Obstructive sleep apnea and cardiovascular disease: a perspective and future directions

Knowledge and Attitudes of Obstructive Sleep Apnea among Jordanian Otolaryngologists: A Cross-Sectional Study

Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder that affects almost one billion individuals worldwide. An estimated 16.8% of adults in Jordan have been diagnosed with OSA. Given the importance of management of OSA by otolaryngologists, we assessed the knowledge and attitudes of Jordanian otolaryngologists in managing OSA in adult and pediatric patients. A survey, conducted anonymously online, was sent present otolaryngology residents and specialist in Jordan, in the English language. The participants were given the OSA Knowledge and Attitude questionnaire (OSAKA, OSAKA-KIDS), which have been previously validated. Data were obtained and then analyzed via SPSS software. A total of 140 residents and specialist of otolaryngology were selected. A significant difference in OSAKA scores were found between otolaryngologists under 30 years of age and those above, with higher scores for the older age group. The proportion of specialists who 'agreed' or 'strongly agreed' they are confident in their ability to manage patients with OSA was significantly higher that junior residents (73.8% vs 33.3%; p = 0.008). More than 10 years at practice was associated with statistically significant higher levels of knowledge towards OSAKA scale (AOR = 0.09; p = 0.044). Additionally, being a senior resident was significantly associated with more knowledge towards OSAKA-KIDS scale (AOR = 0.19; p = 0.03). Otolaryngology residents and specialists' knowledge of OSA was very good. Further improving in the level of the knowledge toward OSA among the otolaryngology resident doctors should be implemented as possible by following the updated guidelines for the diagnosis and management OSA.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-04180-8.

Associations of sleep quality and exercise frequency and the risk of coronary heart disease in Chinese urban elderly: a secondary analysis of cross-sectional data

BACKGROUND

Sleep quality and exercise frequency are closely associated with coronary heart disease (CHD). Few studies focused on the joint effect of initiating sleep, sleep disorders, and exercise frequency on the risk of CHD in the elderly. We used a secondary data analysis based on Boshan Elderly cross-sectional study. We explored the sleep quality, exercise frequency, and their joint effects on the risk of CHD.

METHODS

We collected 678 participants whose age ≥ 60 years old from Boshan District Hospital. We used the Pittsburgh Sleep Quality Index to evaluate the sleep quality and obtained physical examination information from the hospital.

RESULTS

Compared with the non-CHD group, patients with CHD spent more time in initiating sleep (time ≥ 60 min, 34.59% vs. 22.93%, P = 0.025) and less time exercising (exercise frequency < 1 times/week, 23.90% vs. 17.15%, P = 0.024). In multiple logistic regression analysis, sleep latency ≥ 60 min was associated with CHD risk (adjusted OR = 1.83; 95% CI: 1.11, 2.99; P-trend = 0.008). The adjusted OR (95% CI) of CHD was 2.24 (1.16, 4.34) for sleep duration < 5 h versus 5-9 h. Compared with exercise frequency < 1 times/week, the adjusted OR for exercise frequency ≥ 1 times/week was 0.46 (95% CI: 0.26, 0.83; P = 0.010). In addition, the joint effects of long sleep latency (≥ 60 min) and sleep disorders were associated with CHD (adjusted OR = 3.36; 95% CI: 1.41, 8.02). The joint effect of exercise frequency ≥ 1 times/week and sleep onset latency within normal limits (< 30 min) was also associated with CHD, and the adjusted OR (95% CI) was 0.42 (0.21, 0.87).

CONCLUSIONS

Long sleep latency, high frequency of initiating sleep difficulty, sleep disorders, and short sleep duration were positively associated with CHD. In addition, the joint effects of long sleep latency and sleep disorders were positively correlated with CHD incidence. However, the joint effects of exercise frequency ≥ 1 times/week and normal sleep onset latency were negatively associated CHD.

Association between mean platelet volume and cardiovascular disease in obstructive sleep apnea syndrome

Objectives

Obstructive sleep apnea syndrome is associated with cardiovascular diseases. Mean platelet volume has emerged as a marker of prothrombotic conditions and cardiovascular risk. The aim of this study was to investigate the association between the mean platelet volume and cardiovascular diseases in patients with obstructive sleep apnea syndrome.

Methods

The medical records of 207 patients were analyzed. Obstructive sleep apnea syndrome was diagnosed by polygraphy, and patients were classified according to apnea-hypopnea index: control group: individuals with simple snoring (apnea-hypopnea index < 5), mild obstructive sleep apnea syndrome group (5 ⩽ apnea-hypopnea index < 15), moderate obstructive sleep apnea syndrome group (15 ⩽ apnea-hypopnea index < 30), and severe obstructive sleep apnea syndrome group (apnea-hypopnea index ⩾ 30). Mean platelet volume was obtained from medical records. Cardiovascular diseases were defined if patients had hypertension, heart failure, coronary artery disease, or arrythmia. The independent predictors related to cardiovascular diseases in obstructive sleep apnea syndrome were determined by using multiple logistic regression analysis.

Results

Of the patients, 175 were included in the analysis. Sixty-three (36%) were males and 112 (64%) were females. The mean age was 51.85 ± 11 years. There were, 26 (14.9%), 53 (30.3%), 38 (21.7%), and 58 (33.1%) participants in the simple snoring, mild, moderate, and severe obstructive sleep apnea syndrome groups, respectively. Cardiovascular diseases were significantly different between the four groups (p = 0.014). Mean platelet volume in severe obstructive sleep apnea syndrome group was significantly higher than in mild or moderate obstructive sleep apnea syndrome group and simple snoring group (p < 0.05). Moreover, there was a positive correlation between mean platelet volume levels and apnea-hypopnea index (r = 0.424; p < 0.001). The independent predictors of cardiovascular diseases in obstructive sleep apnea syndrome were age (p < 0.001; odds ratio = 1.134; confidence interval: 1.072-1.2), body mass index (p = 0.012; odds ratio: 1.105; confidence interval: 1.022-1.194), and mean platelet volume (p < 0.001; odds ratio: 2.092; confidence interval: 1.386-3.158).

Conclusion

The present study demonstrated that there is an association between mean platelet volume levels and cardiovascular diseases in patients with obstructive sleep apnea syndrome.

Hypoxia Inhibits Subretinal Inflammation Resolution Thrombospondin-1 Dependently

Hypoxia is potentially one of the essential triggers in the pathogenesis of wet age-related macular degeneration (wetAMD), characterized by choroidal neovascularization (CNV) which is driven by the accumulation of subretinal mononuclear phagocytes (MP) that include monocyte-derived cells. Here we show that systemic hypoxia (10% O2) increased subretinal MP infiltration and inhibited inflammation resolution after laser-induced subretinal injury in vivo. Accordingly, hypoxic (2% O2) human monocytes (Mo) resisted elimination by RPE cells in co-culture. In Mos from hypoxic mice, Thrombospondin 1 mRNA (Thbs1) was most downregulated compared to normoxic animals and hypoxia repressed Thbs-1 expression in human monocytes in vitro. Hypoxic ambient air inhibited MP clearance during the resolution phase of laser-injury in wildtype animals, but had no effect on the exaggerated subretinal MP infiltration observed in normoxic Thbs1-/--mice. Recombinant Thrombospondin 1 protein (TSP-1) completely reversed the pathogenic effect of hypoxia in Thbs1-/--mice, and accelerated inflammation resolution and inhibited CNV in wildtype mice. Together, our results demonstrate that systemic hypoxia disturbs TSP-1-dependent subretinal immune suppression and promotes pathogenic subretinal inflammation and can be therapeutically countered by local recombinant TSP-1.

Overweight/Obese Status Synergistically Worsens Nocturnal Time-to-Time Blood Pressure in Children with Obstructive Sleep Apnea

OBJECTIVE

To investigate the influence of obstructive sleep apnea (OSA) severity and weight on blood pressure (BP) during nighttime sleep in children.

METHODS

Habitually snoring children who were 3-14 years old and from Beijing Children's Hospital between 1 January 2018 and 31 December 2020 were recruited. All participants completed polysomnography (PSG) and BP monitoring during different sleep stages using pulse transit time analysis. Subjects were divided into three groups based on the obstructive apnea-hypopnea index (OAHI), ie, primary snoring (PS), mild-to-moderate OSA, and severe OSA group.

