Effects of Exercise Training and CPAP in Patients With Heart Failure and OSA: A Preliminary Study

Impact of Long-Term Exercise-Based Cardiac Rehabilitation in Patients With Chronic Heart Failure - A Systematic Review and Meta-Analysis

BACKGROUND

This study aimed to clarify the effects of exercise-based cardiac rehabilitation (CR) on patients with heart failure.

METHODS AND RESULTS

Patients were divided into groups according to intervention duration (<6 and ≥6 months). We searched for studies published up to July 2023 in Embase, MEDLINE, PubMed, and the Cochrane Library, without limitations on data, language, or publication status. We included randomized controlled trials comparing the efficacy of CR and usual care on mortality, prehospitalization, peak oxygen uptake (V̇O2), and quality of life. Seventy-two studies involving 8,495 patients were included in this review. It was found that CR reduced the risk of rehospitalization for any cause (risk ratio [RR] 0.80; 95% confidence interval [CI] 0.70-0.92) and for heart failure (RR 0.88; 95% CI 0.78-1.00). Furthermore, CR was found to improve exercise tolerance (measured by peak V̇O2and the 6-min walk test) and quality of life. A subanalysis performed based on intervention duration (<6 and ≥6 months) revealed a similar trend.

CONCLUSIONS

Our meta-analysis showed that although CR does not reduce mortality, it is effective in reducing rehospitalization rates and improving exercise tolerance and quality of life, regardless of the intervention duration.

The effects of exercise programs on sleep architecture in obstructive sleep apnea: a meta-analysis of randomized controlled trials

OBJECTIVES

Exercise is an effective intervention for obstructive sleep apnea (OSA). However, the effects of exercise on objective sleep architecture in patients with OSA remain unknown. This meta-analysis aimed to collect data from randomized controlled trials of exercise interventions in patients with OSA, with a specific focus on objective sleep parameters derived from polysomnography.

METHODS

Randomized control trials that targeted patients with OSA aged >18 years, measured sleep using polysomnography after exercise programs, and reported the proportion of sleep stages were included for meta-analysis. Bias was assessed using the revised Cochrane risk-of-bias tool and funnel plots. The random effects model was applied.

RESULTS

Six studies with a total of 236 patients were included in the meta-analysis. There were no significant differences in the total sleep time (TST), sleep efficiency, sleep onset latency, stage N1 sleep, or rapid eye movement sleep between the exercise and control groups. Participation in an exercise program lasting >12 weeks significantly decreased stage N2 and increased stage N3 sleep as observed in the subgroup analysis. Although this tendency did not reach statistical significance in the total-group analysis, it was significant after excluding the possible confounding effects of heart disease.

CONCLUSIONS

The exercise program decreased N2 and increased N3 proportions over the TST among patients with OSA, which may correspond to subjective sleep quality. The beneficial effects were significant when the program lasted >12 weeks and after excluding the confounding effects of heart disease. Exercise program duration should be considered when providing clinical advice.

Adaptive servo-ventilation for sleep-disordered breathing in patients with heart failure with reduced ejection fraction (ADVENT-HF): a multicentre, multinational, parallel-group, open-label, phase 3 randomised controlled trial

BACKGROUND

In patients with heart failure and reduced ejection fraction, sleep-disordered breathing, comprising obstructive sleep apnoea (OSA) and central sleep apnoea (CSA), is associated with increased morbidity, mortality, and sleep disruption. We hypothesised that treating sleep-disordered breathing with a peak-flow triggered adaptive servo-ventilation (ASV) device would improve cardiovascular outcomes in patients with heart failure and reduced ejection fraction.

