Effects of continuous positive airway pressure on blood pressure in patients with resistant hypertension and obstructive sleep apnea: a meta-analysis

Phenotypic Characterisation of Obstructive Sleep Apnoea in Acute Coronary Syndrome

BACKGROUND

Recent neutral randomised clinical trials have created clinical equipoise for treating obstructive sleep apnoea (OSA) for managing cardiovascular risk. The importance of defining the links between OSA and cardiovascular disease is needed with the aim of advancing the robustness of future clinical trials. We aimed to define the clinical correlates and characterise surrogate cardiovascular markers in patients with acute coronary syndrome (ACS) and OSA.

METHOD

Overall, 66 patients diagnosed with ACS were studied. Patients underwent an unattended polysomnogram after hospital discharge (median [interquartile range] 62 [37-132] days). The Epworth Sleepiness Scale, Berlin, and STOP-BANG questionnaires were administered. Surrogate measures of vascular structure and function, and cardiovascular autonomic function were conducted. Pulse wave amplitude drop was derived from the pulse oximetry signals of the overnight polysomnogram.

RESULTS

OSA (apnoea-hypopnea index [AHI] ≥5) was diagnosed in 94% of patients. Moderate-to-severe OSA (AHI≥15) was observed in 68% of patients. Daytime sleepiness (Epworth Sleepiness Scale ≥10) was reported in 17% of patients. OSA screening questionnaires were inadequate to identify moderate-to-severe OSA, with an area under the receiver operating characteristic curve of approximately 0.64. Arterial stiffness (carotid-femoral pulse wave velocity, 6.1 [5.2-6.8] vs 7.4 [6.6-8.6] m/s, p=0.002) and carotid intima-media thickness (0.8 [0.7-1.0] vs 0.9 [0.8-1.0] mm, p=0.027) was elevated in patients with moderate-to-severe OSA. After adjusting for age, sex and body mass index, these relationships were not statistically significant. No relationships were observed in other surrogate cardiovascular markers.

CONCLUSIONS

A high prevalence of OSA in a mostly non-sleepy population with ACS was identified, highlighting a gross underdiagnosis of OSA among cardiovascular patients. The limitations of OSA screening questionnaires highlight the need for new models of OSA screening as part of cardiovascular risk management. A range of inconsistent abnormalities were observed in measures of vascular structure and function, and these appear to be largely explained by confounding factors. Further research is required to elucidate biomarkers for the presence and impact of OSA in ACS patients.

Precision medicine approaches in obstructive sleep apnoea: The role of dentist-sleep physician partnerships

Obstructive Sleep Apnoea (OSA) is a common heterogenous sleep disorder that is associated with a wide range of comorbidities and consequences, including the development of neurocognitive and cardiometabolic disorders. The heterogeneity of OSA necessitates a precision medicine approach to accurately diagnose this condition and to effectively manage patients. One of the primary models of precision medicine is described by the P4 approach of predicting those who are susceptible to disease, preventing the occurrence of disease, personalizing treatment, and encouraging patients to participate in their individual healthcare journey. Recent advances in oral appliance therapy and OSA monitoring techniques have fostered an exciting opportunity for enhanced collaboration between dentists and sleep physicians to optimize OSA precision medicine care. This review aims to discuss the sources of heterogeneity among OSA patients, provide an overview of the growing applications of oral appliance therapy and tailored monitoring programs for OSA that are shifting treatment to a more personalized and participatory model of care, and outline the pivotal role of dentists in managing patients with OSA.

Obstructive sleep apnea -related hypertension: a review of the literature and clinical management strategy

Obstructive Sleep Apnea (OSA) and hypertension have a high rate of co-occurrence, with OSA being a causative factor for hypertension. Sympathetic activity due to intermittent hypoxia and/or fragmented sleep is the most important mechanisms triggering the elevation in blood pressure in OSA. OSA-related hypertension is characterized by resistant hypertension, nocturnal hypertension, abnormal blood pressure variability, and vascular remodeling. In particular, the prevalence of OSA is high in patients with resistant hypertension, and the mechanism proposed includes vascular remodeling due to the exacerbation of arterial stiffness by OSA. Continuous positive airway pressure therapy is effective at lowering blood pressure, however, the magnitude of the decrease in blood pressure is relatively modest, therefore, patients often need to also take antihypertensive medications to achieve optimal blood pressure control. Antihypertensive medications targeting sympathetic pathways or the renin-angiotensin-aldosterone system have theoretical potential in OSA-related hypertension, Therefore, beta-blockers and renin-angiotensin system inhibitors may be effective in the management of OSA-related hypertension, but current evidence is limited. The characteristics of OSA-related hypertension, such as nocturnal hypertension and obesity-related hypertension, suggests potential for angiotensin receptor-neprilysin inhibitor (ARNI), sodium-glucose cotransporter 2 inhibitors (SGLT2i) and glucose-dependent insulinotropic polypeptide receptor/ glucagon-like peptide-1 receptor agonist (GIP/GLP-1 RA). Recently, OSA has been considered to be caused not only by upper airway anatomy but also by several non-anatomic mechanisms, such as responsiveness of the upper airway response, ventilatory control instability, and reduced sleep arousal threshold. Elucidating the phenotypic mechanisms of OSA may potentially advance more personalized hypertension treatment strategies in the future. Clinical characteristics and management strategy of OSA-related hypertension. OSA obstructive sleep apnea, BP blood pressure, ABPM ambulatory blood pressure monitoring, CPAP continuous positive airway pressure, LVH left ventricular hypertrophy, ARB: angiotensin II receptor blocker, SGLT2i Sodium-glucose cotransporter 2 inhibitors, ARNI angiotensin receptor-neprilysin inhibitor, CCB calcium channel blocker, GIP/GLP-1 RA glucose-dependent insulinotropic polypeptide receptor and glucagon-like peptide-1 receptor agonist.

Long-term effect of obstructive sleep apnoea management on blood pressure in patients with resistant hypertension: the SARAH study

BACKGROUND

There is a close relationship between obstructive sleep apnoea (OSA) and resistant hypertension (RH). However, studies assessing the long-term effect of diagnosing and treating OSA on blood pressure (BP) control in these patients are lacking.

METHODS

To address this gap, we recruited 478 RH patients from hypertension units and followed them prospectively after they were screened for OSA through a sleep study. By performing 24-h ambulatory BP monitoring (ABPM) annually, the effect of OSA management was assessed.

RESULTS

The patients had a median (interquartile range (IQR)) age of 64.0 (57.2-69.0) years, 67% were males and most were nonsleepy, with a median (IQR) apnoea-hypopnoea index (AHI) of 15.8 (7.9-30.7) events·h-1. The median (IQR) follow-up time was 3.01 (2.93-3.12) years. At baseline, severe OSA was associated with uncontrolled BP, nocturnal hypertension and a nondipper circadian BP pattern. Moreover, these patients had higher BP values during follow-up than did patients in the other groups. However, among patients with moderate and severe OSA, the management of sleep disordered breathing, including the implementation of continuous positive airway pressure treatment, was associated with a reduction in 24-h ABPM parameters, especially night-time BP values, at the 1-year follow-up. These benefits were attenuated over time and only subjects with severe OSA maintained an ABPM night-time reduction at 3 years. Furthermore, clinical variables such as uncontrolled BP, sex and age showed a predictive value for the BP response at 1 year of follow-up.

CONCLUSION

A favourable long-term decrease in BP was detected by diagnosing and treating OSA in a cohort of RH patients from hypertension units, but over time this decrease was only partially maintained in severe OSA patients.

FOUND Trial: randomised controlled trial study protocol for case finding of obstructive sleep apnoea in primary care using a novel device

INTRODUCTION

Obstructive sleep apnoea (OSA) is a common, but underdiagnosed, sleep disorder. If untreated, it leads to poor health outcomes, including Alzheimer's disease, cancer, cardiovascular disease and all-cause mortality. Our aim is to determine the feasibility and cost-effectiveness of moving the testing for OSA into general practice and how general practitioner (GP)-based screening affects overall detection rates.

METHODS AND ANALYSIS

Randomised controlled trial of case finding of OSA in general practice using a novel Medicines and Healthcare products Regulatory Agency-registered device (AcuPebble SA100) compared with usual care with internal feasibility phase. A diverse sample of general practices (approximately 40) from across the West Midlands Clinical Research Network will identify participants from their records. Eligible participants will be aged 50-70 years with body mass index >30 kg/m2 and diabetes (type 1 or 2) and/or hypertension (office blood pressure >145/90 mm Hg or on treatment). They will exclude individuals with known OSA or chronic obstructive pulmonary disease, or those they deem unable to take part. After eligibility screening, consent and baseline assessment, participants will be randomised to either the intervention or control group. Participants in the intervention arm will receive by post the AcuPebble sleep test kit. Those in the control arm will continue with usual care. Follow-up questionnaires will be completed at 6 months. The study is powered (90%) to detect a 5% difference and will require 606 patients in each arm (713 will be recruited to each arm to allow for attrition). Due to the nature of the intervention, participants and GPs will not be blinded to the allocation.

OUTCOMES

Primary: Detection rate of moderate-to-severe OSA in the intervention group versus control group. Secondary: Time to diagnosis and time to treatment for intervention versus control group for mild, moderate and severe OSA; cost-effectiveness analysis comparing the different testing pathways.