RESULTS

Totally, 284 habitually snoring children were enrolled, including 85 with PS, 152 with mild-to-moderate OSA, and 47 with severe OSA. The differences of age and sex ratio among groups were not statistically significant (all P>0.05). For the normal weight group, compared with those in the PS group, children in the severe OSA group had higher BP, mainly in N2 and R stages, and children in the mild-to-moderate OSA group had lower BP in all sleep and wake stages (all P<0.01). For the overweight/obese group, compared with the PS group, children in the severe OSA group had higher BP in all sleep and wake stages, and children in the mild-to-moderate group had higher BP mainly in sleep stages (all P<0.01). Compared with normal weight children, those who were overweight/obese and had OSA had higher BP in all sleep and wake stages (all P<0.01). There was a synergistic effect of OSA and weight status on BP (P<0.01).

CONCLUSION

The influence of OSA on both systolic and diastolic pediatric BP differs between children with normal weight and overweight/obese status. Overweight/obese status synergistically worsens nocturnal blood pressure in children with OSA. Early diagnosis and risk stratification are more important in overweight/obese children with OSA to achieve timely initiation of treatment.

Obstructive Sleep Apnea with COVID-19

The novel coronavirus disease-2019 (COVID-19) and the ensuing pandemic have greatly impacted the global healthcare system due to its high infectiousness, associated high mortality, and a complete lack of immunity in the population. Globally, the COVID-19 pandemic has unleashed a health crisis that has not only seriously disrupted people's lives but also affected their normal sleep, along with physical and mental health; this situation is especially exacerbated in people suffering from pre-existing conditions, such as sleep apnea. A recent meta-analysis of 18 studies by Miller et al. (September 2020) showed that obstructive sleep apnea (OSA) is related to higher mortality and morbidity in patients with COVID-19 and is most likely independent of other risk factors. A recent meta-analysis indicated that COVID-19 patients with OSA are more severely affected than those without OSA, thereby providing further evidence that concurrent OSA may elevate the severity of COVID-19 infection, along with the risk of mortality. The COVID-19 pandemic has significantly impacted the diagnosis and therapeutic management of patients with OSA. Thus, it is necessary to identify and develop new diagnostic and therapeutic avenues in the future. In this context, the current study summarizes known associations between COVID-19 and OSA and the regular diagnostic and therapeutic strategies for OSA in the light of COVID-19 pandemic prevention and control.

The effect of obstructive sleep apnea on the increased risk of cardiovascular disease: a systematic review and meta-analysis

BACKGROUND

Obstructive sleep apnea (OSA) is a disorder characterized by intermittent airway obstruction during sleep. The association between OSA and the incidence of cardiovascular disease (CVD) has been investigated in many studies; however, the results are not entirely consistent between studies. The aim of this study was to investigate the relationship between OSA and the risk of CVD through a meta-analysis of cohort studies.

METHODS

A systematic review and meta-analysis of literature was conducted using the PubMed, WoS, Embase, ScienceDirect, Scopus, and Web of Science databases up to the year 2020. In order to analyze the eligible studies, the stochastic effects model was used and the heterogeneity of the studies with the I² index was investigated. Data analysis was performed with Comprehensive Meta-Analysis software (Version 2).

RESULTS

A total of 24 studies were included in the meta-analysis according to the inclusion criteria. Twelve studies reported CVD results, 11 studies reported stroke results, 9 studies reported mortality results, and 8 studies reported CVD results. The odds ratio of CVD in patients with OSA 1.71 (1.17-2.27: 95% confidence interval) stroke in patients with OSA, 1.86 (1.28-2.69: 95% confidence interval), mortality in patients with OSA, 1.77 (1.37-2.29: 95% confidence interval) and CHD in patients with OSA, and 1.48 (1.06-2.28: 95% confidence interval) was obtained.

CONCLUSION

OSA is considered a cardiovascular risk factor. There is a relationship between the severity of OSA and the risk of cardiovascular disease. OSA increases the risk of heart attack, CHD, and death from cardiovascular disease.

Excessive daytime sleepiness, morning tiredness and major adverse cardiovascular events in patients with chronic coronary syndrome

BACKGROUND

Sleep-related breathing disorders (SRBDs), particularly obstructive sleep apnoea, are associated with increased cardiovascular (CV) risk. However, it is not known whether individual questions used for SRBD screening are associated with major adverse CV events (MACE) and death specifically in patients with chronic coronary syndrome (CCS).

METHODS

Symptoms associated with SRBD were assessed by a baseline questionnaire in 15,640 patients with CCS on optimal secondary preventive therapy in the STABILITY trial. The patients reported the frequency (never/rarely, sometimes, often and always) of: 1) loud snoring; 2) more than one awakening/night; 3) morning tiredness (MT); 4) excessive daytime sleepiness (EDS); or 5) gasping, choking or apnoea when asleep. In adjusted Cox regression models, associations between the frequency of SRBD symptoms and CV outcomes were assessed with never/rarely as reference.

RESULTS

During a median follow-up time of 3.7 years, 1,588 MACE events (541 CV deaths, 749 nonfatal myocardial infarctions [MI] and 298 nonfatal strokes) occurred. EDS was associated (hazard ratio [HR], 95% confidence interval [CI]) with increased risk of MACE (sometimes 1.14 [1.01-1.29], often 1.19 [1.01-1.40] and always 1.43 [1.15-1.78]), MI (always 1.61 [1.17-2.20]) and all-cause death (often 1.26 [1.05-1.52] and always 1.71 [1.35-2.15]). MT was associated with higher risk of MACE (often 1.23 [1.04-1.45] and always 1.46 [1.18-1.81]), MI (always 1.61 [1.22-2.14]) and all-cause death (always 1.54 [1.20-1.98]). The other SRBD-related questions were not consistently associated with worse outcomes.

CONCLUSIONS

In patients with CCS, gradually higher levels of EDS and MT were independently associated with increased risk of MACE, including mortality.

The effect of acute intermittent hypoxia on postprandial triglyceride levels in humans: a randomized crossover trial

Background

Obstructive sleep apnea (OSA), a sleep disorder frequently observed in individuals living with obesity, consists of repeated involuntary breathing obstructions during sleep, leading to intermittent hypoxia (IH). In humans, acute continuous hypoxia slightly increases plasma triglycerides (TG). However, no study yet compared the postprandial TG response of individuals with or without OSA under intermittent hypoxia.

Methods

Using a randomized crossover design, seven individuals diagnosed with moderate OSA and eight healthy individuals without OSA were given a meal after which they were exposed for 6 h to normoxia or intermittent hypoxia (e.g., 15 hypoxic events per hour). Blood lipid levels were measured hourly during each session.

Results

Peak postprandial TG concentrations tended to be 22% higher under IH irrespective of group (IH × time interaction, p = 0.068). This trend toward higher total plasma TG was attributable to increased levels of denser TG-rich lipoproteins such as very low-density lipoproteins (VLDL) and chylomicrons (CM) remnants. Irrespective of group, the postprandial TG concentrations in denser TG-rich lipoproteins was 20% higher under IH (IH × time interaction, p = 0.036), although IH had virtually no impact on denser TG-rich lipoprotein concentrations in the OSA group.

Conclusion

Acute intermittent hypoxia tends to negatively affect postprandial TG levels in healthy individuals, which is attributable to an increase in denser TG-carrying lipoprotein levels such as VLDL and CM remnants. This altered postprandial TG response to acute intermittent hypoxia was not observed in individuals with OSA.

Cardiovascular issues in obstructive sleep apnoea in children: A brief review

Obstructive sleep apnoea (OSA) is a very common disease with a prevalence that ranges from 1% to 6% in children. It is characterized by intermittent partial or complete occlusion of the upper airway during sleep, leading to recurrent arousals and disturbed sleep architecture, to neurocognitive disorders and alterations in homeostatic gas exchange. Cardiovascular complications may develop in children with OSA through various mechanisms including activation and dysregulation of the sympathetic nervous system, induction of pro-inflammatory and pro-oxidant status and increased risk of systemic hypertension. As the deleterious effects of OSA on the cardio-vascular system may start early in life, in this brief review we focused our attention both on early and late cardiological changes induced by apnoeic events in the paediatric population, by reviewing recent findings in the literature.

Association Between Obstructive Sleep Apnea and Diabetic Macular Edema in Patients with Type 2 Diabetes

PURPOSE

To evaluate the relationship between obstructive sleep apnea (OSA) and diabetic macular edema (DME) and the effect of OSA on refractory DME in patients with type 2 diabetes (T2DM).

DESIGN

Retrospective clinical cohort study.

