Hypertension and obstructive sleep apnea

Screening for treatment-required sleep apnoea in patients with spinal cord injury within one year after injury in a rehabilitation setting

PURPOSE

The current study aims to assess the efficacy of the Stop-Bang Questionnaire (SBQ) in screening treatment-required sleep apnoea following Spinal Cord Injury (SCI). Additionally, we explore the performance of combined questionnaires and pulse oximetry to determine the most cost-effective method.

METHODS

The study employs a cross-sectional observational design. All patients admitted to in-hospital rehabilitation at the Spinal Cord Injury Centre of Western Denmark from September 2022 to February 2023 were continuously enrolled. Participating patients underwent SBQ screening, a standard sleep questionnaire, and cardiorespiratory monitoring, followed by an individual consultation with a physician.

RESULTS

During the study period, 35 SCI patients were admitted, with 24 providing informed consent. Among the 24 included patients, there was a 75% prevalence of mild to severe sleep apnoea, and 46% had treatment-required sleep apnoea. The SBQ missed only one patient with treatment-required sleep apnoea but misclassified eight patients. Combining SBQ with the pulse oximetry demonstrated the best performance in identifying patients with sleep apnoea.

CONCLUSION

The study indicates that SBQ alone is insufficient for screening treatment-required sleep apnoea. Exploratory analysis suggests that combining SBQ with a simple pulse oximetry measurement might enhance accuracy.

European Achondroplasia Forum Practical Considerations for Following Adults with Achondroplasia

Achondroplasia is a lifelong condition requiring lifelong management. There is consensus that infants and children with achondroplasia should be managed by a multidisciplinary team experienced in the condition. However, many people are lost to follow-up after the transition from paediatric to adult care, and there is no standardised approach for management in adults, despite the recent availability of international consensus guidelines. To address this, the European Achondroplasia Forum has developed a patient-held checklist to support adults with achondroplasia in managing their health. The checklist highlights key symptoms of spinal stenosis and obstructive sleep apnoea, both among the most frequent and potentially severe medical complications in adults with achondroplasia. The checklist acts as a framework to support individuals and their primary care provider in completing a routine review. General advice on issues such as blood pressure, pain, hearing, weight, adaptive aids, and psychosocial aspects are also included. The checklist provides key symptoms to be aware of, in addition to action points so that people can approach their primary care provider and be directed to the appropriate specialist, if needed. Additionally, the European Achondroplasia Forum offers some ideas on implementing the checklist during the transition from paediatric to adult care, thus ensuring the existing multidisciplinary team model in place during childhood can support in engaging individuals and empowering them to take responsibility for their own care as they move into adulthood.

Characterization of risk factors for obstructive sleep apnea and its association with absenteeism among nurses

PURPOSE

To characterize risk factors associated with obstructive sleep apnea (OSA) and its relationship with nurses' absenteeism.

METHODS

A cross-sectional study was conducted from 2018 to 2020 at a 1,000-bed academic hospital complex and biomedical research facility in Tehran, Iran. Participants were selected through consecutive sampling after obtaining ethical approval and informed consent. Data on demographics, medical conditions, occupational characteristics, and absenteeism were collected through face-to-face interviews. The STOP-Bang questionnaire was utilized to assess the probability of OSA. Statistical tests included the Mann-Whitney U, t-test, Chi-square, and multivariable regression.

RESULTS

In this study involving 304 nurses, the majority were female (81.3%), with an average age of 35. About 27 participants (8.9%) had a high probability of OSA, with male sex, older age, higher body mass index, neck circumference, and diastolic BP identified as the main determinants of OSA. Additionally, shift work and night shifts were associated with increased absenteeism, while sex showed no significant association with absenteeism rates among nurses.

CONCLUSION

Male sex, neck circumference (obesity), night shifts, and diastolic BP can predict OSA risk. However, unauthorized absence from work is not associated with a high risk for OSA (STOP-BANG ≥3) or the individual risk factors of OSA.

High risk for obstructive sleep apnea and risk of hypertension in military personnel: The CHIEF sleep study

BACKGROUND

Epidemiological studies have revealed an association between obstructive sleep apnea (OSA) and hypertension in the general population, while the association in military personnel was rarely investigated.

AIM

To examine the association between high risk for OSA and hypertension by phenotypes in military young adults.

METHODS

A total of 746 military personnel, aged 27.9 years, were included in the cardiorespiratory fitness and health in armed forces (CHIEF)-sleep study in Taiwan in 2020. Antihypertensive medications were not used by the subjects. High risk for OSA was assessed using the Berlin Questionnaire. Hypertension was defined using the 7th Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) and the 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines. The cutoff levels of systolic and diastolic blood pressure (SBP and DBP) for the 2017 ACC/AHA- and JNC 7-based guidelines were 130/140 mmHg and 80/90 mmHg, respectively. Hypertension phenotypes included isolated systolic and diastolic hypertension (ISH, high SBP only and IDH, high DBP only) and combined hypertension (both high SBP and DBP). Multivariable logistic regression analysis with adjustment for demographics, lifestyle and metabolic biomarkers.

RESULTS

The prevalence of high risk for OSA, JNC 7-based hypertension and 2017 ACC/AHA-based hypertension were 8.0%, 5.2% and 22.0%, respectively. Those with a high risk for OSA had a higher probability of JNC 7-based overall and combined hypertension (odds ratios (ORs) and 95% confidence intervals: 2.82 (1.07-7.42) and 7.54 (1.10-51.54), although the probabilities of ISH and IDH were unaffected by a high risk for OSA (ORs: 1.96 and 2.35, respectively, both P > 0.05). In contrast, no associations for any hypertension phenotypes were found according to the 2017 ACC/AHA criteria.

CONCLUSION

A high risk for OSA was associated with severe hypertension and combined hypertension among Asian military young adults.

The Interplay Between Sleep Disorders and Cardiovascular Diseases: A Systematic Review

Non-communicable diseases (NCDs) have emerged as the predominant cause of global mortality, resulting in a substantial annual loss of human lives. Among these conditions, cardiovascular diseases (CVD) stand out as the primary cause of death. The majority of CVD cases can be attributed to certain factors that, upon modification, have the potential to significantly decrease both the incidence and severity of the disease. For numerous years, the impact of sleep disorders on cardiovascular health has been a prominent subject of extensive discussion. Chronic sleep disturbances are known to have a range of negative health consequences, with the relationship between sleep apnea and hypertension being well-established through numerous studies. However, further exploration is needed to understand other disease associations with sleep apnea and to examine the impact of various sleep disorders, aside from sleep apnea, on cardiovascular health. This systematic review assesses the available evidence on the association between various sleep disorders and cardiovascular diseases by addressing the question: Do sleep disorders contribute to or exacerbate cardiovascular diseases? After a comprehensive review, we identified 122 articles. Following this initial review, seven papers directly aligned with our research topic. Subsequently, we meticulously assessed the remaining seven papers, all meeting our predetermined criteria. Our analysis showed a strong correlation between sleep disruptions and cardiovascular health. Numerous sleep disorders, such as narcolepsy, central sleep apnea, obstructive sleep apnea, and insomnia, have shown different effects on cardiovascular outcomes. Increased risks of illnesses such as acute coronary syndrome (ACS), hypertension, cardiovascular mortality, and coronary artery calcification were included in these consequences. This systematic review underscores the need for early identification and comprehensive management of sleep disturbances to mitigate their potential adverse effects on cardiovascular well-being. Integrating strategies that address sleep disorders and cardiovascular health is imperative in enhancing overall health outcomes. This study paves the way for more effective preventive and therapeutic approaches by focusing on the relationship between sleep disorders and cardiovascular diseases.

A Narrative Review of the Association of Obstructive Sleep Apnea with Hypertension: How to Treat Both When They Coexist?

Hypertension (HT) is a worldwide public health issue and an essential risk factor for cardiovascular and cerebrovascular diseases. Obstructive sleep apnea (OSA) is a condition characterized by recurrent episodes of apnea and hypopnea as a consequence of partial or complete obstruction of the upper airways due to anatomic and/or functional disturbances. There is mounting evidence of a relationship between OSA and HT. In patients with OSA, HT is predominantly nocturnal and characterized by high diastolic blood pressure and usually by a nondipping pattern. Optimizing the blood pressure control is recommended in the current guidelines as the first treatment option in hypertensive patients with OSA. Continuous positive airway pressure (CPAP) therapy may reduce blood pressure, albeit only slightly as a stand-alone treatment. CPAP, as an add-on treatment to antihypertensive medication, appears to be an efficient treatment modality when both conditions coexist. This narrative review aims to summarize the current perspectives on the association of OSA with HT and the treatment options available for adults with OSA-related HT.

