Cardiopulmonary exercise testing in patients with moderate-severe obesity: a clinical evaluation tool for OSA?

Respiratory exchange ratio overshoot during exercise recovery: a promising prognostic marker in HFrEF

BACKGROUND AND AIMS

Transient increases (overshoot) in respiratory gas analyses have been observed during exercise recovery, but their clinical significance is not clearly understood. An overshoot phenomenon of the respiratory exchange ratio (RER) is commonly observed during recovery from maximal cardiopulmonary exercise testing (CPET), but it has been found reduced in patients with heart failure with reduced ejection fraction (HFrEF). The aim of the study was to analyze the clinical significance of these RER recovery parameters and to understand if these may improve the risk stratification of patients with HFrEF.

METHODS

This cross-sectional study includes HFrEF patients who underwent functional evaluation with maximal CPET for the heart transplant checklist at our Sports and Exercise Medicine Division. RER recovery parameters, including RER overshoot as the percentual increase of RER during recovery (RER mag), have been evaluated after CPET with assessment of hard clinical long-term endpoints (MACEs/deaths and transplant/LVAD-free survival).

RESULTS

A total of 190 patients with HFrEF and 103 controls were included (54.6 ± 11.9 years; 73% male). RER recovery parameters were significantly lower in patients with HFrEF compared to healthy subjects (RER mag 24.8 ± 14.5% vs 31.4 ± 13.0%), and they showed significant correlations with prognostically relevant CPET parameters. Thirty-three patients with HFrEF did not present a RER overshoot, showing worse cardiorespiratory fitness and efficiency when compared with those patients who showed a detectable overshoot (VO2 peak: 11.0 ± 3.1 vs 15.9 ± 5.1 ml/kg/min; VE/VCO2 slope: 41.5 ± 8.7 vs 32.9 ± 7.9; ΔPETCO2: 2.75 ± 1.83 vs 4.45 ± 2.69 mmHg, respectively). The presence of RER overshoot was associated with a lower risk of cardiovascular events and longer transplant-free survival.

CONCLUSION

RER overshoot represents a meaningful cardiorespiratory index to monitor during exercise gas exchange evaluation; it is an easily detectable parameter that could support clinicians to comprehensively interpreting patients' functional impairment and prognosis. CPET recovery analyses should be implemented in the clinical decision-making of advanced HF.

Effects of combined exercise training with sleep education in older adults with obstructive sleep apnea: protocol for a randomized clinical trial

Background

Obstructive sleep apnea (OSA) is a common disorder that affects approximately 1 billion people worldwide. Advanced age is a significant risk factor. Various treatment options have been explored to reduce the severity of OSA symptoms and physical exercise has emerged as a potential alternative therapy. Therefore, this study aims to investigate the effects of a combined exercise program with sleep education on sleep quality and on the severity of OSA in older adults.

Methods

This is a randomized clinical trial with two parallel groups that will involve individuals of both genders aged between 60 and 79 years who have an apnea-hypopnea index (AHI) of more than 15 events per hour and who have not received or are currently undergoing treatment for OSA. Older adults who have engaged in regular exercise in the last six months and individuals with contraindications to exercise will be excluded. The study will assess outcomes related to OSA, including AHI, oxygen desaturation index, minimum and mean oxyhemoglobin saturation, sleep efficiency, sleep latency, and the type of respiratory events. Additionally, sleep quality-related outcomes, daytime sleepiness, physical activity, physical fitness, aerobic capacity, cognitive status, anthropometric measures, and health-related quality of life will be analyzed. Participants will be randomized to two groups: a combined exercise group (involving both resistance and aerobic training) with sleep education, and a control group that will receive only educational recommendations for managing OSA. The intervention will last 12 weeks and will consist of three sessions per week, totaling 36 exercise sessions. Sample size calculation indicates a minimum number of 36 participants.

Discussion

If the hypothesis is confirmed, this clinical trial will indicate an effective non-pharmacological intervention for treating OSA in older adults. This intervention could be used as an adjunct to existing approaches designed to improve OSA management.