METHODS

A population-based study was conducted at Chang Gung Memorial Hospital from March 1, 2009, to March 1, 2020. Among 14,152 patients who had undergone polysomnography (PSG) and whose data were registered on the sleep center's PSG database, 121 patients (242 eyes) with T2DM were enrolled according to the International Classification of Diseases, Ninth Revision (ICD-9) code 3620 for diabetic retinopathy (DR). Patients with a secondary cause of macular edema and those lacking medical records were excluded. All patients with T2DM enrolled in our study received both optical coherence tomography (OCT) and PSG. The prevalence of severe (apnea-hypopnea index [AHI] ≥30) and nonsevere (AHI <30) OSA was compared between patients with and without DME and refractory DME.

RESULTS

In total, 102 eyes (54 patients) were divided into groups of 40 eyes with DME or 62 eyes without DME. Severe OSA (odds ratio, 7.36; 95% confidence interval [CI]: 1.32-40.96; P = .023) was significantly associated with DME. Refractory DME was significantly more frequent in patients with severe OSA (27%) than in those with nonsevere OSA (0%; P = .009). Cox proportional hazards regression analysis revealed that OSA (hazard ratio, 2.97; CI, 1.08-8.16; P = .034) independently increased the DME risk after adjustment for age, sex, glycohemoglobin level, hypertension, and hypercholesterolemia.

CONCLUSIONS

Severe OSA is a risk factor for DME and is associated with having refractory DME.

Advances in Treatment of Sleep-Disordered Breathing

BACKGROUND

Sleep-disordered breathing, composed of obstructive sleep apnea (OSA) and central sleep apnea (CSA), affects millions of people worldwide carrying with it significant morbidity and mortality. Diagnosis is made by polysomnography, and severity of sleep apnea is determined by the apnea-hypopnea index (AHI). Positive airway pressure (PAP) therapy has been the gold standard in treating both OSA and CSA. PAP therapy can greatly reduce AHI burden as well as morbidity and mortality and improve quality of life.

AREAS OF UNCERTAINTY

However, patients report difficulties adhering to PAP therapy because of discomfort with mask interface, sensation of excessive pressure, and claustrophobia. Although other options exist to treat sleep apnea, such as mandibular advancement oral appliance devices, positional therapy, and surgery, these additional therapeutic modalities as current options have limitations. Emerging technology is now available to overcome hindrances to standard therapy.

DATA SOURCES

A literature search was performed from the following databases: PubMed, Cochrane Library (Cochrane Database of Systematic Reviews), and Cochrane Central Register of Controlled Trials, and FDA device database (clinicaltrial.gov).

THERAPEUTIC ADVANCES

Other modalities of treating sleep-disordered breathing now include the hypoglossal nerve stimulator, which stimulates the hypoglossal nerve during sleep to alleviate airflow obstruction by contracting the genioglossus muscle thus treating OSA. Similarly, the phrenic nerve stimulator restores a more stable breathing pattern during sleep by stimulating the phrenic nerve to activate the diaphragm during CSA. Both nerve stimulators have been shown to reduce AHI severity and improve quality of life for patients suffering from sleep-disordered breathing.

CONCLUSIONS

PAP therapy, although the gold standard, has limitations in the treatment of sleep apnea. New modalities such as hypoglossal nerve stimulator and phrenic nerve stimulator may help to overcome difficulties with adherence and offer new options for treatment of both obstructive and central sleep apnea.

Snoring severity is associated with carotid vascular remodeling in young adults with overweight and obesity

BACKGROUND

Snoring is often used as a surrogate measure for obstructive sleep apnea (OSA), a sleep disorder associated with cardiovascular disease (CVD) risk. Whether snoring is linked to CVD independent of OSA remains unclear. We aimed to explore the snoring and subclinical CVD association in adults with and without OSA.

METHODS

We conducted a cross-sectional study in 122 overweight/obese participants (24% male; mean age 40.1 years) attending the 24-month follow-up visit of a lifestyle intervention. Using home-based objective measures of sleep-disordered breathing, we stratified participants into 3 snoring/OSA categories using the snoring index (SI), a measure of snoring vibration, and oxygen desaturation index (ODI): (1) OSA (ODI ≥ 5), (2) non-OSA heavy snorer (ODI <5, above-median SI), and (3) non-OSA low snorer (ODI <5, below-median SI). Vascular measures including pulse wave velocity ([PWV]; carotid-femoral [cf], femoral-ankle [fa], brachial-ankle [ba]), carotid intima-media thickness (IMT), and carotid interadventitial diameter (IAD) were compared across snoring/OSA categories. Linear regressions assessed the association between snoring and subclinical CVD independent of traditional CVD risk factors.

RESULTS

Compared to non-OSA low snorers, common carotid IMT and IAD were higher in non-OSA heavy snorers, and faPWV, IMT, and IAD were higher among those with OSA. The difference between non-OSA heavy snorers and low snorers persisted after adjusting for age, race, sex, blood pressure, body mass index, lipids, and insulin resistance (P < .05 for IMT and IAD).

CONCLUSIONS

In overweight/obese young to middle-aged adults, objectively measured snoring was related to vascular remodeling in those without OSA. Snoring may contribute to CVD risk but warrants further examination in larger prospective cohorts.

Auto-adaptive positive airway pressure improves lung function and arterial stiffness parameters in patients with severe obstructive sleep apnea syndrome over a 1 year follow-up

OBJECTIVE

Auto-adaptive positive airway pressure (APAP) is an emerging therapeutic modality for obstructive sleep apnea (OSA) patients. However, their associated physiological effects have not been well-defined. Therefore, we aimed to investigate the impact of a 1 year APAP treatment on lung function and arterial stiffness parameters.

APPROACH

This study enrolled male patients with newly diagnosed severe OSA who have undergone APAP treatment. A total of 35 patients completed a 1 year follow up. Blood pressure, arterial stiffness (PWV, cAIx, pAIx, cSBP), and lung function readings (FEV₁, FVC, FEV₁/FVC, PEF) were obtained basally and after 1, 3, 6, and 12 months of treatment.

MAIN RESULTS

A gradual increase in FEV₁ has been observed over the follow-up (2.92 ± 0.88 versus 3.07 ± 0.92 versus 3.18 ± 0.93 versus 3.28 ± 0.93 versus 3.41 ± 0.97 L), while PWV showed a gradual decrease over the follow-up (9.72 ± 1.64 versus 9.32 ± 1.73 versus 8.89 ± 1.65 versus 8.53 ± 1.61 versus 8.46 ± 1.60 m s^-1), as measured by absolute values. Linear mixed effects model analysis revealed a statistically significantly higher FEV₁ values (coefficient of 0.11, 0.20, and 0.33 for 3rd month, 6th month, and 12th month, respectively, P < 0.001) and lower PWV values (coefficient of -0.69, -0.63, and -0.34 for 3rd month, 6th month, and 12th month, respectively, P < 0.001), after the initiation of APAP treatment.

SIGNIFICANCE

We conclude that APAP treatment improves main lung function and arterial stiffness parameters in male patients with severe OSA over a 1 year follow-up.

Characterization of genetic and phenotypic heterogeneity of obstructive sleep apnea using electronic health records

Background

Obstructive sleep apnea (OSA) is defined by frequent episodes of reduced or complete cessation of airflow during sleep and is linked to negative health outcomes. Understanding the genetic factors influencing expression of OSA may lead to new treatment strategies. Electronic health records (EHRs) can be leveraged to both validate previously reported OSA-associated genomic variation and detect novel relationships between these variants and comorbidities.

Methods

We identified candidate single nucleotide polymorphisms (SNPs) via systematic literature review of existing research. Using datasets available at Geisinger (n = 39,407) and Vanderbilt University Medical Center (n = 24,084), we evaluated associations between 40 previously implicated SNPs and OSA diagnosis, defined using clinical codes. We also evaluated associations between these SNPs and OSA severity measures obtained from sleep reports at Geisinger (n = 6571). Finally, we used a phenome-wide association study approach to help reveal pleiotropic genetic effects between OSA candidate SNPs and other clinical codes and laboratory values available in the EHR.

Results

Most previously reported OSA candidate SNPs showed minimal to no evidence for associations with OSA diagnosis or severity in the EHR-derived datasets. Three SNPs in LEPR, MMP-9, and GABBR1 validated for an association with OSA diagnosis in European Americans; the SNP in GABBR1 was associated following meta-analysis of results from both clinical populations. The GABBR1 and LEPR SNPs, and one additional SNP, were associated with OSA severity measures in European Americans from Geisinger. Three additional candidate OSA SNPs were not associated with OSA-related traits but instead with hyperlipidemia and autoimmune diseases of the thyroid.

