Meta-analysis of effects of obstructive sleep apnea on the renin-angiotensin-aldosterone system

The role of Klotho and sirtuins in sleep-related cardiovascular diseases: a review study

The prevalence of sleep disorders has been reported from 1.6% to 56.0%, worldwide. Sleep deprivation causes cardiovascular diseases (CVDs) including atherosclerosis, vascular aging, hypertension, heart dysfunction, reduced heart rate variability, and cardiac arrhythmia. Reduced tissue oxygen causes various CVDs by activating pro-inflammatory factors and increasing oxidative stress. Sleep disorders are more important and prevalent in older people and cause more severe cardiovascular complications. On the other hand, the reduction of Klotho level, an age-dependent protein whose expression decreases with age, is associated with age-related diseases. Sirtuins, class III histone deacetylases, also are among the essential factors in postponing cellular aging and increasing the lifespan of organisms, and they do this by regulating different pathways in the cell. Sirtuins and Klotho play an important role in the pathophysiology of CVDS and both have anti-oxidative stress and anti-inflammatory activity. Studies have shown that the levels of Klotho and sirtuins are altered in sleep disorders. In this article, alterations of Klotho and sirtuins in sleep disorders and in the development of sleep-related CVDs were reviewed and the possible signaling pathways were discussed. The inclusion criteria were studies with keywords of different types of sleep disorders and CVDs, klotho, SIRT1-7, and sirtuins in PubMed, Scopus, Embase، Science Direct، Web of Sciences and Google Scholar by the end of 2023. The studies revealed there is a bidirectional relationship between sleep disorders and the serum and tissue levels of Klotho and sirtuins and sleep related-CVDs.

Chronic intermittent hypoxia facilitates the development of angiotensin II-induced abdominal aortic aneurysm in male mice

Obstructive sleep apnea (OSA), characterized by episodes of intermittent hypoxia (IH), is highly prevalent in patients with abdominal aortic aneurysm (AAA). However, whether IH serves as an independent risk factor for AAA development remains to be investigated. Here, we determined the effects of chronic (6 mo) IH on angiotensin (Ang II)-induced AAA development in C57BL/6J male mice and investigated the underlying mechanisms of IH in cultured vascular smooth muscle cells (SMCs). IH increased the susceptibility of mice to develop AAA in response to Ang II infusion by facilitating the augmentation of the abdominal aorta's diameter as assessed by transabdominal ultrasound imaging. Importantly, IH with Ang II augmented aortic elastin degradation and the expression of matrix metalloproteinases (MMPs), mainly MMP8, MMP12, and a disintegrin and metalloproteinase-17 (ADAM17) as measured by histology and immunohistochemistry. Mechanistically, IH increased the activities of MMP2, MMP8, MMP9, MMP12, and ADAM17, while reducing the expression of the MMP regulator reversion-inducing cysteine-rich protein with Kazal motifs (RECK) in cultured SMCs. Aortic samples from human AAA were associated with decreased RECK and increased expression of ADAM17 and MMPs. These data suggest that IH facilitates AAA development when additional stressors are superimposed and that this occurs in association with an increased presence of aortic MMPs and ADAM17, potentially due to IH-induced modulation of RECK expression. These findings support a plausible synergistic link between OSA and AAA and provide a better understanding of the molecular mechanisms underlying the pathogenesis of AAA.NEW & NOTEWORTHY IH facilitates Ang II-induced abdominal aortic diameter expansion and AAA development in C57BL/6J male mice. IH upregulates the expression of specific MMPs such as MMP8, MMP12, and ADAM17. IH directly suppresses RECK expression and increases MMPs activity in SMCs. Human AAA tissues exhibit a downregulation of RECK and an upregulation of ADAM17 and MMPs.

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

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

Severe COVID-19 infection: An institutional review and literature overview

BACKGROUND

Our study aimed to describe the group of severe COVID-19 patients at an institutional level, and determine factors associated with different outcomes.

METHODS

A retrospective chart review of patients admitted with severe acute hypoxic respiratory failure due to COVID-19 infection. Based on outcomes, we categorized 3 groups of severe COVID-19: (1) Favorable outcome: progressive care unit admission and discharge (2) Intermediate outcome: ICU care (3) Poor outcome: in-hospital mortality.

RESULTS

Eighty-nine patients met our inclusion criteria; 42.7% were female. The average age was 59.7 (standard deviation (SD):13.7). Most of the population were Caucasian (95.5%) and non-Hispanic (91.0%). Age, sex, race, and ethnicity were similar between outcome groups. Medicare and Medicaid patients accounted for 62.9%. The average BMI was 33.5 (SD:8.2). Moderate comorbidity was observed, with an average Charlson Comorbidity index (CCI) of 3.8 (SD:2.6). There were no differences in the average CCI between groups(p = 0.291). Many patients (67.4%) had hypertension, diabetes (42.7%) and chronic lung disease (32.6%). A statistical difference was found when chronic lung disease was evaluated; p = 0.002. The prevalence of chronic lung disease was 19.6%, 27.8%, and 40% in the favorable, intermediate, and poor outcome groups, respectively. Smoking history was associated with poor outcomes (p = 0.04). Only 7.9% were fully vaccinated. Almost half (46.1%) were intubated and mechanically ventilated. Patients spent an average of 12.1 days ventilated (SD:8.5), with an average of 6.0 days from admission to ventilation (SD:5.1). The intermediate group had a shorter average interval from admission to ventilator (77.2 hours, SD:67.6), than the poor group (212.8 hours, SD:126.8); (p = 0.001). The presence of bacterial pneumonia was greatest in the intermediate group (72.2%), compared to the favorable group (17.4%), and the poor group (56%); this was significant (p<0.0001). In-hospital mortality was seen in 28.1%.

CONCLUSION

Most patients were male, obese, had moderate-level comorbidity, a history of tobacco abuse, and government-funded insurance. Nearly 50% required mechanical ventilation, and about 28% died during hospitalization. Bacterial pneumonia was most prevalent in intubated groups. Patients who were intubated with a good outcome were intubated earlier during their hospital course, with an average difference of 135.6 hours. A history of cigarette smoking and chronic lung disease were associated with poor outcomes.

Nocturia and obstructive sleep apnoea

Nocturia, the need to urinate at night, is a common symptom in patients with obstructive sleep apnoea (OSA). Continuous positive airway pressure treatment can reduce nocturia in some patients, but the underlying mechanisms are complex and not fully understood. OSA affects the autonomic nervous system, oxidative stress and endothelial damage. Furthermore, the commonly held theory attributing polyuria to a false signal of cardiac overload and response natriuresis has limitations. A comprehensive approach to the management of nocturia in OSA, considering factors such as comorbidities, medication use, alcohol consumption and lifestyle, is needed. Effective management of nocturia in OSA requires a multidisciplinary approach, and urologists should be aware of the potential effect of OSA on physiology and refer patients for further testing at a sleep centre. In addition to continuous positive airway pressure, other interventions such as oral appliances and surgical obstruction treatment could be beneficial for some patients. Overall, understanding the complex interplay between OSA and nocturia is crucial for optimizing patient outcomes.

