Untreated Obstructive Sleep Apnea Syndrome Research Articles

An exploratory study evaluating the use of coping strategies while driving in obstructive sleep apnoea syndrome patients and controls.

Sleepiness while driving is potentially fatal, and it is recommended that a driver who starts to feel tired should stop and have a rest. However, some may use various countermeasures to try to stay alert. We devised a questionnaire that assessed various potential coping strategies that might be used against fatigue and compared them between obstructive sleep apnoea syndrome (OSAS) patients and controls and with sleepiness in general (Epworth Sleepiness Scale (ESS)), specifically while driving (Driving Sleepiness Scale (DSS)) and driving incidents. 119 untreated OSAS patients (male 82%, body mass index (BMI) 37±8 kg·m-2, ESS 14±5, DSS 3±2, oxygen desaturation index (ODI) 39±15) and 105 controls (male 70%, BMI 28±6 kg·m-2, ESS 4±3, DSS 7±6) matched for age and driving experience were recruited. All completed a questionnaire relating to their experience over the last year, which included sleepiness in general, sleepiness specifically while driving, 10 questions about various coping strategies they might adopt in order to avoid sleepiness and their history of incidents while driving. As compared to controls, nearly a third of OSAS patients (29.4%) used more than three coping strategies "frequently". OSAS patients who used more than three such strategies had worse ESS (17±4 versus 12±5, p<0.0001); were more likely to feel sleepy while driving (10±8 versus 5±7, p=0.0002) and had more reported accidents (22.85% versus 2.38%, p=0.0002) as compared to OSAS patients who used less than three strategies. There was no difference in patient demographics, severity of OSAS, driving experience or episodes of nodding at the wheel and reported near miss events. Untreated OSAS patients frequently use certain strategies which could be surrogate markers of sleepiness. Enquiring about such strategies in clinical practice may aid the clinician in identifying the patients who are at risk of driving incidents and to advise appropriately.

The complex relation between obstructive sleep apnoea syndrome, hypogonadism and testosterone replacement therapy.

Obstructive sleep apnoea syndrome (OSAS) is an under-recognized medical disease. The main risk factors for OSAS are male sex, older age, obesity, and metabolic syndrome, that are also associated with male hypogonadism (MH). Therefore, obesity has been classically identified as the most evident link between OSAS and MH. However, OSAS is per se linked to the development of MH by a combined effect of hypoxia, increased night-time awakenings, reduced sleep efficiency and fragmented sleep. Similarly, MH might represent a risk factor for OSAS, mainly related to sleep disturbances that are frequently associated with low testosterone. Data on testosterone replacement therapy (TRT) in patients with OSAS are limited. Nevertheless, TRT is generally contraindicated by guidelines in the presence of untreated or severe OSAS. TRT might in fact worse OSAS symptoms in different ways. Furthermore, OSAS has been proposed to be a risk factor for secondary polycythaemia and TRT might exacerbate polycythaemia. Therefore, TRT in hypogonadal men affected by untreated OSAS or severe OSAS should be considered with caution and in a personalised way. Nevertheless, the type and dosage of TRT should be considered, as short-term high-dose TRT might worsen OSAS, whereas long-term lower doses could eventually determine a clinical improvement of symptoms of OSAS. Here we reviewed the data on the association between OSAS, MH and TRT, including the opportunity of assessment of patients who develop signs and symptoms of OSAS during TRT by polysomnography.

Adrenal Hemorrhaging in a Patient with Severe Obstructive Sleep Apnea Syndrome with Elevated Plasma ACTH Levels.

Adrenal hemorrhaging (AH) is a rare condition characterized by bleeding into the suprarenal glands. A 62-year-old man with untreated obstructive sleep apnea syndrome (OSAS) was admitted to our hospital complaining of abdominal stiffness. He was diagnosed with left-sided AH and underwent adrenalectomy. Pre- and post-surgery, elevated plasma adrenocorticotropic hormone (ACTH) levels were observed. However, Cushing's syndrome and adrenal insufficiency were negative, and nasal continuous positive airway pressure (CPAP) normalized the plasma ACTH levels. Elevated ACTH levels are reportedly present in patients with OSAS. ACTH may be associated with the development of AH through the change in blood supply and other mechanisms.

