Effect of exercise training on heart rate variability in patients with obstructive sleep apnea: A randomized controlled trial

Weight loss and lifestyle intervention for cardiorespiratory fitness in obstructive sleep apnea: The INTERAPNEA trial

INTRODUCTION

Although recent trials have shown benefits of weight loss and lifestyle interventions on obstructive sleep apnea (OSA) severity and comorbidities, the effect of these interventions on cardiorespiratory fitness (CRF) remains unknown. This study aimed to investigate the effects of an interdisciplinary weight loss and lifestyle intervention on CRF and self-reported physical fitness in adults with OSA.

METHODS

Eighty-nine men aged 18-65 years with moderate-to-severe OSA and a body mass index ≥25 kg/m2 were randomly assigned to a usual-care group or an 8-week interdisciplinary weight loss and lifestyle intervention. CRF was assessed through the 2-km walking test, and the International Fitness Scale (IFIS) was used to assess self-reported physical fitness.

RESULTS

As compared with usual-care, the intervention group had greater improvements at intervention endpoint in objective CRF (6% reduction in 2-km walking test total time, mean between-group difference, -1.7 min; 95% confidence interval, -2.3 to -1.1), and self-reported overall physical fitness (18% increase in IFIS total score, mean between-group difference, 2.3; 95% CI 1.2 to 3.3). At 6 months after intervention, the intervention group also had greater improvements in both 2-km walking test total time (10% reduction) and IFIS total score (22% increase), with mean between-group differences of -2.5 (CI 95%, -3.1 to -1.8) and 3.0 (CI 95%, 1.8 to 4.1), respectively.

CONCLUSIONS

An 8-week interdisciplinary weight loss and lifestyle intervention resulted in significant and sustainable improvements in CRF and self-reported physical fitness in men with overweight/obesity and moderate-to-severe OSA.

STUDY REGISTRATION

ClinicalTrials.gov registration (NCT03851653).

Obstructive sleep apnea heterogeneity and autonomic function: a role for heart rate variability in therapy selection and efficacy monitoring

Obstructive sleep apnea is a highly prevalent sleep-related breathing disorder, resulting in a disturbed breathing pattern, changes in blood gases, abnormal autonomic regulation, metabolic fluctuation, poor neurocognitive performance, and increased cardiovascular risk. With broad inter-individual differences recognised in risk factors, clinical symptoms, gene expression, physiological characteristics, and health outcomes, various obstructive sleep apnea subtypes have been identified. Therapeutic efficacy and its impact on outcomes, particularly for cardiovascular consequences, may also vary depending on these features in obstructive sleep apnea. A number of interventions such as positive airway pressure therapies, oral appliance, surgical treatment, and pharmaceutical options are available in clinical practice. Selecting an effective obstructive sleep apnea treatment and therapy is a challenging medical decision due to obstructive sleep apnea heterogeneity and numerous treatment modalities. Thus, an objective marker for clinical evaluation is warranted to estimate the treatment response in patients with obstructive sleep apnea. Currently, while the Apnea-Hypopnea Index is used for severity assessment of obstructive sleep apnea and still considered a major guide to diagnosis and managements of obstructive sleep apnea, the Apnea-Hypopnea Index is not a robust marker of symptoms, function, or outcome improvement. Abnormal cardiac autonomic modulation can provide additional insight to better understand obstructive sleep apnea phenotyping. Heart rate variability is a reliable neurocardiac tool to assess altered autonomic function and can also provide cardiovascular information in obstructive sleep apnea. Beyond the Apnea-Hypopnea Index, this review aims to discuss the role of heart rate variability as an indicator and predictor of therapeutic efficacy to different modalities in order to optimise tailored treatment for obstructive sleep apnea.