Conclusions

To our knowledge, this is one of the largest candidate gene studies and one of the first phenome-wide association studies of OSA genomic variation. Results validate genetic associates with OSA in the LEPR, MMP-9 and GABBR1 genes, but suggest that the majority of previously identified genetic associations with OSA may be false positives. Phenome-wide analyses provide evidence of mediated pleiotropy. Future well-powered genome-wide association analyses of OSA risk and severity across populations with diverse ancestral backgrounds are needed. The comprehensive nature of the analyses represents a platform for informing future work focused on understanding how genetic data can be useful to informing treatment of OSA and related comorbidities.

Polysomnographic characteristics of severe obstructive sleep apnea vary significantly between hypertensive and normotensive patients of both genders

PURPOSE

Hypertension is a common finding in patients with obstructive sleep apnea (OSA), but it has remained unclear whether or not the amount of disturbed breathing and characteristics of individual respiratory events differ between hypertensive and normotensive patients with severe OSA.

METHODS

Full polysomnographic recordings of 323 men and 89 women with severe OSA were analyzed. Differences in the duration of individual respiratory events, total apnea and hypopnea times, and the percentage of disturbed breathing from total sleep time (AHT%) were compared between normotensive and hypertensive patients separately by genders. Furthermore, differences in the respiratory event characteristics were assessed between three AHT% groups (AHT% ≤ 30%, 30% < AHT% ≤ 45%, and AHT% > 45%).

RESULTS

Hypertensive women had lower percentage apnea time (15.2% vs. 18.2%, p = 0.003) and AHT% (33.5% vs. 36.5%, p = 0.021) when compared with normotensive women. However, these differences were not observed between hypertensive and normotensive men. Percentage hypopnea time was higher in hypertensive men (13.5% vs. 11.2%, p = 0.043) but not in women (15.2% vs. 12.2%, p = 0.130) compared with their normotensive counterparts. The variation in AHI explained 60.5% (ρ = 0.778) and 65.0% (ρ = 0.806) of the variation in AHT% in normotensive and hypertensive patients, respectively. However, when AHT% increased, the capability of AHI to explain the variation in AHT% declined.

CONCLUSIONS

There is a major inter- and intra-gender variation in percentage apnea and hypopnea times between hypertensive and normotensive patients with severe OSA. OSA is an important risk factor for hypertension and thus, early detection and phenotyping of OSA would allow timely treatment of patients with the highest risk of hypertension.

Pathogenesis of Obstructive Sleep Apnea

The pathogenesis of obstructive sleep apnea (OSA) has undergone major revisions since it was first described in 1978. This article focuses on new advances. Although it is still necessary to have a collapsible airway to develop OSA, it is primarily the response to obstruction that determines OSA severity and clinical presentation. Identifying factors that determine whether the response is stable or unstable through phenotyping is a promising approach that may lead to pharmacologic therapy in selected patients.

Effects of Sleep Duration on Cardiovascular Events

PURPOSE OF REVIEW

Sleep is an essential component of human health, and suboptimal sleep duration has been associated with increased cardiovascular morbidity and mortality. This review summarizes physiological and pathological effects of sleep duration on the cardiovascular system.

RECENT FINDINGS

Both decreased and increased duration of sleep lead to increased cardiovascular mortality and has a U-shaped curve. Sleep apnea is an independent risk factor for atherosclerosis and hypertension, and its treatment with continuous positive airway pressure (CPAP) results in increased survival. Estimated sleep duration of 6-8 h is associated with decreased mortality and major cardiovascular events and should be addressed by clinicians during routine visits.

Reduced Coronary Flow Reserve Is Associated with Impaired Ventricular-vascular Interaction in Patients with Obstructive Sleep Apnea

Background and Objectives

Obstructive sleep apnea (OSA) is associated with cardiac and arterial damage and adverse cardiovascular outcomes. We aimed to determine whether coronary flow reserve (CFR), which represents microvascular dysfunction, might be associated with the ventricular-vascular coupling index (VVI), which represents the afterload-adjusted contractility in patients with OSA.

Methods

We enrolled 281 patients (257 males; mean age, 43±11 years) with newly diagnosed OSA. Transthoracic echocardiography was performed, and adenosine-associated CFR was measured in the left anterior descending coronary artery. We evaluated the differences between the patients with normal CFR ≥2.5 and reduced CFR <2.5. VVI was calculated using the effective arterial elastance (Ea) and left ventricular (LV) end-systolic elastance (Ees) as follows: 10×Ea/Ees.

Results

The normal CFR group (n=214) showed increased Ees (7.28±2.31 vs. 8.14±2.33 mmHg/mL, p=0.016) and preserved VVI (3.17±1.53 vs. 2.78±1.20, p=0.044) compared with the reduced CFR group (n=67). There were no differences in LV dimension, LV ejection fraction, left atrial-volume index, E/e′, left atrial strain and LV global longitudinal strain between the 2 groups (all p>0.05). CFR was significantly correlated to Ees (r=0.139; p=0.023) and VVI (r=−0.137; p=0.025).

Conclusions

Reduced CFR is associated with decreased Ees and impaired VVI in OSA patients. It suggests the necessity of more intensive observation in OSA patients with reduced CFR to improve cardiovascular outcomes.

CPAP and Health-Related Quality of Life in Adults With Coronary Artery Disease and Nonsleepy Obstructive Sleep Apnea in the RICCADSA Trial

STUDY OBJECTIVES

To determine the effect of continuous positive airway pressure (CPAP) treatment on health-related quality of life (HRQoL) in adults with coronary artery disease (CAD) and nonsleepy obstructive sleep apnea (OSA).

METHODS

This was a secondary outcome analysis of the RICCADSA trial, conducted in Sweden between 2005 and 2013. Adults with CAD, nonsleepy OSA (apnea-hypopnea index [AHI] ≥ 15 events/h; Epworth Sleepiness Scale [ESS] score < 10) and complete Short-Form (SF)-36 questionnaires at baseline and after 12 months were included. Patients were randomized to CPAP (n = 102) or no CPAP (n = 104). The primary outcome was the between-group difference in absolute change in the SF-36 components. Within-group changes as well as variables associated with absolute change in the domains in the entire population were also tested.

RESULTS

Mean SF-36 scores were similar at baseline, ranging from 44.9 ± 9.6 to 92.2 ± 15.8 in various domains, and between-group changes from baseline were not statistically significant at 1 year. There was a significant increase in Role physical, Vitality, Role emotional, Mental health and Mental Component Summary (MCS), and a decrease in Bodily pain and General health scores in the CPAP group. The change in Physical Component Summary (PCS) was determined by female sex (beta coefficient -0.19, 95% confidence interval [CI] -7.25 to -0.98, P = .010), baseline AHI (beta coefficient -0.19, 95% CI -0.21 to -0.03, P = .009), CPAP use (h/night) (beta coefficient -0.16, 95% CI -0.93 to -0.06, P = .028), and acute myocardial infarction at baseline (beta coefficient 0.18, 95% CI 0.59 to 5.19, P = .014). Determinants of the change in MCS from baseline were change in the ESS score (beta coefficient -0.14, 95% CI -0.87 to -0.01, P = .054) and change in the Zung Self-rated Depression Scale scores (beta coefficient -0.33, 95% CI -0.58 to -0.24, P < .001).

CONCLUSIONS

Assignment to CPAP treatment compared to no CPAP had no significant effect on HRQoL as measured by the SF-36 in adults with CAD and nonsleepy OSA. Although several components of the SF-36 scores were improved within the CPAP group, CPAP use was associated with a decrease in PCS. The improvement in MCS was determined by the improvement in daytime sleepiness and depressive mood.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Identifier: NCT00519597.

CITATION

Wallström S, Balcan B, Thunström E, Wolf A, Peker Y. CPAP and health-related quality of life in adults with coronary artery disease and nonsleepy obstructive sleep apnea in the RICCADSA trial. J Clin Sleep Med. 2019;15(9):1311-1320.

Sleep Disordered Breathing and Cardiovascular Diseases

Sleep disordered breathing (SDB), which causes sleep deprivation, intermittent hypoxia, and negative intrathoracic pressure swings, can be accompanied by other harmful pathophysiologies relating to cardiovascular diseases (CVD), including sudden death, atrial fibrillation, stroke, and coronary artery disease leading to heart failure. Continuous positive airway pressure (CPAP) therapy for SDB has been reported to provide favorable effects such as lowered systemic blood pressure and improved endothelial function. However, in recent randomized controlled trials, CPAP has failed to demonstrate its beneficial prognostic impact on the primary or secondary setting of CVD. In this review article, we describe the characteristics of SDB complicated with CVD, the prognostic impacts of SDB in CVD, and the beneficial effects of CPAP on CVD.