The role of metalloproteinases in the pathogenesis of Obstructive Sleep Apnea Syndrome

Obstructive Sleep Apnea Syndrome (OSAS) is a common sleep-related breathing disorder. Untreated OSAS leads to significant health consequences, disturbed functioning in society, decreased efficiency in a workplace and increased risk of accidents at work and while driving. The main patomechanisms of OSAS development are hypoxia, oxidative stress and inflammatory process. Intermittent hypoxia in OSAS patients is associated with subsequent episodes of reoxygenation with simultaneous increase of reactive oxygen species and reactive nitrogen species that stimulate secretion of extracellular metalloproteinases (MMPs). These compounds belong to a group of endogenous proteolytic enzymes produced by structural cells of extracellular matrix (ECM) and by cells of inflammatory response as well. ECMs are made of collagen proteins and glycoproteins. They form a scaffold for tissues of the soft palate. MMPs break down collagen molecules, which results in flaccidity of tissues, including tissues of the soft palate. The results of scientific studies have shown that expression, secretion, and activeness of MMPs increase during hypoxia. Thus metalloproteinases may be involved in the process of upper airway tissue damage during the intermittent hypoxia in OSAS.

Positive Airway Pressure Therapy for Pediatric Obstructive Sleep Apnea.

Pediatric obstructive sleep apnea syndrome (OSAS) is a disorder of breathing during sleep, characterized by intermittent or prolonged upper airway obstruction that can disrupt normal ventilation and/or sleep patterns. It can affect an estimated 2–4% of children worldwide. Untreated OSAS can have far reaching consequences on a child’s health, including low mood and concentration as well as metabolic derangements and pulmonary vascular disease. Most children are treated with surgical intervention (e.g., first-line therapy, adenotonsillectomy); however, for those for whom surgery is not indicated or desired, or for those with postoperative residual OSAS, positive airway pressure (PAP) therapy is often employed. PAP therapy can be used to relieve upper airway obstruction as well as aid in ventilation. PAP therapy is effective in treatment of OSAS in children and adults, although with pediatric patients, additional considerations and limitations exist. Active management and care for various considerations important to pediatric patients with OSAS can allow PAP to be an effective and safe therapy in this population.

Paediatrics: how to manage obstructive sleep apnoea syndrome.

Obstructive sleep apnoea syndrome (OSAS) is defined as the intermittent reduction or cessation of airflow due to partial or complete obstruction of the upper airway during sleep. Paediatric OSAS has specific contributing factors, presenting symptoms and management strategies in various age groups. Untreated OSAS can lead to detrimental effects on neurocognitive development and cardiovascular and metabolic functions of a growing child. In the past decade, practice guidelines have been developed to guide the evaluation and management of OSAS. This article provides a narrative review on the current diagnostic and treatment options for paediatric OSAS. Alternative diagnostic tools other than the standard polysomnography are discussed. Adenotonsillectomy is considered the first-line therapy yet it is not suitable for treatment of all OSAS cases. Nocturnal non-invasive positive airway pressure ventilation is effective and could be the priority treatment for patients with complex comorbidities, residual OSAS post-adenotonsillectomy or obesity. However, intolerance and non-adherence are major challenges of positive airway pressure therapy especially in young children. There is increasing evidence for watchful waiting and other gentler alternative treatment options in mild OSAS. The role of anti-inflammatory drugs as the primary or adjunctive treatment is discussed. Other treatment options, including weight reduction, orthodontic procedures and myofunctional therapy, are indicated for selected patients. Nevertheless, the successful management of paediatric OSAS often requires a multidisciplinary team approach.

Efficacy of a Smart Antisnore Pillow in Patients with Obstructive Sleep Apnea Syndrome.

Objective Untreated obstructive sleep apnea syndrome (OSAS) increases the risk of cardiovascular, dementia, and motor vehicle accident events. However, continuous positive airway pressure (CPAP) which is the gold standard treatment is not acceptable for many patients with OSAS. Development of devices for the patients of nonadherence to CPAP is necessary. Materials and Methods We evaluated the effect of the smart antisnore pillow (SAP) in patients with OSAS in a prospective, noncontrolled, nonrandomized, pilot study. According to the apnea-hypopnea index (AHI), they were divided into two groups: mild-to-moderate OSAS group and severe OSAS group. Single-night polysomnography (PSG) with application of a SAP was performed. Thirty patients, 15 males and 15 females, 33–82 years old (mean age, 59.3 ± 12.9 years), completed the smart antisnore pillow therapy test. Among them, 23 patients had mild-to-moderate OSAS. Results The SAP significantly improved the snore number (p = 0.018), snore index (p = 0.013), oxygen denaturation index (p = 0.001), total AHI (p = 0.002), and supine AHI (p = 0.002) in the mild-to-moderate OSAS group, but there was no significant improvement in the severe OSAS group. Conclusions We concluded that the SAP is an effective positional therapy device for patients with OSAS of mild-to-moderate severity.