The impact of a violent community on mental health and the benefits of a sport program for social development

The aim of the present study was to evaluate the impact of a violent environment on mental health and the impact of a sport for social development (SSD) program on quality of life, mental distress symptoms, and heart rate variability (HRV). HRV and psychometric data were measured from 20 men professional athletes assisted by the SSD and 20 men living in the same violent community. The comparison of groups revealed greater sympathetic parameters of HRV, positive affect, and quality of life in the SSD group. Multiple regression analysis showed that the quality of life in the SSD group was positively predicted by positive affect, while in the control group the quality of life was negatively predicted by their history of traumatic events. Both groups reported high levels of exposure to traumatic events and posttraumatic stress symptoms. However, this study demonstrates the benefits of SSD programs in mental health.

The effect of obstructive sleep apnea therapy on cardiovascular autonomic function: a systematic review and meta-analysis

STUDY OBJECTIVES

Autonomic function is impaired in obstructive sleep apnea (OSA) and may mediate the association between OSA and cardiovascular risk. We investigated the effect of OSA therapy on autonomic function through a systematic review and meta-analysis of intervention studies.

METHODS

A systematic search using three databases (Medline, Embase, and Scopus) was performed up to December 9, 2020. Studies of OSA patients ≥ 18 years with autonomic function assessed before and after treatment with positive airway pressure, oral appliance, positional therapy, weight loss, or surgical intervention were included for review. Random effects meta-analysis was carried out for five groups of autonomic function indices. Risk of bias was assessed using the Cochrane Collaboration tool.

RESULTS

Forty-three eligible studies were reviewed with 39 included in the meta-analysis. OSA treatment led to large decreases in muscle sympathetic nerve activity (Hedges' g = -1.08; 95% CI -1.50, -0.65, n = 8) and moderate decreases in catecholamines (-0.60; -0.94, -0.27, n = 3) and radio nucleotide imaging (-0.61; -0.99, -0.24, n = 2). OSA therapy had no significant effect on baroreflex function (Hedges' g = 0.15; 95% CI -0.09, 0.39, n = 6) or heart rate variability (0.02; -0.32, 0.36, n = 14). There was a significant risk of bias due to studies being primarily non-randomized trials.

CONCLUSIONS

OSA therapy selectively improves autonomic function measures. The strongest evidence for the effect of OSA therapy on autonomic function was seen in reduced sympathetic activity as assessed by microneurography, but without increased improvement in parasympathetic function. OSA therapy may reduce the risk of cardiovascular disease in OSA through reduced sympathetic activity.

Targeting autonomic nervous system as a biomarker of well-ageing in the prevention of stroke

Stroke prediction is a key health issue for preventive medicine. Atrial fibrillation (AF) detection is well established and the importance of obstructive sleep apneas (OSA) has emerged in recent years. Although autonomic nervous system (ANS) appears strongly implicated in stroke occurrence, this factor is more rarely considered. However, the consequences of decreased parasympathetic activity explored in large cohort studies through measurement of ANS activity indicate that an ability to improve its activity level and equilibrium may prevent stroke. In support of these observations, a compensatory neurostimulation has already proved beneficial on endothelium function. The available data on stroke predictions from ANS is based on many long-term stroke cohorts. These data underline the need of repeated ANS evaluation for the general population, in a medical environment, and remotely by emerging telemedicine digital tools. This would help uncovering the reasons behind the ANS imbalance that would need to be medically adjusted to decrease the risk of stroke. This ANS unbalance help to draw attention on clinical or non-clinical evidence, disclosing the vascular risk, as ANS activity integrates the cumulated risk from many factors of which most are modifiable, such as metabolic inadaptation in diabetes and obesity, sleep ventilatory disorders, hypertension, inflammation, and lack of physical activity. Treating these factors may determine ANS recovery through the appropriate management of these conditions. Natural aging also decreases ANS activity. ANS recovery will decrease global circulating inflammation, which will reinforce endothelial function and thus protect the vessels and the associated organs. ANS is the whistle-blower of vascular risk and the actor of vascular health. Such as, ANS should be regularly checked to help draw attention on vascular risk and help follow the improvements in response to our interventions. While today prediction of stroke relies on classical cardiovascular risk factors, adding autonomic biomarkers as HRV parameters may significantly increase the prediction of stroke.

