The Association of Obstructive Sleep Apnea and Hypertension

Brain-predicted age difference mediates the association between PROMIS sleep impairment, and self-reported pain measure in persons with knee pain

Knee pain, the most common cause of musculoskeletal pain (MSK), constitutes a severe public health burden. Its neurobiological causes, however, remain poorly understood. Among many possible causes, it has been proposed that sleep problems could lead to an increase in chronic pain symptomatology, which may be driven by central nervous system changes. In fact, we previously found that brain cortical thickness mediated the relationship between sleep qualities and pain severity in older adults with MSK. We also demonstrated a significant difference in a machine-learning-derived brain-aging biomarker between participants with low-and high-impact knee pain. Considering this, we examined whether brain aging was associated with self-reported sleep and pain measures, and whether brain aging mediated the relationship between sleep problems and knee pain. Exploratory Spearman and Pearson partial correlations, controlling for age, sex, race and study site, showed a significant association of brain aging with sleep related impairment and self-reported pain measures. Moreover, mediation analysis showed that brain aging significantly mediated the effect of sleep related impairment on clinical pain and physical symptoms. Our findings extend our prior work demonstrating advanced brain aging among individuals with chronic pain and the mediating role of brain-aging on the association between sleep and pain severity. Future longitudinal studies are needed to further understand whether the brain can be a therapeutic target to reverse the possible effect of sleep problems on chronic pain.

The association between sleep architecture, quality of life, and hypertension in patients with obstructive sleep apnea

OBJECTIVE

The aim of this study was to investigate the association between hypertension and overnight polysomnography measures of sleep duration, sleep architecture, and quality of life (QoL) in patients with obstructive sleep apnea (OSA).

METHODS

Participants were patients suspected of having OSA with or without hypertension. All patients underwent overnight polysomnography and completed the Epworth Sleepiness Scale (ESS), Self-Rating Anxiety Scale, Self-Rating Depression Scale, and 12-item Short-Form Health Survey.

RESULTS

Of 128 patients (mean age 46.2 ± 12.5 years), 53% had hypertension. The average total sleep duration was 344 min (standard deviation 90) or 5.7 h and sleep efficiency was < 70%. There was no significant difference between patients with OSA with/without hypertension in total sleep duration, sleep architecture, anxiety, depression, ESS scores, or QoL. In patients with OSA, nocturnal minimum oxygen saturation was significantly negatively correlated with bodily pain and physical component summary (PCS) scores; mean nocturnal saturation was negatively correlated with bodily pain and social function; anxiety showed a significant negative correlation with role emotional; and depression was significantly negatively correlated with physical function, role physical, general health, role emotional, PCS, and mental component summary (MCS) scores. In the group with OSA and hypertension, N3 duration was negatively correlated with social function, mental health, and MCS scores. Anxiety was significantly negatively correlated with physical function, role physical, vitality, mental health, role emotional, PCS, and MCS scores. Depression was significantly negatively correlated with physical function, role physical, vitality, mental health, role emotional, PCS, and MCS scores. In patients with mild, moderate, and severe OSA, QoL was associated with depression. In mild OSA, PCS was correlated with ESS and anxiety. In moderate OSA, MCS was correlated with apnea-hypopnea index scores. In severe OSA, MCS and PCS were correlated with anxiety.

CONCLUSIONS

There were no significant associations between the presence of hypertension and total sleep duration, sleep architecture, or QoL in patients with OSA. However, hypertension may affect the influencing factors of QoL in patients with OSA. Further cohort studies are needed to confirm these findings.

Etiology and Management of Treatment-Resistant Hypertension in African American Adults ≥18 Years: A Literature Review

Treatment-resistant hypertension (TRH) is defined as blood pressure levels that remain above the therapeutic goal despite concurrent use of three or more antihypertensive medications taken at maximally tolerated doses, one of which should be a diuretic. Additionally, individuals on four or more antihypertensive agents regardless of blood pressure are also considered to have TRH. Amongst people diagnosed with TRH, African American adults face a huge management gap, resulting in increased cardiovascular disease risk. The primary objective of this review was to identify the commonly encountered etiologies and extensively discuss the current management strategies of TRH with a particular focus on African Americans. Relevant studies were identified by analyzing scientific databases and journals such as PubMed, Cochrane, MEDLINE, Cureus, and American Heart Association (AHA). The studies identified and examined common causes of TRH, describing their pathophysiology and highlighting different treatment options for the respective etiologies. The most prevalent etiologies of TRH amongst African Americans were chronic kidney disease (CKD), renal artery stenosis (RAS), fibromuscular dysplasia, obstructive sleep apnea (OSA), endocrine causes (Conn syndrome, Cushing syndrome, etc.), sympathetic nervous system overactivity, lifestyle factors, inaccurate blood pressure measurement, and inappropriate treatment. Of the etiologies reviewed, OSA, lifestyle factors, and CKD exhibited a striking prevalence among the subpopulation studied. Unfortunately, there was a paucity of articles addressing this topic amongst African Americans, and therefore there was not a substantial appreciation of the prevalence of some of the identified etiologies in the population of interest. Thorough diagnostic testing for associated or underlying conditions provides a basis for successful management. This review brought to the fore the need for doctors and patients to collaborate in order to improve TRH management and help patients lead healthier lives.