Sleep and Nocturia in Under Age 50 Male Patients with Obstructive Sleep Apnea Syndrome

Objectives To investigate the prevalence of nocturia in young patients with obstructive sleep apnea syndrome (OSAS) and to find out the risk factors of nocturia in the patients. Methods We enrolled 415 untreated male OSAS patients (apnea-hypopnea index, AHI ≥5/h on polysomnography) who were under 50 years old (mean age 37.5±8.0 years). Participants completed Korean version of Beck depression inventory II (K-BDI-II), Pittsburgh sleep quality index-Korean (PSQI-K), insomnia severity index (ISI), and Epworth sleepiness scale (ESS). Participants were classified into nocturia and non-nocturia group according to the following question “Do you find yourself waking up to urinate more than twice each night?” All information was compared between two groups. Results 22.7% (94/415) of patients reported to have nocturia. Patients with nocturia had higher score of K-BDI-II, PSQI-K, ISI, and ESS although their age and the proportion of consumption of alcohol or caffeine and metabolic diseases were not different from patients without nocturia. AHI was not significantly higher in nocturia group (38.0±29.2/h) than non-nocturia group (32.8±25.7/h, p=0.118), however, parameters indicating sleep quality were worse in nocturia group, i.e. lesser non-rapid eye movement sleep stage 3 (N3) sleep % and higher arousal index, total apnea index, and 90% oxygen desaturation index (ODI). 90% ODI and N3 sleep % were revealed to be independent factors associated with nocturia. Conclusions Considerable numbers of male OSAS patients who are under 50 years suffer from nocturia and they have worse sleep quality compared to non-nocturia patients. Higher oxygen desaturation and lesser N3 sleep % are highly predictive factors for nocturia rather than AHI in these patients. Keywords: Nocturia; Sleep apnea, obstructive; Sleep; Hypoxia

Perioperative care of the obese patient.

Obesity has become an increasing problem worldwide during the past few decades. Hence, surgeons and anaesthetists will care for an increasing number of obese patients in the foreseeable future, and should be prepared to provide optimal management for these individuals. This review provides an update of recent evidence regarding perioperative strategies for obese patients. A search for papers on the perioperative care of obese patients (English language only) was performed in July 2019 using the PubMed, Scopus, Web of Science and Cochrane Library electronic databases. The review focused on the results of RCTs, although observational studies, meta-analyses, reviews, guidelines and other reports discussing the perioperative care of obese patients were also considered. When data from obese patients were not available, relevant data from non-obese populations were used. Obese patients require comprehensive preoperative evaluation. Experienced medical teams, appropriate equipment and monitoring, careful anaesthetic management, and an adequate perioperative ventilation strategy may improve postoperative outcomes. Additional perioperative precautions are necessary in patients with severe morbid obesity, metabolic syndrome, untreated or severe obstructive sleep apnoea syndrome, or obesity hypoventilation syndrome; patients receiving home ventilatory support or postoperative opioid therapy; and obese patients undergoing open operations, long procedures or revisional surgery.

The severity of obstructive sleep apnea syndrome cannot predict the accumulation of brain amyloid by imaging with [11C]-Pittsburgh compound B PET computed tomography in patients with a normal cognitive function.

Disturbed sleep due to obstructive sleep apnea syndrome (OSAS) might accelerate amyloidβ (Aβ) deposition, which can be a crucial factor in Alzheimer's disease. We studied Aβ deposition in untreated OSAS patients with normal cognition. We performed polysomnography (PSG) and Aβ imaging with [11C]-Pittsburgh compound B PET computed tomography (11C-PiB PET CT) in 14 untreated OSAS patients (apnea-hypopnea index: 43.8 ± 26.3/h). The abnormal accumulation of enhanced 11C-PiB PET was observed only one patient with severe, but not the most severe. The OSAS severity alone may not predict Aβ deposition in OSAS patients with normal cognition.

Correlation of lung function and respiratory muscle strength with functional exercise capacity in obese individuals with obstructive sleep apnea syndrome.