ETHICS AND DISSEMINATION

The trial started on 1 November 2022. Ethical approval was granted from the South Central Oxford A Research Ethics Committee on 9 June 2023 (23/SC/0188) (protocol amendment version 1.3; update with amendment and approval to renumber to V2.0 on 29 August 2023). Patient recruitment began on 7 January 2024; initial planned end date will be on 31 April 2025.Results will be uploaded to the ISRCTN register within 12 months of the end of the trial date, presented at conferences, submitted to peer-reviewed journals and distributed via our patient and public involvement networks.The University of Warwick will act as the trial sponsor. The trial will be conducted in accordance with the Sponsor and Primary Care Clinical Trials Unit standard operating procedures.

TRIAL REGISTRATION NUMBER

ISRCTN 16982033.

Obstructive sleep apnea and cardiovascular risk

Patients with obstructive sleep apnea (OSA) experience repetitive episodes of upper airway obstruction due to recurrent collapse during sleep. This leads to intermittent hypoxia episodes, which, through complex pathophysiological mechanisms, trigger sympathetic overactivation, endothelial dysfunction, hypercoagulation, and metabolic dysregulation. Consequently, other cardiovascular risk factors such as hypertension, metabolic syndrome, and diabetes are induced. Furthermore, this enhances target organ damage, affecting the heart, arteries, and kidneys, leading to an increased risk of cardiovascular morbidity and mortality. Among the various treatments for OSA, Continuous Positive Airway Pressure (CPAP) has been extensively studied. To date, this treatment has shown mild benefits in reducing blood pressure, particularly noticeable in patients with resistant hypertension. Furthermore, CPAP treatment appears to reduce cardiovascular events, both in primary and secondary prevention, though this benefit is limited to individuals with good compliance (CPAP use ≥4h/night). Future research perspectives in OSA seem to focus on identifying patients in whom the condition significantly influences cardiovascular risk, thus determining those who would benefit the most from treatment in the reduction of cardiovascular risk.

Hypoxia-Induced Insulin Resistance Mediates the Elevated Cardiovascular Risk in Patients with Obstructive Sleep Apnea: A Comprehensive Review

Patients with obstructive sleep apnea (OSA) experience insulin resistance and its clinical consequences, including hypertriglyceridemia, reduced high density lipoprotein-associated cholesterol (HDL-c), visceral adiposity, hepatic steatosis, increased epicardial fat thickness, essential hypertension, glucose intolerance, increased risk for type 2 diabetes, chronic kidney disease, subclinical vascular damage, and increased risk for cardiovascular events. Obesity is a major contributor to OSA. The prevalence of OSA is almost universal among patients with severe obesity undergoing bariatric surgery. However, insulin resistance and its clinical complications occur in OSA patients irrespective of general obesity (body mass index). In OSA patients, apnea episodes during sleep induce oxyhemoglobin desaturation and tissue hypoxia. Insulin resistance is an adaptive response to tissue hypoxia and develops in conditions with limited tissue oxygen supply, including healthy subjects exposed to hypobaric hypoxia (high altitude) and OSA patients. Indicators of oxyhemoglobin desaturation have been robustly and independently linked to insulin resistance and its clinical manifestations in patients with OSA. Insulin resistance mediates the elevated rate of type 2 diabetes, chronic kidney disease, and cardiovascular disease unexplained with traditional cardiovascular risk factors present in OSA patients. Pathophysiological processes underlying hypoxia-induced insulin resistance involve hypoxia inducible factor-1 upregulation and peroxisome proliferator-activated receptor-gamma (PPAR- γ ) downregulation. In human adipose tissue, PPAR- γ activity promotes glucose transport into adipocytes, lipid droplet biogenesis, and whole-body insulin sensitivity. Silencing of PPAR- γ in the adipose tissue reduces glucose uptake and fat accumulation into adipocytes and promotes insulin resistance. In conclusion, tissue hypoxia drives insulin resistance and its clinical consequences in patients with OSA, regardless of body mass index.

Influence of intelligent management mode based on Internet of Things on self-management ability and prognosis of elderly patients with hypertensive heart disease: An observational study

Hypertensive heart disease was difficult to cure with drugs, and most patients had poor compliance, leading to recurrent disease and poor quality of life. The intelligent management mode based on the Internet of Things avoided the excessive dependence of the elderly patients on medical institutions in the traditional medical model and enabled patients to monitor themselves. This study aimed to explore the impact on self-management ability and prognosis of elderly patients with hypertensive heart disease. A total of 150 elderly patients with hypertensive heart disease who received treatment from April 2020 to April 2022 were selected and divided into control group (n = 75 cases) and observation group (n = 75 cases) by random number table method. The control group was given routine intervention, and the observation group was given intelligent management mode based on the Internet of Things. Blood pressure fluctuation, self-management ability, and prognosis of the 2 groups were compared after intervention. After the intervention of the intelligent management mode based on the Internet of Things, the systolic and diastolic blood pressure levels in the observation group were lower than those in the control group (P < .05). After intervention, the scores of self-management ability in diet control, self-care skills, rehabilitation exercise, and self-monitoring in observation group were higher than those in control group (P < .05). After intervention, the total incidence of chest tightness, dyspnea, arrhythmia, edema, and nausea in the observation group was 5 (6.67%), which was significantly lower than that in the control group 12 (16.00%) (P < .05). The application of intelligent management mode based on the Internet of Things could effectively improve patients' blood pressure level, improve patients' self-management ability, and significantly improve the prognosis, which was worthy of popularization and application.

Effect of Continuous Positive Airway Pressure on Blood Pressure in Patients with Resistant Hypertension and Obstructive Sleep Apnea: An Updated Meta-analysis

PURPOSE OF REVIEW

The effect of continuous positive airway pressure (CPAP) on resistant hypertension in patients at high risk with obstructive sleep apnea (OSA) needs further investigation. We aimed to determine the effect of CPAP on blood pressure in patients with resistant hypertension and OSA. Databases including PubMed, EMBASE, MEDLINE, the Cochrane Library, and CMB were searched. Data were pooled using a random-effects or fixed-effects model to derive weighted mean differences (WMDs) and 95% confidence intervals (CIs).

RECENT FINDINGS

A total of 12 trials and 718 participants were included. Compared with control, CPAP significantly reduced 24-h systolic blood pressure (SBP) (WMD: - 5.92 mmHg [ - 8.72, - 3.11]; P＜0.001), 24-h diastolic blood pressure (DBP) (WMD: - 4.44 mmHg [- 6.26 , - 2.62]; P  ＜0.001),   daytime SBP (WMD: - 5.76 mmHg [ - 9.16,  - 2.36]; P ＜0.001),  daytime DBP (WMD: - 3.92 mmHg [- 5.55,  - 2.30];  nighttime SBP (WMD: - 4.87 mmHg [ - 7.96 ,  - 1.78]; P = 0.002), and nighttime DBP (WMD: - 2.05 mmHg [- 2.99,  - 1.11]; P＜0.001) in patients with resistant hypertension and OSA. CPAP improved the blood pressure both in the short (＜3 months) and long term (≥ 3  months). No significant impact on mean heart rate was noted (WMD: -2.76 beats per min [- 7.50, 1.97]; P = 0.25). CPAP treatment was associated with BP reduction in patients with resistant hypertension and OSA.

Comorbidity of patients with noncommunicable diseases in general practice. Eurasian guidelines

Создание руководства поддержано Советом по терапевтическим наукам отделения клинической медицины Российской академии наук.

A risk prediction nomogram for resistant hypertension in patients with obstructive sleep apnea

Patients with obstructive sleep apnea (OSA) are liable to have resistant hypertension (RH) associated with unfavorable cardiovascular events. It is of necessity to predict OSA patients who are susceptible to resistant hypertension. Hence, we conducted a retrospective study based on the clinical records of OSA patients admitted to Yixing Hospital Affiliated to Jiangsu University from January 2018 to December 2022. According to different time periods, patients diagnosed between January 2018 and December 2021 were included in the training set (n = 539) for modeling, and those diagnosed between January 2022 and December 2022 were enrolled into the validation set (n = 259) for further assessment. The incidence of RH in the training set and external validation set was comparable (P = 0.396). The related clinical data of patients enrolled were collected and analyzed through univariate analysis and least absolute shrinkage and selection operator (LASSO) logistic regression analysis to identify independent risk factors and construct a nomogram. Finally, five variables were confirmed as independent risk factors for OSA patients with RH, including smoking, heart disease, neck circumference, AHI and T90. The nomogram established on the basis of variables above was shown to have good discrimination and calibration in both the training set and validation set. Decision curve analysis indicated that the nomogram was useful for a majority of OSA patients. Therefore, our nomogram might be useful to identify OSA patients at high risk of developing RH and facilitate the individualized management of OSA patients in clinical practice.

Secondary hypertension as a cause of treatment resistance

In secondary hypertension, elevated blood pressure is caused by a known and/or potentially treatable underlying disease.Although the prevalence of secondary hypertension depends on the patient population and the thoroughness of applied diagnostic approaches, arterial hypertension is classified in 90 to 95% as primary in nature. In young patients, individuals without a family history of hypertension, late onset of hypertension or worsening of a previous well-controlled hypertension as well as in patients who have a difficult to treat hypertension, the prevalence of secondary hypertension is significantly higher.Because the identification and the specific therapy of secondary hypertension may result in normalisation or improvement of elevated blood pressure in many cases, a targeted diagnostics is of great importance.