Obstructive sleep apnoea-hypopnoea syndrome

Obstructive sleep apnoea-hypopnoea syndrome (OSAHS) is a common disorder characterised by repetitive episodes of the complete or partial collapse of the pharyngeal airway during sleep. This results in cessation (apnoea) or reduction (hypopnoea) of airflow, leading to oxygen desaturation and sleep fragmentation. An individual's disposition to develop OSAHS depends on the collapsibility of a segment of the upper airway. The degree of collapsibility can be quantified by the balance between occluding or extraluminal pressures of the surrounding tissues. Patients can experience snoring, unrefreshing sleep, witnessed apnoeas, waking with a choking sensation and excessive daytime sleepiness. OSAHS has a broad range of consequences, including cardiovascular, metabolic, and neurocognitive sequelae. Treatment options include lifestyle measures, in particular weight loss, and strategies to maintain upper airway patency overnight, including continuous positive airway pressure, mandibular advancement devices and positional modifiers.

Serum levels of carbohydrate antigen 125 in patients with heart failure and obstructive sleep apnea syndrome: a retrospective analysis

Background

Obstructive sleep apnea syndrome (OSAS) combined with heart failure (HF) has become a serious disease that threatens human health. Therapeutic interventions targeting OSAS have been shown to improve outcomes in patients with HF, so the identification of severe OSAS in HF is critical. Carbohydrate antigen 125 (CA125) is associated with inflammation and volume overload. The levels of CA125 are elevated in the serum of patients with HF and might be further elevated in patients with HF and OSAS. The aim of this study was to measure CA125 levels in patients with HF with and without OSAS and to analyze affecting factors.

Methods

In this single-center retrospective cohort study, a total of 95 patients diagnosed with HF hospitalized in Zhongda Hospital from April 2021 to April 2022 were recruited, including 55 patients with OSAS and 40 patients without OSAS. Participants with a history of central sleep apnea syndrome, severe chronic obstructive pulmonary disease, tumors, severe infection, or who were pregnant were excluded. The histories of the participants were recorded, and laboratory examinations were performed. Binary logistic regression analysis was performed to determine the relationship between serum CA125 levels and OSAS in patients with HF.

Results

The serum CA125 levels were higher in the HF + OSAS group than in the HF group (29.60 vs. 9.68 U/mL, P<0.001). According to the univariate analysis, CA125 (>35 U/mL) was significantly related to pleural effusion, acute HF, apnea-hypopnea index (AHI), left ventricular ejection fraction (LVEF) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels. Finally, the AHI demonstrated statistical significance in multiple analyses (OR 1.070, 95% CI: 1.019-1.124, P=0.006). Spearman rank correlation coefficient analysis showed that CA125 was positively correlated with AHI, and Ln(CA125) (Ln is the natural logarithm based on e) gradually increased with increasing AHI (r=0.551, P<0.0001).

Conclusions

The levels of CA125 were further increased in patients with HF and OSAS, and CA125 (>35 U/mL) was positively correlated with AHI. As a biomarker associated with inflammation and congestion, serum CA125 may have certain value in the diagnosis of patients with HF combined with OSAS.

Effect of Sleep Duration on Blood Pressure in Patients with SARS-CoV-2 Infection and Hypertensive Urgencies in Shanghai Fangcang Shelter Hospital

Objective

To evaluate the effect of sleep duration on blood pressure in patients with hypertension urgencies combined with SARS-CoV-2 infection in a Fangcang shelter hospital.

Methods

From April 10, 2020 to May 20, 2022, we statistically analyzed the blood pressure and sleep conditions of 52 patients with combined hypertension urgencies and SARS-CoV-2 infection admitted in Shanghai National Convention and Exhibition Center Fangcang shelter hospital. They were divided into the short-term (daily sleep duration: <7 h) and normal sleep group (7-9 h). We performed a comparison of the control effects of basic antihypertensive drugs. Additionally, patients in the short-term sleep group underwent drug therapy for sleep regulation and continuous monitoring of blood pressure.

Results

Among these patients, the blood pressure was higher in the short-term sleep group than that of the normal sleep group, and also more difficult to control (p <0.05). Furthermore, the blood pressure of the patients in the short-term sleep group was more easily controlled after treatment with drugs for sleep regulation and basic antihypertensive drugs (p <0.05).

Conclusion

The blood pressure level in patients with combined SARS-CoV-2 infection and hypertension urgencies was higher in those with a shorter duration of daily sleep, and also more difficult to control in Fangcang shelter hospital. Drug therapy for sleep regulation should be administered early to obtain sufficient blood pressure control effects.

Prevalence of primary aldosteronism in patients with concomitant hypertension and obstructive sleep apnea, baseline data of a cohort

Obstructive sleep apnea (OSA) and primary aldosteronism (PA) often coexist in hypertension, whereas whether hypertensive patients with OSA should be screened for PA is controversial and whether gender, age, obesity and OSA severity should be considered is unexplored. We explored cross-sectionally prevalence and associated factors of PA in co-existent hypertension and OSA by considering gender, age, obesity and OSA severity. OSA was defined as AHI ≥5 events/h. PA diagnosis was defined, based on the 2016 Endocrine Society Guideline. We included 3306 patients with hypertension (2564 with OSA). PA prevalence was significantly higher in hypertensives with OSA than in those without OSA (13.2 vs 10.0%, P = 0.018). In gender-specific analysis, PA prevalence was significantly higher in hypertensive men with OSA, compared to non-OSA ones (13.8 vs 7.7%, P = 0.001). In further analysis, PA prevalence was significantly higher in hypertensive men with OSA aged <45 years (12.7 vs 7.0%), 45-59 years (16.6 vs 8.5%), and with overweight and obesity (14.1 vs 7.1%) than did their counterparts (P < 0.05). For OSA severity, men participants showed increased PA prevalence from non to moderate OSA and a decrease in the severe OSA group (7.7 vs 12.9 vs 15.1 vs 13.7%, P = 0.008). Young and middle age, moderate-severe OSA, weight, and blood pressure showed a positive independent association with PA presence in logistic regression. In conclusion, PA is prevalent in co-existent hypertension and OSA, indicating the need for PA screening. Studies are needed for women, older and lean population due to the smaller samples in this study.

[Clinical Characteristics of Obstructive Sleep Apnea and Comorbid Primary Aldosteronism]

Objective

To explore the characteristics of patients with obstructive sleep apnea (OSA) and comorbid primary aldosteronism (PA) and to explore the relevant factors affecting plasma aldosterone concentration.