Management of hypertension in obstructive sleep apnea

Obstructive sleep apnea (OSA) plays an important role in the development of hypertension. Thus, this review summarizes pharmacological and non-pharmacological approaches to blood pressure (BP) control in patients with OSA. Current treatments for OSA, such as continuous positive airway pressure, are effective at lowering BP. However, they only provide a modest BP reduction, and pharmacological treatment remains important for achieving optimal BP control. Furthermore, current guidelines for the treatment of hypertension do not make specific recommendations on pharmacological treatment protocols for controlling BP in patients with OSA. Moreover, the BP-lowering effects of various classes of antihypertensives may be different in hypertensive patients with OSA than in those without OSA due to the underlying mechanisms that promote hypertension in OSA. The acute and chronic increase in sympathetic nerve activity in patients with OSA explain the effectiveness of beta blockers in controlling BP in these patients. As activation of the renin-angiotensin-aldosterone system may also promote hypertension in OSA, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers have generally been found effective for lowering BP in hypertensive patients with OSA. The aldosterone antagonist spironolactone also produces a good antihypertensive response in patients with OSA and resistant hypertension. However, there are limited data available that compare the effects of various classes of antihypertensive medication on BP control in those with OSA, and most data have been obtained from small-scale studies. This demonstrates the need for large-scale randomized controlled trials to evaluate a range of BP-lowering regimens in patients with OSA and hypertension.

Obstructive sleep apnea, chronic obstructive pulmonary disease and hypertensive microvascular disease: a cross-sectional observational cohort study

Hypertensive microvascular disease is associated with an increased risk of diastolic heart failure, vascular dementia and progressive renal impairment. This study examined whether individuals with obstructive sleep apnoea (OSA) had more retinal hypertensive microvascular disease than those with chronic obstructive pulmonary disease (COPD) and hospital controls. This was a single-centre, cross-sectional, observational study of participants recruited consecutively from a general respiratory clinic and a general medical clinic. OSA was diagnosed on overnight polysomnography study (apnoea:hypopnoea index ≥ 5), and controls with COPD had a forced expiratory volume/forced vital capacity (forced expiratory ratio) < 70%. Individuals with both OSA and COPD were excluded. Hospital controls had no COPD on respiratory function testing and no OSA on specialist physician questioning. Study participants completed a medical questionnaire, and underwent resting BP measurement, and retinal photography with a non-mydriatic camera. Images were deidentified and graded for microvascular retinopathy (Wong and Mitchell classification), and arteriole and venular calibre using a semiautomated method at a grading centre. Individuals with OSA (n = 79) demonstrated a trend to a higher mean arterial pressure than other hospital patients (n = 143) (89.2 ± 8.9 mmHg, p = 0.02), and more microvascular retinopathy (p < 0.001), and narrower retinal arterioles (134.2 ± 15.9 μm and 148.0 ± 16.2 μm respectively, p < 0.01). Microvascular retinopathy and arteriolar narrowing were still more common in OSA than hospital controls, after adjusting for age, BMI, mean arterial pressure, smoking history and dyslipidaemia (p < 0.01, p < 0.01, respectively). Individuals with OSA demonstrated a trend to a higher mean arterial pressure than those with COPD (n = 132, 93.2 ± 12.2 mmHg and 89.7 ± 12.8 mmHg respectively, p = 0.07), and more microvascular retinopathy (p = 0.0001) and narrower arterioles (134.2 ± 15.9 and 152.3 ± 16.8, p < 0.01). Individuals with OSA alone had more systemic microvascular disease than those with COPD alone or other hospital patients without OSA and COPD, despite being younger in age.

Updated Blood Pressure Guidelines: Implications for Athletes

PURPOSE OF REVIEW

To review the prevalence, short- and long-term impact of exercise on blood pressure, and the evaluation and treatment of hypertension in competitive athletes.

RECENT FINDINGS

Due, in part, to inconsistencies in measurement and the definitions used, the true prevalence of hypertension is unknown as reports range from 0 to 83%. With recent changes in the blood pressure guidelines, the proportion of athletes that meet criteria for elevated blood pressure or stage 1 hypertension has increased dramatically with over one-third of collegiate and professional athletes meeting criteria for hypertension. Data consistently show that American-style football players, particularly linemen, display the highest rates of hypertension. These athletes typically have a larger body mass index, higher body fat percentage, and weight gain in serial follow-up. Many athletes with hypertension have traditional risk factors, and, to date, there is no evidence of a causal relationship between long-term sport participation and increased risk of developing hypertension. Many more athletes now meet criteria for hypertension, given the updated blood pressure guidelines. This should be taken as an opportunity for early intervention, as athletes are not immune to the development of cardiovascular risk factors and disease.

Interactions between Obstructive Sleep Apnea Syndrome Severity, Obesity, Sex Difference and Attention-Deficit/Hyperactivity Disorder on Health-Related Quality of Life: A Non-Interventional Prospective Observational Study

Obstructive sleep apnea syndrome (OSAS) severity, obesity, sex difference, and attention-deficit/hyperactivity disorder (ADHD) had a complex impact on health-related quality of life (HRQoL). However, the interactive effects among these features on HRQoL remained to be clarified. This study aimed to investigate the individual and interactive associations between the four characteristics of interest and HRQoL as determined by 36-Item Short Form Health Survey, Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS). This non-interventional, prospective, observational study enrolled a total of 132 patients with suspected OSAS for analysis. While OSAS severity and ADHD detected by adult ADHD Self-Report Scale, termed as screened ADHD, interact with each other, all the four studied features were individually associated with HRQoL. After adjusting for potential physiological and polysomnographic confounders, screened ADHD was independently correlated with PSQI > 5 (OR = 4.126, 95% CI, 1.490−11.424), mental component score < 50 (OR = 5.873, 95% CI, 2.262−15.251) and ESS > 10 (OR = 3.648, 95% CI, 1.738−7.657). Our results show that ADHD detection is necessary and should be incorporated into clinical practice for OSAS management.

Markers of ventricular repolarization and overall mortality in sleep disordered breathing

INTRODUCTION

Variability and prolongation of ventricular repolarization - measured by changes in QT interval and QT variability are independently associated with ventricular arrhythmias, sudden death, and mortality but such studies did not examine the role of sleep-disordered breathing. We aimed to determine whether sleep-disordered breathing moderated the association between measures of ventricular repolarization and overall mortality.

METHODS

Eight hundred participants were randomly selected from each of the following four groups in the Sleep Heart Health Study: mild, moderate, severe or no sleep disordered breathing (n = 200 each). Overnight electrocardiograms were analyzed for QTc duration and QT variability (standard deviation of QT intervals, normalized QT interval variance and the short-term interval beat-to-beat QT variability). Cox proportional hazards penalized regression modeling was used to identify predictors of mortality.

RESULTS

Eight hundred of 5600 participants were randomly selected. The participants (68 ± 10 years; 56.8% male) were followed for an average of 8.2 years during which time 222 (28.4%) died. QTc, SDQT, and QTVN were associated with the presence of SDB (p = 0.002, p = 0.014, and p = 0.024, respectively). After adjusting for covariates, the presence of sleep-disordered breathing did not moderate the association between QTc length, QT variability and mortality (p > 0.05).

CONCLUSION

Sleep-disordered breathing was associated with some measures of ventricular repolarization. However, sleep-disordered breathing was not an effect modifier for the relationship between QTc and QT variability and mortality.

