Prevalence, Characteristics, and Association of Obstructive Sleep Apnea with Blood Pressure Control in Patients with Resistant Hypertension

The Effect of Obstructive Sleep Apnea on Subclinical Target Organ Damage in Patients With Resistant Hypertension

INTRODUCTION

Among all patients with hypertension, those with resistant hypertension (RH) have the highest rates of subclinical organ damage (SOD). The prevalence of obstructive sleep apnea (OSA) is high in RH patients, and it could contribute to SOD. We aimed to investigate how OSA and its treatment are related to SOD in a large cohort of RH patients.

METHODS

This is an ancillary analysis to the SARAH study, a multicentre observational cohort aiming to evaluate the impact of OSA on RH. Individuals with RH who were undergoing a sleep study and have information on at least one of the SOD variables (vascular, cardiac or renal damage) were selected. Patients were followed-up for three years.

RESULTS

In total, 503 subjects were included. The participants were predominantly male, obese, and the median (IQR) apnea-hypopnea index (AHI) was 15.5 (7.90-31.5)events/h. No differences in the presence of vascular or cardiac damage were observed between OSA and non-OSA patients. A lower estimated glomerular filtration rate (eGFR) was observed in participants with OSA than in those without OSA, with an adjusted effect of -8.69mL/min/1.73m2 (-13.59, -3.79; p value<0.001). Kidney damage was also greater in subjects with OSA, with an adjusted OR (95% CI) of 1.77 (1.09, 2.87; p value=0.02). The eGFR showed a linear dose-response relationship with OSA severity. Among patients treated with CPAP, lower eGFR values were observed in noncompliant subjects.

CONCLUSIONS

OSA could contribute to worsening renal function in patients with RH. No compliance with CPAP was associated with lower values of eGFR.

Acid-sensing ion channel 1 in nucleus tractus solitarii neurons contributes to the enhanced CO2-stimulated cardiorespiratory effect in spontaneously hypertensive rats

AIMS

Activation of central respiratory chemoreceptors provides excitatory drive to both respiratory and sympathetic outputs. The enhanced respiratory-sympathetic coupling contributes to the onset and development of hypertension. However, the specific central targets and molecular mechanisms involved in this process remain elusive. This study aimed to investigate the role of acid-sensing ion channel 1 (ASIC1) in nucleus tractus solitarii (NTS) neurons in CO2-stimulated cardiorespiratory effects in spontaneously hypertensive rats (SHRs).

MAIN METHODS

Respiration and blood pressure of conscious rats were recorded by whole-body plethysmography and telemetry, respectively. Western blot was used to detect the expression difference of ASIC1 protein in NTS region between Wistar-Kyoto (WKY) rats and SHRs. Excitability of NTS neurons were assessed by extracellular recordings.

KEY FINDINGS

Compared to WKY rats, the enhanced CO2-stimulated cardiopulmonary effect and up-regulation of ASIC1 in the NTS were already observed in 4-week-old prehypertensive SHRs. Furthermore, specific blockade of ASIC1 effectively attenuated the CO2-stimulated increase in firing rate of NTS neurons in anesthetized adult SHRs. Intracerebroventricular injections of the ASIC1a blocker PcTx1 or knockdown Asic1 in NTS neurons significantly reduced the heightened CO2-stimulated ventilatory response, and diminished the CO2-stimulated increase in arterial pressure and heart rate in adult SHRs.

SIGNIFICANCE

These findings showed that dysregulated ASIC1 signaling in the NTS contribute to the exaggerated CO2-stimulated cardiorespiratory effects observed in SHRs.