Methods

A total of 105 patients diagnosed with PA and admitted at West China Hospital, Sichuan University between January 2016 and December 2021 were retrospectively analyzed. The subjects were divided into a PA with comorbid snoring group (n=20) and a PA with comorbid OSA group (n=85) based on the results of polysomnography (PSG). The PA with comorbid OSA group was further divided into mild, moderate, and severe subgroups according to the apnea-hypopnea index (AHI). A total of 85 outpatients diagnosed with OSA were included as the control group. Demographic, clinical, biochemical, and PSG data were compared between the groups.

Results

Compared with patients with only OSA, a significantly higher proportion of patients with OSA and comorbid PA had hypertension and elevated levels of systolic and diastolic blood pressure (P<0.05). In addition, patients with OSA and comorbid PA had significantly increased AHI and significantly decreased mean oxygen saturation and sleep efficiency (P<0.05). The more severe the OSA was, the higher levels of BMI, cholesterol, low-density lipoprotein, and uric acid the PA patients had. Linear regression analysis showed that the lowest oxygen saturation (β=－0.222, P=0.045) was negatively correlated with plasma aldosterone concentration.

Conclusion

Comorbidity with PA can aggravate the clinical manifestations of OSA, while OSA further disrupted the metabolism of lipids and uric acid in PA patients. Plasma aldosterone concentrations in patients with comorbid OSA and PA were affected by the lowest oxygen saturation level.

Influence and implications of the renin-angiotensin-aldosterone system in obstructive sleep apnea: An updated systematic review and meta-analysis

Obstructive sleep apnea is a chronic, sleep-related breathing disorder, which is an independent risk factor for cardiovascular disease. The renin-angiotensin-aldosterone system regulates salt and water homeostasis, blood pressure, and cardiovascular remodelling. Elevated aldosterone levels are associated with excess morbidity and mortality. We aimed to analyse the influence and implications of renin-angiotensin-aldosterone system derangement in individuals with and without obstructive sleep apnea. We pooled data from 20 relevant studies involving 2828 participants (1554 with obstructive sleep apnea, 1274 without obstructive sleep apnea). The study outcomes were the levels of renin-angiotensin-aldosterone system hormones, blood pressure and heart rate. Patients with obstructive sleep apnea had higher levels of plasma renin activity (pooled wmd+ 0.25 [95% confidence interval 0.04-0.46], p = 0.0219), plasma aldosterone (pooled wmd+ 30.79 [95% confidence interval 1.05-60.53], p = 0.0424), angiotensin II (pooled wmd+ 5.19 [95% confidence interval 3.11-7.27], p < 0.001), systolic (pooled wmd+ 5.87 [95% confidence interval 1.42-10.32], p = 0.0098) and diastolic (pooled wmd+ 3.40 [95% confidence interval 0.86-5.94], p = 0.0086) blood pressure, and heart rate (pooled wmd+ 3.83 [95% confidence interval 1.57-6.01], p = 0.0009) compared with those without obstructive sleep apnea. The elevation remained significant (except for renin levels) when studies involving patients with resistant hypertension were removed. Sub-group analysis demonstrated that levels of angiotensin II were significantly higher only among the Asian population with obstructive sleep apnea compared with those without obstructive sleep apnea. Body mass index accounted for less than 10% of the between-study variance in elevation of the renin-angiotensin-aldosterone system parameters. Patients with obstructive sleep apnea have higher levels of renin-angiotensin-aldosterone system hormones, blood pressure and heart rate compared with those without obstructive sleep apnea, which remains significant even among patients without resistant hypertension.

The Impact of Intermittent Hypoxia on Metabolism and Cognition

Intermittent hypoxia (IH), one of the primary pathologies of sleep apnea syndrome (SAS), exposes cells throughout the body to repeated cycles of hypoxia/normoxia that result in oxidative stress and systemic inflammation. Since SAS is epidemiologically strongly correlated with type 2 diabetes/insulin resistance, obesity, hypertension, and dyslipidemia included in metabolic syndrome, the effects of IH on gene expression in the corresponding cells of each organ have been studied intensively to clarify the molecular mechanism of the association between SAS and metabolic syndrome. Dementia has recently been recognized as a serious health problem due to its increasing incidence, and a large body of evidence has shown its strong correlation with SAS and metabolic disorders. In this narrative review, we first outline the effects of IH on the expression of genes related to metabolism in neuronal cells, pancreatic β cells, hepatocytes, adipocytes, myocytes, and renal cells (mainly based on the results of our experiments). Next, we discuss the literature regarding the mechanisms by which metabolic disorders and IH develop dementia to understand how IH directly and indirectly leads to the development of dementia.

Obstructive Sleep Apnea and Cardiovascular Diseases: Sad Realities and Untold Truths regarding Care of Patients in 2022

Obstructive sleep apnea (OSA) is one of the most common and serious sleep-related breathing disorders with a high prevalence among patients with cardiovascular (CV) diseases. Despite its widespread presence, OSA remains severely undiagnosed and untreated. CV mortality and morbidity are significantly increased in the presence of OSA as it is associated with an increased risk of resistant hypertension, heart failure, arrhythmias, and coronary artery disease. Evaluation and treatment of OSA should focus on recognizing patients at risk of developing OSA. The use of screening questionnaires should be routine, but a formal polysomnography sleep study is fundamental in establishing and classifying OSA. Recognition of OSA patients will allow for the institution of appropriate therapy that should alleviate OSA-related symptoms with the intent of decreasing adverse CV risk. In this review, we focus on the impact OSA has on CV disease and evaluate contemporary OSA treatments. Our goal is to heighten awareness among CV practitioners.

Diabetes, Polycystic Ovarian Syndrome, Obstructive Sleep Apnea, and Obesity: A Systematic Review and Important Emerging Themes

Type 2 diabetes mellitus (DM), polycystic ovarian syndrome (PCOS), obstructive sleep apnea (OSA), and obesity represent four large and growing patient populations. A great deal of scientific and clinical knowledge has been developed for them individually, and significant advancements made. Taken as a group, however, the interrelationships are not as well understood. The purpose of this systematic review is to identify the body of existing research that ties them together and then to identify and discuss the prevailing themes, particularly for cause-and-effect mechanisms. PubMed, Google Scholar, and ScienceDirect were used to identify systematic reviews and meta-analysis articles to establish the broadest reach. Initially, 434 articles were carefully screened, out of which 22 most relevant studies were reviewed. Five important themes were distilled from these papers based on continued and consistent emphasis in the literature. These themes include topics such as the importance of considering visceral obesity rather than Body Mass Index (BMI), the most effective treatment approaches, including mounting support for melatonin and circadian rhythm management, the results of OSA in its feed-forward contribution to hormone imbalance, the role of non-obesity-related risk factors to PCOS and OSA such as age and genetic predisposition, and growing evidence to suggest the importance of mental health as a comorbidity in addition to the more traditional ones such as cardiovascular pathology. A new framework for investigating the interaction across these four disorders is offered that includes a revised perspective on the specific role of PCOS, perhaps being further upstream relative to the others. There currently exists a lack of well-designed randomized controlled trials in this particular area of medicine, an endeavor we believe could result in significant value, particularly as it relates to treatment approaches.