Effects of Exercise on Patients with Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis

With exercise being more frequently utilized in treatment for obstructive sleep apnea (OSA), a systematic review of the intervention efficacy of exercise on OSA is necessary. PubMed, EBSCO, Web of Science, VIP, and CNKI databases were searched to collect randomized controlled trials (RCTs) of exercise applied to OSA from January 2000 to January 2022. The literature screening, data extraction, and risk of bias assessment of included studies were conducted independently by two reviewers. Meta-analysis was then performed using Rev Man 5.4 software. A total of 9 RCTs were included, including 444 patients. Compared with the control group, exercise made an improvement in apnea-hypopnea index (AHI) [MD = -6.65, 95% CI (-7.77, -5.53), p < 0.00001], minimum oxygen saturation (SaO_2min%) [MD = 1.67, 95% CI (0.82, 2.52), p = 0.0001], peak oxygen uptake (VO_2peak) [SMD = 0.54, 95% CI (0.31, 0.78), p < 0.00001], Pittsburgh sleep quality index (PSQI) [MD = -2.08, 95% CI (-3.95, -0.21), p = 0.03], and Epworth Sleepiness Scale (ESS) values [MD = -1.64, 95% CI, (-3.07, -0.22), p = 0.02]. However, there were no significant changes in body mass index (BMI). As for the results of subgroup analysis, aerobic exercise combined with resistance exercise [MD = -7.36, 95% CI (-8.64, -6.08), p < 0.00001] had a better effect on AHI reduction than aerobic exercise alone [MD = -4.36, 95% CI (-6.67, -2.06), p = 0.0002]. This systematic review demonstrates that exercise reduces the severity of OSA with no changes in BMI, and the effect of aerobic exercise combined with resistance training is better than aerobic exercise alone in AHI reduction. Exercise also improves cardiopulmonary fitness, sleep quality, and excessive daytime sleepiness.

Reduction of Cardiac Autonomic Modulation and Increased Sympathetic Activity by Heart Rate Variability in Patients With Long COVID

Although several clinical manifestations of persistent long coronavirus disease (COVID-19) have been documented, their effects on the cardiovascular and autonomic nervous system over the long term remain unclear. Thus, we examined the presence of alterations in cardiac autonomic functioning in individuals with long-term manifestations. The study was conducted from October 2020 to May 2021, and an autonomic assessment was performed to collect heart rate data for the heart rate variability (HRV) analysis. The study participants were divided into the long COVID clinical group, the intragroup, which included patients who were hospitalized, and those who were not hospitalized and were symptomatic for different periods (≤3, >3, ≤6, and >6 months), with and without dyspnoea. The control group, the intergroup, comprised of COVID-free individuals. Our results demonstrated that the long COVID clinical group showed reduced HRV compared with the COVID-19-uninfected control group. Patients aged 23–59 years developed COVID symptoms within 30 days after infection, whose diagnosis was confirmed by serologic or reverse-transcription polymerase chain reaction (swab) tests, were included in the study. A total of 155 patients with long COVID [95 women (61.29%), mean age 43.88 ± 10.88 years and 60 men (38.71%), mean age 43.93 ± 10.11 years] and 94 controls [61 women (64.89%), mean age 40.83 ± 6.31 and 33 men (35.11%), mean age 40.69 ± 6.35 years] were included. The intragroup and intergroup comparisons revealed a reduction in global HRV, increased sympathetic modulation influence, and a decrease in parasympathetic modulation in long COVID. The intragroup showed normal sympathovagal balance, while the intergroup showed reduced sympathovagal balance. Our findings indicate that long COVID leads to sympathetic excitation influence and parasympathetic reduction. The excitation can increase the heart rate and blood pressure and predispose to cardiovascular complications. Short-term HRV analysis showed good reproducibility to verify the cardiac autonomic involvement.