To evaluate lung function and inspiratory muscle strength, correlating them with exercise tolerance, in obese individuals with obstructive sleep apnea syndrome (OSAS). The sample comprised 31 adult subjects with moderate-to-severe OSAS diagnosed by polysomnography. We used spirometry to measure FVC, FEV1, and FVC/FEV1 ratio, using pressure manometry to measure MIP and MEP. The incremental shuttle walk test (ISWT) and the six-minute walk test (6MWT) were used in order to determine functional exercise capacity. In this sample, the mean values for FVC (% of predicted), FEV1 (% of predicted): MIP, and MEP were 76.4 ± 12.3%, 80.1 ± 6.3%, 60.0 ± 21.9 cmH2O, and 81.3 ± 22.2 cmH2O, respectively. The mean distances covered on the ISWT and 6MWT were 221 ± 97 m and 480.8 ± 67.3 m, respectively. The ISWT distance showed moderate positive correlations with FVC (r = 0.658; p = 0.001) and FEV1 (r = 0.522; p = 0.003). In this sample of obese subjects with untreated OSAS, lung function, inspiratory muscle strength, and exercise tolerance were all below normal. In addition, we found that a decline in lung function, but not in respiratory muscle strength, was associated with exercise tolerance in these patients.

Correlation of lung function and respiratory muscle strength with functional exercise capacity in obese individuals with obstructive sleep apnea syndrome

ABSTRACTObjective:To evaluate lung function and inspiratory muscle strength, correlating them with exercise tolerance, in obese individuals with obstructive sleep apnea syndrome (OSAS). Methods:The sample comprised 31 adult subjects with moderate-to-severe OSAS diagnosed by polysomnography. We used spirometry to measure FVC, FEV1, and FVC/FEV1 ratio, using pressure manometry to measure MIP and MEP. The incremental shuttle walk test (ISWT) and the six-minute walk test (6MWT) were used in order to determine functional exercise capacity. Results:In this sample, the mean values for FVC (% of predicted), FEV1 (% of predicted): MIP, and MEP were 76.4 ± 12.3%, 80.1 ± 6.3%, 60.0 ± 21.9 cmH2O, and 81.3 ± 22.2 cmH2O, respectively. The mean distances covered on the ISWT and 6MWT were 221 ± 97 m and 480.8 ± 67.3 m, respectively. The ISWT distance showed moderate positive correlations with FVC (r = 0.658; p = 0.001) and FEV1 (r = 0.522; p = 0.003). Conclusions:In this sample of obese subjects with untreated OSAS, lung function, inspiratory muscle strength, and exercise tolerance were all below normal. In addition, we found that a decline in lung function, but not in respiratory muscle strength, was associated with exercise tolerance in these patients.

Matrix Metalloproteinase-9 Is a Predictive Factor for Systematic Hypertension and Heart Dysfunction in Patients with Obstructive Sleep Apnea Syndrome.

Patients with obstructive sleep apnea syndrome (OSAS) showed higher prevalence in cardiovascular diseases due to aberrant hypoxia and oxidative stress. However, not all OSAS patients end up with cardiovascular disorders, and identification of novel biomarker will be invaluable for differentiating patients at risk. Here we tested the serum matrix metalloproteinase-9 (MMP-9) levels in 47 untreated OSAS patients and found that the MMP-9 level was positively correlated with severity of OSAS, which was consistent with hypoxia degree and duration. Besides, the MMP-9 level was higher in patients complicated with systematic hypertension (P < 0.001). Furthermore, we selected those OSAS patients without any cardiovascular dysfunction (n = 35) and followed up for up to five years. By the end of follow-up, 12 patients had hypertension onset and 3 patients had left ventricular hypertrophy. By analyzing the clinical outcomes with MMP-9 expression, we demonstrated that high serum MMP-9 in OSAS patients was a risk factor for occurrence of cardiovascular diseases. In addition, we cultured the vascular endothelial cells (VEC) from rat aorta in hypoxia condition to investigate whether MMP-9 was elevated due to hypoxia in OSAS patients. Cellular results revealed that the expression, secretion, and activity of MMP-9 were all upregulated by hypoxia and can cleave the beta2-adrenergic receptor (β2AR) on VEC surface. Our results not only determined MMP-9 as a risk factor for cardiovascular diseases in OSAS patients, but also showed the possible involvement of hypoxia-MMP-9-β2AR signaling axis.

Melatonin Effects in REM Sleep Behavior Disorder Associated with Obstructive Sleep Apnea Syndrome: A Case Series.