METHODS

We conducted a multicentre, multinational, parallel-group, open-label, phase 3 randomised controlled trial of peak-flow triggered ASV in patients aged 18 years or older with heart failure and reduced ejection fraction (left ventricular ejection fraction ≤45%) who were stabilised on optimal medical therapy with co-existing sleep-disordered breathing (apnoea-hypopnoea index [AHI] ≥15 events/h of sleep), with concealed allocation and blinded outcome assessments. The trial was carried out at 49 hospitals in nine countries. Sleep-disordered breathing was stratified into predominantly OSA with an Epworth Sleepiness Scale score of 10 or lower or predominantly CSA. Participants were randomly assigned to standard optimal treatment alone or standard optimal treatment with the addition of ASV (1:1), stratified by study site and sleep apnoea type (ie, CSA or OSA), with permuted blocks of sizes 4 and 6 in random order. Clinical evaluations were performed and Minnesota Living with Heart Failure Questionnaire, Epworth Sleepiness Scale, and New York Heart Association class were assessed at months 1, 3, and 6 following randomisation and every 6 months thereafter to a maximum of 5 years. The primary endpoint was the cumulative incidence of the composite of all-cause mortality, first admission to hospital for a cardiovascular reason, new onset atrial fibrillation or flutter, and delivery of an appropriate cardioverter-defibrillator shock. All-cause mortality was a secondary endpoint. Analysis for the primary outcome was done in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT01128816) and the International Standard Randomised Controlled Trial Number Register (ISRCTN67500535), and the trial is complete.

FINDINGS

The first and last enrolments were Sept 22, 2010, and March 20, 2021. Enrolments terminated prematurely due to COVID-19-related restrictions. 1127 patients were screened, of whom 731 (65%) patients were randomly assigned to receive standard care (n=375; mean AHI 42·8 events per h of sleep [SD 20·9]) or standard care plus ASV (n=356; 43·3 events per h of sleep [20·5]). Follow-up of all patients ended at the latest on June 15, 2021, when the trial was terminated prematurely due to a recall of the ASV device due to potential disintegration of the motor sound-abatement material. Over the course of the trial, 41 (6%) of participants withdrew consent and 34 (5%) were lost to follow-up. In the ASV group, the mean AHI decreased to 2·8-3·7 events per h over the course of the trial, with associated improvements in sleep quality assessed 1 month following randomisation. Over a mean follow-up period of 3·6 years (SD 1·6), ASV had no effect on the primary composite outcome (180 events in the control group vs 166 in the ASV group; hazard ratio [HR] 0·95, 95% CI 0·77-1·18; p=0·67) or the secondary endpoint of all-cause mortality (88 deaths in the control group vs. 76 in the ASV group; 0·89, 0·66-1·21; p=0·47). For patients with OSA, the HR for all-cause mortality was 1·00 (0·68-1·46; p=0·98) and for CSA was 0·74 (0·44-1·23; p=0·25). No safety issue related to ASV use was identified.

INTERPRETATION

In patients with heart failure and reduced ejection fraction and sleep-disordered breathing, ASV had no effect on the primary composite outcome or mortality but eliminated sleep-disordered breathing safely.

FUNDING

Canadian Institutes of Health Research and Philips RS North America.

The Interplay of Comorbidities in Chronic Heart Failure: Challenges and Solutions

BACKGROUND

Chronic heart failure (HF) is frequently associated with various comorbidities. These comorbid conditions, such as anemia, diabetes mellitus, renal insufficiency, and sleep apnea, can significantly impact the prognosis of patients with HF.

OBJECTIVE

This review aims to synthesize current evidence on the prevalence, impact, and management of comorbidities in patients with chronic HF.

METHODS

A comprehensive review was conducted, with a rigorous selection process. Out of an initial pool of 59,030 articles identified across various research modalities, 134 articles were chosen for inclusion. The selection spanned various research methods, from randomized controlled trials to observational studies.

RESULTS

Comorbidities are highly prevalent in patients with HF and contribute to increased hospitalization rates and mortality. Despite advances in therapies for HF with reduced ejection fraction, options for treating HF with preserved ejection fraction remain sparse. Existing treatment protocols often lack standardization, reflecting a limited understanding of the intricate relationships between HF and associated comorbidities.

CONCLUSION

There is a pressing need for a multidisciplinary, tailored approach to manage HF and its intricate comorbidities. This review underscores the importance of ongoing research efforts to devise targeted treatment strategies for HF patients with various comorbid conditions.

Association between Obstructive Sleep Apnea and Heart Failure in Adults-A Systematic Review

BACKGROUND

Heart failure (HF) patients commonly experience obstructive sleep apnea (OSA), which may worsen their condition. We reviewed a diverse range of studies to investigate the prevalence of OSA in HF patients, the effects of positive airway pressure (PAP) treatment, and the potential impact of sodium-glucose cotransporter-2 inhibitors (SGLT2i) and sacubitril/valsartan on OSA outcomes.