Obstructive Sleep Apnea Syndrome: The Effect of Acute and Chronic Responses of Exercise

Obstructive Sleep Apnea Syndrome (OSAS) is a sleep disorder with high prevalence in general population, but alarmingly low in clinicians' differential diagnosis. We reviewed the literature on PubMed and Scopus from June 1980–2021 in order to describe the altered systematic pathophysiologic mechanisms in OSAS patients as well as to propose an exercise program for these patients. Exercise prevents a dysregulation of both daytime and nighttime cardiovascular autonomic function, reduces body weight, halts the onset and progress of insulin resistance, while it ameliorates excessive daytime sleepiness, cognitive decline, and mood disturbances, contributing to an overall greater sleep quality and quality of life.

Effect of exercise training on body composition in patients with obstructive sleep apnea: a systematic review and meta-analysis

Reduction in adiposity is considered a cornerstone in the treatment of obstructive sleep apnea (OSA). Exercise training is one of the interventions used in the treatment of OSA. However, it remains unclear whether exercise training alleviates OSA by improving body composition. This study aimed to verify the effect of exercise training on body composition and the apnea-hypopnea index (AHI) in patients with OSA. This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was registered in PROSPERO. PubMed/Medline, Scopus, and Cochrane databases were used for systematic review. Analyses were performed using Review Manager software (version 5.3; R Foundation for Statistical Computing, Vienna, Austria). Exercise training significantly reduced body mass index (mean difference = -0.55 kg/m²; 95% CI = -0.95 to -0.15), body fat percentage (mean difference = -1.19%; 95% CI = -2.03 to -0.35), neck circumference (mean difference = -0.55 cm; 95% CI = -1.08 to -0.02), total body weight (mean difference = -2.13 kg; 95% CI = -4.30 to 0.04), and AHI -8.06 events/hour; 95% CI = -10.47 to -5.66). Although body composition was improved by exercise, this improvement was clinically small. Moreover, improvement in AHI by exercise may not be entirely due to improvements in adiposity. PROSPERO #: CRD42020210509.

Exercise capacity and comorbidities in patients with obstructive sleep apnea

STUDY OBJECTIVES

There are few studies evaluating (1) exercise capacity as assessed by the 6-minute walking distance (6MWD) test in large populations with obstructive sleep apnea (OSA); and (2) correlations with patients' comorbidities.

METHODS

This study presents a cluster analysis performed on the data of 1,228 patients. Severity of exercise limitation was defined on the basis of 6MWD.

RESULTS

Sixty-one percent showed exercise limitation (29.2% and 31.9% mild and severe exercise limitation, respectively). About 60% and 40% of patients were included in cluster 1 (CL1) and 2 (CL2), respectively. CL1 included younger patients with high prevalence of apneas, desaturations, and hypertension with better exercise tolerance. CL2 included older patients, all with chronic obstructive pulmonary disease (COPD), high prevalence of chronic respiratory failure (CRF), fewer apneas but severe mean desaturation, daytime hypoxemia, more severe exercise limitation, and exercise-induced desaturations. Only CRF and COPD significantly (P < .001) correlated with 6MWD < 85% of predicted value. 6MWD correlated positively with apnea-hypopnea index, oxygen desaturation index, nocturnal pulse oxygen saturation (SpO₂), resting arterial oxygen tension, mean SpO₂ on exercise, and negatively with age, body mass index, time spent during night with SpO₂ < 90%, mean nocturnal desaturation, arterial carbon dioxide tension, and number of comorbidities. Patients without severe comorbidities had higher exercise capacity than those with severe comorbidities, (P < .001). Exercise limitation was significantly worse in OSA severity class I when compared to other classes (P < .001).

CONCLUSIONS

A large number of patients with OSA experience exercise limitation. Older age, comorbidities such as COPD and CRF, OSA severity class I, severe mean nocturnal desaturation, and daytime hypoxemia are associated with worse exercise tolerance.