REM sleep behavior disorder (RBD), with its main clinical symptoms of nightmares with dream-enacting behavior, is considered as a possible precursor of neurodegenerative disease. Obstructive Sleep Apnea Syndrome (OSAS) is known to be capable of provoking RBD-like symptoms by apneic event related arousals. The two sleep related pathologies must coincide in a relevant number of individuals because of overlapping prevalence in similar age groups. Until now RBD symptoms coexisting with OSAS are rarely described in scientific literature and in fact considered as OSAS mimicking RBD. We report four cases with a severe clinical RBD syndrome which were polysomnographically also diagnosed with concomitant OSAS (AHI range: 10.1 -53.2/h). Treatment with 2 mg prolonged release melatonin led to a relevant clinical improvement of RBD symptoms in all patients, so far untreated for the sleep related breathing disorder. Measure of REM sleep without atonia (RSWA) in polysomnography showed values ranging from 5.1 to 20.4% determined with the Montplaisir method. Surprisingly, RSWA values in PSG with melatonin were high, probably because of the still untreated OSAS. We presume that in patients with RBD and OSAS both pathologies contribute in varying degrees to the emergence of RBD symptoms by a destabilization of REM sleep. We suggest by consequence to consider a therapeutic strategy including the treatment of both disorders for an optimal therapeutic response.

Multiscale Entropy Analysis of Unattended Oximetric Recordings to Assist in the Screening of Paediatric Sleep Apnoea at Home

Untreated paediatric obstructive sleep apnoea syndrome (OSAS) can severely affect the development and quality of life of children. In-hospital polysomnography (PSG) is the gold standard for a definitive diagnosis though it is relatively unavailable and particularly intrusive. Nocturnal portable oximetry has emerged as a reliable technique for OSAS screening. Nevertheless, additional evidences are demanded. Our study is aimed at assessing the usefulness of multiscale entropy (MSE) to characterise oximetric recordings. We hypothesise that MSE could provide relevant information of blood oxygen saturation (SpO2) dynamics in the detection of childhood OSAS. In order to achieve this goal, a dataset composed of unattended SpO2 recordings from 50 children showing clinical suspicion of OSAS was analysed. SpO2 was parameterised by means of MSE and conventional oximetric indices. An optimum feature subset composed of five MSE-derived features and four conventional clinical indices were obtained using automated bidirectional stepwise feature selection. Logistic regression (LR) was used for classification. Our optimum LR model reached 83.5% accuracy (84.5% sensitivity and 83.0% specificity). Our results suggest that MSE provides relevant information from oximetry that is complementary to conventional approaches. Therefore, MSE may be useful to improve the diagnostic ability of unattended oximetry as a simplified screening test for childhood OSAS.

Prevalence of snoring and the risk of sleep apnea in hospital staff.

Untreated Obstructive sleep apnea syndrome (OSAS) as a common breathing sleep disorder results in impaired work performance. The economic burden of untreated OSAS accounts for billions of dollars per year. The aim of this study was to evaluate the prevalence of snoring and the risk of OSAS in healthcare system staff. This cross-sectional study was performed on 715 staff of Dr. Masih Daneshvari Hospital in 2012. The Berlin questionnaire was used to identify the prevalence of snoring and the risk of sleep apnea. Additional information, including demographic characteristics, night work, night sleep less than 4 hours, smoking, underlying disease, and quality of sleep were evaluated as well. The information was analyzed using SPSS 15. 12.6% reported snoring. 6.9% and 93.1% were categorized into the high and low risk groups for OSAS respectively. There was an association between the risk of OSAS and age group (P-value = 0.007), gender (P-value = 0.028), marital status (P-value = 0.008), educational level (P-value = 0.035), chronic disease (P-value = 0.008), night sleep less than 4 hours (P-value = 0.001), difficulty in staying asleep (P-value = 0.000) and waking up too early (P-value = 0.006). Even logistic regression analysis demonstrated the relationship between the risk of OSAS and night sleep less than 4 hours (P-value = 0.019) and difficulty in staying asleep (P-value = 0.009). The results showed that the risk of OSAS is significant in healthcare system staff. Hope to provide a special screening program for OSAS in a regular occupational examination.

Obstructive sleep apnea might trigger acute pulmonary embolism: results from a cohort study.

Obstructive sleep apnea (OSA) might be an independent risk factor for acute pulmonary embolism (APE). A prospective cohort study was conducted to investigate if APE is sleep-related in untreated OSA syndrome or not. 206 APE patients were evaluated by portable monitoring and polysomnography. APE symptoms which caused an arousal from sleep or occurred within the first hour after wake-up were considered to be sleep-related. APE manifestation is significantly more often sleep-related in patients with moderate or severe OSA compared to subjects with an apnea-hypopnea index ≤15/h (p<0.001). The relative risk of sleep-related APE increases with the severity of OSA. OSA might trigger APE, possibly reflecting a pathophysiological relationship between these two conditions.

