.38 (1.17-1.63), p < 0.0001.

Cardiopulmonary Exercise Testing and Surgery.

The surgical patient population is increasingly elderly and comorbid and poses challenges to perioperative physicians. Accurate preoperative risk stratification is important to direct perioperative care. Reduced aerobic fitness is associated with increased postoperative morbidity and mortality. Cardiopulmonary exercise testing is an integrated and dynamic test that gives an objective measure of aerobic fitness or functional capacity and identifies the cause of exercise intolerance. Cardiopulmonary exercise testing provides an individualized estimate of patient risk that can be used to predict postoperative morbidity and mortality. This technology can therefore be used to inform collaborative decision-making and patient consent, to triage the patient to an appropriate perioperative care environment, to diagnose unexpected comorbidity, to optimize medical comorbidities preoperatively, and to direct individualized preoperative exercise programs. Functional capacity, evaluated as the anaerobic threshold and peak oxygen uptake ([Formula: see text]o2peak) predicts postoperative morbidity and mortality in the majority of surgical cohort studies. The ventilatory equivalents for carbon dioxide (an index of gas exchange efficiency), is predictive of surgical outcome in some cohorts. Prospective cohort studies are needed to improve the precision of risk estimates for different patient groups and to clarify the best combination of variables to predict outcome. Early data suggest that preoperative exercise training improves fitness, reduces the debilitating effects of neoadjuvant chemotherapy, and may improve clinical outcomes. Further research is required to identify the most effective type of training and the minimum duration required for a positive effect.