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.

Association of objective and subjective parameters of obstructive sleep apnea with plasma aldosterone concentration in 2,066 hypertensive and 25,368 general population

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) severity has been suggested in aldosterone elevation in resistant hypertension, whereas it is undetermined in the rest population. We explored the association of OSA parameters with plasma aldosterone concentration (PAC) in participants with and without hypertension.

METHODS

We enrolled clinically hypertensive patients with polysomnography and PAC data under no interfering agents, compared (log) PAC, and assessed the linearity of log PAC by tertiles (T1/2/3) of sleep parameters and their association using linear regression by gender and age. We enrolled participants with and without hypertension who had No-SAS scale and PAC data from the community and duplicated the observations from clinical setting considering age, gender, and presence of hypertension.

RESULTS

Of the 2,066 clinical patients with hypertension (1,546 with OSA), men participants (n=1,412), log apnea-hypopnea index (p=0.043), apnea index (AI, p=0.010), and lowest oxygen saturation (LSaO₂, p=0.013) showed significant linearity with log PAC. Log AI (B=0.04, 95%CI: 0.01,0.07, p=0.022) and log LSaO₂ (B=-0.39, 95%CI: -0.78,-0.01, p=0.044) showed significant positive and negative linear associations with log PAC in regression. In community dwellers, 6,417 participants with untreated hypertension (2,642 with OSA) and 18,951 normotensive participants (3,000 with OSA) were included. Of the men participants with and without hypertension, the OSA group showed significantly higher (log) PAC than did their counterparts, and log No-SAS score showed positive association with log PAC (hypertension: B=0.072, 95%CI: 0.002,0.142, p=0.043; normotension: B=0.103, 95%CI: 0.067,0.139, p<0.001) in linear regression analysis, which were consistent in all age groups.

CONCLUSIONS

OSA parameters were positively associated with PAC in normotensive and hypertensive participants, indicating that OSA may increase circulating aldosterone, especially in men.

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.

Sleep Dysfunction in COVID-19 Patients: Prevalence, Risk Factors, Mechanisms, and Management

During the COVID-19 pandemic, the need to establish the prevalence of sleep dysfunction and psychological distress, identify predisposing and protective factors, and explore effective management strategies remains an important priority. Evidence to date suggests that a considerable proportion of COVID-19 patients experience significant sleep disturbances (estimated to afflict up to 50-75%) as well as psychological distress such as depression, anxiety, and traumatic stress. Duration of hospitalization, pre-existing mental health concerns, lower absolute lymphocyte count, and increased neutrophil-to-lymphocyte ratio have been all associated with a greater risk of sleep dysfunction in infected and hospitalized patients. Furthermore, in this review, we discuss the link between sleep deprivation, susceptibility to viral infections, and psychosocial wellbeing in relevance to COVID-19 and summarize the existing evidence regarding the presence and role of sleep apnea in infected individuals. Finally, we highlight the importance of suitable interventions in order to prevent and manage sleep dysfunction and avoid long-term physical and psychological implications. Future research should aim to provide high-quality information including in high risk, underserved, or difficult to reach populations and on the long-term consequences and effectiveness of applied interventions.

Obstructive Sleep Apnea in Adults: What Primary Care Physicians Need to Know

Obstructive sleep apnea (OSA) remains a prominent disease state characterized as the recurrent collapse of the upper airway while sleeping and is estimated to plague 936 million adults globally. Although the initial clinical presentation of OSA appears harmless, it increases the risk of cardiovascular diseases such as heart failure, stroke, and hypertension; metabolic disorders; and an overall decrease in quality of life, in addition to increasing mortality. Current treatment of OSA includes lifestyle changes, behavioral modification, mandibular advancement devices, surgical treatment, and continuous positive airway pressure, which remains the gold standard. It is crucial to identify OSA early on and initiate treatment to mitigate the adverse health risks it imposes. This review will discuss the pathophysiology, epidemiology, management strategies, and medical treatment of OSA.

Intermittent Hypoxia Upregulates the Renin and Cd38 mRNAs in Renin-Producing Cells via the Downregulation of miR-203

Sleep apnea syndrome is characterized by recurrent episodes of oxygen desaturation and reoxygenation (intermittent hypoxia [IH]), and it is a known risk factor for hypertension. The upregulation of the renin-angiotensin system has been reported in IH, and the correlation between renin and CD38 has been noted. We exposed human HEK293 and mouse As4.1 renal cells to experimental IH or normoxia for 24 h and then measured the mRNA levels using a real-time reverse transcription polymerase chain reaction. The mRNA levels of Renin (Ren) and Cd38 were significantly increased by IH, indicating that they could be involved in the CD38-cyclic ADP-ribose signaling pathway. We next investigated the promotor activities of both genes, which were not increased by IH. Yet, a target mRNA search of the microRNA (miRNA) revealed both mRNAs to have a potential target sequence for miR-203. The miR-203 level of the IH-treated cells was significantly decreased when compared with the normoxia-treated cells. The IH-induced upregulation of the genes was abolished by the introduction of the miR-203 mimic, but not the miR-203 mimic NC negative control. These results indicate that IH stress downregulates the miR-203 in renin-producing cells, thereby resulting in increased mRNA levels of Ren and Cd38, which leads to hypertension.

Non-dipping nocturnal blood pressure correlates with obstructive sleep apnoea severity in normotensive subjects and may reverse with therapy

Background

Obstructive sleep apnoea (OSA) is strongly associated with systemic hypertension, but there are limited data on the relationship with blood pressure (BP) in normotensive subjects. Here, we examined the relationship of OSA with nocturnal BP in a documented diurnal normotensive cohort, explored potential intermediate pathways and assessed the effects on BP of continuous positive airways pressure (CPAP) therapy.

Methods

65 males referred for assessment of possible OSA and normotensive on 24-hour BP monitoring underwent overnight inpatient polysomnography (age 41±7 years, body mass index (BMI) 34±6 kg·m⁻², apnoea–hypopnoea index (AHI) 14 (interquartile range 5–26)). Urine and serum were assessed for markers of sympathetic activation, renin–angiotensin–aldosterone system activity, oxidative stress, endothelial function and systemic inflammation. In a subset of patients, 24-hour BP monitoring was repeated after CPAP therapy.

Results

Within this normotensive cohort, night-time systolic and diastolic BP and nocturnal BP dip were highest in the fourth OSA severity quartile (p<0.05). Nocturnal BP dip correlated with AHI (r=−0.327, p<0.05) and oxygen desaturation index (ODI) (r=−0.371, p<0.05), but only ODI was an independent predictor of BP dip (B=–0.351, p<0.01) and non-dipping status (B=0.046, p<0.05). Overnight urinary norepinephrine correlated with nocturnal systolic BP (r=0.387, p<0.01) with a trend towards correlation with systolic dipping (p=0.087). In 20 CPAP-treated patients, night-time systolic BP decreased (p<0.05) and mean nocturnal BP dip increased (p≤0.05).