Clinical trail registration

Brazil Clinical Trials Registry (ReBEC), identifier RBR-9hk6pgz.

Effect of high-intensity interval training on obstructive sleep apnea severity: A randomized controlled trial

Vigorous physical activity has been associated with a reduced risk of developing obstructive sleep apnea (OSA). However, whether high-intensity interval training (HIIT) reduces OSA severity remains unclear. Thus, this study aimed to investigate the impact of 12 weeks of HIIT on the apnea-hypopnea index (AHI) and sleep parameters in participants with moderate-severe OSA. In this randomized controlled trial, 36 adults (19 males; 52.2 ± 9.8 years; body mass index = 34.2 ± 5.8) with moderate to severe OSA (AHI = 42.0 ± 22.9 e/h) were randomly assigned to HIIT [5 periods of 4 min of walking or running on a treadmill at 90-95 % of maximum heart rate (HRmax) interspersed with 3 min of walking at 50-55 % of HRmax performed three times per week for 12 weeks] or a control group (CG; stretching exercises performed two times per week for 12 weeks). Sleep parameters were assessed at baseline and after 12 weeks through overnight polysomnography. Generalized estimated equations assessed differences between groups over time. There was not group × time interaction for body mass index between groups (p = 0.074). However, significant group × time interactions were observed for AHI (CG change = 8.2 ± 3.7, HIIT change = -8.6 ± 4.8; p = 0.005), SaO2 minimum (CG change = -1.6 ± 1.6 %, HIIT change = 0.4 ± 2.3 %; p = 0.030), total sleep time (CG change = -31.5 ± 19.5 min, HIIT change = 33.7 ± 19.3 min; p = 0.049), and sleep efficiency (CG change = -3.2 ± 4.4 %, HIIT change = 9.9 ± 3.5 %; p = 0.026). Moreover, there was a significant time × group interaction for maximum oxygen consumption (VO2max; CG change = -1.1 ± 1.0 mL/kg/min, HIIT change = 4.8 ± 0.9 mL/kg/min; p < 0.001)]. However, In patients with OSA, 12 weeks of HIIT decreases sleep apnea severity, improves sleep quality, and cardiorespiratory fitness. CLINICAL TRIAL REGISTRATION: (Registro Brasileiro de Ensaios Clínicos [ReBec]): # RBR-98jdt3.

Cardiovascular capacity in adults with obstructive sleep apnoea

BACKGROUND: Obstructive sleep apnoea (OSA) patients have a decreased exercise capacity. Potential cardiovascular capacity in patients with OSA with different severity without known cardiovascular disease has not been described.OBJECTIVE: To evaluate impaired potential exercise cardiovascular capacity during cardiopulmonary exercise testing (CPET) in OSA patients and to compare cardiovascular performance reaction with different severity during graded exercise stages.DESIGN: All participants were accompanied without cardiovascular disease, especially hypertension and arrhythmia. Parameters of different stages were compared between subjects with and without OSA, and among OSA patients with varied severity.RESULTS: Despite having significantly higher peak exercise diastolic blood pressure (DBP) and ventilatory equivalent for CO2 (EQCO₂), patients with OSA had a lower peak oxygen uptake (VO₂), heart rate (HR), heart rate recovery (HRR) and respiratory reserve (BR) than normal subjects. Furthermore, significant correlations were found between VO₂, DBP, EQCO₂, HRR, BR and the apnoea-hypopnea index. In severe OSA, there was a greater difference in HR and HRR during the anaerobic threshold stages.CONCLUSIONS: OSA patients demonstrate reduced potential cardiovascular capacity, even without documented cardiovascular disease. Patients with severe OSA develop impaired exercise capacity at early stage during exercise. These data point to exaggerated haemodynamic response to graded exercise and delayed post-exercise cardiovascular response recovery in OSA patients. CPET can be a supplement for assessment of OSA severity.