Sleep-Disordered Breathing and Prevalent Hypertension in Men With and Without HIV

BACKGROUND

Sleep-disordered breathing (SDB) is a known risk factor for hypertension. Despite the well-established link between HIV infection and hypertension, it remains to be determined whether HIV infection modifies the association between SDB and hypertension.

SETTING

The Multicenter AIDS Cohort Study.

METHODS

SDB was assessed using in-home polysomnography in 779 men (436 with and 343 without HIV). The apnea-hypopnea index (AHI) based on oxyhemoglobin desaturation threshold of ≥3% or arousal (AHI 3a ) and ≥4% (AHI 4 ) along with oxygen desaturation index (ODI) were used to quantify SDB severity. Hypertension was defined as a blood pressure ≥140/90 mm Hg, use of antihypertensive medication, or self-report of a clinical diagnosis. The associations between HIV, SDB, and hypertension were characterized using multivariable logistic regression.

RESULTS

The prevalence of hypertension and SDB (AHI 3a ≥ 5 events/hr) was high, with estimates of 53.8% and 82.8%, respectively. Among men without SDB, HIV was independently associated with hypertension, with an adjusted odds ratio (OR) of 3.05 [95% confidence interval (CI): 1.33 to 7.01]. In men without HIV, SDB was associated with hypertension (OR: 2.93; 95% CI: 1.46 to 5.86). No significant increase in the odds of hypertension was noted in men with both HIV and SDB compared with men with either factor alone, with an OR of 3.24 (95% CI: 1.62 to 6.47). These results were consistent across different measures used to define SDB (AHI 3a , AHI 4 , ODI 3 , and ODI 4 ).

CONCLUSIONS

Predictors of hypertension differed by HIV status. SDB was associated with hypertension in men without HIV, but not in men with HIV. Among men with HIV, SDB did not affect the odds of hypertension.

Effects of continuous positive airway pressure on cardiac events and metabolic components in patients with moderate to severe obstructive sleep apnea and coronary artery disease: a meta-analysis

STUDY OBJECTIVES

This meta-analysis aimed to systematically assess the effects of continuous positive airway pressure (CPAP) in secondary prevention of major cardiovascular events (MACEs) in patients with moderate-to-severe obstructive sleep apnea and coronary artery disease.

METHODS

PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov were searched for observational studies and randomized controlled trials that compared CPAP with usual care in patients with moderate-to-severe obstructive sleep apnea with coronary artery disease. The primary outcomes were MACEs, all-cause death, acute coronary syndrome, rehospitalization for heart failure, repeat revascularization, and arrhythmia.

RESULTS

A total of 11 studies (5 randomized controlled trials and 6 observational studies) with 5,410 patients reported outcomes of MACEs. Treatment with CPAP was associated with a modest risk reduction in MACEs (risk ratio [RR] 0.87, 95% confidence interval [CI] 0.78 to 0.98; P = .02). Similarly, CPAP significantly reduced the risk of all-cause and cardiovascular death by 23% (RR 0.77, 95% CI 0.60 to 0.99; P = .04; I2 = 0%). Subgroup analysis revealed that CPAP adherence time ≥ 4 hours/night had a greater benefit on MACEs by 42% (RR 0.58, 95% CI 0.42 to 0.79; P < .001; I2 = 0%) and repeat revascularization by 44% (RR 0.56, 95% CI 0.34 to 0.92; P = .02; I2 = 0%). Also, CPAP had a positive effect on systolic and diastolic blood pressure.

CONCLUSIONS

CPAP therapy might prevent subsequent MACEs and all-cause death among patients with moderate to severe obstructive sleep apnea and concomitant coronary artery disease. CPAP use exceeding 4 hours/night may add more benefits on MACEs, repeat revascularization, and blood pressure.

CLINICAL TRIAL REGISTRATION

Registry: PROSPERO database; Name: Effects of Continuous Positive Airway Pressure on Cardiovascular Events and Metabolic Components in Patients with Obstructive Sleep Apnea and Coronary Artery Disease; URL: https://www.crd.york.ac.uk/prospero/display_record.php?ID= CRD42020213546; Identifier: CRD42020213546.

CITATION

Yang D, Li L, Dong J, Yang W, Liu Z. Effects of continuous positive airway pressure on cardiac events and metabolic components in patients with moderate to severe obstructive sleep apnea and coronary artery disease: a meta-analysis. J Clin Sleep Med. 2023;19(12):2015-2025.

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.

Adherence to CPAP in summer to autumn predicts self-reported common cold symptoms in patients with obstructive sleep apnea in winter: A prospective observational study

OBJECTIVE

We conducted a prospective observational study to determine the relationship between adherence to continuous positive airway pressure (CPAP) and susceptibility to the common cold in moderate-to-severe obstructive sleep apnea (OSA) patients.

METHODS

We prospectively investigated the number of days with common cold symptoms from November 2019 to February 2020. The rate of CPAP use for 4 h/night in the preceding four months (July to October 2019) was used as a measure of CPAP adherence. Multiple generalized linear models were used to evaluate the association to days of common cold symptoms after controlling for demographic variables, habitual short sleep duration, and insomnia severity.

RESULTS

We included 123 outpatients (median age 63 years) with moderate-to-severe OSA treated with CPAP. In the multivariate generalized linear model, better CPAP adherence was independently significantly associated with days with fewer common cold symptoms (β = -0.248, P = 0.031); meanwhile, the severity of insomnia and habitual short sleep duration was not significantly associated with it. Subgroup analyses revealed that the association between CPAP adherence and days with common cold symptoms was also significant in young to middle-aged (<65 years) participants (β = -0.407, P = 0.005). In contrast, the association was negligible in older (≥65 years) participants.

CONCLUSIONS

CPAP adherence may be protective against viral infections in patients with moderate-to-severe OSA. This effect appears to be more pronounced in young to middle-aged patients with OSA.

Association of continuous positive airway pressure therapy on cardiac hypertrophy in patients with sleep apnea comorbid with type 2 diabetes mellitus

Previous reports indicated the therapeutic effect of chronic continuous positive airway pressure (CPAP) therapy on cardiac hypertrophy due to sleep apnea syndrome. However, little is known for cases involving diabetic complications. This retrospective observational study examined the effects of CPAP therapy on left ventricular hypertrophy (LVH) in patients with obstructive sleep apnea syndrome (OSAS) and type 2 diabetes mellitus (T2DM). For all cases, the observation period was 3 years from the time when the patient was introduced to CPAP therapy. Overall, 123 patients were divided into a good CPAP group (CPAP ≥4 h/day, n = 63) and non-adherence group (CPAP <4 h/day, n = 60). The mean CPAP usage times were 5.58 ± 1.23 and 1.03 ± 1.17 h/day in the good CPAP and non-adherence groups, respectively. Regression tendencies of the thickness of the left ventricular posterior (-0.30 ± 1.19 mm) and interventricular septal walls (-0.48 ± 1.22 mm) were observed in the good CPAP group. Hypertrophic tendencies of the left ventricular posterior wall (+0.59 ± 1.44 mm) and interventricular septal wall thickness (+0.59 ± 1.43) were observed in the non-adherence group. Left ventricular posterior wall thickness (coefficient: -0.254, p = 0.0376) and interventricular septal wall thickness (coefficient: -0.426, p = 0.0006) were more likely to be greater in the non-adherence group than in the good CPAP group. Patients in the non-adherence group with an apnea hypopnea index ≥30 had increased left ventricular posterior wall thickness (coefficient: -0.263, p = 0.0673) and interventricular septal wall thickness (coefficient: -0.450, p = 0.0011). In conclusion, appropriate CPAP therapy is an effective treatment for LVH in patients with T2DM and OSAS, especially for severe cases.

T cell receptor repertoire as a novel indicator for identification and immune surveillance of patients with severe obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is the most prevalent sleep disturbance that affects approximately 936 million people worldwide and leads to extensively increased incidence of cardiovascular disease, metabolic syndrome, neurological disorders, and traffic accidents. Severe OSA patients suffer a significantly higher risk of complications and worse comorbidity outcomes. Notwithstanding, with inadequate access to contact diagnosis based on polysomnography (PSG), numerous patients with severe sleep apnea have not been diagnosed, especially during the pandemic. Moreover, how the T cell immunity is impaired in OSA remains largely unknown.

Methods

We primarily investigated the T cell receptor (TCR) repertoires of 50 patients with severe OSA, 23 patients with mild-to-moderate OSA, 23 patients without OSA, and 157 healthy individuals, from their peripheral blood. Firstly, we compared the clinical characteristics, blood cell counts, the ratio of neutrophil-to-lymphocyte (NLR), platelet-to-lymphocyte (PLR), and CD4+/CD8+T cell count between groups. Then, we compared the diversity, clonotypes, unique VJ alleles in patients with different disease severity. Furthermore, by identifying a series of disease-associated amino acid sequences, we employed a repeated hold-out machine learning strategy to explore the optimal algorithm for calculating the TCR repertoire characteristic Index (OSA-TCI). We further confirmed its relation with clinical features by linear regression analysis. Moreover, in followup of severe OSA patients who accepted adherent non-invasive ventilation, we assessed the changes of TCR repertoires, OSA-TCI, ESS, NLR, PLR, and CD4+/CD8+T after therapy.