The Complex Relationship between Neuromodulators, Circadian Rhythms, and Insomnia in Patients with Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) has been linked to disruptions in circadian rhythm and neurotrophin (NFT) signaling. This study explored the link between neuromodulators, chronotype, and insomnia in OSA. The participants (n = 166) underwent polysomnography (PSG) before being categorized into either the control or the OSA group. The following questionnaires were completed: Insomnia Severity Index (ISI), Epworth Sleepiness Scale, Chronotype Questionnaire (morningness-eveningness (ME), and subjective amplitude (AM). Blood samples were collected post-PSG for protein level assessment using ELISA kits for brain-derived neurotrophic factor (BDNF), proBDNF, glial-cell-line-derived neurotrophic factor, NFT3, and NFT4. Gene expression was analyzed utilizing qRT-PCR. No significant differences were found in neuromodulator levels between OSA patients and controls. The controls with insomnia exhibited elevated neuromodulator gene expression (p < 0.05). In the non-insomnia individuals, BDNF and NTF3 expression was increased in the OSA group compared to controls (p = 0.007 for both); there were no significant differences between the insomnia groups. The ISI scores positively correlated with all gene expressions in both groups, except for NTF4 in OSA (R = 0.127, p = 0.172). AM and ME were predicting factors for the ISI score and clinically significant insomnia (p < 0.05 for both groups). Compromised compensatory mechanisms in OSA may exacerbate insomnia. The correlation between chronotype and NFT expression highlights the role of circadian misalignments in sleep disruptions.

Higher ambient temperatures may worsen obstructive sleep apnea: A nationwide smartwatch-based analysis of 6.2 million person-days

Obstructive sleep apnea (OSA) is a serious type of sleep disorder that can lead to cardiometabolic and neurocognitive diseases. We utilized smart device-based photoplethysmography technology to collect sleep data from the Chinese population from 2019 to 2022. Distributed lag nonlinear models combined with a generalized nonlinear model or a linear mixed effects model were used to investigate the short-term associations between daily temperature and indicators of OSA severity. We included a total of 6,232,056 d of sleep monitoring data from 51,842 participants with moderate to severe risk of OSA from 313 Chinese cities. The relationships between ambient temperature and OSA exacerbation, apnea-hypopnea index (AHI), and minimum oxygen saturation (MinSpO2) were almost linear and present only on the same day. Higher temperatures were associated with a greater risk of OSA exacerbation, with an 8.4% (95% confidence interval (CI): 7.6%-9.3%) increase per 10 °C increase in temperature. A 10 °C increase in daily temperature corresponded to an AHI increase of 0.70 events/h (95% CI: 0.65-0.76) and a MinSpO2 decrease of 0.18% (95% CI: 0.16%-0.19%). Exposure to elevated temperatures during the night can also lead to adverse effects. The effects of higher temperatures on OSA severity were stronger among men, participants with a body mass index ≥ 24 kg/m2, those aged 45 years and older, individuals with a history of hypertension and diabetes, and during the cold season. This large-scale, nationwide, longitudinal study provides robust evidence suggesting that higher ambient temperatures may immediately worsen OSA.

Sleep Apnea and Hypertension Control among Hispanic/Latino Adults in the United States: Results from the Hispanic Community Health Study / Study of Latinos (HCHS/SOL)

Objectives

Hispanic/Latino adults have a high prevalence of uncontrolled hypertension predisposing them to CVD. We hypothesize that sleep apnea severity is associated with uncontrolled blood pressure (BP) and resistant hypertension in Hispanic/Latino adults.

Methods

This was a cross-sectional study of 2,849 Hispanic Community Health Study/Study of Latinos participants with hypertension (i.e., systolic BP ≥130 mm Hg, or diastolic BP ≥80 mm Hg or self-reported antihypertensive medication use) who were taking at least one class of antihypertensive medication. Participants were categorized as having controlled (BP < 130/80 mmHg among those on hypertension treatment) , uncontrolled (BP ≥ 130/80 mmHg using one or two classes of antihypertensive medications), or resistant hypertension (BP ≥ 130/80 mmHg while on ≥ 3 classes of antihypertensive medications or the use of ≥ 4 classes of antihypertensive medications regardless of BP control). Sleep apnea was classified based on the respiratory event index (REI; events/h) as mild (REI ≥ 5 and < 15), moderate-to-severe (REI ≥ 15), or no sleep apnea (REI < 5).