Sindrome delle apnee ostruttive del sonno e rischio di incidenti stradali: doveri del medico e possibili responsabilità del paziente

[Obstructive Sleep Apnea Syndrome and road accident risk: physician’s duties and patient’s potential liability] Obstructive Sleep Apnea Syndrome (OSAS) is the most common sleep disorder associated with excessive daytime sleepiness (EDS), and it is estimated to affect 1,600,000 people in Italy. Untreated OSAS is significantly associated with an increased risk of driving accidents. This article reviews the main professional duties of physicians dealing with patients with OSAS, and the patient’s potential liability in case of sleep-related road accidents. Physician’s duties were divided into the following: 1. duties related to certification according to the law 120/2010 and the Decree 22 December 2015; and 2. duties related to patient education about the risks related to EDS and about his/her potential liability in case of driving accidents. The latter issue was reviewed in light of several Italian Supreme Court decisions about the criminal and civil liability in case of motor vehicle crashes due to sudden “sleep attack”. Finally, since in Italy there is not a specific law requiring physicians to report the drivers affected by OSAS associated with EDS, circumstances in which physicians may (or have to) inform driving licence authorities are discussed. Indiscriminate reporting of patients is not recommended, but it should be limited to selected and actually dangerous patients.

Clinical consequences and economic costs of untreated obstructive sleep apnea syndrome.

ObjectiveTo provide an overview of the healthcare and societal consequences and costs of untreated obstructive sleep apnea syndrome.Data sourcesPubMed database for English-language studies with no start date restrictions and with an end date of September 2014.MethodsA comprehensive literature review was performed to identify all studies that discussed the physiologic, clinical and societal consequences of obstructive sleep apnea syndrome as well as the costs associated with these consequences. There were 106 studies that formed the basis of this analysis.ConclusionsUndiagnosed and untreated obstructive sleep apnea syndrome can lead to abnormal physiology that can have serious implications including increased cardiovascular disease, stroke, metabolic disease, excessive daytime sleepiness, work-place errors, traffic accidents and death. These consequences result in significant economic burden. Both, the health and societal consequences and their costs can be decreased with identification and treatment of sleep apnea.Implications for practiceTreatment of obstructive sleep apnea syndrome, despite its consequences, is limited by lack of diagnosis, poor patient acceptance, lack of access to effective therapies, and lack of a variety of effective therapies. Newer modes of therapy that are effective, cost efficient and more accepted by patients need to be developed.

Effect of beta-blocker therapy on heart rate response in patients with hypertension and newly diagnosed untreated obstructive sleep apnea syndrome

BackgroundBeta1-receptor antagonists (BBs) are commonly administered in the treatment of cardiovascular disease (CVD). The reported benefits of BB use in CVD patients with concomitant obstructive sleep apnea (OSA) may be limited by their impact on apnea-induced bradycardias. Therefore the aim of the study was to test the influence of BBs on periapneic heart rate (HR) fluctuations in hypertensive patients with newly-detected and untreated OSA. MethodsWe studied 88 hypertensive patients (56 on BBs and 32 BB naive) with newly-diagnosed moderate-to-severe OSA who were free of major pulmonary comorbidities and did not require antiarrhythmic therapy. ECGs recorded during sleep were investigated for heart rate (HR) responses to apneas allowing to compare extreme HR accelerations and decelerations between the groups. ResultsAverage sleep-time HR was comparable in BB-naive (BB−) and BB-treated (BB+) patients. Direct comparisons showed that HR decelerations were also similar in the two subgroups (53.8±9.6 vs. 54.4±7.8bpm; P=0.78, for BB− and BB+, respectively) however, BBs blunted the OSA-induced HR accelerations (82.3±12.2 vs. 74.3±10.0; P=0.003). After adjusting for baseline HR and magnitude of desaturations, HR decelerations were more evident in BB-naive group whereas tachycardic responses remained blunted in the BB+ group. The incidence of ectopies and conduction abnormalities were comparable across two groups. ConclusionsBeta-blockers do not potentiate apnea-induced HR decelerations, attenuate apnea-induced increases in heart rate and do not influence incidence of ectopies and conduction abnormalities in patients with hypertension and moderate-to-severe, untreated OSA.