Results

We found an unexpected increase in diversity and clonotypes in the TCR repertoire of OSA patients. Furthermore, we successfully developed a novel indicator termed OSA-TCI to summarize the unique repertoire alteration, which provided 90% of sensitivity and 87% of specificity in distinguishing severe OSA. In rationalization, OSA-TCI was found correlated to AHI, BMI, hemoglobin, N1, N2 percentage of sleep, snoring, smoking and lowest oxygen saturation, but only independently related to AHI (R = 0.603) and smoking (R = 0.22). Finally, we observed OSA-TCI in the eight severe patients decreased significantly after home noninvasive ventilation for three months during follow-up, consistently in line with the TCR repertoire improvement. In contrast, NLR, PLR, and the ratio of CD4+/CD8+T cell count were found useless to diagnose and therapeutic surveillance of severe OSA.

Conclusions

Our study is the first to unveil the TCR repertoire alteration in OSA, indicates possible insidious autoimmune mechanisms underlying OSA, and suggests that TCR repertoires serve as a convenient peripheral blood biomarker for OSA assessment without long-time contact and facility/instrument occupation. It may shed light on future diagnostic, immunological, pathophysiological, and prognostic research on OSA.

The Association Between 24-Hour Blood Pressure Profiles and Dementia

Midlife hypertension increases risk for dementia. Around one third of adults have diagnosed hypertension; however, many adults are undiagnosed, or remain hypertensive despite diagnosis or treatment. Since blood pressure (BP) follows a circadian rhythm, ambulatory BP monitoring allows for the assessment of BP over a 24-hour period and provides an important tool for improving the diagnosis and management of hypertension. The measurement of 24-hour BP profiles, especially nocturnal BP, demonstrate better predictive ability for cardiovascular disease and mortality than office measurement. However, few studies have examined 24-hour BP profiles with respect to dementia risk. This is an important topic since improvements in BP management could facilitate the primary prevention of vascular cognitive impairment and dementia. Therefore, this review discusses the evidence linking BP to dementia, with a focus on whether the implementation of 24-hour BP measurements can improve risk prediction and prevention strategies. Pathways linking nocturnal BP to dementia are also discussed as are risk reduction strategies. Overall, limited research suggests an association between 24-hour BP elevation and poorer cognition, cerebral small vessel disease, and dementia. However, most studies were cross-sectional. Further evidence is needed to substantiate 24-hour BP profiles, over and above office BP, as predictors of vascular cognitive impairment and incident dementia.

Non-dipping blood pressure pattern is associated with higher risk of new-onset diabetes in hypertensive patients with obstructive sleep apnea: UROSAH data

OBJECTIVE

Impairment of circadian blood pressure (BP) patterns has been associated with cardiovascular risks and events in individuals with hypertension and in general populations, which are more likely to be found in obstructive sleep apnea (OSA). The aim of this study was to investigate the association of non-dipping BP pattern with new-onset diabetes in hypertensive patients with OSA, based on Urumqi Research on Sleep Apnea and Hypertension (UROSAH) data.

MATERIALS AND METHODS

This retrospective cohort study included 1841 hypertensive patients at least 18 years of age, who were diagnosed with OSA without baseline diabetes and had adequate ambulatory blood pressure monitoring (ABPM) data at enrollment. The exposure of interest for the present study was the circadian BP patterns, including non-dipping and dipping BP pattern, and the study outcome was defined as the time from baseline to new-onset diabetes. The associations between circadian BP patterns and new-onset diabetes were assessed using Cox proportional hazard models.

RESULTS

Among 1841 participants (mean age: 48.8 ± 10.5 years, 69.1% male), during the total follow-up of 12172 person-years with a median follow-up of 6.9 (inter quartile range: 6.0-8.0) years, 217 participants developed new-onset diabetes with an incidence rate of 17.8 per 1000 person-years. The proportion of non-dippers and dippers at enrollment in this cohort was 58.8% and 41.2%, respectively. Non-dippers were associated with higher risk of new-onset diabetes compared with dippers (full adjusted hazard ratio [HR]=1.53, 95% confidence interval [CI]: 1.14-2.06, P=0.005). Multiple subgroup and sensitivity analyses yielded similar results. We further explored the association of systolic and diastolic BP patterns with new-onset diabetes separately, and found that diastolic BP non-dippers were associated with higher risk of new-onset diabetes (full adjusted HR=1.54, 95% CI: 1.12-2.10, P=0.008), whereas for systolic BP non-dippers, the association was nonsignificant after adjusted the confounding covariates (full adjusted HR=1.35, 95% CI: 0.98-1.86, P=0.070).

CONCLUSIONS

Non-dipping BP pattern is associated with an approximately 1.5-fold higher risk of new-onset diabetes in hypertensive patients with OSA, suggesting that non-dipping BP pattern may be an important clinical implication for the early prevention of diabetes in hypertensive patients with OSA.

Symptoms Underestimate the Presence of Obstructive Sleep Apnea in Patients with Spontaneous Cerebrospinal Fluid Leaks of the Temporal Bone

OBJECTIVE

To determine the severity of symptoms and degree of obstructive sleep apnea (OSA) in patients with spontaneous cerebrospinal fluid (sCSF) leaks of the temporal bone given the known association between sCSF leaks and OSA.

STUDY DESIGN

Retrospective case review.

SETTING

Ambulatory clinics in tertiary referral centers.

PATIENTS

Polysomnogram testing in 34 consecutive patients who had been diagnosed with sCSF leaks of the temporal bone was examined. Diagnosis of sCSF leak was defined as biochemically confirmed CSF from middle ear fluid with no other obvious source.

INTERVENTION

Diagnostic.

MAIN OUTCOMES MEASURES

Patient characteristics (age, sex, body mass index, Epworth Sleepiness Scale score, presence of hypoxia, overnight change in blood pressure, and apnea hypopnea index [AHI]) were recorded. Diagnosis of OSA was defined as mild when AHI ≥5 and <15/h, moderate when AHI ≥15 and <30/h, and severe when AHI ≥30/h.

RESULTS

Of the 34 patients, 28 (82%) had a confirmed diagnosis of OSA. There was a male predisposition in those with OSA, and 17 of 28 (61%) were male. A majority were overweight, and the mean body mass index was 30.1 (SD, 4.8; range, 23.2-40) kg/m2. The mean severity of OSA was moderate, and the mean AHI was 28.7 (SD, 21.9; range, 5.4-92.8). Of the 28 patients, 13 with OSA (46%) had Epworth Sleepiness Scale scores higher than 8, suggesting that many were asymptomatic for excessive daytime sleepiness at the time of presentation.

CONCLUSION

OSA is highly prevalent among patients with sCSF leaks of the temporal bone. Patients with sCSF leaks irrespective of symptoms of OSA should undergo formal polysomnogram testing.

The multisystemic effects of oral appliance therapy for obstructive sleep apnea: A narrative review

Obstructive sleep apnea (OSA) is a chronic condition accompanied by repeated obstruction of the upper airway during sleep despite respiratory efforts, resulting in intermittent hypoxemia, altered sleep structure, and sympathetic activation. Previous studies have shown a significant association between OSA and general health issues such as cardiovascular diseases, endocrine disorders, neurocognitive function decline, and poor quality of life. Continuous positive airway pressure (CPAP) has been considered as the first line treatment for OSA. However, accumulating evidence supports the role of oral appliance (OA) therapy, including mandibular advancement devices, as an alternative option for snoring and OSA patients who do not comply with or refuse CPAP usage. Despite a generally favorable outcome of OA therapy for OSA related respiratory indices, studies focusing on the impact of systemic effects of OA therapy in OSA patients are relatively scarce compared with the extensive literature focusing on the systemic effects of CPAP. Therefore, this article aimed to provide an overview of the current evidence regarding the multisystemic effects of OA therapy for OSA.

Effect of continuous positive airway pressure treatment on ambulatory blood pressures in high-risk sleep apnea patients: a randomized controlled trial

STUDY OBJECTIVES

The long-term effect of continuous positive airway pressure (CPAP) on 24-hour blood pressure (BP) in high-risk patients with obstructive sleep apnea (OSA) is uncertain. We aimed to determine the effect of CPAP treatment on ambulatory BP in individuals with moderate or severe OSA and cardiovascular disease (CVD) or multiple CVD risk factors without severe sleepiness.

METHODS

In this randomized, controlled, parallel group study, 169 participants were randomly assigned to CPAP treatment or the control group. The primary outcome was the change in mean 24-hour systolic BP between groups from baseline to the average of 6 and 12 month measurements using mixed effect linear regression models.

RESULTS

The 24-hour systolic BP did not significantly differ by group, although there was a trend of decrease in the CPAP group (treatment effect -2.7 mm Hg [95% confidence interval -5.9 to 0.6]; P=0.105) compared with control. CPAP had the greatest effect on nighttime systolic BP (treatment effect -5.9 mm Hg [95% confidence interval -9.9 to -1.9]; P=0.004). Similar improvements in other nocturnal BP indices were observed.

CONCLUSIONS

In high risk patients with moderate-severe OSA without severe sleepiness, CPAP resulted in modest BP improvements over 6 to 12 months of follow-up, with possibly larger effects for nocturnal BP. Use of office blood pressure may under-estimate the effect of CPAP on BP profile in patients with OSA.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: Sleep Apnea Intervention for Cardiovascular Disease Reduction; Identifier: NCT01261390; URL: https://clinicaltrials.gov/ct2/show/NCT01261390.

Pathways of Microcirculatory Endothelial Dysfunction in Obstructive Sleep Apnea: A Comprehensive Ex Vivo Evaluation in Human Tissue

BACKGROUND

The mechanism and markers of cardiovascular disease (CVD) in obstructive sleep apnea (OSA) remain unknown. The microcirculation is the site of early changes in OSA patients who are free of CVD risk.