Polysomnographic Evaluation of Sleep Bruxism Intensity and Sleep Architecture in Nonapneic Hypertensives: A Prospective, Observational Study

Sleep bruxism (SB) is a repetitive jaw muscle activity characterized by clenching or grinding of the teeth, which is classified under sleep-related movement disorders in the International Classification of Sleep Disorders—Third Edition. Because the potential common pathomechanism of SB and arterial hypertension is the activation of the sympathetic system as well as an increase in inflammatory factors, we aimed to examine the intensity of SB and the sleep architecture among patients with arterial hypertension. The study included a total of 91 Caucasian adult patients, among whom 31 had arterial hypertension diagnosed according to the current European Society of Cardiology/European Society of Hypertension (ESC/EHS) hypertension guidelines. The control group consisted of 61 normotensive patients. Patients with obstructive sleep apnea were excluded. A single full-night polysomnographic examination was conducted in the Sleep Laboratory, and then the results were analyzed based on the guidelines of the American Academy of Sleep Medicine. Bruxism episode index (BEI) was higher in the hypertensive group compared to normotensives. The groups also showed statistically significant differences in polysomnographic sleep indexes. Similar to BEI, arousal index, apnea–hypopnea index, and snoring were higher in hypertensives compared to normotensives. On the other hand, the mean and minimal oxygen saturation were lower in hypertensives compared to normotensives. A statistically significant positive correlation was observed between oxygen desaturation index and BEI in the hypertensive group, whereas this correlation was not statistically significant in the case of normotensives. In summary, nonapneic hypertensives had higher SB intensity, altered sleep architecture, decreased mean oxygen saturation, and increased snoring compared to normotensives. The results suggest that dental screening is necessary for patients with arterial hypertension, especially those presenting with the symptoms of SB.

Obstruktive Schlafapnoe und arterielle Hypertonie

Hintergrund

In Deutschland leiden rund 19 Mio. Patienten an einer diagnostizierten arteriellen Hypertonie (aHT). Die Schnittmenge zwischen Menschen mit aHT und obstruktiver Schlafapnoe (OSA) ist groß. Aufwachreaktionen und Hypoxämie im Rahmen einer OSA können zu einem gesteigerten Sympathikotonus und endothelialer Dysfunktion und somit zu aHT führen.

Fragestellung

Der vorliegende Übersichtsartikel soll die Zusammenhänge zwischen OSA und aHT sowie Behandlungsmöglichkeiten darstellen.

Materialien und Methoden

Es erfolgte eine Literaturrecherche von Original- und Übersichtsartikeln, die bis 2021 in der PubMed-Datenbank veröffentlicht wurden.

Ergebnisse

Obstruktive Schlafapnoe kann sowohl die Entstehung als auch die Verschlechterung einer aHT verursachen. Betroffene profitieren von einer CPAP-Behandlung mit einer durchschnittlichen Senkung des systolischen Blutdrucks um −4,4 mm Hg sowie des diastolischen Blutdrucks um −2,9 mm Hg. Prädiktoren für eine Reduktion des Blutdrucks unter kontinuierlicher Positivdrucktherapie (CPAP) sind junges Alter, therapieresistente aHT, schwere OSA-bedingte Sauerstoffentsättigungen und ein „Non-Dipping-Blutdruckmuster“.

Schlussfolgerung

Die adäquate Behandlung einer aHT fordert häufig einen multimodalen Ansatz. Neben einer medikamentösen antihypertensiven Therapie und einer Modifikation des Lebensstils sollte auch die Diagnose und gegebenenfalls die Behandlung einer OSA berücksichtigt werden.

Current and future strategies for diagnostic and management of obstructive sleep apnea

INTRODUCTION

Obstructive sleep apnea (OSA) is a common sleep disorder with multiple comorbidities including hypertension, diabetes, and cardiovascular disorders. Detected based on an overnight sleep study is called polysomnography (PSG); OSA still remains undiagnosed in majority of the population mainly attributed to lack of awareness. To overcome the limitations posed by PSG such as patient discomfort and overnight hospitalization, newer technologies are being explored. In addition, challenges associated with current management of OSA using continuous positive airway pressure (CPAP), etc. presents several pitfalls.

AREAS COVERED

Conventional and modern detection/management techniques including PSG, CPAP, smart wearable/pillows, bio-motion sensors, etc., have both pros and cons. To fulfill the limitations in OSA diagnostics, there is an imperative need for new technology for screening of symptomatic and more importantly asymptomatic OSA patients to reduce the risk of several associated life-threatening comorbidities. In this line, molecular marker-based diagnostics have shown great promises.

EXPERT OPINION

A detailed overview is presented on the OSA management and diagnostic approaches and recent advances in the molecular screening methods. The potentials of biomarker-based detection and its limitations are also portrayed and a comparison between the standard, current modern approaches, and promising futuristic technologies for OSA diagnostics and management is set forth.ABBREVIATIONS AHI: Apnea hypopnea index; AI: artificial intelligence; CAM: Cell adhesion molecules; CPAP: Continuous Positive Airway Pressure; COVID-19: Coronavirus Disease 2019; CVD: Cardiovascular disease; ELISA: Enzyme linked immunosorbent assay; HSAT: Home sleep apnea testing; IR-UWB: Impulse radio-ultra wideband; MMA: maxillomandibular advancement; PSG: Polysomnography; OSA: Obstructive sleep apnea; SOD: Superoxide dismutase; QD: Quantum dot.

Effect of Maternal Obstructive Sleep Apnea-Hypopnea on 24-Hour Blood Pressure, Nocturnal Blood Pressure Dipping and Arterial Stiffness in Hypertensive Disorders of Pregnancy

Rationale: Maternal obstructive sleep apnea-hypopnea (OSAH) is associated with hypertensive disorders of pregnancy (HDP). Attenuation of the normal nocturnal blood pressure (BP) decline (non-dipping) is associated with adverse pregnancy outcomes. OSAH is associated with nocturnal non-dipping in the general population, but this has not been studied in pregnancy. We therefore analyzed baseline data from an ongoing RCT (NCT03309826) assessing the impact of OSAH treatment on HDP outcomes, to evaluate the relationship of OSAH to 24-h BP profile, in particular nocturnal BP dipping, and measures of arterial stiffness.

Methods: Women with a singleton pregnancy and HDP underwent level II polysomnography. Patients with OSAH (apnea-hypopnea index (AHI) ≥ 5 events/h) then underwent 24-h ambulatory BP monitoring and arterial stiffness measurements (applanation tonometry, SphygmoCor). Positive dipping was defined as nocturnal systolic blood pressure (SBP) dip ≥ 10%. The relationships between measures of OSAH severity, measures of BP and arterial stiffness were evaluated using linear regression analyses.

Results: We studied 51 HDP participants (36.5 ± 4.9 years, BMI 36.9 ± 8.6 kg/m²) with OSAH with mean AHI 27.7 ± 26.4 events/h at 25.0 ± 4.9 weeks’ gestation. We found no significant relationships between AHI or other OSA severity measures and mean 24-h BP values, although BP was generally well-controlled. Most women were SBP non-dippers (78.4%). AHI showed a significant inverse correlation with % SBP dipping following adjustment for age, BMI, parity, gestational age, and BP medications (β = −0.11, p = 0.02). Significant inverse correlations were also observed between AHI and DBP (β = −0.16, p = 0.01) and MAP (β = −0.13, p = 0.02) % dipping. Oxygen desaturation index and sleep time below SaO₂ 90% were also inversely correlated with % dipping. Moreover, a significant positive correlation was observed between carotid-femoral pulse wave velocity (cfPWV) and REM AHI (β = 0.02, p = 0.04) in unadjusted but not adjusted analysis.

Conclusion: Blood pressure non-dipping was observed in a majority of women with HDP and OSAH. There were significant inverse relationships between OSAH severity measures and nocturnal % dipping. Increased arterial stiffness was associated with increasing severity of OSAH during REM sleep in unadjusted although not adjusted analysis. These findings suggest that OSAH may represent a therapeutic target to improve BP profile and vascular risk in HDP.

Influence of obstructive sleep apnea on auditory event-related potentials

PURPOSE

To evaluate the influence of obstructive sleep apnea (OSA) on the P300 response of auditory event-related potentials (ERPs) and to correlate the electrophysiological findings with OSA severity.

METHODS

Patients with no OSA and mild, moderate, and severe OSA according to polysomnography (PSG) with normal hearing and no comorbidities were studied. Individuals with a body mass index (BMI) ≥ 40 kg/m², hypertension, diabetes, dyslipidemia, the use of chronic medications, and a risk of hearing loss were excluded. All patients underwent full PSG and auditory ERP measurement using the oddball paradigm with tone burst and speech stimuli. For P300 analysis (latencies and amplitudes), normal multiple linear regression models were adjusted with the groups (No OSA, Mild OSA, Moderate OSA, Severe OSA), age, BMI, and Epworth score as explanatory variables.