Associations Between Obstructive Sleep Apnea and Measures of Arterial Stiffness

STUDY OBJECTIVES

The aim of this study was to determine whether severity measures of obstructive sleep apnea (OSA) are associated with arterial stiffness and central blood pressure (two important cardiovascular risk factors) in a large group of patients with OSA.

METHODS

Baseline data from six studies on OSA in which arterial stiffness and central aortic blood pressure measures were determined using applanation tonometry were pooled. Associations between measures of arterial stiffness (heart rate corrected augmentation index [AI75]), central aortic blood pressure (central systolic pressure [CSP] and heart rate corrected central augmentation pressure [CAP75]) and measures of OSA severity were explored using stepwise regression modelling.

RESULTS

Data from 362 participants (M:F ratio 13:1) with mean (standard deviation) age 49.2 (11.0) years, body mass index 31.9 (5.3) kg/m², apnea-hypopnea index (AHI) 35.7 (20.7) events/h were included in the analyses. The AHI, oxygen desaturation index (ODI3%), and sleep time with SpO₂ < 90% (T90) were all associated with arterial stiffness (AI75), (AHI: adj. β = .069; P = .01; ODI3%: adj. β = .072; P = .01; T90: adj. β = .18; P < .0001) and CAP75 (AHI: adj. β = .030; P = .01; ODI3%: adj. β = .027; P = .02; T90: adj. β = .080; P < .0001). AHI was also associated with CSP (AHI: adj. β = .11; P = .002).

CONCLUSIONS

OSA severity was significantly associated with augmentation index and CAP75 although the relationships were not strong.

Recognizable clinical subtypes of obstructive sleep apnea across international sleep centers: a cluster analysis

Study Objectives

A recent study of patients with moderate-severe obstructive sleep apnea (OSA) in Iceland identified three clinical clusters based on symptoms and comorbidities. We sought to verify this finding in a new cohort in Iceland and examine the generalizability of OSA clusters in an international ethnically diverse cohort.

Methods

Using data on 972 patients with moderate-severe OSA (apnea-hypopnea index [AHI] ≥ 15 events per hour) recruited from the Sleep Apnea Global Interdisciplinary Consortium (SAGIC), we performed a latent class analysis of 18 self-reported symptom variables, hypertension, cardiovascular disease, and diabetes.

Results

The original OSA clusters of disturbed sleep, minimally symptomatic, and excessively sleepy replicated among 215 SAGIC patients from Iceland. These clusters also generalized to 757 patients from five other countries. The three clusters had similar average AHI values in both Iceland and the international samples, suggesting clusters are not driven by OSA severity; differences in age, gender, and body mass index were also generally small. Within the international sample, the three original clusters were expanded to five optimal clusters: three were similar to those in Iceland (labeled disturbed sleep, minimal symptoms, and upper airway symptoms with sleepiness) and two were new, less symptomatic clusters (labeled upper airway symptoms dominant and sleepiness dominant). The five clusters showed differences in demographics and AHI, although all were middle-aged (44.6-54.5 years), obese (30.6-35.9 kg/m2), and had severe OSA (42.0-51.4 events per hour) on average.

Conclusions

Results confirm and extend previously identified clinical clusters in OSA. These clusters provide an opportunity for a more personalized approach to the management of OSA.

Obesity modulates the association between sleep apnea treatment and CHI3L1 levels but not CHIT1 activity in moderate to severe OSA: an observational study

Purpose

The inflammatory markers chitinase-3-like protein 1 (CHI3L1) and chitotriosidase (CHIT1) have both been associated with cardiovascular complications. The aim of this preliminary observational study was to assess the roles and interaction of obstructive sleep apnea (OSA) severity and body mass index (BMI) with plasma CHI3L1 levels and CHIT1 activity in patients with moderate to severe OSA. The second aim was to assess the roles and interaction of positive airway pressure (PAP) treatment and BMI on the expression of the same proteins.

Methods

The study included 97 OSA patients with an apnea–hypopnea index (AHI) ≥ 15 and full usage of PAP treatment after 4 months. Plasma CHI3L1 levels and CHIT1 activity were measured before and after treatment.

Results

Multiple linear regression analysis demonstrated an independent association of BMI on CHI3L1 levels (p < 0.05) but not on CHIT1 activity. The OSA severity markers (AHI and oxygen desaturation index) did not independently or in interaction with BMI levels associate with CHI3L1 levels or with CHIT1 activity (p > 0.05). A two-way repeated measures ANOVA revealed a significant interaction between PAP treatment effect (before vs. after) and BMI groups (< 35 kg/m² vs. ≥ 35 kg/m²) on CHI3L1 levels (p = 0.03) but not on CHIT1 activity (p = 0.98).

Conclusions

Obesity independently associated with CHI3L1 levels. Association between OSA severity and CHI3L1 levels or CHIT1 activity (independent of or dependent on obesity level) could not be confirmed. However, decrease was observed in CHI3L1 levels after PAP treatment in severely obese OSA patients but not in those less obese.

Electronic supplementary material

The online version of this article (10.1007/s11325-018-1731-6) contains supplementary material, which is available to authorized users.

Neuroanatomical Basis of State-Dependent Activity of Upper Airway Muscles

Obstructive Sleep Apnea (OSA) is a common sleep-related respiratory disorder that is associated with cognitive, cardiovascular, and metabolic morbidities. The major cause of OSA is the sleep-related reduction of upper airway muscle tone that leads to airway obstructions in individuals with anatomically narrow upper airway. This reduction is mainly due to the suppressant effect of sleep on hypoglossal motoneurons that innervate upper airway muscles. The hypoglossal motoneurons have state-dependent activity, which is decreased during the transition from wakefulness to non-rapid eye movement sleep and is further suppressed during rapid eye movement sleep. Multiple neurotransmitters and their receptors have been implicated in the control of hypoglossal motoneuron activity across the sleep-wake states. However, to date, the results of the rigorous testing show that withdrawal of noradrenergic excitation and cholinergic inhibition essentially contribute to the depression of hypoglossal motoneuron activity during sleep. The present review will focus on origins of noradrenergic and cholinergic innervation of hypoglossal motoneurons and the functional role of these neurons in the state-dependent activity of hypoglossal motoneurons.

Increased risk for new-onset hypertension in midlife male snorers: The 14-year follow-up study

While the association between sleep-related breathing disorders such as snoring and hypertension has been well established, it still remains unclear whether the association differs by age and gender. Therefore, in this 14-year follow-up study, we examined the independent association between self-reported snoring and the incidence of hypertension by gender and age groups in a large cohort of Korean adults. A total of 4,954 adults, aged 40-69 years, free of hypertension at baseline were enrolled. Participants were divided into three groups based on a self-reported snoring frequency: never; occasional (snoring <4 nights per week); and habitual snorer (snoring ≥4 nights). At baseline and biennial follow-up visits, blood pressure was measured by trained examiners. Incident hypertension was defined as the first occurrence at any follow-up examination where the participants had blood pressure ≥140/90 mmHg or were being treated with antihypertensive medication. After adjusting for known cardiovascular risk factors, only in men aged ≤45 years was habitual snoring significantly associated with a 1.5 times higher risk for incident hypertension than never snoring. In this age group, habitual snoring was significantly associated with increased risk for the development of hypertension, regardless of the presence of excessive daytime sleepiness. In women, snoring was not significantly associated with hypertension incidence in any age group. The present study suggests that young male snorers may be at high risk for the future development of hypertension, which has important clinical implications for early detection and treatment of snoring to reduce the burden of cardiovascular disease.

Obstructive sleep apnoea is associated with progression of arterial stiffness independent of obesity in participants without hypertension: A KoGES Prospective Cohort Study

Accumulating evidence shows that obstructive sleep apnoea (OSA) is associated with an increased risk of cardiovascular disease. However, there are no published prospective studies on the relationship between OSA and the progression of arterial stiffness. We hypothesised that OSA would increase the risk of arterial stiffness progression, independent of obesity. In the present large cohort study, 1921 participants were randomly selected and underwent polysomnography. The brachial ankle pulse wave velocity (baPWV) was measured at baseline and during the follow-period using a standard protocol. Elevated baPWV was defined as a value greater than the cut-off of highest tertile level in the complete study cohort. The percentage of elevated baPWV and the ΔbaPWV significantly increased with OSA severity. After adjusting for potential confounding factors, participants with moderate-to-severe OSA without hypertension had a significantly higher risk of elevated ΔbaPWV than those without OSA. More importantly, using multivariate mixed-effect models, we found that the ΔbaPWV over 6 years significantly differed according to OSA severity. Therefore, moderate-to-severe OSA in participants without hypertension was a predictor of future burden of arterial stiffness progression, independent of obesity, suggesting that it may contribute to the increased risk of cardiovascular disease.