METHODS

Patients with newly diagnosed moderate to severe OSA (n = 7) were studied before and 12 weeks after intensive treatment with continuous positive airway pressure (CPAP), along with weight and age matched controls (n = 7). Microcirculatory vessels were isolated from gluteal biopsies and changes in critical functional genes were measured.

RESULTS

The following genes changed after 12 weeks of intensive CPAP therapy in the microcirculatory vessels: angiotensin receptor type 1 (AGTR-1) (11.6 (3.4) to 6 (0.8); P = 0.019); NADPH oxidase (NOX4) (0.85 (0.02) to 0.79 (0.11); P = 0.016); and dimethylarginine dimethylaminohydrolase (DDAH 1) (1 (0.31) to 0.55 (0.1); P = 0.028). Despite decreased nitric oxide (NO) availability as measured indirectly through brachial artery flow-mediated dilation, endothelial NO synthase (NOS3) did not change with CPAP. Other disease markers of OSA that changed with treatment in the microcirculation were endothelin, hypoxia inducible factor 1a, nuclear factor kappa B, interleukin-8, and interleukin-6.

CONCLUSIONS

In this ex vivo evaluation of the microcirculation of patients with OSA and no CVD risk, several pathways of CVD were activated supporting that OSA independently induces microcirculatory endothelial dysfunction and serving as disease-specific markers for future pharmacological targeting of OSA-related CVD risk. The findings support the role of renin-angiotensin activation and endothelial oxidative stress in the decreased microcirculatory NO availability in OSA.

Impact of sleep apnea and treatments on cardiovascular disease

Cardiovascular diseases (CVDs) are the leading causes of mortality worldwide, accounting for nearly 18 million deaths per year. Among other considerations, treating CVDs requires better understanding their risk factors. Sleep-disordered breathing, especially obstructive sleep apnea (OSA), is a likely contributor to several CVDs. We review key epidemiological data that addresses the link between OSA and cardiovascular outcomes such as hypertension, atrial fibrillation (AF), stroke, atherosclerosis, and heart failure (HF), and proposed pathophysiological mechanisms underlying this association. There are several biological pathways linking OSA and an increased propensity to cardiovascular diseases, and we discuss the evidence on the benefits of treatments of OSA on the prevalence of cardiovascular complications.

Effect of an Interdisciplinary Weight Loss and Lifestyle Intervention on Obstructive Sleep Apnea Severity: The INTERAPNEA Randomized Clinical Trial

Importance

Obesity is the leading cause of obstructive sleep apnea (OSA); however, the effects of weight loss and lifestyle interventions on OSA and comorbidities remain uncertain.

Objective

To evaluate the effect of an interdisciplinary weight loss and lifestyle intervention on OSA and comorbidities among adults with moderate to severe OSA and overweight or obesity.

Design, Setting, and Participants

The Interdisciplinary Weight Loss and Lifestyle Intervention for OSA (INTERAPNEA) study was a parallel-group open-label randomized clinical trial conducted at a hospital-based referral center in Granada, Spain, from April 1, 2019, to October 23, 2020. The study enrolled 89 Spanish men aged 18 to 65 years with moderate to severe OSA and a body mass index (calculated as weight in kilograms divided by height in meters squared) of 25 or greater who were receiving continuous positive airway pressure (CPAP) therapy. The sole inclusion of men was based on the higher incidence and prevalence of OSA in this population, the differences in OSA phenotypes between men and women, and the known effectiveness of weight loss interventions among men vs women.

Interventions

Participants were randomized to receive usual care (CPAP therapy) or an 8-week weight loss and lifestyle intervention involving nutritional behavior change, aerobic exercise, sleep hygiene, and alcohol and tobacco cessation combined with usual care.

Main Outcomes and Measures

The primary end point was the change in the apnea-hypopnea index (AHI) from baseline to the intervention end point (8 weeks) and 6 months after intervention. Secondary end points comprised changes in other OSA sleep-related outcomes, body weight and composition, cardiometabolic risk, and health-related quality of life.

Results

Among 89 men (mean [SD] age, 54.1 [8.0] years; all of Spanish ethnicity; mean [SD] AHI, 41.3 [22.2] events/h), 49 were randomized to the control group and 40 were randomized to the intervention group. The intervention group had a greater decrease in AHI (51% reduction; change, -21.2 events/h; 95% CI, -25.4 to -16.9 events/h) than the control group (change, 2.5 events/h; 95% CI, -2.0 to 6.9 events/h) at the intervention end point, with a mean between-group difference of -23.6 events/h (95% CI, -28.7 to -18.5 events/h). At 6 months after intervention, the reduction in AHI was 57% in the intervention group, with a mean between-group difference of -23.8 events/h (95% CI, -28.3 to -19.3 events/h). In the intervention group, 18 of 40 participants (45.0%) no longer required CPAP therapy at the intervention end point, and 6 of 40 participants (15.0%) attained complete OSA remission. At 6 months after intervention, 21 of 34 participants (61.8%) no longer required CPAP therapy, and complete remission of OSA was attained by 10 of 34 participants (29.4%). In the intervention vs control group, greater improvements in body weight (change, -7.1 kg [95% CI, -8.6 to -5.5 kg] vs -0.3 kg [95% CI, -1.9 to 1.4 kg]) and composition (eg, change in fat mass, -2.9 kg [95% CI, -4.5 to -1.3 kg] vs 1.4 kg [95% CI, -0.3 to 3.1 kg]), cardiometabolic risk (eg, change in blood pressure, -6.5 mm Hg [95% CI, -10.3 to -2.6 mm Hg] vs 2.2 mm Hg [95% CI, -2.1 to 6.6 mm Hg]), and health-related quality of life (eg, change in Sleep Apnea Quality of Life Index, 0.8 points [95% CI, 0.5-1.1 points] vs 0.1 points [95% CI, -0.3 to 0.4 points]) were also found at the intervention end point.

Conclusions and Relevance

In this study, an interdisciplinary weight loss and lifestyle intervention involving Spanish men with moderate to severe OSA and had overweight or obesity and were receiving CPAP therapy resulted in clinically meaningful and sustainable improvements in OSA severity and comorbidities as well as health-related quality of life. This approach may therefore be considered as a central strategy to address the substantial impact of this increasingly common sleep-disordered breathing condition.

Trial Registration

ClinicalTrials.gov Identifier: NCT03851653.

Prevention of Incident Hypertension in Patients With Obstructive Sleep Apnea Treated With Uvulopalatopharyngoplasty or Continuous Positive Airway Pressure: A Cohort Study

Purpose

To determine whether treatment with uvulopalatopharyngoplasty (UPPP) or continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea (OSA) prevents hypertension, compared to those not receiving any treatment.

Methods

A retrospective cohort study was conducted among 413 patients with OSA (age ≥ 35 years) at the Shuang Ho Hospital between 2009 and 2016. The patients were divided into three groups: UPPP, CPAP, and non-treatment groups. Data about the personal characteristics, history of comorbidities, and polysomnography (PSG) reports were collected at baseline. A Cox model with inverse probability of treatment weighting was used to adjust for confounders and baseline diversity.

Results

After multivariate adjustment and weighting for incident hypertension, patients in both the CPAP and UPPP groups showed a significant preventive effect on hypertension than in the non-treatment group. Moreover, patients in the CPAP group had lower event rates than those in the UPPP group.

Conclusion

UPPP can prevent the development of new-onset hypertension in patients with OSA. CPAP had a better preventive effect than UPPP. UPPP might be a good alternative for reducing the risk of the onset of hypertension when compliance to CPAP is poor.

Obstructive Sleep Apnea and Hypertension: Updates to a Critical Relationship

Purpose of Review

Obstructive sleep apnea (OSA) is an underdiagnosed illness linked to essential hypertension (HTN), resistant hypertension (r-HTN), and cardiovascular disease (CVD). This review provides updates on the epidemiology, pathophysiology, and treatments of OSA-associated HTN.

Recent Findings

Mild sleep apnea increases the risk for HTN. Eighty-nine percent of young patients aged 18–35 with HTN not attributed to secondary causes have underlying OSA. Home sleep studies are noninferior to formal polysomnography for OSA diagnosis. Nocturnal oxygen desaturation rate is positively correlated with HTN severity. Gut microbiome neo-colonization in response to high-fat diet cravings in patients with OSA alters immune function and worsens HTN. Carbonic anhydrase inhibitors and probiotics show newfound potential for OSA-associated HTN treatment. OSA recognition improves hospital outcomes after a STEMI. Hypoxia-inducible factor (HIF) transcription increases in a dose-dependent manner to hypoxia, and HIFs are strongly linked to cancer growth.

Summary

OSA and HTN are comorbid conditions with adversely connected pathophysiology including sympathetic hyperactivity, gut dysbiosis, proinflammation, endothelial damage, rostral fluid shifts, pharyngeal collapse, intravascular fluid retention, nocturnal energy expenditure, and metabolic derangements. The dose–response effect of OSA on HTN severity challenges blood pressure (BP) control, so those with refractory HTN should be screened for OSA.