METHODS

We analyzed case-control, observational studies, and randomized controlled trials. Prevalence rates, PAP treatment, and HF pharmacotherapy were assessed.

RESULTS

Numerous studies revealed a high prevalence of OSA in HF patients, particularly with preserved ejection fraction. PAP treatment consistently improved an apnea-hypopnea index, left ventricular ejection fraction, oxygen saturation, and overall quality of life. Emerging evidence suggests that SGLT2i and sacubitril/valsartan might influence OSA outcomes through weight loss, improved metabolic profiles, and potential direct effects on upper airway muscles.

CONCLUSIONS

The complex interplay between OSA and HF necessitates a multifaceted approach. PAP treatment has shown promising results in improving OSA symptoms and HF parameters. Additionally, recent investigations into the effects of HF pharmacotherapy on OSA suggest their potential as adjunctive therapy. This review provides insights for clinicians and researchers, highlighting the importance of addressing OSA and HF in patient management strategies.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Pathophysiological mechanisms and therapeutic approaches in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is a common breathing disorder in sleep in which the airways narrow or collapse during sleep, causing obstructive sleep apnea. The prevalence of OSAS continues to rise worldwide, particularly in middle-aged and elderly individuals. The mechanism of upper airway collapse is incompletely understood but is associated with several factors, including obesity, craniofacial changes, altered muscle function in the upper airway, pharyngeal neuropathy, and fluid shifts to the neck. The main characteristics of OSAS are recurrent pauses in respiration, which lead to intermittent hypoxia (IH) and hypercapnia, accompanied by blood oxygen desaturation and arousal during sleep, which sharply increases the risk of several diseases. This paper first briefly describes the epidemiology, incidence, and pathophysiological mechanisms of OSAS. Next, the alterations in relevant signaling pathways induced by IH are systematically reviewed and discussed. For example, IH can induce gut microbiota (GM) dysbiosis, impair the intestinal barrier, and alter intestinal metabolites. These mechanisms ultimately lead to secondary oxidative stress, systemic inflammation, and sympathetic activation. We then summarize the effects of IH on disease pathogenesis, including cardiocerebrovascular disorders, neurological disorders, metabolic diseases, cancer, reproductive disorders, and COVID-19. Finally, different therapeutic strategies for OSAS caused by different causes are proposed. Multidisciplinary approaches and shared decision-making are necessary for the successful treatment of OSAS in the future, but more randomized controlled trials are needed for further evaluation to define what treatments are best for specific OSAS patients.

Global psychological assessment with the evaluation of life and sleep quality and sexual and cognitive function in a large number of patients with acromegaly: a cross-sectional study

OBJECTIVE

Acromegaly is associated with somatic disfigurements which impair self-perception of well-being and quality of life. Nowadays, limited data are available on the interplay between hormonal excess and psychological discomfort. The study aimed at investigating the psychological profile, sleep quality, sexual function, cognitive functions, and quality of life in patients with acromegaly.

METHODS

In 223 acromegaly patients from 5 referral centres, global psychological profile, sleep quality, sexual function, cognitive function, and quality of life were investigated.

RESULTS

Depression was found in ~30% of patients, and anxiety in two-thirds, together with severe discomfort in body image mainly in women. Obstructive sleep apnoea syndrome risk and sleep disorders were found in >50% of patients and daily sleepiness in ~20%. Sexual dysfunction was reported in most of the patients, with the most severe impairment in women. Cognitive functions were compromised in ~10% of cases. Disease duration and patient's age and gender were the main determinants of these psychopathological conditions. Depression (P = 0.047), somatic-affective mood lowering (P = 0.021), state (P < 0.001) and trait (P = 0.013) anxiety, and body image distortion in body uneasiness test A (P < 0.001) and B (P = 0.006) were significantly worsened in patients <45 years and slightly worsened in those with disease duration less than 2 years. Male (P < 0.001) and female (P < 0.001) sexual function scores were significantly worsened in patients aged >64 years and slightly worsened in those with disease duration for more than 10 years, particularly in presence of cardiometabolic and respiratory complications. Cognitive symptoms were slightly worsened in older patients and in those with long disease duration.