RESULTS

We studied 54 individuals (47 males) aged 35 ± 8 years with a BMI of 28.4 ± 4.3 kg/m². Patients were divided according to the apnea-hypopnea index (AHI) derived from PSG into no OSA (n = 14), mild (n = 16), moderate (n = 12), and severe OSA (n = 12) groups. Patients with severe OSA presented prolonged P300 latencies with tone burst stimuli compared to patients with no OSA and those with mild and moderate OSA.

CONCLUSION

Severe OSA is associated with impairment of the P300 response of auditory ERPs, suggesting a decrease in the processing speed of acoustic information that may be mediated by the level of somnolence.

Role of olfactory receptor78 in carotid body-dependent sympathetic activation and hypertension in murine models of chronic intermittent hypoxia

Chronic intermittent hypoxia (CIH) is a hallmark manifestation of obstructive sleep apnea (OSA), a widespread breathing disorder. CIH-treated rodents exhibit activation of the sympathetic nervous system and hypertension. Heightened carotid body (CB) activity has been implicated in CIH-induced hypertension. CB expresses high abundance of olfactory receptor (Olfr) 78, a G-protein coupled receptor. Olfr 78 null mice exhibit impaired CB sensory nerve response to acute hypoxia. Present study examined whether Olfr78 participates in CB-dependent activation of the sympathetic nervous system and hypertension in CIH-treated mice and in hemeoxygenase (HO)-2 null mice experiencing CIH as a consequence of naturally occurring OSA. CIH-treated wild-type (WT) mice showed hypertension, biomarkers of sympathetic nerve activation, and enhanced CB sensory nerve response to hypoxia and sensory long-term facilitation (sLTF), and these responses were absent in CIH-treated Olfr78 null mice. HO-2 null mice showed higher apnea index (AI) (58 ± 1.2 apneas/h) than WT mice (AI = 8 ± 0.8 apneas/h) and exhibited elevated blood pressure (BP), elevated plasma norepinephrine (NE) levels, and heightened CB sensory nerve response to hypoxia and sLTF. The magnitude of hypertension correlated with AI in HO-2 null mice. In contrast, HO-2/Olfr78 double null mice showed absence of elevated BP and plasma NE levels and augmented CB response to hypoxia and sLTF. These results demonstrate that Olfr78 participates in sympathetic nerve activation and hypertension and heightened CB activity in two murine models of CIH.NEW & NOTEWORTHY Carotid body (CB) sensory nerve activation is essential for sympathetic nerve excitation and hypertension in rodents treated with chronic intermittent hypoxia (CIH) simulating blood O₂ profiles during obstructive sleep apnea (OSA). Here, we report that CIH-treated mice and hemeoxygenase (HO)-2-deficient mice, which show OSA phenotype, exhibit sympathetic excitation, hypertension, and CB activation. These effects are absent in Olfr78 null and Olfr78/HO-2 double null mice.

Obstructive sleep apnea in Norwegian adults with achondroplasia: a population-based study

Background

Previous studies have found a high prevalence of obstructive sleep apnea (OSA) in children with achondroplasia, but clinical studies on this complication in adults with achondroplasia are lacking.

Objectives

This population-based, cross-sectional study investigated the prevalence, severity, and predictive factors of OSA in Norwegian adults with achondroplasia.

Methods

We collected clinical data on 49 participants. Participants without a preexisting diagnosis of OSA had an overnight sleep registration. OSA was defined as an apnea–hypopnea index (AHI) ≥ 5 plus characteristic clinical symptoms, or AHI ≥ 15. We used the Berlin Questionnaire to assess clinical symptoms of OSA.

Results

OSA was found in 59% (29/49) of the participants (95% confidence interval 44 to 73%), of whom 59% (17/29) had moderate to severe OSA (AHI ≥ 15), and 48% (14/29) were previously undiagnosed. Variables predictive of OSA were: excessive daytime sleepiness; unrested sleep; loud snoring; observed nocturnal breathing stops; hypertension; age > 40 years; and BMI > 30 kg/m².

Conclusion

OSA was highly prevalent in Norwegian adults with achondroplasia, which we believe is representative of this population worldwide. Follow-up of adults with achondroplasia should include assessment of symptoms and signs of OSA, with a low threshold for conducting an overnight sleep registration if findings suggestive of OSA are present.

Smart Mandibular Advancement Device for Intraoral Monitoring of Cardiorespiratory Parameters and Sleeping Postures

Obstructive sleep apnea (OSA), as a highly prevalent sleep disorder, causes several serious health complaints. It has been proved that using intraoral mandibular advancement devices (MADs) during sleep is an efficient treatment for OSA. However, due to limited number of sleep study laboratories, effectiveness of MAD therapy is not regularly monitored. This paper proposes a smart MAD with the capability of continuously monitoring of cardiorespiratory parameters as well as sleeping postures and breathing routes. In this regard, a flexible hybrid wireless sensing platform based on the intraoral photoplethysmography (PPG), temperature and accelerometry monitoring is developed. It is qualitatively and quantitatively discussed that the intraorally captured PPG signals by the smart MAD have similar features as the ones received from the conventional anatomical position, i.e., the left index fingertip. Extensive experimental measurements indicate that the proposed smart MAD can estimate heart-rate (HR), respiration rate (RR) and blood oxygen saturation (SpO₂) with the maximum mean-absolute-errors of 2.4 bpm, 2.52 breaths/min, and 0.8%, respectively, in comparison to the reference measurements, while such a capability is not dependent on subject's positions and breathing routes. It is also shown that the smart MAD can readily identify different sleeping postures, namely, supine, left, right, and prone and breathing routes. The reliability and stability of the proposed smart MAD's measurements are proved by examining a group of subjects. The proposed smart MAD has potential to monitor the effectiveness of MAD treatment and eliminate untreated OSA without the requirement of attaching an extra monitoring platform to the patient's body.

Assessment of Nocturnal Autonomic Cardiac Imbalance in Positional Obstructive Sleep Apnea. A Multiscale Nonlinear Approach

Positional obstructive sleep apnea (POSA) is a major phenotype of sleep apnea. Supine-predominant positional patients are frequently characterized by milder symptoms and less comorbidity due to a lower age, body mass index, and overall apnea-hypopnea index. However, the bradycardia-tachycardia pattern during apneic events is known to be more severe in the supine position, which could affect the cardiac regulation of positional patients. This study aims at characterizing nocturnal heart rate modulation in the presence of POSA in order to assess potential differences between positional and non-positional patients. Patients showing clinical symptoms of suffering from a sleep-related breathing disorder performed unsupervised portable polysomnography (PSG) and simultaneous nocturnal pulse oximetry (NPO) at home. Positional patients were identified according to the Amsterdam POSA classification (APOC) criteria. Pulse rate variability (PRV) recordings from the NPO readings were used to assess overnight cardiac modulation. Conventional cardiac indexes in the time and frequency domains were computed. Additionally, multiscale entropy (MSE) was used to investigate the nonlinear dynamics of the PRV recordings in POSA and non-POSA patients. A total of 129 patients (median age 56.0, interquartile range (IQR) 44.8-63.0 years, median body mass index (BMI) 27.7, IQR 26.0-31.3 kg/m2) were classified as POSA (37 APOC I, 77 APOC II, and 15 APOC III), while 104 subjects (median age 57.5, IQR 49.0-67.0 years, median BMI 29.8, IQR 26.6-34.7 kg/m2) comprised the non-POSA group. Overnight PRV recordings from positional patients showed significantly higher disorderliness than non-positional subjects in the smallest biological scales of the MSE profile (τ = 1: 0.25, IQR 0.20-0.31 vs. 0.22, IQR 0.18-0.27, p < 0.01) (τ = 2: 0.41, IQR 0.34-0.48 vs. 0.37, IQR 0.29-0.42, p < 0.01). According to our findings, nocturnal heart rate regulation is severely affected in POSA patients, suggesting increased cardiac imbalance due to predominant positional apneas.

Obstructive Sleep Apnea, Hypertension, and Cardiovascular Risk: Epidemiology, Pathophysiology, and Management

PURPOSE OF REVIEW

Given the rising prevalence of obstructive sleep apnea (OSA), we aimed to review the epidemiologic and pathophysiologic relationship of OSA, hypertension, and cardiovascular disease, and to summarize recent advances in the treatment of OSA.