Evaluation and Management of Secondary Hypertension

Hypertension is a major cause of cardiovascular morbidity and mortality globally. Many patients with hypertension have secondary causes of hypertension that merit further evaluation. For example, secondary hypertension can result in target organ damage to the heart, kidneys, and brain independent of the effects of blood pressure. Several causes benefit from targeted therapies to supplement first-line antihypertensive agents. However, secondary hypertension is often underrecognized. The goal of this review is to highlight optimal approaches to the diagnosis and management of common causes of secondary hypertension, including primary aldosteronism, renovascular hypertension, obstructive sleep apnea, and drug-induced hypertension.

Sleep Apnea Syndrome (SAS) Clinical Practice Guidelines 2020

The prevalence of sleep disordered breathing (SDB) is reportedly very high. Among SDBs, the incidence of obstructive sleep apnea (OSA) is higher than previously believed, with patients having moderate-to-severe OSA accounting for approximately 20% of adult males and 10% of postmenopausal women not only in Western countries but also in Eastern countries, including Japan. Since 1998, when health insurance coverage became available, the number of patients using continuous positive airway pressure (CPAP) therapy for sleep apnea has increased sharply, with the number of patients about to exceed 500,000 in Japan. Although the "Guidelines for Diagnosis and Treatment of Sleep Apnea Syndrome (SAS) in Adults" was published in 2005, a new guideline was prepared in order to indicate the standard medical care based on the latest trends, as supervised by and in cooperation with the Japanese Respiratory Society and the "Survey and Research on Refractory Respiratory Diseases and Pulmonary Hypertension" Group, of Ministry of Health, Labor and Welfare and other related academic societies, including the Japanese Society of Sleep Research, in addition to referring to the previous guidelines. Because sleep apnea is an interdisciplinary field covering many areas, this guideline was prepared including 36 clinical questions (CQs). In the English version, therapies and managements for SAS, which were written from CQ16 to 36, were shown. The Japanese version was published in July 2020 and permitted as well as published as one of the Medical Information Network Distribution Service (Minds) clinical practice guidelines in Japan in July 2021.

Sleep Apnea Syndrome (SAS) Clinical Practice Guidelines 2020

The prevalence of sleep-disordered breathing (SDB) is reportedly very high. Among SDBs, the incidence of obstructive sleep apnea (OSA) is higher than previously believed, with patients having moderate-to-severe OSA accounting for approximately 20% of adult males and 10% of postmenopausal women not only in Western countries but also in Eastern countries, including Japan. Since 1998, when health insurance coverage became available, the number of patients using continuous positive airway pressure (CPAP) therapy for sleep apnea has increased sharply, with the number of patients about to exceed 500,000 in Japan. Although the "Guidelines for Diagnosis and Treatment of Sleep Apnea Syndrome (SAS) in Adults" was published in 2005, a new guideline was prepared to indicate the standard medical care based on the latest trends, as supervised by and in cooperation with the Japanese Respiratory Society and the "Survey and Research on Refractory Respiratory Diseases and Pulmonary Hypertension" Group, of Ministry of Health, Labor and Welfare and other related academic societies, including the Japanese Society of Sleep Research, in addition to referring to the previous guidelines. Since sleep apnea is an interdisciplinary field covering many areas, this guideline was prepared including 36 clinical questions (CQs). In the English version, therapies and managements for SAS, which were written from CQ16 to 36, were shown. The Japanese version was published in July 2020 and permitted as well as published as one of the Medical Information Network Distribution Service (Minds) clinical practice guidelines in Japan in July 2021.

Immunoregulatory Effect of Short-Chain Fatty Acids from Gut Microbiota on Obstructive Sleep Apnea-Associated Hypertension

The intestine is the largest bacterial ecosystem and immune response organ of the human body. The microbiota regulates the metabolic and immune functions of the host through their metabolites. Short-chain fatty acids (SCFAs) are part of the metabolites of the gut microbiota (GM), providing energy to intestinal epithelial cells and regulating the immune system. A decrease in SCFA-producing bacteria, imbalanced effector T-helper cells (Th cells), and increasing corresponding inflammatory cytokine were found in both animal models and clinical patients with obstructive sleep apnea (OSA) and hypertension (HTN). Intervention with probiotics, prebiotics, or postbiotics in animal models simulating OSA-associated HTN restored blood pressure to normal, which allows the hypothesis that GM are involved in the pathophysiology of OSA-induced HTN patients through their metabolites' SCFAs; however, the exact regulatory mechanism is not completely clear. This review describes the potential mechanisms of SCFAs, a major metabolite of the GM, in the pathology of OSA-induced HTN, from the perspective of immune system regulation in the available studies.

Effect of CPAP treatment on BP in resistant hypertensive patients according to the BP dipping pattern and the presence of nocturnal hypertension

High heterogeneity in the blood pressure (BP) response to continuous positive airway pressure (CPAP) exists in patients with resistant hypertension (RH). Only nondipper normotensive and hypertensive patients exhibited BP reductions when treated with CPAP; the baseline BP dipping pattern has been proposed as a predictor of BP response to CPAP but has never been explored in patients with RH. This study aimed to assess the effect of CPAP on BP in subjects with RH with respect to BP dipping pattern or nocturnal hypertension. This is an ancillary study of the SARAH study. RH subjects with an apnea/hypopnea index (AHI) ≥ 15/h and who received CPAP treatment for 1 year were included. Subjects underwent a sleep study and ambulatory BP monitoring (ABPM) at baseline and at the 1-year follow-up. Eighty-nine RH subjects were included. The subjects were mainly male (77.5%) and obese, with a mean age of 66 years (25th-75th percentile; 59.0; 70.0) and an AHI of 32.7/h (25th-75th percentile; 25.0; 54.7). A total of 68.5% of participants were nondippers, and 71.9% had nocturnal hypertension. After 1 year of CPAP, no significant differences in ABPM parameters were observed between dippers and nondippers. According to nighttime BP, subjects with nocturnal normotension did not show significant changes in ABPM parameters, while nocturnal hypertensive subjects achieved a significant reduction in mean nighttime BP of -4.38 mmHg (-7.10 to -1.66). The adjusted difference between groups was 3.04 (-2.25 to 8.34), which was not significant. This study shows that the BP response to CPAP in patients with RH does not differ according to the BP dipping pattern (dipper and nondipper) and suggests a differential response according to the presence of nocturnal hypertension (ClinicalTrials.gov: NCT03002558).

Sleep-Disordered Breathing is frequently associated with idiopathic normal pressure hydrocephalus but not other types of hydrocephalus

STUDY OBJECTIVES

Previous studies have shown sleep-disordered breathing (SDB) to be highly prevalent in patients with idiopathic normal pressure hydrocephalus (iNPH). The current study aimed to estimate and compare the prevalence of SDB in patients with different types of hydrocephalus and test if SDB was associated with changed CO2.

METHODS

We investigated the prevalence of SDB in a prospective cohort of 48 hydrocephalus patients with nocturnal polysomnography (PSG). Twenty-three of the patients also had simultaneous CO2 measurements.

RESULTS

The prevalence of SDB was high in patients with iNPH, with moderate-to-severe SDB in 21/22 (96%) of the patients and an apnea-hypopnea index (AHI) of 43.5 (95% CI 33.8-52.2). Patients with pediatric-onset hydrocephalus had moderate-to-severe SDB in 7/16 (44%), with an AHI of 16.1 (95% CI 8.16-23.8). Except for one patient, all patients with adult-onset obstructive hydrocephalus (9/10) had normal respiration or mild SDB with an AHI of 8.4 (95% CI 5.5-10.5). None of the 23 patients measured with CO2 had elevated CO2 associated with SDB and had normal CO2 during sleep, with 40.8 ± 5.5 mmHg, 42.7 ± 4.1 mmHg, 34.5-45.8 mmHg for patients with iNPH, pediatric-onset, and adult-onset, respectively.

CONCLUSION

We found a high prevalence of SDB in patients with iNPH, confirming previous findings. We extended this with the finding that the prevalence of SDB in patients with other types of hydrocephalus is not significantly different from that in the general population. Additionally, we did not find elevations of CO2 associated with SDB or CO2 retention during sleep.

Effects of Pressure Control Device (SensAwake™) on Obstructive Sleep Apnea (OSA) Patients Who Remove the Mask for Unknown Reasons during Automatic Continuous Positive Airway Pressure (Auto-CPAP) Therapy: A Prospective Randomized Crossover Trial

Backgroundand Objectives: Obstructive sleep apnea (OSA) patients may remove their mask unconsciously during automatic continuous positive airway pressure (Auto-CPAP) therapy and therefore cannot receive good treatment. The discomfort from the airflow of Auto-CPAP may be one reason for interrupted sleep. Sens Awake (SA) can detect the arousal and lower the pressure to prevent patients from fully awakening from sleep. Materials and Methods: To evaluate the effect of SA, we designed a prospective, randomized, crossover trial comparing Auto-CPAP with and without SA on Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), Nasal Obstruction Symptom Evaluation (NOSE) Scale and recorded data from the auto-CPAP machine. Results: In the 25 patients who completed the study, the gender, age, body mass index, neck circumference, polysomnography data, and previous CPAP use were not significantly different between the two arms. The average and 90th percentile pressures were significantly lower during SA on (SA on vs. off: 6.9 ± 2.7 vs. 7.3 ± 2.6 [p = 0.032] and 8.6 ± 3.0 vs. 9.2 ± 2.9 [p = 0.002], respectively). The time used, days used, compliance, average and 90th percentile leaks, and the residual Apnea-Hypopnea Index (AHI) were not significantly changed between the SA on-and-off. Based on the subjective evaluation, PSQI, ESS, and NOSE were not significantly different between the SA on-and-off; however, based on additional analyses which were compared with baseline data, the ESS was significantly lower when the SA was on (SA on vs. baseline: 11.1 ± 6.1 vs. 13.2 ± 6.0 [p = 0.023]). Conclusions: CPAP therapy with or without two weeks of the SA had a similar effect on CPAP use, sleep quality, daytime sleepiness, and nasal obstruction. The SA may have a tendency to improve daytime sleepiness, but needs further study with a longer duration of treatment.