CONCLUSIONS

Acromegaly is associated with a relevant impairment of psychological profile persisting despite remission and long-term medical treatment.

Positive airway pressure therapy in heart failure patients comorbid with obstructive sleep apnea: Cardiovascular outcomes and nighttime-duration effect

BACKGROUND

Comorbidity of obstructive sleep apnea (OSA) and heart failure (HF) is becoming increasingly common. This is a global analysis of positive airway pressure (PAP) efficacy for the cardiovascular outcomes in those HF Patients with comorbid OSA.

METHODS

Related randomized controlled trials were included. Analysed indicators covered primary outcomes (cardiac function, motor ability and life quality) and secondary outcomes (blood pressure and OSA-accompanying symptoms). Weighted mean difference was used to analyse the PAP-control difference in different experimental phases and the baseline-post difference in different groups.

RESULTS

Compared with control group, PAP was associated with a 3.48% increase in left ventricle ejection fraction (LVEF) (p < .00001) and little decrease in heart rate (HR) (p = .67). Over 6 h of mean nighttime use was associated with a greater increase in LVEF of 5.21% (p = .0002) and a significant reduction in HR of 3.81 bpm (p = .03). There was no significant difference between PAP and control group in their association with change in motor ability and life quality. Besides, PAP was associated with a 13.08 mm Hg decrease in systolic blood pressure and great improvements in OSA-accompanying symptoms: Apnea-Hypopnea Index, -23.73 e/h; mean oxygen saturation, 1.86%; minimum oxygen saturation, 8.78%; Epworth Sleepiness Scale, -1.39 point; arousal index, -16.41 e/h. There was also no significant difference in diastolic blood pressure.

CONCLUSIONS

Positive airway pressure treatment improves cardiac function in HF patients with comorbid OSA, but the improved magnitude is associated with the duration of nighttime use rather than the duration of treatment.

Effects of exercise-based cardiac rehabilitation delivery modes on exercise capacity and health-related quality of life in heart failure: a systematic review and network meta-analysis

Background

This review aimed to compare the relative effectiveness of different exercise-based cardiac rehabilitation (ExCR) delivery modes (centre-based, home-based, hybrid and technology-enabled ExCR) on key heart failure (HF) outcomes: exercise capacity, health-related quality of life (HRQoL), HF-related hospitalisation and HF-related mortality.

Methods and results

Randomised controlled trials (RCTs) published through 20 June 2021 were identified from six databases, and reference lists of included studies. Risk of bias and certainty of evidence were evaluated using the Cochrane tool and Grading of Recommendations Assessment, Development and Evaluation, respectively. Bayesian network meta-analysis was performed using R. Continuous and binary outcomes are reported as mean differences (MD) and ORs, respectively, with 95% credible intervals (95% CrI). One-hundred and thirty-nine RCTs (n=18 670) were included in the analysis. Network meta-analysis demonstrated improvements in VO₂peak following centre-based (MD (95% CrI)=3.10 (2.56 to 3.65) mL/kg/min), home-based (MD=2.69 (1.67 to 3.70) mL/kg/min) and technology-enabled ExCR (MD=1.76 (0.27 to 3.26) mL/kg/min). Similarly, 6 min walk distance was improved following hybrid (MD=84.78 (31.64 to 138.32) m), centre-based (MD=50.35 (30.15 to 70.56) m) and home-based ExCR (MD=36.77 (12.47 to 61.29) m). Incremental shuttle walk distance did not improve following any ExCR delivery modes. Minnesota living with HF questionnaire improved after centre-based (MD=−10.38 (−14.15 to –6.46)) and home-based ExCR (MD=−8.80 (−13.62 to –4.07)). Kansas City Cardiomyopathy Questionnaire was improved following home-based ExCR (MD=20.61 (4.61 to 36.47)), and Short Form Survey 36 mental component after centre-based ExCR (MD=3.64 (0.30 to 6.14)). HF-related hospitalisation and mortality risks reduced only after centre-based ExCR (OR=0.41 (0.17 to 0.76) and OR=0.42 (0.16 to 0.90), respectively). Mean age of study participants was only associated with changes in VO₂peak.

Conclusion

ExCR programmes have broader benefits for people with HF and since different delivery modes were comparably effective for improving exercise capacity and HRQoL, the selection of delivery modes should be tailored to individuals’ preferences.