Overshoot of the Respiratory Exchange Ratio during Recovery from Maximal Exercise Testing in Young Patients with Congenital Heart Disease

Introduction: The overshoot of the respiratory exchange ratio (RER) after exercise is reduced in patients with heart failure. Aim: The present study aimed to investigate the presence of this phenomenon in young patients with congenital heart disease (CHD), who generally present reduced cardiorespiratory fitness. Methods: In this retrospective study, patients with CHD underwent a maximal cardiopulmonary exercise testing (CPET) assessing the RER recovery parameters: the RER at peak exercise, the maximum RER value reached during recovery, the magnitude of the RER overshoot and the linear slope of the RER increase after the end of the exercise. Results: In total, 117 patients were included in this study. Of these, there were 24 healthy age-matched control subjects and 93 young patients with CHD (transposition of great arteries, Fontan procedure, aortic coarctation and tetralogy of Fallot). All patients presented a RER overshoot during recovery. Patients with CHD showed reduced aerobic capacity and cardiorespiratory efficiency during exercise, as well as a lower RER overshoot when compared to controls. RER magnitude was higher in the controls and patients with aortic coarctation when compared to those with transposition of great arteries, previous Fontan procedure, and tetralogy of Fallot. The RER magnitude was found to be correlated with the most relevant cardiorespiratory fitness and efficiency indices. Conclusions: The present study proposes new recovery indices for functional evaluation in patients with CHD. Thus, the RER recovery overshoots analysis should be part of routine CPET evaluation to further improve prognostic risk stratifications in patients with CHD.

The Effect of Exercise Training on Irisin Secretion in Patients with Type 2 Diabetes: A Systematic Review

INTRODUCTION

Irisin is a myokine considered to be a potential mediator of exercise-induced energy metabolism and its secretion is known to promote the browning of beige fat cells in white adipose tissue. However, it is currently not known which exercise protocol is the best to enhance irisin concentration in patients with type 2 diabetes (T2D).

OBJECTIVE

The purpose of this study is to provide a review investigating the irisin response to different exercise training modalities and intensities in T2D.

METHODS

A systematic literature search was performed in May 2022.

RESULTS

After the selection process from 938 articles, six studies were included. Selected papers presented different exercise training interventions regarding intensity and modality. One study reported no significant differences in serum irisin levels after exercise training, whereas the other five showed a higher increase in serum irisin levels after exercise training with higher differences in irisin secretion after high-intensity training (HIT). No consideration was possible on exercise modalities.

CONCLUSIONS

The impact of training intensity and modality was found to be partly discordant but data seem to suggest that HIT promotes greater irisin secretion. Despite the limited evidence, HIT, both in interval and continuous modalities, could be suggested as valid exercise training to increase circulating irisin in patients with T2D.

Exercise Capacity and Cardiorespiratory Fitness in Children with Congenital Heart Diseases: A Proposal for an Adapted NYHA Classification

OBJECTIVE

To propose and evaluate an adapted NYHA classification for children with congenital heart disease (CHD) as a feasible clinical tool for classifying patients' fitness, cardiorespiratory efficiency and functional limitations during their ordinary daily activities, which are also characterized by vigorous and competitive physical exercise among peers.

METHODS

This cross-sectional investigation analyzed 332 patients (13.1 ± 3.01 y/o) who underwent surgical repair of CHD and performed Cardiopulmonary Exercise Testing (CPET). Patients were divided into NYHA class I, IIA and IIB by specific questioning regarding functional limitation and performance compared to peers and at strenuous intensity. Class IIA was characterized by slight exercise limitation only for strenuous/competitive activities, whereas IIB for already ordinary physical activities. These NYHA classes were compared with maximal CPET on treadmill.

RESULTS

Patients' exercise capacity (exercise time, METs), aerobic capacity (VO2peak) and chronotropic response were found progressively impaired when NYHA class I was compared with IIA and IIB. Indeed, ventilatory-perfusion mismatch (PETCO2, VE/VCO2) significantly worsened from NYHA class I to IIA, while no difference was found between IIA and IIB.

CONCLUSION

This adapted NYHA-CHD classification could allow regular functional evaluations and accurate assessments by clinicians, leading to facilitated clinical management and timely medical interventions.