Obstructive Sleep Apnea Syndrome In Vitro Model: Controlled Intermittent Hypoxia Stimulation of Human Stem Cells-Derived Cardiomyocytes

Cardiovascular morbidity is the leading cause of death of obstructive sleep apnea (OSA) syndrome patients. Nocturnal airway obstruction is associated with intermittent hypoxia (IH). In our previous work with cell lines, incubation with sera from OSA patients induced changes in cell morphology, NF-κB activation and decreased viability. A decrease in beating rate, contraction amplitude and a reduction in intracellular calcium signaling was also observed in human cardiomyocytes differentiated from human embryonic stem cells (hESC-CMs). We expanded these observations using a new controlled IH in vitro system on beating hESC-CMs. The Oxy-Cycler system was programed to generate IH cycles. Following IH, we detected the activation of Hif-1α as an indicator of hypoxia and nuclear NF-κB p65 and p50 subunits, representing pro-inflammatory activity. We also detected the secretion of inflammatory cytokines, such as MIF, PAI-1, MCP-1 and CXCL1, and demonstrated a decrease in beating rate of hESC-CMs following IH. IH induces the co-activation of inflammatory features together with cardiomyocyte alterations which are consistent with myocardial damage in OSA. This study provides an innovative approach for in vitro studies of OSA cardiovascular morbidity and supports the search for new pharmacological agents and molecular targets to improve diagnosis and treatment of patients.

Screening of plasma exosomal lncRNAs to identify potential biomarkers for obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is highly prevalent, but frequently undiagnosed. The existing biomarkers of OSA are relatively insensitive and inaccurate. Long non-coding RNAs (lncRNAs) have no protein-coding ability but have a role in regulating gene expression. They are stably expressed in exosomes, easily and rapidly measurable. Changes in expression of exosomal lncRNAs can be useful for disease diagnoses. However, there are few reports on the association of exosomal lncRNAs with OSA. We aimed to investigate the exosomal lncRNA profiles to establish the differences between non-OSA, OSA with or without hypertension (HTN) and serve as a potential diagnostic biomarker.

Methods

This diagnostic test included 63 participants: [normal control (NC) =25], (OSA =23), and (HTN-OSA =15). Expression profiling of lncRNAs in isolated exosomes was performed through high-throughput sequencing in 9 participants. Subsequently, OSA/HTN-OSA related lncRNAs were selected for validation by droplet digital polymerase chain reaction (ddPCR), receiver operating characteristic (ROC) curves were used to determine the diagnostic value. The reliabilities of the screened gene were further validated in another independent cohort: (NC =10), (OSA mild =10), (OSA moderate =11), and (OSA severe =10), the correlation between clinical features and its expression was analyzed. The MiRanda software was used to predict the binding sites of interaction between microRNA (miRNA) and target genes regulated by screened lncRNA.

Results

We identified the differentially expressed lncRNAs and mRNAs in plasma exosomes of the NC, OSA, HTN-OSA groups. Most pathways enriched in differentially expressed lncRNAs and mRNAs had previously been linked to OSA. Among them, ENST00000592016 enables discrimination between NC and OSA individuals [area under curve (AUC) =0.846, 95% confidence interval (CI): 0.72–0.97]. The severity of OSA was associated with changes in the ENST00000592016 expression. Furthermore, ENST00000592016 affected the PI3K-Akt, MAPK, and TNF pathways by regulating miRNA expressions.

Conclusions

This is the first report about differential expression of lncRNA in OSA and HTN-OSA exosomes. ENST00000592016 enables discrimination between NC and OSA individuals. This work enabled characterization of OSA and provided the preliminary work for the study of biomarker of OSA.

Association between obstructive sleep apnea and cardiovascular diseases

Obstructive sleep apnea (OSA) is a common respiratory disorder characterized by partial obstruction of upper respiratory tract and repetitive cessation of breathing during sleep. The etiology behind OSA is associated with the occurrence of intermittent hypoxemia, recurrent arousals and intrathoracic pressure swings. These contributing factors may turn on various signaling mechanisms including elevated sympathetic tone, oxidative stress, inflammation, endothelial dysfunction, cardiovascular variability, abnormal coagulation and metabolic defect ( e.g., insulin resistance, leptin resistance and altered hepatic metabolism). Given its close tie with major cardiovascular risk factors, OSA is commonly linked to the pathogenesis of a wide array of cardiovascular diseases (CVDs) including hypertension, heart failure, arrhythmias, coronary artery disease, stroke, cerebrovascular disease and pulmonary hypertension (PH). The current standard treatment for OSA using adequate nasal continuous positive airway pressure (CPAP) confers a significant reduction in cardiovascular morbidity. Nonetheless, despite the availability of effective therapy, patients with CVDs are still deemed highly vulnerable to OSA and related adverse clinical outcomes. A better understanding of the etiology of OSA along with early diagnosis should be essential for this undertreated disorder in the clinical setting.