RECENT FINDINGS

OSA is associated with an elevated risk of hypertension and cardiovascular disease. Several pathophysiologic factors contribute to the relationship between OSA and vascular risk, including neurohormonal dysregulation, endothelial dysfunction, and inflammation. While CPAP reduces blood pressure, it has not been demonstrated to reduce cardiovascular risk. The combination of CPAP and weight loss has a synergistic effect on blood pressure and several metabolic parameters. Adherence to CPAP is poor across studies, potentially contributing to the attenuation of perceived cardiovascular benefit from CPAP therapy. A greater emphasis on adherence to CPAP and the combination of CPAP and weight loss are central to reducing cardiovascular risk among individuals with OSA.

Genetic and environmental factors on heart rate, mean arterial pressure and carotid intima-media thickness: A longitudinal twin study

BACKGROUND

Heart rate (HR), mean arterial pressure (MAP) and carotid intima-media thickness (cIMT) are moderately heritable cardiovascular traits, but the environmental effects on the longitudinal change of their heritability have never been investigated.

METHODS

368 Italian and Hungarian twins (107 monozygotic, 77 dizygotic) underwent oscillometric measurement and B-mode sonography of bilateral carotid arteries in 2009/2010 and 2014. Within- -individual/cross-study wave, cross-twin/within-study wave and cross-twin/cross-study wave correlations were estimated, and bivariate Cholesky models were fitted to decompose the total variance at each wave and covariance between study waves into additive genetic, shared and unique environmental components.

RESULTS

For each trait, a moderate longitudinal stability was observed, with within-individual/crosswave correlations of 0.42 (95% CI: 0.33-0.51) for HR, 0.34 (95% CI: 0.24-0.43) for MAP, and 0.23 (95% CI: 0.12-0.33) for cIMT. Cross-twin/cross-wave correlations in monozygotic pairs were all significant and substantially higher than the corresponding dizygotic correlations. Genetic continuity was the main source of longitudinal stability, with across-time genetic correlations of 0.52 (95% CI: 0.29-0.71) for HR, 0.56 (95% CI: 0.31-0.81) for MAP, and 0.36 (95% CI: 0.07-0.64) for cIMT. Overlapping genetic factors explained respectively 57%, 77%, and 68% of the longitudinal covariance of the HR, MAP and cIMT traits.

CONCLUSIONS

Genetic factors have a substantial role in the longitudinal change of HR, MAP and cIMT; however, the influence of unique environmental factors remains relevant. Further studies should better elucidate whether epigenetic mechanisms have a role in influencing the stability of the investigated traits over time.

The epidemiology of obstructive sleep apnoea and cardiovascular disease

Obstructive sleep apnoea, the most common form of sleep-disordered breathing, is highly prevalent in patients with cardiovascular disease. The last 30 years has seen a plethora of large scale epidemiological studies investigating the relationship between sleep apnoea and cardiovascular outcomes. This review highlights the key epidemiological studies addressing the links between sleep apnoea and hypertension, cardiac arrhythmias, cerebrovascular disease, coronary artery disease, heart failure and pulmonary hypertension, with a particular focus on some of the most recent reports.

X-search: an open access interface for cross-cohort exploration of the National Sleep Research Resource

BACKGROUND

The National Sleep Research Resource (NSRR) is a large-scale, openly shared, data repository of de-identified, highly curated clinical sleep data from multiple NIH-funded epidemiological studies. Although many data repositories allow users to browse their content, few support fine-grained, cross-cohort query and exploration at study-subject level. We introduce a cross-cohort query and exploration system, called X-search, to enable researchers to query patient cohort counts across a growing number of completed, NIH-funded studies in NSRR and explore the feasibility or likelihood of reusing the data for research studies.

METHODS

X-search has been designed as a general framework with two loosely-coupled components: semantically annotated data repository and cross-cohort exploration engine. The semantically annotated data repository is comprised of a canonical data dictionary, data sources with a data dictionary, and mappings between each individual data dictionary and the canonical data dictionary. The cross-cohort exploration engine consists of five modules: query builder, graphical exploration, case-control exploration, query translation, and query execution. The canonical data dictionary serves as the unified metadata to drive the visual exploration interfaces and facilitate query translation through the mappings.

RESULTS

X-search is publicly available at https://www.x-search.net/ with nine NSRR datasets consisting of over 26,000 unique subjects. The canonical data dictionary contains over 900 common data elements across the datasets. X-search has received over 1800 cross-cohort queries by users from 16 countries.

CONCLUSIONS

X-search provides a powerful cross-cohort exploration interface for querying and exploring heterogeneous datasets in the NSRR data repository, so as to enable researchers to evaluate the feasibility of potential research studies and generate potential hypotheses using the NSRR data.

Vascular Response During Mental Stress in Sedentary and Physically Active Patients With Obstructive Sleep Apnea

STUDY OBJECTIVES

To compare vascular function of sedentary (SED) versus physically active (ACTIVE) patients with obstructive sleep apnea (OSA) during rest and mental stress.

METHODS

Patients with untreated OSA without other comorbidities were classified into SED and ACTIVE groups according to the International Physical Activity Questionnaire. Blood pressure (BP), heart rate (HR), forearm blood flow (FBF) (plethysmography), and forearm vascular conductance (FVC = FBF / mean BP × 100) were continuously measured at rest (4 minutes) followed by 3 minutes of mental stress (Stroop Color Word Test).

RESULTS

We studied 40 patients with OSA (men = 24, age = 50 ± 1 years, body mass index = 29.3 ± 0.5 kg/m², apnea-hypopnea index = 39.3 ± 4 events/h). Leisure time physical activity domain in SED (n = 19) and ACTIVE (n = 21) was 20 ± 8 and 239 ± 32 min/wk, (P < .05). Baseline profile and perception of stress were similar in both groups. Baseline FBF (3.5 ± 0.2 mL/min/100 mL versus 2.4 ± 0.14 mL/min/100 mL) and FVC (3.5 ± 0.2 U versus 2.3 ± 0.1 U) were significantly lower in the SED group than in the ACTIVE group, respectively (P < .05). HR and BP increased similarly during mental stress test in both groups. Changes during mental stress in FBF (0.65 ± 0.12 versus 1.04 ± 0.12) and FVC (0.58 ± 0.11 versus 0.99 ± 0.11) were significantly lower in the SED group than in the ACTIVE group, respectively (P < .05). There was a significant correlation between leisure time physical activity and FBF (r = .57, P < .05) and FVC (r = .48, P < .05) during mental stress.

CONCLUSIONS

The vascular response among patients with OSA is influenced by the level of physical activity. A high level of physical activity may partially protect against the cardiovascular dysfunction associated with OSA.

Association of Adenotonsillectomy With Blood Pressure Among Hypertensive and Nonhypertensive Children With Obstructive Sleep Apnea

Importance

Hypertension in childhood may continue into adulthood and lead to adverse cardiovascular outcomes. Evidence suggests that adenotonsillectomy for childhood obstructive sleep apnea (OSA) may be associated with blood pressure (BP) improvement. However, how adenotonsillectomy is associated with BP in hypertensive and nonhypertensive children with OSA remains unclear.

Objective

To investigate disparities in BP changes after adenotonsillectomy in hypertensive and nonhypertensive children with OSA.

Design, Setting, and Participants

From January 1, 2010, to April 30, 2016, children (aged <18 years) with symptoms of OSA treated at National Taiwan University Hospital were enrolled in this retrospective case series study.

Interventions

Children underwent polysomnography for diagnosis of OSA (apnea-hypopnea index >1). All children with OSA underwent adenotonsillectomy.

Main Outcomes and Measures

Preoperative and postoperative overnight polysomnographic data were obtained. Office BP was measured in a sleep center before (nocturnal BP) and after (morning) polysomnography.

Results

A total of 240 nonobese children (mean [SD] age, 7.3 [3.0] years; 160 [66.7%] male and 80 [33.3%] female) with OSA were recruited. Postoperatively, the apnea-hypopnea index decreased significantly from 12.1 to 1.7 events per hour (95% CI of difference, -12.3 to -8.4 events per hour). The whole cohort had a significant decrease in nocturnal diastolic BP (66.9 to 64.5 mm Hg; 95% CI of difference, -4.1 to -0.7 mm Hg) and morning diastolic BP (66.9 to 64.4 mm Hg; 95% CI of difference, -4.2 to -0.8 mm Hg). The number (percentage) of patients with diastolic BP in the greater than 95th percentile decreased significantly nocturnally (48 [20.0%] to 33 [13.8%]; 95% CI of difference, -12.1% to -0.4%) and in the morning (52 [21.7%] to 34 [14.2%]; 95% CI of difference, -13.6% to -1.4%). Postoperatively, hypertensive children had a significant decrease in all BP measures, including mean (SD) nocturnal and morning systolic BP (nocturnal: 107.5 [8.6] mm Hg; morning: 106.0 [9.4] mm Hg), systolic BP index (nocturnal: -4.3 [8.6]; morning: -5.7 [8.5]), diastolic BP (nocturnal: 65.1 [11.5] mm Hg; morning: 64.4 [10.1] mm Hg), and diastolic BP index (nocturnal: -10.7 [17.3]; morning: -11.6 [15.7]), whereas the nonhypertensive group had a slight increase in nocturnal systolic BP (103.8 to 105.9 mm Hg; 95% CI of difference, 0.4-3.9 mm Hg). A generalized estimating equation model for subgroup comparisons revealed that children with hypertension, compared with those without, had greater improvement in all BP measures.