Sleep: important considerations for the prevention of cardiovascular disease

PURPOSE OF REVIEW

Sleep plays many roles in maintenance of cardiovascular health. This review summarizes the literature across several areas of sleep and sleep disorders in relation to cardiometabolic disease risk factors.

RECENT FINDINGS

Insufficient sleep duration is prevalent in the population and is associated with weight gain and obesity, inflammation, cardiovascular disease, diabetes, and mortality. Insomnia is also highly present and represents an important risk factor for cardiovascular disease, especially when accompanied by short sleep duration. Sleep apnea is a well-characterized risk factor for cardiometabolic disease and cardiovascular mortality. Other issues are relevant as well. For example, sleep disorders in pediatric populations may convey cardiovascular risks. Also, sleep may play an important role in cardiovascular health disparities.

SUMMARY

Sleep and sleep disorders are implicated in cardiometabolic disease risk. This review addresses these and other issues, concluding with recommendations for research and clinical practice.

Systolic Blood Pressure Elevation in Children with Obstructive Sleep Apnea Is Improved with Positive Airway Pressure Use

INTRODUCTION

To evaluate the effect of continuous positive airway pressure (CPAP) treatment on blood pressure (BP) in children with obstructive sleep apnea (OSA).

STUDY DESIGN

Retrospective chart review of children aged 7-17 referred to Benioff Children's Hospital Oakland for the evaluation of snoring. Data collected included age, body mass index (BMI), BP, heart rate, apnea-hypopnea index, and oxygen saturation nadir. Children were divided into 3 groups: snorers, untreated OSA, and OSA treated with CPAP. Seventy-five children were identified, 25 in each group.

RESULTS

There was no difference in age or apnea-hypopnea index among the groups. The CPAP group had higher BMI than the snorers and untreated OSA groups. Systolic BP was higher in the 2 OSA groups compared with the snorers. After CPAP treatment, systolic BP decreased. The BP decrease was significantly greater in patients with higher BMI at baseline. There was no significant change in diastolic BP in the 3 groups.

CONCLUSION

Children with OSA have higher systolic BP than habitual snorers. Treatment with CPAP in children with OSA for 6 months reduced their systolic BP despite a small increase in their BMI.

Sleep Health and Predicted Cardiometabolic Risk Scores in Employed Adults From Two Industries

STUDY OBJECTIVES

Sleep disorders and sleep deficiency can increase the risk for cardiovascular disease. Less is known about whether multiple positive attributes of sleep health known as the SATED (satisfaction, alertness, timing, efficiency, and duration) model, can decrease future cardiovascular disease risks. We examined whether and how a variety of indicators of sleep health predicted 10-year estimated cardiometabolic risk scores (CRS) among employed adults.

METHODS

Workers in two industries-extended care (n = 1,275) and information technology (IT; n = 577)-reported on habitual sleep apnea symptoms and sleep sufficiency, and provided 1 week of actigraphy data including nighttime sleep duration, wake after sleep onset (WASO), sleep timing, and daytime napping. Workers also provided biomarkers to calculate future cardiometabolic risk.

RESULTS

More sleep apnea symptoms predicted higher CRS in both industries. More sleep sufficiency, less WASO, and less daytime napping (having no naps, fewer naps, and shorter nap duration) were also linked to lower CRS, but only in the extended care workers. There was no effect of sleep duration in both industries. In the IT employee sample, shorter sleep duration (≤ 6 hours versus 6-8 hours) and more naps strengthened the link between sleep apnea and CRS.

CONCLUSIONS

Sleep health, measured by both subjective and objective methods, was associated with lower cardiometabolic disease risks among extended care workers (lower to middle wage workers). Sleep apnea was an important predictor of CRS; for the IT workers, the link between sleep apnea and CRS was exacerbated when they had poorer sleep health behaviors.

Lower plasma choline levels are associated with sleepiness symptoms

Sleepiness and cardiovascular disease share common molecular pathways; thus, metabolic risk factors for sleepiness may also predict cardiovascular disease risk. Daytime sleepiness predicts mortality and cardiovascular disease, although the mechanism is unidentified. This study explored the associations between subjective sleepiness and metabolite concentrations in human blood plasma within the oxidative and inflammatory pathways, in order to identify mechanisms that may contribute to sleepiness and cardiovascular disease risk.

METHODS

An exploratory case-control sample of 36 subjects, categorized based on the Epworth Sleepiness Scale (ESS) questionnaire as sleepy (ESS ≥ 10) or non-sleepy (ESS < 10), was recruited among subjects undergoing an overnight sleep study for suspected sleep apnea at the University of Pennsylvania Sleep Center. The average age was 42.4 ± 10.5 years, the mean body mass index (BMI) was 40.0 ± 9.36 kg/m², median Apnea Hypopnea Index (AHI) was 8.2 (IQR: 2.5-26.5), and 52% were male. Fasting morning blood plasma samples were collected after an overnight sleep study. Biomarkers were explored in subjects with sleepiness versus those without using the multiple linear regression adjusting for age, BMI, smoking, Apnea Hypopnea Index (sleep apnea severity), study cohort, and hypertension.

RESULTS

The level of choline is significantly lower (P = 0.003) in sleepy subjects (N = 18; mean plasma choline concentration of 8.19 ± 2.62 μmol/L) compared with non-sleepy subjects (N = 18; mean plasma choline concentration of 9.14 ± 2.25 μmol/L). Other markers with suggestive differences (P < 0.1) include isovalerylcarnitine, Alpha-Amino apidipic acid, Spingosine 1 Phosphate, Aspartic Acid, Propionylcarnitine, and Ceramides (fatty acids; C14-C16 and C-18).

CONCLUSION

This pilot study is the first to show that lower levels of plasma choline metabolites are associated with sleepiness. Further exploration of choline and other noted metabolites and their associations with sleepiness will guide targeted symptom management.

Obstructive Sleep Apnea-Induced Hypertension: Role of the Gut Microbiota

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA) is a significant risk factor for systemic hypertension and other cardiovascular diseases. While this relationship has been firmly established, a detailed understanding of how OSA leads to hypertension is lacking. This review will examine the emerging idea that the gut microbiota plays a role in the development of hypertension, including that associated with OSA.

RECENT FINDINGS

Disruption of the normal composition of the gut microbiota, termed dysbiosis, has been identified in a number of metabolic and cardiovascular diseases, including diabetes, obesity, and atherosclerosis. Recently, a number of studies have demonstrated gut dysbiosis in various animal models of hypertension as well as in hypertensive patients. Evidence is now emerging that gut dysbiosis plays a causal role in the development of OSA-induced hypertension. In this review, we will examine the evidence that gut dysbiosis plays a role in OSA-induced hypertension. We will discuss potential mechanisms linking OSA to gut dysbiosis, examine how gut dysbiosis may be linked to hypertension, and highlight how this understanding may be utilized for the development of future therapeutics.

Concurrent Presence of Obstructive Sleep Apnea and Elevated Homocysteine Levels Exacerbate the Development of Hypertension: A KoGES Six-year Follow-up Study

Accumulating evidence has revealed that obstructive sleep apnea (OSA) and high homocysteine (Hcy) levels play important roles in the increased risk of hypertension and cardiovascular disease. We investigated whether the presence of elevated Hcy levels among individuals with OSA increase the risk of hypertension in a cohort study. A total of 1825 participants were selected from the cohort study. A high homocysteine level (Hcy) was defined as those in the 75th percentile of Hcy levels of the study cohort. The prevalence of hypertension was higher among subjects with OSA and high Hcy levels than among the other groups stratified by the presence of OSA and high Hcy levels. The incidence of hypertension at 6-year follow-up was: Hcy[-]/OSA[-] vs. Hcy[+]/OSA[-] vs. Hcy[-]/OSA[+] vs. Hcy[+]/OSA[+], 14.2% vs. 19.8% vs. 24.2% vs. 36.1%. After adjusting for confounding factors, subjects with OSA and high Hcy levels had a 1.86-fold risk of developing hypertension compared to those without OSA and high Hcy levels. Moderate to severe OSA group with the highest tertile of Hcy levels had a 2.31-fold increased risk of developing hypertension. Interaction between Hcy and OSA on development of hypertension was significant, suggesting that these conditions may constitute an important determinant.