Sleep Disordered Breathing and Cardiovascular Disease: JACC State-of-the-Art Review

Sleep disordered breathing causes repetitive episodes of nocturnal hypoxemia, sympathetic nervous activation, and cortical arousal, often associated with excessive daytime sleepiness. Sleep disordered breathing is common in people with, or at risk of, cardiovascular (CV) disease including those who are obese or have hypertension, coronary disease, heart failure, or atrial fibrillation. Current therapy of obstructive sleep apnea includes weight loss (if obese), exercise, and positive airway pressure (PAP) therapy. This improves daytime sleepiness. Obstructive sleep apnea is associated with increased CV risk, but treatment with PAP in randomized trials has not been shown to improve CV outcome. Central sleep apnea (CSA) is not usually associated with daytime sleepiness in heart failure or atrial fibrillation and is a marker of increased CV risk, but PAP has been shown to be harmful in 1 randomized trial. The benefits of better phenotyping, targeting of higher-risk patients, and a more personalized approach to therapy are being explored in ongoing trials.

Incidence of hypertension in obstructive sleep apnea using hypopneas defined by 3 percent oxygen desaturation or arousal but not by only 4 percent oxygen desaturation

STUDY OBJECTIVES

This analysis determined ∼5-year incident hypertension rates using the 2017 American College of Cardiology/American Heart Association blood pressure (BP) guidelines in individuals with obstructive sleep apnea (OSA) with hypopneas defined by a ≥ 3% oxygen desaturation or arousal but not by a hypopnea criterion of ≥ 4% oxygen desaturation (4% only).

METHODS

Data were analyzed from participants in the Sleep Heart Health Study exam 2 (n = 1219) who were normotensive (BP ≤ 120/80 mm Hg) at exam 1. The AHI at exam 1 was classified into 4 categories of OSA severity: < 5, 5 ≤ 15, 15 ≤ 30, and ≥ 30 events/h using both the 3% oxygen desaturation or arousal and the 4% only definitions. Three definitions of hypertension-elevated BP (> 120/80 mm Hg), stage 1 (> 130/80 mm Hg), and stage 2 (> 140/90 mm Hg)-were used to determine incidence rates at exam 2.

RESULTS

Five-year follow-up was available for 476 participants classified as having OSA by the 3% oxygen desaturation or arousal criterion but not by the 4% only standard at exam 1. Incident hypertension using American College of Cardiology/American Heart Association-defined BP categories in these discordantly classified individuals were 15% (elevated BP), 15% (stage 1), and 6% (stage 2). Hypertensive medications were used in 4% of participants who were normotensive. The overall incidence rate of at least an elevated BP was 40% (191/476) in those with OSA defined using the 3% oxygen desaturation or arousal criterion but not by the 4% only criterion.

CONCLUSIONS

Use of the 4% only hypopnea definition resulted in the failure to identify a significant number of individuals with OSA who eventually developed hypertension and could have benefited from earlier diagnosis and treatment.

Effect of adenotonsillectomy on blood pressure in children with obstructive sleep apnea: a meta-analysis

BACKGROUND

While adenotonsillectomy (T&A) is widely recognized as the first-line therapy for pediatric obstructive sleep apnea (OSA), effects of T&A on blood pressure (BP) remain unclear. This meta-analysis evaluates the associations between T&A and BP in children with OSA.

METHODS

The study protocol was registered on PROSPERO (CRD42020154425). Two authors independently searched the PubMed, Medline, EMBASE, and Cochrane databases. The keywords used were "sleep apnea syndromes," "adenotonsillectomy," and "child." A random-effects model was applied to determine office systolic BP (SBP), diastolic BP (DBP), and ambulatory BP changes.

RESULT

Twelve studies with 1193 children were analyzed (mean age: 7.6 y; 54% boys). The apnea-hypopnea index significantly reduced of 9.4 events/h (95% CI, -12.0 to -6.8) after T&A. Office SBP (-0.24 mmHg; 95% CI, -1.64 to 1.16) and DBP (-1.65 mmHg; 95% CI, -3.47 to 0.17) did not decrease significantly after surgery. No significant decreases were observed in 24-h ambulatory BP after T&A. Subgroup analysis showed a significant postoperative decrease in office SBP (-6.23 mmHg; 95% CI, -7.78 to -4.67) and DBP (-7.93 mmHg; 95% CI, -10.37 to -5.48) among children with hypertension but a slight increase in office SBP (2.50 mmHg; 95% CI, 1.14 to 3.86) and DBP (1.98 mmHg; 95% CI, -0.02 to 3.98) in those without (P for heterogeneity < 0.001).

CONCLUSION

This meta-analysis suggests the office and ambulatory BP changes after T&A in children with OSA are trivial. Moreover, children with hypertension experience a significantly greater decrease in office BP than children without hypertension.

Continuous positive airway pressure adherence and blood pressure lowering in patients with obstructive sleep apnoea syndrome and nocturnal hypertension

PURPOSE

We investigated continuous positive airway pressure (CPAP) adherence and its association with the blood pressure (BP) and pulse rate changes in patients with obstructive sleep apnoea syndrome (OSAS) and hypertension.

MATERIALS AND METHODS

In a single-blind trial, patients were randomly assigned to CPAP or sham CPAP treatment for 3 months. We performed clinic, ambulatory and home BP measurements at baseline and during follow-up. CPAP adherence was assessed as the CPAP frequency per week and time per night. Non-adherence was defined as a CPAP use for <5 days/week or <4 h/night.

RESULTS

In the CPAP (n = 26) and sham CPAP groups (n = 21), the CPAP frequency was 5.5 and 4.8 days/week (p = 0.17), respectively, and the CPAP time was 5.0 and 4.1 h/night (p = 0.03), respectively. The corresponding prevalence of non-adherence was 46.2% and 66.7% (p = 0.16), respectively. The CPAP frequency but not time tended to be associated with the changes in BP and pulse rate at 3 months of follow-up, especially home systolic/diastolic BP in the CPAP group (3.2/1.3 mmHg greater reductions per 1 day increment, p ≤ 0.01). Adherent, compared with non-adherent patients, had greater reductions in BP or pulse rate at 3 months of follow-up. In the CPAP and sham CPAP groups combined, statistical significance was achieved for the adjusted between adherence and non-adherence differences in home systolic/diastolic BP (-5.0/-3.8 mmHg) and 24-h, daytime and night-time ambulatory pulse rate (-6.2, -7.8 and -4.4 beats/min, respectively, p ≤ 0.04).

CONCLUSION

CPAP adherence was associated with the BP lowering and pulse rate slowing effects, especially the CPAP frequency.

Sleep disordered breathing as a cause and consequence of stroke: A review of pathophysiological and clinical relationships

Stroke is the leading cause of death and disability globally. Sleep disordered breathing (SDB), a potentially modifiable risk factor of stroke, is highly prevalent in stroke survivors. Evidence supports a causal, bidirectional relationship between SDB and stroke. SDB may increase the risk of stroke occurrence and recurrence, and worsen stroke outcome. While SDB is associated with an increased incidence of hypertension and cardiac arrhythmias, both of which are traditional stroke risk factors, SDB is also an independent risk factor for stroke. A number of characteristics of SDB may increase stroke risk, including intermittent hypoxemia, sympathetic activation, changes in cerebral autoregulation, oxidative stress, systemic inflammation, hypercoagulability, and endothelial dysfunction. On the other hand, stroke may also cause new SDB or aggravate preexisting SDB. Continuous positive airway pressure treatment of SDB may have a beneficial role in reducing stroke risk and improving neurological outcome after stroke. The treatment should be considered as early as possible, particularly when SDB is present post-stroke. The goal of this review is to highlight the strong link between SDB and stroke and to raise awareness for practitioners to consider the possibility of SDB being present in all stroke survivors.

Continuous positive airway pressure improves blood pressure and serum cardiovascular biomarkers in obstructive sleep apnoea and hypertension

RATIONALE

The impact of treatment for obstructive sleep apnoea (OSA) on reduction of cardiovascular risk is unclear. This study aimed to examine the effect of continuous positive airway pressure (CPAP) on ambulatory blood pressure (BP) and subclinical myocardial injury in subjects with OSA and hypertension.

METHODS

Subjects with hypertension requiring at least three anti-hypertensive medications and moderate-severe OSA were enrolled. Eligible subjects were randomized (1:1) to receive either CPAP treatment or control (no CPAP) for eight weeks. Changes in ambulatory BP and serum biomarkers were compared. Stratified analysis according to circadian BP pattern was performed.