Conclusions and Relevance

Hypertensive children with OSA had a significant improvement in BP after adenotonsillectomy. Hypertensive children with OSA should be screened and treated by adenotonsillectomy because proper treatment not only eases OSA symptoms but also potentially prevents future cardiovascular and end-organ disease.

Sleep apnoea in patients with nocturnal hypertension - a multicenter study in the Czech Republic

Sleep apnoea (SA) is common in patients with hypertension. Nowadays, limited data on the prevalence of SA in nocturnal hypertension (NH) exist. Therefore, we studied the occurrence of SA in Czech patients and its association with 24-h ambulatory blood pressure monitoring (ABPM), breathing disturbances in sleep, anthropometric data, Mallampati score and Epworth sleepiness scale (ESS) using the Apnea Link device. Undiagnosed SA was found in 72.9 % patients (29.3 % mild, 26.6 % moderate, 17.0 % severe) of 188 patients with NH measured by ABPM. The median of the apnoea-hypopnoea index (AHI) was 12.0 (25th-75th percentile 5.0-23.8). Moderate/severe SA (AHI>/=15) was associated with BMI, waist circumference, mean night saturation (SpO(2)), t90, oxygen desaturation index (ODI), ESS (daytime BP only) (p</=0.032), but not ABPM parameters and Mallampati score (p>0.09). A likelihood of moderate/severe SA was enhanced by ODI>14.5 events/h (odds ratio=57.49, 95 % CI=22.79-145.01), t90>6.5 % (8.07, 4.09-15.92), mean night SpO(2)<93.5 % (3.55, 1.92-6.59), BMI>29.05 kg/m(2) (6.22, 3.10-12.49), circum waist>105.5 cm (3.73, 1.57-8.83), but not by any ABPM parameter. In conclusion, a high incidence of SA (72.9 %) was observed in Czech patients with NH. SA severity was associated with body characteristics and oxygenation parameters, but not with ABMP parameters and Mallampati score.

Quantitative Retinal Vascular Changes in Obstructive Sleep Apnea

PURPOSE

To examine the relationship between both static and dynamic retinal vascular caliber and the severity of obstructive sleep apnea (OSA).

DESIGN

Prospective cross-sectional study.

METHODS

Adult patients undergoing diagnostic polysomnography studies at a private Australian university teaching hospital were recruited. OSA severity was defined by the apnea-hypopnea index (AHI): severe >30, moderate >15-30, mild 5-15, and controls <5. Of 115 patients recruited (73 male; mean age 58 ± 13 years), there were 41 severe, 35 moderate, and 25 mild OSA patients and 14 controls. Static retinal vascular caliber was measured as the average diameter of retinal arterioles (CRAE) and venules (CRVE), and summarized as the arteriovenous ratio (AVR). Dynamic retinal vascular caliber was evaluated as the average pulsation amplitude of retinal arterioles (SRAP) and venules (SRVP). Comparisons across groups were performed using multivariate linear regression analysis. All results were adjusted for age, body mass index, and mean arterial pressure.

RESULTS

Increasing AHI was significantly associated with decreasing AVR (P = .008) and CRAE (P = .016). A significant relationship was demonstrated between increasing AHI and attenuated retinal vascular pulsation amplitude (arterioles P = .028; venules P < .0001).

CONCLUSIONS

Increasing OSA severity is independently associated with retinal arteriolar narrowing and attenuated vascular pulsation amplitude. The retinal vasculature is easily imaged, and may be a surrogate biomarker of cerebral and systemic vascular risk in patients with OSA requiring further comprehensive investigation.

Obstructive sleep apnea: Influence of hypertension on adiponectin, inflammatory markers and dyslipidemia

Obstructive sleep apnea (OSA) is a common but often unrecognized condition with potentially serious complications. The aim of this study was to explore the possible mechanisms linking hypertension (HT), a common cardiovascular disease (CVD), with obstructive sleep apnea (OSA) by investigating the levels of morning and evening serum adiponectin, inflammatory markers (TNF-α, IL-6), and lipid profiles in OSA patients with and without HT. Four groups were enrolled in this case-control analytic study: control, OSA, OSA+HT, and HT groups, each of which included 22 subjects. The results revealed low morning and evening serum adiponectin levels in patients with OSA and OSA+HT compared with their control and HT counterparts. Serum adiponectin levels declined progressively with increasing severity of OSA. Also, morning adiponectin levels were significantly decreased at the same time that a loss of the normal diurnal rhythm was observed in the OSA and OSA+HT groups. Both TNF-α and IL-6 levels were significantly increased in the OSA and OSA+HT groups compared with levels in the control and HT groups. Altered lipid profiles was noticed in the same groups. These findings were more pronounced in the OSA+HT than in the OSA group. In conclusion, the biochemical findings of this study demonstrate predominantly low adiponectin levels, increased levels of inflammatory markers, and atherogenic lipid profiles in OSA patients with HT compared with those of the other patients studied. This highlights the possible contributing role of these factors to the pathogenesis of HT as a common cardiovascular complication in OSA patients.

Circulating exosomes in obstructive sleep apnea as phenotypic biomarkers and mechanistic messengers of end-organ morbidity

Obstructive sleep apnea (OSA), the most severe form of sleep disordered breathing, is characterized by intermittent hypoxia during sleep (IH), sleep fragmentation, and episodic hypercapnia. OSA is associated with increased risk for morbidity and mortality affecting cardiovascular, metabolic, and neurocognitive systems, and more recently with non-alcoholic fatty liver disease (NAFLD) and cancer-related deaths. Substantial variability in OSA outcomes suggests that genetically-determined and environmental and lifestyle factors affect the phenotypic susceptibility to OSA. Furthermore, OSA and obesity often co-exist and manifest activation of shared molecular end-organ injury mechanisms that if properly identified may represent potential therapeutic targets. A challenge in the development of non-invasive diagnostic assays in body fluids is the ability to identify clinically relevant biomarkers. Circulating extracellular vesicles (EVs) include a heterogeneous population of vesicular structures including exosomes, prostasomes, microvesicles (MVs), ectosomes and oncosomes, and are classified based on their size, shape and membrane surface composition. Of these, exosomes (30-100nm) are very small membrane vesicles derived from multi-vesicular bodies or from the plasma membrane and play important roles in mediating cell-cell communication via cargo that includes lipids, proteins, mRNAs, miRNAs and DNA. We have recently identified a unique cluster of exosomal miRNAs in both humans and rodents exposed to intermittent hypoxia as well as in patients with OSA with divergent morbid phenotypes. Here we summarize such recent findings, and will focus on exosomal miRNAs in both adult and children which mediate intercellular communication relevant to OSA and endothelial dysfunction, and their potential value as diagnostic and prognostic biomarkers.

Association between high nocturnal blood pressure and white matter change and its interaction by obstructive sleep apnoea among normotensive adults

OBJECTIVES

A reverse dipping pattern, characterized by higher night-time blood pressure (BP) than daytime BP, is associated with the increased risk for cerebrovascular disease, cardiovascular events and all-cause mortality. However, little has known about the association between white matter change (WMC) and reverse dipping pattern, particularly in normotensive adults. We aimed to examine whether WMC is associated with BP dipping patterns as measured with a 24-h ambulatory BP monitoring and whether obstructive sleep apnoea (OSA) is involved in this relationship

METHODS

: A total of 703 normotensive adults were from an ongoing longitudinal study in a general population. WMC was measured with brain MRI. BP dipping patterns were defined as the ratio of the change in night-time and daytime SBP. OSA was categorized with the apnoea-hypopnea index, as measured with polysomnography. To avoid the influence of hypertensive medications, we only included normotensive adults for the final analysis. To examine the associations between WMC and dipping patterns, we built logistic models. To elucidate the role of OSA, we also conducted both modification and mediation tests.