Application of Personalized, Predictive, Preventative, and Participatory (P4) Medicine to Obstructive Sleep Apnea. A Roadmap for Improving Care?

Dr. Leroy Hood promotes a paradigm to advance medical care that he calls P4 medicine. The four Ps are: personalized, predictive, preventative, and participatory. P4 medicine encourages a convergence of systems medicine, the digital revolution, and consumer-driven healthcare. Might P4 medicine be applicable to obstructive sleep apnea (OSA)? OSA should be personalized in that there are different structural and physiological pathways to disease. Obesity is a major risk factor. The link between obesity and OSA is likely to be fat deposits in the tongue compromising the upper airway. Clinical features at presentation also vary between patients. There are three distinct subgroups: (1) patients with a primary complaint of insomnia, (2) relatively asymptomatic patients with a high prevalence of cardiovascular comorbidities, and (3) excessively sleepy patients. Currently, there have been limited efforts to identify subgroups of patients on the basis of measures obtained by polysomnography. Yet, these diagnostic studies likely contain considerable predictive information. Likewise, there has currently been limited application of -omic approaches. Determining the relative role of obesity and OSA for particular consequences is challenging, because they both affect the same molecular pathways. There is evidence that the effects of OSA are modified by the level of obesity. These insights may lead to improvements in predicting outcomes to personalized therapies. The final P-participatory-is ideally suited to OSA, with technology to obtain extensive data remotely from continuous positive airway pressure machines. Providing adherence data directly to patients increases their use of continuous positive airway pressure. Thus, the concept of P4 medicine is very applicable to obstructive sleep apnea and can be the basis for future research efforts.

Sleep-disordered breathing in patients with sickle cell disease

Sickle cell disease is one of the most common hereditary hemoglobinopathies worldwide, and its vaso-occlusive and hemolytic crises cause considerable patient morbidity. A growing body of evidence has shown that sleep-disordered breathing, and in particular, obstructive sleep apnea, occurs at high frequency in the sickle cell population, and that there is significant overlap in the underlying pathophysiology of these two conditions. Through a variety of mechanisms including nocturnal hypoxemia and increased oxidative stress, production of pro-inflammatory cytokines, and endothelial dysfunction, sickle cell anemia and sleep-disordered breathing potentiate each other's clinical effects and end-organ complications. Here, we will review the shared pathophysiologic mechanisms of these conditions and discuss their clinical sequelae. We will also examine the results of studies that have been carried out with clinical intervention of nocturnal hypoxemia in patients with sickle cell disease in the attempts to overcome the complications of the disease. Finally, we will propose the areas of investigation that merit further investigations in future in patients with sickle cell disease and sleep-disordered breathing.

Prevalence of Obstructive Sleep Apnoea Among Patients Admitted for Bariatric Surgery. A Prospective Multicentre Trial

BACKGROUND

Obesity has become one of the greatest public health concerns worldwide and is known to be the most important risk factor for obstructive sleep apnoea (OSA). Prevalence of OSA has increased over the last two decades, but it is estimated that the majority of cases still remain undiagnosed. The aim of this study was to investigate the prevalence of OSA in Finnish bariatric surgery candidates.

METHODS

In this prospective multicentre study, standard overnight cardiorespiratory recording was conducted in 197 consecutive patients from three different hospitals. A sleep questionnaire was also administered. Anthropometric and demographic measurements included age, weight, body mass index (BMI) and waist and neck circumference.

RESULTS

Altogether, 71 % of the patients were diagnosed with OSA. The prevalence was higher in males (90 %) than in females (60 %) (p < 0.001). In OSA patients' group, the mean neck and waist circumference was larger (p < 0.001) and the body weight higher (p < 0.01) than in non-OSA group. When separating patients by gender, a significant difference remained only concerning neck circumference in female patients.

CONCLUSIONS

OSA is very common among bariatric surgery patients, especially in men. Considering this and the increased long-term morbidity and mortality generally related to OSA, a routine screening for OSA seems indicated in bariatric patients, particularly men.

Evaluation of carotid arterial elasticity in patients with obstructive sleep apnea hypopnea syndrome by two-dimensional speckle tracking imaging

The objective is to evaluate carotid arterial elasticity in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) by two-dimensional speckle tracking imaging (2D-STI).Sixty-two hospitalized patients with OSAHS and 20 healthy subjects were studied. The OSAHS patients were divided into 3 subgroups: a mild group, a moderate group, and severe group. All subjects underwent complete left common carotid artery (LCCA) examination by echo-tacking technique and 2D-STI. The stiffness parameter (β), elastic modulus (Eρ), stiffness β single pulse wave velocity (PWVβ), and arterial compliance (AC) were automatically calculated by echo-tracking technique. And the global and segmental peak systolic circumferential artery strain (CAS) values were made off-line using 2D-STI.The β, Ep, and PWVβ values of the carotid artery in the moderate and severe groups were greater than those in the control group (P < .05). In addition, the systolic peak global CAS and the segments between 5 and 7 o'clock in the moderate and severe groups were lower than those in the control group (P < .05). Compared with mild group, the β, PWVp, and Ep values of the carotid artery in the moderate and severe groups were higher (P < .05) and the systolic peak global CAS lower than in the control group (P < .05). The systolic peak global CAS was significantly inversely correlated with stiffness (β, r = - 0.61, P < .05) and stiffness β single pulse wave velocity (PWVβ, r = -0.59, P < .05). Through stepwise multiple linear regression analysis, age and SaO2 were the significant variables that determined the systolic peak global CAS2D-STI provides a new method to investigate carotid arterial elasticity in patients with OSAHS.

Managing resistant hypertension: focus on mineralocorticoid-receptor antagonists

Mineralocorticoid-receptor antagonists (MRAs) have proven to be effective in some types of hypertension, especially in resistant hypertension (RHTN). In this phenotype of hypertension, the renin-angiotensin-aldosterone pathway plays an important role, with MRAs being especially effective in reducing blood pressure. In this review, we show the relevance of aldosterone in RHTN, as well as some clinical characteristics of this condition and the main concepts involving its pathophysiology and cardiovascular damage. We analyzed the mechanisms of action and clinical effects of two current MRAs - spironolactone and eplerenone - both of which are useful in RHTN, with special attention to the former. RHTN represents a significant minority (10%-15%) of hypertension cases. However, primary-care physicians, cardiologists, nephrologists, neurologists, and geriatricians face this health problem on a daily basis. MRAs are likely one of the best pharmacological options in RHTN patients; however, they are still underused.

Evidence Base for Multidisciplinary Care of Pediatric/Adolescent Bariatric Surgery Patients

PURPOSE OF REVIEW

Severe childhood obesity, defined as having a body mass index (BMI) greater than the 99th percentile for age and gender, is rising in most countries and is associated with early morbidity and mortality. Optimal management of the health of the child with obesity requires a multidisciplinary approach that identifies and treats associated derangements.

RECENT FINDINGS

Lifestyle interventions such as diet, exercise, and behavioral therapy for the severely obese pediatric patient are generally not effective. Few centers worldwide offer bariatric surgery for adolescents in a multidisciplinary setting, and we are the only center that offers a multidisciplinary approach that incorporates bariatric surgery for severely obese children and adolescents across all age groups. In this paper, we review up-to-date evidence in this subject including ours, and provide details on the multidisciplinary approach to pediatric obesity that accommodates bariatric surgery for children across all age groups.

Catecholaminergic A1/C1 neurons contribute to the maintenance of upper airway muscle tone but may not participate in NREM sleep-related depression of these muscles

Neural mechanisms of obstructive sleep apnea, a common sleep-related breathing disorder, are incompletely understood. Hypoglossal motoneurons, which provide tonic and inspiratory activation of genioglossus (GG) muscle (a major upper airway dilator), receive catecholaminergic input from medullary A1/C1 neurons. We aimed to determine the contribution of A1/C1 neurons in control of GG muscle during sleep and wakefulness. To do so, we placed injections of a viral vector into DBH-cre mice to selectively express the hMD4i inhibitory chemoreceptors in A1/C1 neurons. Administration of the hM4Di ligand, clozapine-N-oxide (CNO), in these mice decreased GG muscle activity during NREM sleep (F_1,1,3=17.1, p<0.05); a similar non-significant decrease was observed during wakefulness. CNO administration had no effect on neck muscle activity, respiratory parameters or state durations. In addition, CNO-induced inhibition of A1/C1 neurons did not alter the magnitude of the naturally occurring depression of GG activity during transitions from wakefulness to NREM sleep. These findings suggest that A1/C1 neurons have a net excitatory effect on GG activity that is most likely mediated by hypoglossal motoneurons. However, the activity of A1/C1 neurons does not appear to contribute to NREM sleep-related inhibition of GG muscle activity, suggesting that A1/C1 neurons regulate upper airway patency in a state-independent manner.