Longer-term effects of supervised physical activity on obstructive sleep apnea and subsequent health consequences

Although recent trials have shown promising benefits of exercise on obstructive sleep apnea (OSA) severity, the long-term effect of these interventions remains unknown. The aim of this study was to assess the effect of a 9-month community physical activity program on OSA severity one year later in free-living conditions. OSA patients, previously included in a 9-month randomized controlled trial (EXESAS study) evaluating the effects of supervised community physical activity on OSA severity, were invited to participate in an extra one-year observational study. Twenty-eight patients completed the study. Although OSA severity did not significantly worsen over the real-life period (9 to 21 months of follow-up), reductions in apnea-hypopnea index (AHI) and oxygen desaturation index were no longer significant after 21 months of follow-up compared to baseline (baseline AHI: 22.2 ± 6.3 /h; 9 months: 16.3 ± 6.4 /h; 21 months: 18.7 ± 8.9 /h). Benefits observed at 9 months on daytime sleepiness and mental health were preserved at 21 months, whereas cardiorespiratory fitness slightly decreased. Per-protocol analysis revealed that patients who stopped exercise at 9 months had worsened OSA severity compared to those who continued exercise during the real-life period (AHI: +9.0 ± 8.8 vs. -1.3 ± 5.3 /h; p < .01). In conclusion, our study suggested that improvements in OSA severity remain transient and is dependent on long-term adherence to regular physical activity practice.

Effects of exercise training on autonomic modulation and mood symptoms in patients with obstructive sleep apnea

We evaluated the effects of exercise training (ET) on the profile of mood states (POMS), heart rate variability, spontaneous baroreflex sensitivity (BRS), and sleep disturbance severity in patients with obstructive sleep apnea (OSA). Forty-four patients were randomized into 2 groups, 18 patients completed the untrained period and 16 patients completed the exercise training (ET). Beat-to-beat heart rate and blood pressure were simultaneously collected for 5 min at rest. Heart rate variability (RR interval) was assessed in time domain and frequency domain (FFT spectral analysis). BRS was analyzed with the sequence method, and POMS was analyzed across the 6 categories (tension, depression, hostility, vigor, fatigue, and confusion). ET consisted of 3 weekly sessions of aerobic exercise, local strengthening, and stretching exercises (72 sessions, achieved in 40±3.9 weeks). Baseline parameters were similar between groups. The comparisons between groups showed that the changes in apnea-hypopnea index, arousal index, and O2 desaturation in the exercise group were significantly greater than in the untrained group (P<0.05). The heart rate variability and BRS were significantly higher in the exercise group compared with the untrained group (P<0.05). ET increased peak oxygen uptake (P<0.05) and reduced POMS fatigue (P<0.05). A positive correlation (r=0.60, P<0.02) occurred between changes in the fatigue item and OSA severity. ET improved heart rate variability, BRS, fatigue, and sleep parameters in patients with OSA. These effects were associated with improved sleep parameters, fatigue, and cardiac autonomic modulation, with ET being a possible protective factor against the deleterious effects of hypoxia on these components in patients with OSA.

Effects of short-term aerobic training versus CPAP therapy on heart rate variability in moderate to severe OSA patients