Conclusion

In this normotensive cohort, OSA severity was associated with higher nocturnal BP, which improved following CPAP therapy, and intermittent hypoxia was the most important OSA-related variable in this relationship.

There is a strong association in a normotensive cohort between OSA and nocturnal blood pressure, with intermittent hypoxia as an important mechanistic pathwayhttps://bit.ly/2SFvWiB

The COVID-19 Lockdown and CPAP Adherence: The More Vulnerable Ones Less Likely to Improve Adherence?

PURPOSE

Due to the possible interplay of factors predisposing to severe COVID-19 outcomes and negative health consequences of poorly controlled OSA, adherence to continuous positive airway pressure (CPAP) therapy among OSA patients might be crucial during COVID-19 pandemics. Lockdown-related changes in CPAP adherence were investigated in CPAP users willing to participate in this study. Pre-lockdown adherence, age, gender, comorbidities and anxiety were analyzed as predictors of COVID-19 lockdown adherence.

PATIENTS AND METHODS

A cross-sectional study performed at Split Sleep Medicine Center included 101 severe OSA patients (78.2% male). CPAP memory cards were assessed during 6 months of pre-lockdown and 40 days of lockdown (March/April 2020) period. A total of 81 patients in pre-lockdown met good CPAP adherence criteria (≥4 hours/night on 70% nights).

RESULTS

CPAP adherence improved during COVID-19 lockdown in the total sample of severe OSA patients. The percentage of adherent nights and CPAP usage hours per night increased during lockdown in good pre-lockdown CPAP adherers (p=0.011 and p=0.001, respectively), women (p=0.003 and p=0.001, respectively) and respondents younger than 58 years (p=0.007 and p<0.001, respectively). Out of 20/101 poor pre-lockdown CPAP adherers, 9 have shifted to good lockdown adherence. When comorbidities, BMI and anxiety were taken into account, older and male respondents were recognized as less likely to improve CPAP usage hours during lockdown (R2=9.4%; p=0.032).

CONCLUSION

The lockdown-related CPAP adherence improved in severe OSA patients, with a shift in almost half of poor pre-lockdown adherers towards good lockdown CPAP adherence. Women, younger and good pre-lockdown CPAP adherers were more adherent during lockdown. Despite being vulnerable groups for both OSA and COVID-19, no expected adherence improvements were observed in men and older patients.

Prevalence and Risk Factors of Obstructive Sleep Apnea in Hypertensive Emergency

Introduction:

Obstructive sleep apnea (OSA) is a common factor associated with hypertensive crises. There is limited evidence of prevalence and risk factors of OSA in hypertensive emergency.

Methods:

This study recruited adult patients who diagnosed as hypertensive emergency and tested for OSA. The study period was between July 2019 and January 2020. The patients were categorized as OSA and non-OSA groups by the evidence from polysomnography. Prevalence and risk factors for OSA were executed.

Results:

During the study, there were 52 eligible patients. Of those, 30 patients (57.69%) were diagnosed with OSA. The stepwise logistic regression analysis for predicting OSA had two remaining factors: body mass index and diastolic blood pressure. Only body mass index was independently associated with OSA with an adjusted odds ratio of 1.166 (95% confidence interval of 1.033, 1.316). The body mass index of 25.02 kg/m² gave sensitivity and specificity of 80.00% and 59.09%, respectively. The area under the receiver operating characteristic curve was 70.98%.

Conclusion:

OSA had high incidence rate in patients with hypertensive emergency. High body mass index was a predictor for OSA associated with hypertensive emergency.

An umbrella review of systematic reviews and meta-analyses of observational investigations of obstructive sleep apnea and health outcomes

Purpose

The previous analysis of systematic reviews and meta-analyses have illustrated that obstructive sleep apnea (OSA) is correlated with multiple health outcomes. In the present research, our main aim was to execute an umbrella review to assess the available evidence for the associations between OSA and health outcomes.

Methods

Herein, a meta-analysis of previous observational investigations that have reported associations between OSA and health outcomes in all human populations and settings was performed. We used these studies to execute an umbrella review of available meta-analyses and systematic reviews.

Results

Sixty-six articles comprising 136 unique outcomes were enrolled in this analysis. Of the 136 unique outcomes, 111 unique outcomes had significant associations (p < 0.05). Only 7 outcomes (coronary revascularization after PCI, postoperative respiratory failure, steatosis, alaninetrans aminase (ALT) elevation, metabolic syndrome (MS), psoriasis, and Parkinson’s disease) had a high quality of evidence. Twenty-four outcomes had a moderate quality of evidence, and the remaining 80 outcomes had a weak quality of evidence. Sixty-nine outcomes exhibited significant heterogeneity. Twenty-five outcomes exhibited publication bias. Sixty-three (95%) studies showed critically low methodological quality.

Conclusion

Among the 66 meta-analyses exploring 136 unique outcomes, only 7 statistically significant outcomes were rated as high quality of evidence. OSA may correlate with an increased risk of coronary revascularization after PCI, postoperative respiratory failure, steatosis, ALT elevation, MS, psoriasis, and Parkinson’s disease.

A systematic review of COVID-19 and obstructive sleep apnoea

The aims of the study were to review the rapidly emerging COVID-19 literature to determine 1) the relationship between obstructive sleep apnoea (OSA) and adverse COVID-19 outcomes and, 2) potential causal mechanisms 3) what effect COVID-19 has had on OSA diagnosis and 4) what effect COVID-19 has had on treatment and management of OSA during this period. PubMed was systematically searched up to 020620. Studies were included if they had examined the relationship between COVID-19 and OSA. Studies were included that were in English and had the full text available. The findings from this study suggest that many of the risk factors and co-morbidities associated for OSA which include obesity, hypertension and diabetes mellitus are associated with poor COVID-19 outcomes. There are plausible mechanisms by which OSA may independently increase one's risk of morbidity and mortality associated with COVID-19 and data from the newly published CORONADO study suggests that OSA treated patients may be at increased risk of death from COVID-19. It is clear that the pandemic has had a major effect on the treatment management and diagnosis of OSA and moving forward it may be necessary to explore new diagnosis and treatment pathways for these individuals.

Clinical Characteristics of Hypertensive Patients with Obstructive Sleep Apnoea Syndrome Developing Different Types of Left Ventricular Geometry

Objective

The objective of the study was to compare polygraphic parameters and selected laboratory parameters in patients with obstructive sleep apnoea (OSA) who develop various types of left ventricular (LV) geometry. Material and Methods. The research covered 122 patients with obstructive sleep apnoea and coexisting effectively treated systemic hypertension (95 men, 27 women, average age: 54 ± 10.63). Overnight polygraphy, echocardiography, carotid artery ultrasonography, and laboratory measurements were performed. The patients were classified into four groups, depending on LV geometry. Group 1 comprised patients with normal LV geometry, group 2 included those with LV concentric remodelling. Group 3 and group 4 were patients with LV hypertrophy, concentric or eccentric, respectively.