Sleep Deficiency: A Symptoms Perspective: Exemplars from Chronic Heart Failure, Inflammatory Bowel Disease, and Breast Cancer

Sleep deficiency is associated with disabling daytime symptoms, including excessive daytime sleepiness (EDS) and fatigue. The purpose of this article is to discuss the contributions of sleep deficiency and sleep disorders to fatigue and EDS among people with chronic conditions. We use exemplars from the literature on chronic heart failure, inflammatory bowel disease, and breast cancer to (1) describe the prevalence of fatigue and EDS and their consequences; (2) examine the evidence for the contributions of sleep deficiency and sleep disorders to these symptoms; and (3) recommend implications for future research and practice.

Abnormal Sleep-Related Breathing Related to Heart Failure

Sleep-disordered breathing (SDB) is highly prevalent in patients with heart failure (HF). Untreated obstructive sleep apnea (OSA) and central sleep apnea (CSA) in patients with HF are associated with worse outcomes. Detailed sleep history along with polysomnography (PSG) should be conducted if SDB is suspected in patients with HF. First line of treatment is the optimization of medical therapy for HF and if symptoms persist despite optimization of the treatment, positive airway pressure (PAP) therapy will be started to treat SDB. At present, there is limited evidence to prescribe any drugs for treating CSA in patients with HF. There is limited evidence for the efficacy of continuous positive airway pressure (CPAP) or adaptive servo-ventilation (ASV) in improving mortality in patients with heart failure with reduced ejection fraction (HFrEF). There is a need to perform well-designed studies to identify different phenotypes of CSA/OSA in patients with HF and to determine which phenotype responds to which therapy. Results of ongoing trials, ADVENT-HF, and LOFT-HF are eagerly awaited to shed more light on the management of CSA in patients with HF. Until then the management of SDB in patients with HF is limited due to the lack of evidence and guidance for treating SDB in patients with HF.

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.

Current Management of Residual Excessive Daytime Sleepiness Due to Obstructive Sleep Apnea: Insights for Optimizing Patient Outcomes

Although excessive daytime sleepiness (EDS) attributable to obstructive sleep apnea (OSA) can be resolved by consistent usage of and effective treatment (often with the use of continuous positive airway pressure therapy), 12–58% of patients report residual EDS (REDS). While REDS is difficult to treat, a proportion of cases are possibly due to reversible issues, and wake-promoting medications can prove useful for the remaining cases. Given the challenges associated with effective management of REDS and its relationship to multiple comorbidities, multidisciplinary management of patients with REDS is often recommended. Here we aim to bridge the knowledge gap on the burden, risk factors, prevalence, and potential pathophysiologic mechanisms of REDS in patients with OSA after first-line treatment. The roles of primary care physicians and sleep specialists, as well as the importance of the use of objective assessment tools for the evaluation of REDS and the effective management of comorbidities, are discussed. An update of approved treatments and emerging candidate treatments is also presented.

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.

Feasibility of Transcatheter Caval Valve Implantation to Improve -Disordered Breathing in Patients With Severe Tricuspid Regurgitation-A Pilot Study

Transcatheter caval valve implantation (CAVI) has been evaluated as a treatment option for inoperable patients with severe symptomatic tricuspid regurgitation (TR). We studied the effect of CAVI on sleep disorder breathing (SDB) in patients with right heart failure and TR. Twenty right heart failure patients with severe symptomatic TR who underwent portable monitoring of SDB (ApneaLink), echocardiography, cardiopulmonary exercise (CPET), and laboratory testing were enrolled. This was a single-center, nonblinded study. There were no significant changes in sleep variables, echocardiographic parameters, laboratory results, lung function, and CPET after CAVI. In conclusion, these data suggest that CAVI may not have an effect on SDB; however, additional follow-up fully powered studies with appropriate statistical analyses are needed.