Association of Positive Airway Pressure With Cardiovascular Events and Death in Adults With Sleep Apnea: A Systematic Review and Meta-analysis

IMPORTANCE

Sleep apnea (obstructive and central) is associated with adverse cardiovascular risk factors and increased risks of cardiovascular disease. Positive airway pressure (PAP) provides symptomatic relief, whether delivered continuously (CPAP) or as adaptive servo-ventilation (ASV), but the associations with cardiovascular outcomes and death are unclear.

OBJECTIVE

To assess the association of PAP vs control with cardiovascular events and death in patients with sleep apnea.

DATA SOURCES AND STUDY SELECTION

MEDLINE, EMBASE, and the Cochrane Library were systematically searched from inception date to March 2017 for randomized clinical trials that included reporting of major adverse cardiovascular events or deaths.

DATA EXTRACTION AND SYNTHESIS

Two authors independently extracted data using standardized forms. Summary relative risks (RRs), risk differences (RDs) and 95% CIs were obtained using random-effects meta-analysis.

MAIN OUTCOMES AND MEASURES

The main outcomes were a composite of acute coronary syndrome (ACS) events, stroke, or vascular death (major adverse cardiovascular events); cause-specific vascular events; and death.

RESULTS

The analyses included data from 10 trials (9 CPAP; 1 ASV) of patients with sleep apnea (N = 7266; mean age, 60.9 [range, 51.5 to 71.1] years; 5847 [80.5%] men; mean [SD] body mass index, 30.0 [5.2]. Among 356 major adverse cardiovascular events and 613 deaths recorded, there was no significant association of PAP with major adverse cardiovascular events (RR, 0.77 [95% CI, 0.53 to 1.13]; P = .19 and RD, -0.01 [95% CI, -0.03 to 0.01]; P = .23), cardiovascular death (RR, 1.15 [95% CI, 0.88 to 1.50]; P = .30 and RD -0.00 [95% CI, -0.02 to 0.02]; P = .87), or all-cause death (RR, 1.13 [95% CI, 0.99 to 1.29]; P = .08 and RD, 0.00 [95% CI, -0.01 to 0.01]; P = .51). The same was true for ACS, stroke, and heart failure. There was no evidence of different associations for CPAP vs ASV (all P value homogeneity >.24), and meta-regressions identified no associations of PAP with outcomes for different levels of apnea severity, follow-up duration, or adherence to PAP (all P values > .13).

CONCLUSIONS AND RELEVANCE

The use of PAP, compared with no treatment or sham, was not associated with reduced risks of cardiovascular outcomes or death for patients with sleep apnea. Although there are other benefits of treatment with PAP for sleep apnea, these findings do not support treatment with PAP with a goal of prevention of these outcomes.

The efficacy of continuous positive airway pressure therapy in reducing cardiovascular events in obstructive sleep apnea: a systematic review

Prospective studies show an association between obstructive sleep apnea and cardiovascular disease. Continuous positive airway pressure (CPAP) is the treatment of choice and effectively reduces subjective sleepiness and apneic and hypopneic events. However, randomized trials have not shown a reduction in cardiovascular outcomes with CPAP therapy. We review the past 10 years of randomized trial evidence regarding the therapeutic efficacy of CPAP on cardiovascular outcomes and mortality in adults with obstructive sleep apnea. The majority of studies found no significant improvement in cardiovascular outcomes with CPAP, although many noted nonsignificant benefits. Adjusted analysis in several trials showed significant cardiovascular benefit in those patients with higher CPAP compliance. Existing trials may lack sufficient follow-up and CPAP compliance, among other limitations.

Obstructive Sleep Apnea Screening Using a Piezo-Electric Sensor

In this study, we propose a novel method for obstructive sleep apnea (OSA) detection using a piezo-electric sensor. OSA is a relatively common sleep disorder. However, more than 80% of OSA patients remain undiagnosed. We investigated the feasibility of OSA assessment using a single-channel physiological signal to simplify the OSA screening. We detected both snoring and heartbeat information by using a piezo-electric sensor, and snoring index (SI) and features based on pulse rate variability (PRV) analysis were extracted from the filtered piezo-electric sensor signal. A support vector machine (SVM) was used as a classifier to detect OSA events. The performance of the proposed method was evaluated on 45 patients from mild, moderate, and severe OSA groups. The method achieved a mean sensitivity, specificity, and accuracy of 72.5%, 74.2%, and 71.5%; 85.8%, 80.5%, and 80.0%; and 70.3%, 77.1%, and 71.9% for the mild, moderate, and severe groups, respectively. Finally, these results not only show the feasibility of OSA detection using a piezo-electric sensor, but also illustrate its usefulness for monitoring sleep and diagnosing OSA.

Obstructive Sleep Apnea-Induced Hypertension: Role of the Gut Microbiota

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA) is a significant risk factor for systemic hypertension and other cardiovascular diseases. While this relationship has been firmly established, a detailed understanding of how OSA leads to hypertension is lacking. This review will examine the emerging idea that the gut microbiota plays a role in the development of hypertension, including that associated with OSA.

RECENT FINDINGS

Disruption of the normal composition of the gut microbiota, termed dysbiosis, has been identified in a number of metabolic and cardiovascular diseases, including diabetes, obesity, and atherosclerosis. Recently, a number of studies have demonstrated gut dysbiosis in various animal models of hypertension as well as in hypertensive patients. Evidence is now emerging that gut dysbiosis plays a causal role in the development of OSA-induced hypertension. In this review, we will examine the evidence that gut dysbiosis plays a role in OSA-induced hypertension. We will discuss potential mechanisms linking OSA to gut dysbiosis, examine how gut dysbiosis may be linked to hypertension, and highlight how this understanding may be utilized for the development of future therapeutics.

Correlation between Calpain-10 single-nucleotide polymorphisms and obstructive sleep apnea/hypopnoea syndrome with ischemic stroke in a Chinese population: A population-based study

BACKGROUND

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a common chronic disorder which is followed by various complications. Calpain-10 belongs to a commonly expressed member of the Calpain-like cysteine protease family, which acts as risk marker for some diseases. The purpose of this study is to elucidate correlation between Calpain-10 single-nucleotide polymorphisms (SNPs) and the incidence of OSAHS followed by ischemic stroke (IS).

METHODS

OSAHS patients were divided as OSAHS + IS, OSAHS, and control groups, respectively. Immunohistochemistry was performed for Calpain-10 protein expression, polymerase chain reaction (PCR)-restriction fragment length polymorphism for detection of gene polymorphisms of SNP 43 and SNP 19, and PCR-allele specific amplification for SNP 44. Polysomnography was conducted to check the nocturnal polysomnography indicators, and also Montreal Cognitive Assessment (MoCA), Scientific Data System scores cognition and anxiety of patients, respectively. Logistic analysis was used for the risky factors for OSAHS.

RESULTS

Calpain-10 protein expression was significantly increased in the OSAHS + IS and OSAHS groups compared with the control group. Significant differences in SNP 43 and SNP 44 genotype, and also allele frequency were observed in 3 groups, among which the OSAHS + IS group had higher SNP 43 and SNP 44 allele frequency than the control and OSAHS groups. There were differences regarding apnea-hypopnea index, minimum fingertip blood oxygen saturation (LSaO2 [%]), oxygen reduction index (ODI) between patients with different genotypes of SNP 43 and SNP 44 in OSAHS patients, and also GC and AT frequency in the OSAHS + IS and OSAHS groups. As compared with the OSAHS group, the MoCA scores and MoCA subitems in the OSAHS + IS group were declined, whereas the Scientific Data System scores were elevated. Additionally, GG 43 genotype, high apnea-hypopnea index, and body mass index were detected as the risk factors of OSAHS.

CONCLUSION

These findings indicate that the Calpain-10 SNP 43 may be related to OSAHS with IS, with SNP 43 GG genotype as a risk factor for OSAHS with IS.