Results

The most frequent type of LV geometry in the examined population was eccentric hypertrophy (36%). The highest average values of BMI and T-Ch were observed in the group of patients with concentric remodelling (group 2). The most severe respiratory disorders were found in the group of patients developing LV concentric hypertrophy (group 3); however, these differences were not statistically significant in comparison to other groups. Patients with LV eccentric hypertrophy had significantly decreased LV ejection fraction (p = 0.0008).

Conclusions

LV eccentric hypertrophy is the most frequent type of LV geometry in OSA patients. Patients with severe sleep-disordered breathing are more likely to develop concentric hypertrophy, while concentric remodelling occurs more frequently among OSA patients with other coexisting conditions, such as obesity or lipid-related disorders.

The Role of Aldosterone in OSA and OSA-Related Hypertension

Obstructive sleep apnea (OSA) is regarded as an independent risk factor for hypertension. The possible mechanism includes oxidative stress, endothelial injury, sympathetic excitement, renin-angiotensin-aldosterone system activation, etc. Clinical studies have found that there is a high coexistence of OSA and primary aldosteronism in patients with hypertension and that elevated aldosterone levels are independently associated with OSA severity in resistant hypertension. The underlying mechanism is that aldosterone excess can exacerbate OSA through increasing overnight fluid shift and affecting the mass and function of upper airway muscles during the sleep period. Thus, a bidirectional influence between OSA and aldosterone exists and contributes to hypertension in OSA patients, especially resistant hypertension.

Acute inorganic nitrate supplementation and the hypoxic ventilatory response in patients with obstructive sleep apnea

Patients with obstructive sleep apnea (OSA) have increased cardiovascular disease risk largely attributable to hypertension. Heightened peripheral chemoreflex sensitivity (i.e., exaggerated responsiveness to hypoxia) facilitates hypertension in these patients. Nitric oxide blunts the peripheral chemoreflex, and patients with OSA have reduced nitric oxide bioavailability. We therefore investigated the dose-dependent effects of acute inorganic nitrate supplementation (beetroot juice), an exogenous nitric oxide source, on blood pressure and cardiopulmonary responses to hypoxia in patients with OSA using a randomized, double-blind, placebo-controlled crossover design. Fourteen patients with OSA (53 ± 10 yr, 29.2 ± 5.8 kg/m², apnea-hypopnea index = 17.8 ± 8.1, 43%F) completed three visits. Resting brachial blood pressure and cardiopulmonary responses to inspiratory hypoxia were measured before, and 2 h after, acute inorganic nitrate supplementation [∼0.10 mmol (placebo), 4.03 mmol (low dose), and 8.06 mmol (high dose)]. Placebo increased neither plasma [nitrate] (30 ± 52 to 52 ± 23 μM, P = 0.26) nor [nitrite] (266 ± 153 to 277 ± 164 nM, P = 0.21); however, both increased following low (29 ± 17 to 175 ± 42 μM, 220 ± 137 to 514 ± 352 nM) and high doses (26 ± 11 to 292 ± 90 μM, 248 ± 155 to 738 ± 427 nM, respectively, P < 0.01 for all). Following placebo, systolic blood pressure increased (120 ± 9 to 128 ± 10 mmHg, P < 0.05), whereas no changes were observed following low (121 ± 11 to 123 ± 8 mmHg, P = 0.19) or high doses (124 ± 13 to 124 ± 9 mmHg, P = 0.96). The peak ventilatory response to hypoxia increased following placebo (3.1 ± 1.2 to 4.4 ± 2.6 L/min, P < 0.01) but not low (4.4 ± 2.4 to 5.4 ± 3.4 L/min, P = 0.11) or high doses (4.3 ± 2.3 to 4.8 ± 2.7 L/min, P = 0.42). Inorganic nitrate did not change the heart rate responses to hypoxia (beverage-by-time P = 0.64). Acute inorganic nitrate supplementation appears to blunt an early-morning rise in systolic blood pressure potentially through suppression of peripheral chemoreflex sensitivity in patients with OSA.NEW & NOTEWORTHY The present study is the first to examine the acute effects of inorganic nitrate supplementation on resting blood pressure and cardiopulmonary responses to hypoxia (e.g., peripheral chemoreflex sensitivity) in patients with obstructive sleep apnea (OSA). Our data indicate inorganic nitrate supplementation attenuates an early-morning rise in systolic blood pressure potentially attributable to blunted peripheral chemoreflex sensitivity. These data show proof-of-concept that inorganic nitrate supplementation could reduce the risk of cardiovascular disease in patients with OSA.

Moderating Effect of BMI on the Relationship Between Sympathetic Activation and Blood Pressure in Males with Obstructive Sleep Apnea

BACKGROUND

Sympathetic activation is a primary mechanism mediating increased blood pressure (BP) in obstructive sleep apnea (OSA). However, the relationships between overweight/obesity, sympathetic activation and BP in OSA are not well understood. We hypothesized that increased sympathetic drive is associated with increased BP in normal weight, but not in overweight/obese males with OSA. We therefore examined the effects of body mass index (BMI) on the association between sympathetic activation and BP in males with OSA.

METHODS

We studied 115 males with OSA recruited consecutively from clinic. Twenty-four-hour urinary norepinephrine was used to assess sympathetic activation. Blood pressure was measured both in the evening and in the morning. Hypertension was defined based on either BP measurements or an existing diagnosis. Linear and logistic regressions were conducted to examine the associations between sympathetic activation and both BP and risk of hypertension.

RESULTS

We found 24-hour urinary norepinephrine levels were associated with systolic and diastolic BP (SBP, β=0.157, p=0.082; DBP, β=0.212, p=0.023) and mean arterial pressure (MAP, β=0.198, p=0.032) after adjusting for confounders. Interestingly, these associations were modified by overweight/obesity. After adjusting for confounders, increased 24-hour urinary norepinephrine levels were significantly associated with elevated SBP (β=0.454, p=0.012), DBP (β=0.399, p=0.041), and MAP (β=0.432, p=0.023) in normal weight, but not in overweight/obese patients (all p>0.2). Similar findings were observed in the associations between 24-hour urinary norepinephrine levels and hypertension.

CONCLUSION

Sympathetic activation is associated with elevated BP in normal weight but not in overweight/obese males with OSA, suggesting that BMI may moderate the association between sympathetic activation and BP in males with OSA.