A systematic review of rehabilitation in chronic heart failure: evaluating the reporting of exercise interventions

A large body of research supports the use of exercise to improve symptoms, quality of life, and physical function in patients with chronic heart failure. Previous reviews have focused on reporting outcomes of exercise interventions such as cardiorespiratory fitness. However, none have critically examined exercise prescription. The aim of this review was to evaluate the reporting and application of exercise principles in randomised control trials of exercise training in patients with chronic heart failure. A systematic review of exercise intervention RCTs in patients with CHF, using the Consensus on Exercise Reporting Template (CERT), was undertaken. The Ovid Medline/PubMed, Embase, Scopus/Web of Science, and Cochrane Library and Health Technology Assessment Databases were searched from 2000 to June 2020. Prospective RCTs in which patients with CHF were randomized to a structured exercise programme were included. No limits were placed on the type or duration of exercise structured exercise programme or type of CHF (i.e. preserved or reduced ejection fraction). We included 143 studies, comprising of 181 different exercise interventions. The mean CERT score was 10 out of 19, with no study achieving a score of 19. Primarily, details were missing regarding motivational strategies, home-based exercise components, and adherence/fidelity to the intervention. Exercise intensity was the most common principle of exercise prescription missing from intervention reporting. There was no improvement in the reporting of exercise interventions with time (R²  = 0.003). Most RCTs of exercise training in CHF are reported with insufficient detail to allow for replication, limiting the translation of evidence to clinical practice. We encourage authors to provide adequate details when reporting future interventions. Where journal word counts are restrictive, we recommend using supplementary material or publishing trial protocols prior to beginning the study.

An Update on Obstructive Sleep Apnea for Atherosclerosis: Mechanism, Diagnosis, and Treatment

The occurrence and development of atherosclerosis could be influenced by intermittent hypoxia. Obstructive sleep apnea (OSA), characterized by intermittent hypoxia, is world-wide prevalence with increasing morbidity and mortality rates. Researches remain focused on the study of its mechanism and improvement of diagnosis and treatment. However, the underlying mechanism is complex, and the best practice for OSA diagnosis and treatment considering atherosclerosis and related cardiovascular diseases is still debatable. In this review, we provided an update on research in OSA in the last 5 years with regard to atherosclerosis. The processes of inflammation, oxidative stress, autonomic nervous system activation, vascular dysfunction, platelet activation, metabolite dysfunction, small molecule RNA regulation, and the cardioprotective occurrence was discussed. Additionally, improved diagnosis such as, the utilized of portable device, and treatment especially with inconsistent results in continuous positive airway pressure and mandibular advancement devices were illustrated in detail. Therefore, further fundamental and clinical research should be carried out for a better understanding the deep interaction between OSA and atherosclerosis, as well as the suggestion of newer diagnostic and treatment options.

Evaluation and Management of Adults with Obstructive Sleep Apnea Syndrome

Obstructive sleep apnea syndrome (OSAS) is a common and underdiagnosed medical condition characterized by recurrent sleep-dependent pauses and reductions in airflow. While a narrow, collapsible oropharynx plays a central role in the pathophysiology of OSAS, there are other equally important nonanatomic factors including sleep-stage dependent muscle tone, arousal threshold, and loop gain that drive obstructive apneas and hypopneas. Through mechanisms of intermittent hypoxemia, arousal-related sleep fragmentation, and intrathoracic pressure changes, OSAS impacts multiple organ systems. Risk factors for OSAS include obesity, male sex, age, specific craniofacial features, and ethnicity. The prevalence of OSAS is rising due to increasing obesity rates and improved sensitivity in the tools used for diagnosis. Validated questionnaires have an important but limited role in the identification of patients that would benefit from formal testing for OSA. While an in-laboratory polysomnography remains the gold standard for diagnosis, the widespread availability and accuracy of home sleep apnea testing modalities increase access and ease of OSAS diagnosis for many patients. In adults, the most common treatment involves the application of positive airway pressure (PAP), but compliance continues to be a challenge. Alternative treatments including mandibular advancement device, hypoglossal nerve stimulator, positional therapies, and surgical options coupled with weight loss and exercise offer possibilities of an individualized personal approach to OSAS. Treatment of symptomatic patients with OSAS has been found to be beneficial with regard to sleep-related quality of life, sleepiness, and motor vehicle accidents. The benefit of treating asymptomatic OSA patients, particularly with regard to cardiovascular outcomes, is controversial and more data are needed.