We compared the effects of 2-month CPAP or exercise training (ET) therapies on the autonomic balance in moderate to severe obstructive sleep apnea (OSA) through heart rate variability (HRV) analysis. Thirty-nine OSA patients were divided into CPAP (n = 18) and ET (n = 21) groups, being further split into hypertensive and non-hypertensive subgroups. All patients were submitted to continuous ECG recordings for HRV analysis. Hemodynamic parameters were recorded by oscillometry. Excessive daytime sleepiness and sleep quality were assessed through the Epworth Sleepiness Scale and the Pittsburgh questionnaire, respectively. ET decreased systolic arterial pressure in hypertensive and non-hypertensive participants when compared to baseline values, whereas diastolic arterial pressure was decreased only in non-hypertensive ones. CPAP had no effect over hemodynamic parameters in either subgroup. ET significantly increased the HRV parameters SDNN and pNN50 in non-hypertensive participants, while reducing the LF/HF ratio in both subgroups. CPAP significantly decreased SDNN in both subgroups. ET significantly decreased excessive daytime sleepiness in both subgroups, but did not affect sleep quality. CPAP significantly improved sleep quality in both subgroups, although global scores were still those of poor sleepers, while excessive daytime sleepiness was normalized only in hypertensive patients. In conclusion, while short-term ET modulated different HRV parameters, leading to a predominant vagal tone in the cardiac sympathovagal balance and decreasing blood pressure in moderate to severe OSA, short-term CPAP had next to no effect in these parameters. We believe ET should be considered as an adjunct interventional strategy in the conservative management of hypertensive or non-hypertensive OSA patients.

Physical exercise in sickle cell anemia: a systematic review

INTRODUCTION AND OBJECTIVE

Sickle cell anemia (SCA) is a genetic condition that alters the conformation of deoxygenated red blood cells, which results in their stiffening and the occurrence of vaso-occlusive crises, endothelium damage, organ dysfunction and systemic complications. Additionally, SCA limits the participation of individuals in physical and social activities. As we consider that physical exercise promotes the recovery of functional capacity and cardiorespiratory conditioning, we aim to verify the patterns of prescription, the effects and safety of exercise for individuals with SCA.

METHODOLOGY

We systematically reviewed the published literature focusing on clinical trials that correlated physical exercise with SCA patients and cross-sectional studies that applied the stress test. The data research was based on the PRISMA recommendations and the following databases were used: Medline by PubMed, Cochrane, PEDro, Scielo.

RESULTS

Six studies which were based on the evaluation of 212 patients aged between 13 and 40 years, were selected from 122 identified studies. Those studies associated the individual effort tolerance improvement, its inflammatory profile adjustment and the absence of alteration in the autonomic nervous system activity to physical exercise or stress test.

CONCLUSION

Low-to-moderate intensity physical exercise increased the SCA individual tolerance without causing vaso-occlusive crises, nor changes in the hemorheological and inflammatory profiles.

The Impact of Auricular Vagus Nerve Stimulation on Pain and Life Quality in Patients with Fibromyalgia Syndrome

The purpose of this study is to evaluate the impact of auricular vagus nerve stimulation, applied in conjunction with an exercise treatment program, on pain and life quality in patients with fibromyalgia syndrome (FMS). To achieve the study objectives, 60 female patients between the ages 18 and 50, with diagnosed FMS according to the American College of Rheumatology (ACR) 2010 diagnostic criteria, were randomly divided into 2 groups of 30. The first group was assigned 20 sessions of a home-based exercise program, while the second group was assigned 20 sessions of auricular vagus nerve stimulation and 20 sessions of a home-based exercise program. Patients were assessed before and after the treatments using the Visual Analog Scale (VAS) for pain, Beck Depression Scale for depression, Beck Anxiety Scale for anxiety, Fibromyalgia Impact Questionnaire (FIQ) for functional evaluation, and Short Form-36 (SF-36) for life quality. In this randomized controlled trial, comparisons within the groups revealed that both groups had statistically significant improvements in pain, depression, anxiety, functionality, and life quality scores (p < 0.05), while comparisons across the groups revealed that the group experiencing the vagus nerve stimulation had no statistically significant differences between the baseline scores, except for those of SF-36's subparameters of physical function, social functionality, and pain. In fact, comparisons across the groups after the interventions revealed that the group experiencing the vagus nerve stimulation had better scores but not statistically significant. From analysis of this data, we observed that vagus nerve stimulation in FMS treatment did not give additional benefit together with exercise, except for three subparameters of SF-36. It was identified that further studies which separately investigate the effects of vagus nerve stimulation and exercise on FMS with longer follow-up periods and an increased number of patients are needed.