Lifestyle interventions for the prevention and treatment of hypertension

Hypertension affects approximately one third of the world's adult population and is a major cause of premature death despite considerable advances in pharmacological treatments. Growing evidence supports the use of lifestyle interventions for the prevention and adjuvant treatment of hypertension. In this Review, we provide a summary of the epidemiological research supporting the preventive and antihypertensive effects of major lifestyle interventions (regular physical exercise, body weight management and healthy dietary patterns), as well as other less traditional recommendations such as stress management and the promotion of adequate sleep patterns coupled with circadian entrainment. We also discuss the physiological mechanisms underlying the beneficial effects of these lifestyle interventions on hypertension, which include not only the prevention of traditional risk factors (such as obesity and insulin resistance) and improvements in vascular health through an improved redox and inflammatory status, but also reduced sympathetic overactivation and non-traditional mechanisms such as increased secretion of myokines.

Putative contributions of circadian clock and sleep in the context of SARS-CoV-2 infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the aetiological agent of the pandemic coronavirus disease 2019 (COVID-19), is a newly found member of the Coronaviridae family, and is closely related to, albeit with important differences from, SARS-CoV [1]. It enters human cells through the binding of surface spike (S) glycoprotein with angiotensin-converting enzyme 2 (ACE2) [2–4]. The distal S1 subunit of the S protein is responsible for receptor binding, while the transmembrane S2 subunit mediates fusion between the viral envelope and the target cell membrane following proteolytic cleavage by specific cellular enzymes such as transmembrane serine protease 2 for S protein priming [5]. As it is likely that expression levels of ACE2 affect the efficiency of virus attachment and entry, as well as disease severity [6], and the interactions between viral S protein and ACE2 may directly cause lung injury [7], ACE2 may be a potential target of therapeutic and preventative interventions [8].

Circadian deregulation and poor or insufficient sleep may facilitate COVID-19 infection and severity https://bit.ly/2VUlIIJ

Obstructive Sleep Apnea and Hypertension: A Review of the Relationship and Pathogenic Association

Obstructive sleep apnea (OSA) is defined as episodes of hypopnea or apnea, which leads to a partial or complete block of airways. Hypertension, on the other hand, is defined as an increase in systemic arterial blood pressure to a certain threshold. OSA and hypertension share many common factors in pathophysiology, such as gender, obesity, unhealthy lifestyle, impaired quality of sleep, renin-angiotensin system, and increased fluid distribution. In order to manage our patients effectively, we need to explore further the correlation between the two conditions.

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.

Serum Vitamin D, Sleep Pattern and Cardiometabolic Diseases: Findings from the National Health and Nutrition Examination Survey

OBJECTIVE

Although poor sleep health and vitamin D deficiency may be associated with diabetes and hypertension, whether this association shows a trend depending on vitamin D concentration is unclear.

SUBJECTS AND METHODS

We analyzed data from 10,742 participants (4997 men) from the 2007-2014 National Health and Nutrition Examination Survey. Abnormal sleep pattern (ie, short sleep duration, sleep complaint, and/or sleep disorder), lifestyle factors, serum vitamin D level, and the status of diabetes and hypertension were assessed. Logistic regression was performed to estimate the odds ratio (OR) and 95% confidence interval (CI).

RESULTS

Serum vitamin D significantly interacted with short sleep duration and abnormal sleep pattern (both p = 0.003) on the association with diabetes in men. Short sleep duration (OR: 1.82, 95% CI = 1.29, 2.57) and abnormal sleep pattern (OR: 1.95, 95% CI = 1.38, 2.77) were associated with diabetes in men with serum vitamin D of >75 nmol/L. Serum vitamin D significantly interacted with sleep complaint on the association with hypertension in men and women (both p < 0.05). The magnitude of association between sleep complaint and hypertension in men was stronger when serum vitamin D level was <50 nmol/L (OR: 2.26, 95% CI = 1.57, 3.25) than when the level was >75 nmol/L (OR: 1.28, 95% CI = 0.90, 1.83). Similarly, the magnitude of association between sleep complaint and hypertension in women was stronger when serum vitamin D level was <50 nmol/L (OR: 2.09, 95% CI = 1.53, 2.86) than when the level was >75 nmol/L (OR: 1.64, 95% CI = 0.98, 2.72). No significant interactions were observed between serum vitamin D level and other sleep variables.

CONCLUSION

Abnormal sleep pattern is associated with a high risk of diabetes and hypertension. The relationship between sleep complaint and hypertension may be strong in people with vitamin D deficiency, and this observation should be verified by prospective studies.

Associations between primary aldosteronism and diabetes, poor bone health, and sleep apnea-what do we know so far?

Primary aldosteronism (PA), the most common cause of secondary hypertension, is a well-recognized condition that can lead to cardiovascular and renal complications. PA is frequently left undiagnosed and untreated, leading to aldosterone-specific morbidity and mortality. In this review we highlight the evidence linking PA with other conditions such as (i) diabetes mellitus, (ii) obstructive sleep apnea, and (iii) bone health, along with clinical implications and proposed underlying mechanisms.

Association of serum adiponectin level with cystatin C in male patients with obstructive sleep apnea syndrome

PURPOSE

Obstructive sleep apnea syndrome (OSAS) was suggested to exert an effect on renal function. However, the specific mechanism was still unknown. We try to find the association among OSAS, adiponectin, and cystatin C and the effect of adiponectin on renal function in OSAS patients.

METHODS

Seventeen healthy men and seventy-three men which only had OSAS were included in the end. Apnea-hypopnea index (AHI), oxygen desaturation index (ODI), the percentage of total sleep time spent with SpO₂ < 90% (T90%), lowest O₂ saturation (LaSO₂), Epworth Sleepiness Scale (ESS) score, serum adiponectin, and high-sensitive C-reactive protein (hsCRP) were detected in all subjects, and renal function was evaluated with creatinine, cystatin C, and estimated glomerular filtration rate (eGFR).

RESULTS

Demographic data, creatinine, and eGFR did not differ among the studied groups. Decreased serum adiponectin levels were associated with severe OSAS. OSAS patients had a higher hsCRP and cystatin C than those without OSAS. Serum adiponectin levels had a negative association with cystatin C. After adjusted for confounders, adiponectin, hsCRP, and ODI had a significant prediction on the cystatin C (β = - 0.218, p = 0.011; β = 0.226, p = 0.037; and β = 0.231, p = 0.029).

CONCLUSIONS

Decreased serum adiponectin was associated with increased cystatin C in male OSAS patients. These results suggest that serum adiponectin might be a regulatory factor for renal function in OSAS.

Resistant Hypertension Updated Guidelines

PURPOSE OF REVIEW

To discuss the current definition as well as recommendations for diagnosis and treatment of resistant hypertension (RH) based on the 2018 American Heart Association (AHA) guidelines and recent literature.