Leptin: Master Regulator of Biological Functions that Affects Breathing

Obesity is a global epidemic in developed countries accounting for many of the metabolic and cardiorespiratory morbidities that occur in adults. These morbidities include type 2 diabetes, sleep-disordered breathing (SDB), obstructive sleep apnea, chronic intermittent hypoxia, and hypertension. Leptin, produced by adipocytes, is a master regulator of metabolism and of many other biological functions including central and peripheral circuits that control breathing. By binding to receptors on cells and neurons in the brainstem, hypothalamus, and carotid body, leptin links energy and metabolism to breathing. In this comprehensive article, we review the central and peripheral locations of leptin's actions that affect cardiorespiratory responses during health and disease, with a particular focus on obesity, SDB, and its effects during early development. Obesity-induced hyperleptinemia is associated with centrally mediated hypoventilation with decrease CO₂ sensitivity. On the other hand, hyperleptinemia augments peripheral chemoreflexes to hypoxia and induces sympathoexcitation. Thus, "leptin resistance" in obesity is relative. We delineate the circuits responsible for these divergent effects, including signaling pathways. We review the unique effects of leptin during development on organogenesis, feeding behavior, and cardiorespiratory responses, and how undernutrition and overnutrition during critical periods of development can lead to cardiorespiratory comorbidities in adulthood. We conclude with suggestions for future directions to improve our understanding of leptin dysregulation and associated clinical diseases and possible therapeutic targets. Lastly, we briefly discuss the yin and the yang, specifically the contribution of relative adiponectin deficiency in adults with hyperleptinemia to the development of metabolic and cardiovascular disease. © 2020 American Physiological Society. Compr Physiol 10:1047-1083, 2020.

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

Obstructive sleep apnea (OSA) has many effects on subjective parameters of the disease, such as reduction in quality of life (QoL), sleep quality (SQ), and increases in daytime sleepiness. Studies have reported the beneficial effect of exercise training on OSA severity; however, whether it improves subjective parameters remains unclear. The purpose of the present review was to investigate the effect of exercise training on QoL, daytime sleepiness, and SQ in adults with OSA by summarizing the results of clinical trials. The study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was registered in PROSPERO. A systematic review of the PubMed, Scopus, and Cochrane (CENTRAL) databases was conducted. Risk of bias analysis was performed using the Cochrane tool, and Review Manager version 5.2 (R Foundation for Statistical Computing, Vienna, Austria) was used to perform the meta-analysis. Of the 1573 studies initially retrieved, 8 relevant studies with 228 participants were included in the analysis. The studies presented moderate risk of bias. Exercise training significantly improved QoL (mean difference, 12.9 [95% confidence interval (CI) 6.4 to 19.5]) and SQ (mean difference, -2.0 [95% CI -3.6 to -0.5]), and reduced daytime sleepiness (mean difference, -3.7 [95% CI -6.1 to -1.2]), and OSA severity (mean difference, -11.4 [95% CI -13.4 to -9.4 events/h]). Thus, physical exercise training was effective in improving subjective parameters and reducing the severity of OSA. Additional randomized clinical trials, however, should be performed to confirm these findings.

Apneas of Heart Failure and Phenotype-Guided Treatments: Part One: OSA

Sleep-disordered breathing (SDB), including OSA and central sleep apnea, is highly prevalent in patients with heart failure (HF). Multiple studies have reported this high prevalence in asymptomatic as well as symptomatic patients with reduced left ventricular ejection fraction (HFrEF), as well as in those with HF with preserved ejection fraction. The acute pathobiologic consequences of OSA, including exaggerated sympathetic activity, oxidative stress, and inflammation, eventually could lead to progressive left ventricular dysfunction, repeated hospitalization, and excessive mortality. Large numbers of observational studies and a few small randomized controlled trials have shown improvement in various cardiovascular consequences of SDB with treatment. There are no long-term randomized controlled trials to show improved survival of patients with HF and treatment of OSA. One trial of positive airway pressure treatment of OSA included patients with HF and showed no improvement in clinical outcomes. However, any conclusions derived from this trial must take into account several important pitfalls that have been extensively discussed in the literature. With the role of positive airway pressure as the sole therapy for SDB in HF increasingly questioned, a critical examination of long-accepted concepts in this field is needed. The objective of this review was to incorporate recent advances in the field into a phenotype-based approach to the management of OSA in HF.