RESULTS

Reverse dipping pattern was significantly associated with WMC (odds ratio 1.49, 95% confidence interval 1.02-2.18). Further, OSA modified the association between dipping patterns and WMC (P = 0.0118). No mediation effect of OSA was assessed.

CONCLUSION

In 703 normotensive adults, the reverse dipping pattern showed a significant association with WMC, after adjusting for covariates. Further, according to the presence of OSA, the association between reverse dipping and WMC was varied.

Continuous positive airway pressure reduces blood pressure in patients with obstructive sleep apnea; a systematic review and meta-analysis with 1000 patients

BACKGROUND

Obstructive sleep apnea (OSA) may lead to the development of hypertension and therapy with continuous positive airway pressure (CPAP) can promote reduction in blood pressure.

OBJECTIVE

The objective of this study is to review systematically the effects of CPAP on blood pressure in patients with OSA.

METHODS

The search was conducted in the following databases, from their beginning until February 2013: MEDLINE, Embase, Cochrane CENTRAL, Lilacs and PEDro. In addition, a manual search was performed on references of published studies. Randomized clinical trials (RCTs) that used CPAP compared with placebo CPAP or subtherapeutic CPAP for treatment of patients with OSA and that evaluated office SBP and DBP and 24-h ambulatory blood pressure were selected.

RESULTS

Sixteen RCTs were included among 3409 publications, totaling 1166 patients. The use of CPAP resulted in reductions in office SBP [-3.20  mmHg; 95% confidence interval (CI) -4.67 to -1.72] and DBP (-2.87  mmHg; 95% CI -5.18 to -0.55); in night-time SBP (-4.92  mmHg; 95% CI -8.70 to -1.14); in mean 24-h blood pressure (-3.56  mmHg; 95% CI -6.79 to -0.33), mean night-time blood pressure (-2.56  mmHg; 95% CI -4.43 to -0.68) and 24-h DBP (-3.46  mmHg; 95% CI -6.75 to -0.17). However, no significant change was observed in daytime SBP (-0.74  mmHg; 95% CI -3.90 to 2.41) and daytime DBP (-1.86  mmHg; 95% CI -4.55 to 0.83).

CONCLUSION

Treatment with CPAP promoted significantly but small reductions in blood pressure in individuals with OSA. Further studies should be performed to evaluate the effects of long-term CPAP and the impact on cardiovascular risk.

Obstructive sleep apnea: management considerations in psychiatric patients

Psychiatric disorders and obstructive sleep apnea (OSA) are often comorbid. However, there is limited information on the impact of psychotropic medications on OSA symptoms, on how to manage psychiatric pharmacotherapy in patients presenting with OSA, or on the effectiveness and challenges of OSA treatments in patients with comorbid mental illness. As such, the objective of this article is to provide an overview of some epidemiological aspects of OSA and treatment considerations in the management of OSA in individuals with comorbid psychiatric disorders. Predefined keywords were used to search for relevant literature in electronic databases. Data show that OSA is particularly prevalent in patients with psychiatric disorders. The medical care that patients with these comorbidities require can be challenging, as some of the psychiatric medications used by these patients may exacerbate OSA symptoms. As such, continuous positive airway pressure continues to be the first-line treatment, even in patients with psychiatric comorbidity. However, more controlled studies are required, particularly to determine continuous positive airway pressure compliance in patients with mental illness, the impact of treating OSA on psychiatric symptoms, and the impact of the use of psychotropic medications on OSA symptoms.

Prevalence and associations of respiratory-related leg movements: the MrOS sleep study

OBJECTIVES

Obstructive respiratory events often terminate with an associated respiratory-related leg movement (RRLM). Such leg movements are not scored as periodic leg movements (periodic limb movements during sleep, PLMS), although the criteria for distinguishing RRLM from PLMS differ between the American Academy of Sleep Medicine (AASM) and the World Association of Sleep Medicine (WASM)/ International Restless Legs Syndrome Study Group (IRLSSG) scoring manuals. Such LMs may be clinically significant in patients with obstructive sleep apnea (OSA). The prevalence and correlation of RRLM in men with OSA were examined.

METHODS

A case-control sample of 575 men was selected from all men with an apnea-hypopnea index (AHI, ≥3% desaturation criteria) ≥ 10 and good data from piezoelectric leg movement sensors at the first in-home sleep study in the MrOS cohort (mean age = 76.8 years). Sleep studies were rescored for RRLMs using five different RRLM definitions varying in both latency of leg movement onset from respiratory event termination and duration of the leg movement. The quartile of RRLM% (the number of RRLM/the number of hypopneas + apneas) was derived.

RESULTS

The nonparametric densities of RRLM% were most influenced by alterations in the latency rather than the duration of the LM. The most liberal RRLM definition (latency 0-5 s, duration 0.5-10 s) led to a median RRLM% of 23.4 (interquartile range 12.41, 37.12) in this sample. The average AHI and arousal index increased as the quartile of RRLM% increased, as well as the prevalence of chronic obstructive pulmonary disease (COPD). The prevalence of those with a history of hypertension decreased as RRLM% increased. The non-Caucasian race was associated with lower RRLM%.

CONCLUSION

Within an elderly sample with moderate to severe OSA, piezoelectric-defined RRLM% is associated with a number of sleep-related and demographic factors. Further study of the optimal definition, predictors, and consequences of RRLM is warranted.

Self-reported obstructive sleep apnea, simple snoring, and various markers of sleep-disordered breathing as predictors of cardiovascular risk

PURPOSE

Our objective was to investigate whether self-reported obstructive sleep apnea (OSA), simple snoring, and various markers of sleep-disordered breathing (SDB) are associated with cardiovascular risk.

METHODS

We examined a representative nationwide cohort of 5177 Finnish adults aged ≥30 years. The participants underwent measurement of traditional cardiovascular risk factors and answered SDB-related questions derived from the Basic Nordic Sleep Questionnaire, which were used to operationalize self-reported OSA. The primary end point was incidence of a cardiovascular event (cardiovascular mortality, non-fatal myocardial infarction, non-fatal stroke, hospitalization for heart failure, or coronary interventions).

RESULTS

During a median follow-up of 11.2 years and 52,910 person-years of follow-up, 634 participants suffered a cardiovascular event. In multivariable-adjusted Cox models, self-reported OSA (hazard ratio [HR] 1.34; 95 % confidence interval [CI] 1.04-1.73; p = 0.03) was an independent predictor of cardiovascular events. Self-reported simple snoring by itself was not associated with future cardiovascular events (HR 0.88 versus non-snorers, 95 % CI 0.75-1.04, p = 0.15). However, among snorers (n = 3152), frequent breathing cessations (HR 2.19, 95 % CI 1.26-3.81, p = 0.006) and very loud and irregular snoring (HR 1.82, 95 % CI 1.31-2.54, p < 0.001) were associated with cardiovascular risk.

CONCLUSIONS

Self-reported OSA and SDB-related snoring variables are associated with cardiovascular risk, whereas simple snoring is not. In clinical practice and in surveys, questions concerning only habitual snoring should be amended with questions focusing on respiratory pauses and snoring stertorousness, which can be used to estimate the risk of OSA and cardiovascular events.

Clinical consequences and economic costs of untreated obstructive sleep apnea syndrome

Objective

To provide an overview of the healthcare and societal consequences and costs of untreated obstructive sleep apnea syndrome.

Data sources

PubMed database for English-language studies with no start date restrictions and with an end date of September 2014.

Methods

A 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.

Conclusions

Undiagnosed 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 practice

Treatment 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.

Symptoms of Insomnia and Sleep Duration and Their Association with Incident Strokes: Findings from the Population-Based MONICA/KORA Augsburg Cohort Study

Objective

To examine the relationship between symptoms of insomnia and sleep duration and incident total (non-fatal plus fatal) strokes, non-fatal strokes, and fatal strokes in a large cohort of men and women from the general population in Germany.

Methods

In four population-based MONICA (monitoring trends and determinants in cardiovascular disease)/KORA (Cooperative Health Research in the Region of Augsburg) surveys conducted between 1984 and 2001, 17,604 men and women (aged 25 to 74 years) were asked about issues like sleep, health behavior, and medical history. In subsequent surveys and mortality follow-ups, incident stroke cases (cerebral hemorrhage, ischemic stroke, transient ischemic attack, unknown stroke type) were gathered prospectively until 2009. Sex-specific hazard ratios (HR) and their 95% confidence intervals (CI) were estimated using sequential Cox proportional hazards regression models.