RECENT FINDINGS

RH is defined as uncontrolled blood pressure (BP) on ≥ 3 anti-hypertensives, one of which should be a diuretic, prescribed at maximally tolerated doses and appropriate dosing frequency. The diagnosis of RH requires exclusion of white coat effect and medication non-adherence, underscoring the importance of out-of-office BP measurements. Secondary causes of hypertension must be excluded in all patients with RH. A step-wise approach to treatment focusing on lifestyle modifications and medication optimization can be effective in > 50% of the patients with RH. Device-based interventional therapies for RH are currently investigational. Out-of-office BP measurements are central to the diagnosis of RH. Medication optimization is successful in most patients. Further studies are needed to define the role of device-based interventions.

The effect of high evening blood pressure on obstructive sleep apnea-related morning blood pressure elevation: does sex modify this interaction effect?

PURPOSE

Obstructive sleep apnea (OSA) can lead to increased morning blood pressure (BP). We hypothesized that high evening BP may aggravate OSA-related morning BP elevation. Additionally, this interactional effect may be modified by sex.

METHODS

This retrospective, cross-sectional study included newly diagnosed OSA patients with an apnea-hypopnea index (AHI) ≥ 5 per hour on a full-night polysomnography. An analysis of covariance (ANCOVA) was used to determine whether severe OSA (AHI ≥ 30) was associated with higher morning BP than mild-to-moderate OSA (5 ≤ AHI < 30) and whether there was an interaction between apnea severity and evening BP on morning BP. To identify the sex effects, analyses were performed separately in each sex group.

RESULTS

A total of 1445 patients with an average age of 51.9 years (SD 11.7) (male 77.9% vs. female 22.1%; high evening BP group 22.4% vs. normal evening BP group 59.6%) were included in the study. Based on the ANCOVA, patients with severe OSA had significantly higher morning systolic BP (SBP) (p = 0.003), diastolic BP (DBP) (p < 0.001), and mean BP (MBP) (p < 0.001) than the mild-to-moderate group in male subjects. A significant interaction between apnea severity and evening BP was identified on morning DBP and MBP in male subjects. However, there were no differences in morning BP between severe and mild-to-moderate OSA groups in female subjects.

CONCLUSIONS

In male subjects, severe OSA contributed to higher morning BP than mild-to-moderate OSA. OSA-associated morning BP elevation was more prominent in the high evening BP group than in the normal BP group. Such relations were not found in female subjects.

The Association of Obstructive Sleep Apnea and Hypertension

Obstructive sleep apnea (OSA) is a condition characterized by recurrent episodes of partial or complete upper airway obstruction during sleep. Hypertension (HTN) is defined by the presence of a chronic elevation of systemic arterial pressure above a certain threshold value (≥140 mm Hg systolic or ≥90 mm Hg diastolic). On the surface, OSA and HTN appear very different from one another. Despite this, they share several common risk factors including obesity, male gender, and advancing age. In 2003, the Seventh Joint National Committee (JNC VII) recognized OSA as a secondary cause of HTN. As physicians, our goal is to understand the OSA-HTN association better through academic study regarding its epidemiology, its pathophysiology, and its treatment. 

Clinical characteristics of snoring patients with primary aldosteronism and obstructive sleep apnea-hypopnea syndrome

The 2016 guideline on the work-up of primary aldosteronism recommended that patients with obstructive sleep apnea–hypopnea syndrome (OSAS) be screened. This study aimed to identify the clinical characteristics of snoring patients with primary aldosteronism (PA) complicated by OSAS. Sixty-eight self-reported or witnessed snoring patients and 609 non-snoring patients diagnosed with PA between 2010 and 2015 were recruited in this retrospective study. Compared to non-snoring patients, snoring patients had significantly (P < 0.05) higher body mass index (BMI), diastolic blood pressure (DBP), and serum and urinary sodium, as well as lower estimated glomerular filtration rate (eGFR). Moreover, snoring patients exhibited significantly (P < 0.01) higher plasma renin activity levels and lower plasma aldosterone levels and aldosterone-to-renin activity ratios (ARRs) than patients with PA alone. When age, sex, duration of hypertension, and BMI were matched between groups, snoring patients still showed significantly (P < 0.05) higher plasma renin activity, serum and urinary sodium, and lower ARR and eGFR than those in the PA-only group. All 68 snoring patients underwent polysomnography, with 7 having mild (apnea–hypopnea index (AHI) ≥ 5 and <15), 21 moderate (AHI ≥ 15 and <30), and 40 severe (AHI ≥ 30) OSAS. The BMI of patients with OSAS was negatively correlated with the lowest SaO₂ (r = −0.318, P = 0.018) but not with the AHI. In conclusion, snoring patients with PA tend to have increased BMI and DBP, as well as decreased eGFR and ARR. Snoring patients with PA had higher prevalence of moderate-to-severe OSAS.

Resistant Hypertension: Detection, Evaluation, and Management: A Scientific Statement From the American Heart Association

Resistant hypertension (RH) is defined as above-goal elevated blood pressure (BP) in a patient despite the concurrent use of 3 antihypertensive drug classes, commonly including a long-acting calcium channel blocker, a blocker of the renin-angiotensin system (angiotensin-converting enzyme inhibitor or angiotensin receptor blocker), and a diuretic. The antihypertensive drugs should be administered at maximum or maximally tolerated daily doses. RH also includes patients whose BP achieves target values on ≥4 antihypertensive medications. The diagnosis of RH requires assurance of antihypertensive medication adherence and exclusion of the "white-coat effect" (office BP above goal but out-of-office BP at or below target). The importance of RH is underscored by the associated risk of adverse outcomes compared with non-RH. This article is an updated American Heart Association scientific statement on the detection, evaluation, and management of RH. Once antihypertensive medication adherence is confirmed and out-of-office BP recordings exclude a white-coat effect, evaluation includes identification of contributing lifestyle issues, detection of drugs interfering with antihypertensive medication effectiveness, screening for secondary hypertension, and assessment of target organ damage. Management of RH includes maximization of lifestyle interventions, use of long-acting thiazide-like diuretics (chlorthalidone or indapamide), addition of a mineralocorticoid receptor antagonist (spironolactone or eplerenone), and, if BP remains elevated, stepwise addition of antihypertensive drugs with complementary mechanisms of action to lower BP. If BP remains uncontrolled, referral to a hypertension specialist is advised.

Review of and Updates on Hypertension in Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a prevalent sleep disorder as is hypertension (HTN) in the 21st century with the rising incidence of obesity. Numerous studies have shown a strong association of OSA with cardiovascular morbidity and mortality. There is overwhelming evidence supporting the relationship between OSA and hypertension (HTN). The pathophysiology of HTN in OSA is complex and dependent on various factors such as sympathetic tone, renin-angiotensin-aldosterone system, endothelial dysfunction, and altered baroreceptor reflexes. The treatment of OSA is multifactorial ranging from CPAP to oral appliances to lifestyle modifications to antihypertensive drugs. OSA and HTN both need prompt diagnosis and treatment to help address the growing cardiovascular morbidity and mortality due to these two entities.