MAIN RESULTS

Ninety two subjects (75% men; age, 51±8 years; apnoea-hypopnoea index 40±8 events·h^-1, taking average of 3.4 anti-hypertensive drugs [range 3-6]) were randomised. The group on CPAP treatment, compared to the control group, demonstrated significant reduction in 24-h systolic BP (-4.4 mmHg, 95% CI -8.7 to -0.1, p=0.046), 24-h diastolic BP (-2.9 mmHg, 95% CI -5.5 to -0.2, p=0.032), daytime systolic BP (-5.4 mmHg, -9.7 to -1.0, p=0.016) and daytime diastolic BP (-3.4 mmHg, 95% CI -6.1 to -0.8, p=0.012). CPAP treatment was associated with significant BP lowering only in non-dippers, but not in dippers. Serum troponin I (mean difference -1.74 pg·mL^-1, 95% CI -2.97 to -0.5, p=0.006) and brain natriuretic peptide (-9.1 pg·mL^-1, 95% CI -17.6 to -0.6, p=0.036) were significantly reduced in CPAP compared to control group.

CONCLUSION

In a cohort with OSA and multiple cardiovascular risk factors including difficult-to-control hypertension, short-term CPAP treatment improved ambulatory BP and alleviated subclinical myocardial injury and strain.

Obstructive Sleep Apnea-Induced Neurogenic Nocturnal Hypertension: A Potential Role of Renal Denervation?

There is a bidirectional, causal relationship between obstructive sleep apnea (OSA) and hypertension. OSA-related hypertension is characterized by high rates of masked hypertension, elevated nighttime blood pressure, a nondipper pattern of nocturnal hypertension, and abnormal blood pressure variability. Hypoxia/hypercapnia-related sympathetic activation is a key pathophysiological mechanism linking the 2 conditions. Intermittent hypoxia also stimulates the renin-angiotensin-aldosterone system to promote hypertension development. The negative and additive cardiovascular effects of OSA and hypertension highlight the importance of effectively managing these conditions, especially when they coexist in the same patient. Continuous positive airway pressure is the gold standard therapy for OSA but its effects on blood pressure are relatively modest. Furthermore, this treatment did not reduce the cardiovascular event rate in nonsleepy patients with OSA in randomized controlled trials. Antihypertensive agents targeting sympathetic pathways or the renin-angiotensin-aldosterone system have theoretical potential in comorbid hypertension and OSA, but current evidence is limited and combination strategies are often required in drug resistant or refractory patients. The key role of sympathetic nervous system activation in the development of hypertension in OSA suggests potential for catheter-based renal sympathetic denervation. Although long-term, randomized controlled trials are needed, available data indicate sustained and relevant reductions in blood pressure in patients with hypertension and OSA after renal denervation, with the potential to also improve respiratory parameters. The combination of lifestyle interventions, optimal pharmacological therapy, continuous positive airway pressure therapy, and perhaps also renal denervation might improve cardiovascular risk in patients with OSA.

Diagnostic and Therapeutic Approach to Sleep Disorders, High Blood Pressure and Cardiovascular Diseases: A Consensus Document by the Italian Society of Hypertension (SIIA)

Hypertension is a major contributor to fatal/nonfatal cardiovascular diseases, and timely identification and appropriate management of factors affecting hypertension and its control are mandatory public health issues. By inducing neurohormonal alterations and metabolic impairment, sleep disorders have an impact on a variety of cardiovascular risk factors, including hypertension, and ultimately increase the risk of cardiovascular events. There is evidence that qualitative and quantitative sleep disorders are associated with resistant hypertension and with impaired circadian blood pressure variations. However, sleep disturbances are often unrecognized, or heterogeneity exists in their management by non-specialists in the field. This document by the Italian Society of Hypertension summarizes the updated evidence linking sleep disorders to hypertension and cardiovascular diseases, the major underlying mechanisms, and the possible management strategies. A simplified, evidence-based diagnostic and therapeutic algorithm for comorbid hypertension and common sleep disorders, namely obstructive sleep apnoea and insomnia, is proposed.

Effect of Sleep Disturbances on Blood Pressure

This review summarizes recent literature addressing the association of short sleep duration, shift work, and obstructive sleep apnea with hypertension risk, blood pressure (BP) levels, and 24-hour ambulatory BP. Observational studies demonstrate that subjectively assessed short sleep increases hypertension risk, though conflicting results are observed in studies of objectively assessed short sleep. Intervention studies demonstrate that mild and severe sleep restriction are associated with higher BP. Rotating and night shift work are associated with hypertension as shift work may exacerbate the detrimental impact of short sleep on BP. Further, studies demonstrate that shift work may increase nighttime BP and reduce BP control in patients with hypertension. Finally, moderate to severe obstructive sleep apnea is associated with hypertension, particularly resistant hypertension. Obstructive sleep apnea is also associated with abnormal 24-hour ambulatory BP profiles, including higher daytime and nighttime BP, nondipping BP, and a higher morning surge. Continuous positive airway pressure treatment may lower BP and improve BP dipping. In conclusion, efforts should be made to educate patients and health care providers about the importance of identifying and treating sleep disturbances for hypertension prevention and management. Empirically supported sleep health interventions represent a critical next step to advance this research area and establish causality.

Effects of Weight Loss on Obstructive Sleep Apnea Severity. Ten-Year Results of the Sleep AHEAD Study

Rationale: Weight loss is recommended to treat obstructive sleep apnea (OSA).Objectives: To determine whether the initial benefit of intensive lifestyle intervention (ILI) for weight loss on OSA severity is maintained at 10 years.Methods: Ten-year follow-up polysomnograms of 134 of 264 adults in Sleep AHEAD (Action for Health in Diabetes) with overweight/obesity, type 2 diabetes mellitus, and OSA were randomized to ILI for weight loss or diabetes support and education (DSE).Measurements and Main Results: Change in apnea-hypopnea index (AHI) was measured. Mean ± SE weight losses of ILI participants of 10.7 ± 0.7, 7.4 ± 0.7, 5.1 ± 0.7, and 7.1 ± 0.8 kg at 1, 2, 4, and 10 years, respectively, were significantly greater than the 1-kg weight loss at 1, 2, and 4 years and 3.5 ± 0.8 kg weight loss at 10 years for the DSE group (P values ≤ 0.0001). AHI was lower with ILI than DSE by 9.7, 8.0, and 7.9 events/h at 1, 2, and 4 years, respectively (P values ≤ 0.0004), and 4.0 events/h at 10 years (P = 0.109). Change in AHI over time was related to amount of weight loss, baseline AHI, visit year (P values < 0.0001), and intervention independent of weight change (P = 0.01). OSA remission at 10 years was more common with ILI (34.4%) than DSE (22.2%).Conclusions: Participants with OSA and type 2 diabetes mellitus receiving ILI for weight loss had reduced OSA severity at 10 years. No difference in OSA severity was present between ILI and DSE groups at 10 years. Improvement in OSA severity over the 10-year period with ILI was related to change in body weight, baseline AHI, and intervention independent of weight change.

Efficacy of continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea (OSA) and resistant hypertension (RH): Systematic review and meta-analysis

Approximately 70-85% of patients with resistant hypertension (RH) report obstructive sleep apnea (OSA). However, whether therapy with continuous positive airway pressure (CPAP) improves blood pressure (BP) in this population is not clear. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to determine the efficacy of CPAP in patients with OSA and RH. Two reviewers performed the literature search, risk of bias analysis, and data extraction. The pooled data were analyzed in a meta-analysis using the DerSimonian-Laird method. We calculated the mean difference (MD) in systolic blood pressure (SBP) and diastolic blood pressure (DBP) measured at 24 h and in the daytime and nighttime. We also evaluated changes in aortic stiffness and aldosterone excretion. A total of 10 RCTs and 606 participants were included. CPAP was associated with changes in 24-h SBP (-5.06 mmHg; CI, -7.98, -2.13), 24-h DBP (-4.21 mmHg; CI, -6.5, -1.93), daytime SBP (-2.34 mmHg; CI, -6.94, +2.27), daytime DBP (-2.14 mmHg; CI, -4.96, -0.67), nighttime SBP (-4.15 mmHg; CI, -7.01, -1.29), and nighttime DBP (-1.95 mmHg; CI, -3.32, -0.57). We found no benefit for aortic stiffness, but it did lead to a mild reduction in aldosterone secretion. CPAP therapy improved BP, especially nighttime BP, in this population.

Evaluation of a multicomponent grading system for obstructive sleep apnoea: the Baveno classification

New findings on pathophysiology, epidemiology, and outcome have raised concerns on the relevance of the apnoea-hypopnoea index (AHI) in the classification of obstructive sleep apnoea (OSA) severity. Recently, a multicomponent grading system decision integrating symptomatology and comorbidities (Baveno classification), was proposed to characterise OSA and to guide therapeutic decisions. We evaluated whether this system reflects the OSA population, whether it translates into differences in outcomes, and whether the addition of AHI improves the scheme. A total of 14 499 OSA patients from the European Sleep Apnoea Database cohort were analysed. The groups were homogeneously distributed and were found to clearly stratify the population with respect to baseline parameters. Differences in sleepiness and blood pressure between the groups were analysed in a subgroup of patients after 24-36 months of treatment. Group A (minor symptoms and comorbidities) did not demonstrate any effect of treatment on outcome. However, groups B (severe symptoms, minor comorbidities), C (minor symptoms, severe comorbidities) and D (severe symptoms and comorbidities) were associated with improvement in either or both parameters with treatment. The AHI is an essential prerequisite of the diagnosis; however, adding the AHI did not improve the classification. Rather, it was inferior with respect to guiding the treatment decision. Thus, the Baveno classification allows a better stratification of the OSA population and may provide a better guidance for therapeutic decisions in OSA.