Results

During a mean follow-up of 14 years, 917 strokes (710 non-fatal strokes and 207 fatal strokes) were observed. Trouble falling asleep and difficulty staying asleep were not significantly related to any incident stroke outcome in either sex in the multivariable models. Among men, the HR for the association between short (≤5 hours) and long (≥10 hours) daily sleep duration and total strokes were 1.44 (95% CI: 1.01–2.06) and 1.63 (95% CI: 1.16–2.29), after adjustment for basic confounding variables. As for non-fatal strokes and fatal strokes, in the analyses adjusted for age, survey, education, physical activity, alcohol consumption, smoking habits, body mass index, hypertension, diabetes, and dyslipidemia, the increased risks persisted, albeit somewhat attenuated, but no longer remained significant. Among women, in the multivariable analyses the quantity of sleep was also not related to any stroke outcome.

Conclusion

In the present study, symptoms of insomnia and exceptional sleep duration were not significantly predictive of incident total strokes, non-fatal strokes, and fatal strokes in either sex.

[Clinical features of obstructive sleep apnea syndrome in patients with acromegaly]

AIM

To investigate the incidence of sleep-related breathing disorders (SRBDs) in patients with active acromegaly (AM), to specify risk factors influencing apnea/hypopnea index (AHI), and to reveal the specific features of obstructive sleep apnea (OSA) in patients with AM versus those with OSA without AM.

SUBJECTS AND METHODS

Fifty patients with active AM were examined and divided into 3 groups: control group 1 did not differ from the study group in body mass index (BMI); control group 2 did not similar in AHI from the AM group. Polysomnography was done in all the patients.

RESULTS

SRBDs were detected in 40 (80%) patients. Obstructive apnea was found in all cases. Correlation analysis revealed the relationships between AHI and gender (AHI was higher in the men), BMI, disease duration, and insulin-like growth factor 1 (GF-1). There were no correlations between AHI and gender, maximum adenoma size, and growth hormone levels. Compared with control group 1, the AM group had a statistically significantly higher median AHI [16 (1-92) and 4.7 (0-31.3) episodes per hour of sleep (p < 0.001)]. In control group 2, the median BMI was considerably higher than in the control group [29.2 (19.9-44.3) and 35 (24-56) kg/m2 (p < 0.001).

CONCLUSION

The detection rate of SRBDs in patients with active AM was 80%, with obstructive disorders being prevalent. There was a positive relationship between SRBD severity and BMI, AM duration, IGF-1 level. Compared to the controls, the patients with AM developed SRBDs similar in severity with lower BMI; severer SRBDs were detected in the patients with active AM with the similar BMI.

Established vascular effects of continuous positive airway pressure therapy in patients with obstructive sleep apnoea-an update

The aim of this review was to summarize the current data from randomised controlled trials (RCTs) on vascular effects of continuous positive airway pressure (CPAP) therapy in patients with obstructive sleep apnoea (OSA). There is good evidence from RCTs that CPAP lowers blood pressure (BP) to a clinically significant amount. The effect seems to be dependent on the hours of nightly CPAP usage. Data from RCTs have also proven a beneficial effect of CPAP on measures of vascular function such as endothelial function and arterial stiffness. However, there is still a lack of evidence from RCTs proving that CPAP reduces vascular events and mortality.

Obstructive sleep apnea is independently associated with inflammation and insulin resistance, but not with blood pressure, plasma catecholamines, and endothelial function in obese subjects

OBJECTIVES

Obstructive sleep apnea (OSA) is associated with an increased risk of cardiovascular disease (CVD). Several of the proposed mechanisms for the development of CVD in OSA are similar to those proposed for the increased risk of CVD in obesity, so that it is difficult to determine the influence of OSA on these pathogenic mechanisms in obese individuals. The aim of this study was to evaluate the relationship of OSA with endothelial function, oxidative stress, inflammatory biomarkers, metabolic profile, sympathetic nervous system activity, and blood pressure (BP) in obese individuals.

METHODS

This cross-sectional study included 53 obese adults (28 women). Sleep study was performed with WatchPAT 200 (Itamar Medical, Caesarea, Israel) and the diagnosis of OSA was made when apnea-hypopnea index (AHI) ≥5 events/h (n = 33). All participants underwent evaluation of: body adiposity, BP, plasma catecholamines, high sensitivity C-reactive protein (hs-CRP), adiponectin, malondialdehyde, glucose, insulin, lipid profile, and endothelial function (EndoPAT 2000).

RESULTS

In univariate analysis, participants with OSA compared with those without OSA exhibited higher values of neck circumference, glucose, noradrenaline, and systolic BP. After adjustment for confounders, including adiposity, only glucose and hs-CRP were significantly higher in OSA patients. In correlation analysis, after controlling for confounders, AHI was positively and significantly associated with neck circumference and hs-CRP, while minimum O2 saturation was associated negatively and significantly with neck circumference, insulin and homeostatic model assessment-insulin resistance (HOMA-IR).

CONCLUSIONS

The present study suggests that in obese individuals OSA is independently associated with inflammation and insulin resistance, but not with BP, plasma catecholamines and endothelial function.

Blood Pressure after Surgery among Obese and Nonobese Children with Obstructive Sleep Apnea

Objectives

Treating obstructive sleep apnea in children is found to be associated with blood pressure decreases. However, exactly how adenotonsillectomy (T&A) affects blood pressure in obese and nonobese children remains unclear. This study assesses how obesity affects blood pressure in children with sleep apnea after T&A.

Study Design

Case series with chart review.

Setting

A tertiary referral center.

Subjects and Methods

From 2010 to 2012, a total of 78 children were included. Based on propensity score methods (age, sex, and preoperative apnea-hypopnea index matched), children were assigned to either the obese group (n = 39) or the nonobese group (n = 39). All children received adenotonsillectomy. We recorded clinical symptoms, preoperative overnight polysomnography (PSG), and subsequent PSG within 3 months after T&A. We measured blood pressure 3 times before PSG (nocturnal blood pressure) and after PSG (morning blood pressure) in a sleep laboratory.

Results

Following surgery, the nonobese group had a significantly decreased nocturnal diastolic blood pressure (DBP) index (–12.0 to −18.8, P = .018), morning systolic blood pressure (SBP; 111.1 to 105.8 mm Hg, P = .014), SBP index (–5.4 to −10.9, P = .008), and DBP (–12.0 to −18.7, P = .023). Nevertheless, all blood pressure parameters in the obese group were not significantly changed postoperatively. The nonobese group improved more than obese group in nocturnal and morning DBP and DBP index by 2-way analysis of variance.

Conclusion

Among the children receiving T&A as treatment for OSA, nonobese children improved more than obese children did in terms of blood pressure, allowing us to infer that obese children with OSA may benefit less from T&A in cardiovascular morbidities.

Incident atrial fibrillation hazard in hypertensive population: a risk function from and for clinical practice

Determining the risk of atrial fibrillation within the hypertensive population without ischemic vascular disease would aid in decision making on preventive approaches. Accordingly, we aimed to estimate the risk of incident atrial fibrillation in this population. We conducted an historical cohort study between July 1, 2006, and December 31, 2011, using anonymized longitudinal patient information from primary care and hospital discharge records contained in the System for the Development of Research in Primary Care database. We included 255 440 hypertensive patients, aged ≥55 years at the time of study entry. Individuals with previous atrial fibrillation, ischemic heart disease, stroke, and peripheral artery disease were excluded. To build the incident atrial fibrillation risk function, a derivation and a validation cohort were defined, representing 60% and 40% of the entire database, respectively, and a Cox proportional hazards model was fitted. Atrial fibrillation incidence was 7.24 per 1000 person-years (95% confidence interval, 7.08-7.40). The final model included age, weight, total cholesterol, heart failure, valvular heart disease, and antihypertensive treatment. Its concordance index (standard error) was 0.769 (0.004) and 0.768 (0.005) in the derivation and validation datasets, respectively. This research provides a tool, built with variables from daily clinical practice, that can be readily used in the primary care setting to predict atrial fibrillation incidence in the hypertensive population without ischemic vascular disease. The tool may help tailor individualized diagnostic and preventive care decisions.