PAI-1: A Major Player in the Vascular Dysfunction in Obstructive Sleep Apnea?

Obstructive sleep apnea is a chronic and prevalent condition that is associated with endothelial dysfunction, atherosclerosis, and imposes excess overall cardiovascular risk and mortality. Despite its high prevalence and the susceptibility of CVD patients to OSA-mediated stressors, OSA is still under-recognized and untreated in cardiovascular practice. Moreover, conventional OSA treatments have yielded either controversial or disappointing results in terms of protection against CVD, prompting the need for the identification of additional mechanisms and associated adjuvant therapies. Plasminogen activator inhibitor-1 (PAI-1), the primary inhibitor of tissue-type plasminogen activator (tPA) and urinary-type plasminogen activator (uPA), is a key regulator of fibrinolysis and cell migration. Indeed, elevated PAI-1 expression is associated with major cardiovascular adverse events that have been attributed to its antifibrinolytic activity. However, extensive evidence indicates that PAI-1 can induce endothelial dysfunction and atherosclerosis through complex interactions within the vasculature in an antifibrinolytic-independent matter. Elevated PAI-1 levels have been reported in OSA patients. However, the impact of PAI-1 on OSA-induced CVD has not been addressed to date. Here, we provide a comprehensive review on the mechanisms by which OSA and its most detrimental perturbation, intermittent hypoxia (IH), can enhance the transcription of PAI-1. We also propose causal pathways by which PAI-1 can promote atherosclerosis in OSA, thereby identifying PAI-1 as a potential therapeutic target in OSA-induced CVD.

Hypertensive crisis in patients with obstructive sleep apnea-induced hypertension

Background

Hypertensive crisis is an urgent/emergency condition. Although obstructive sleep apnea (OSA) in resistant hypertension has been thoroughly examined, information regarding the risk factors and prevalence of hypertensive crisis in co-existing OSA and hypertension is limited. This study thus aimed to determine prevalence of and risk factors for hypertensive crisis in patients with hypertension caused by OSA.

Methods

The inclusion criteria were age of 18 years or over and diagnosis of co-existing OSA and hypertension. Those patients with other causes of secondary hypertension were excluded. Patients were categorized by occurrence of hypertensive crisis. Factors associated with hypertensive crisis were calculated using multivariate logistic regression analysis.

Results

There were 121 patients met the study criteria. Of those, 19 patients (15.70%) had history of hypertensive crisis. Those patients in hypertensive crisis group had significant higher systolic and diastolic blood pressure at regular follow-ups than those without hypertensive crisis patients (177 vs. 141 mmHg and 108 vs. 85 mmHg; p value < 0.001 for both factors). After adjusted for age, sex, and Mallampati classification, only systolic blood pressure was independently associated with hypertensive crisis with adjusted odds ratio (95% CI) of 1.046 (1.012, 1.080).

Conclusions

The prevalence of hypertensive crisis in co-existing OSA and hypertension was 15.70% and high systolic blood pressure or uncontrolled blood pressure associated with hypertensive crisis in patients with OSA-associated hypertension.

Prevalence and factors correlated with hypertension secondary from obstructive sleep apnea

Background

In 2003, the JNC 7 reported obstructive sleep apnea (OSA) as a cause of secondary hypertension. The prevalence of OSA in hypertension ranges from 30-80%. There are limited data on the prevalence and risk factors of OSA in hypertensive patients. This study thus aimed to evaluate prevalence and clinical predictors of obstructive sleep apnea (OSA) in these patients.

Methods

This was a cross-sectional study and conducted at the hypertension clinic at Khon Kaen University’s Srinagarind Hospital, Thailand. We enrolled patients with hypertension treated at the clinic. OSA was defined as apnea-hypopnea index of 5 events/hour or over according to cardiopulmonary monitoring. Patients whose hypertension was due to any other causes were excluded. The prevalence of OSA was calculated and risk factors for OSA were analyzed using multivariate logistic regression.

Results

There were 726 hypertensive patients treated at the clinic. Out of those, 253 (34.8%) were randomly studied and categorized as either non-OSA (147 patients, 58.1%) or OSA (106 patients, 41.9%). There were four independent factors associated with OSA-induced hypertension: age, sex, history of snoring, and history of headache. Headache had an adjusted odds ratio (95% confidence interval) of 3.564 (95% confidence interval of 1.510, 8.411).

Conclusion

Age, male sex, history of snoring, and headache were independent predictors of hypertension caused by OSA.

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.