Results

In multinomial logistic regression, moderate-to-severe sleep apnea (vs. no sleep apnea) was associated with higher odds of resistant hypertension (Odds Ratio [OR], 2.15; 95% CI, 1.36-3.39 at 4% desaturation and OR 1.68; 95% CI, 1.05-2.67 at 3% desaturation). Neither mild nor moderate-to-severe sleep apnea was associated with uncontrolled hypertension.

Conclusion

Among diverse Hispanic/Latino persons, moderate-to-severe but not mild sleep apnea was associated with resistant hypertension. Identification and management of sleep apnea in this population may improve BP control and subsequently prevent adverse cardiovascular outcomes.

A risk prediction nomogram for resistant hypertension in patients with obstructive sleep apnea

Patients with obstructive sleep apnea (OSA) are liable to have resistant hypertension (RH) associated with unfavorable cardiovascular events. It is of necessity to predict OSA patients who are susceptible to resistant hypertension. Hence, we conducted a retrospective study based on the clinical records of OSA patients admitted to Yixing Hospital Affiliated to Jiangsu University from January 2018 to December 2022. According to different time periods, patients diagnosed between January 2018 and December 2021 were included in the training set (n = 539) for modeling, and those diagnosed between January 2022 and December 2022 were enrolled into the validation set (n = 259) for further assessment. The incidence of RH in the training set and external validation set was comparable (P = 0.396). The related clinical data of patients enrolled were collected and analyzed through univariate analysis and least absolute shrinkage and selection operator (LASSO) logistic regression analysis to identify independent risk factors and construct a nomogram. Finally, five variables were confirmed as independent risk factors for OSA patients with RH, including smoking, heart disease, neck circumference, AHI and T90. The nomogram established on the basis of variables above was shown to have good discrimination and calibration in both the training set and validation set. Decision curve analysis indicated that the nomogram was useful for a majority of OSA patients. Therefore, our nomogram might be useful to identify OSA patients at high risk of developing RH and facilitate the individualized management of OSA patients in clinical practice.

Symptom and comorbidity burden in hypertensive patients with obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is an important but frequently overlooked risk factor for hypertension (HTN). The prevalence of hypertension is high in patients with OSA, but the differences in clinical symptoms and comorbidities between patients with OSA with hypertension and those with normal blood pressure have not been fully defined.

Methods

This study retrospectively analyzed OSA patients diagnosed for the first time in Lihuili Hospital Affiliated to Ningbo University from 2016 to 2020. Patients were divided into an OSA group with hypertension and an OSA group without hypertension. The sociodemographic information, clinical symptoms, comorbidities, and polysomnography results of the two groups were compared. The independent risk factors associated with hypertension in patients with OSA were explored.

Results

A total of 1108 patients with OSA initially diagnosed were included in the study, including 387 with hypertension and 721 without. Compared with OSA patients without hypertension, OSA patients with hypertension were older; had a higher body mass index (BMI) and Epworth sleepiness score (ESS); a higher incidence of nocturia; and a higher proportion of diabetes mellitus, coronary heart disease, and cerebrovascular disease. Multivariate analysis showed age (odds ratio [OR]:1.06, 95% confidence interval [CI]:1.04-1.08), BMI (OR:1.17, 95% CI:1.11-1.23), ESS score (OR:0.97, 95%CI: 0.94-1.00) and nocturia symptoms (OR:1.64, 95% CI:1.19-2.27) was independently associated with hypertension in OSA patients, and comorbid diabetes (OR: 3.86, 95% CI: 2.31-6.45), coronary heart disease (OR: 1.90, 95% CI:1.15-3.16), and ischemic stroke (OR: 3.69,95% CI:1.31-10.40) was independently associated with hypertension in OSA patients.

Conclusion

Compared to OSA patients with normal blood pressure, OSA patients with hypertension had more significant daytime sleepiness, more frequent nocturnal urination, and a higher risk of diabetes, coronary heart disease, and cerebrovascular disease.

Device's design and clinical perspectives for resistant hypertension therapy

Introduction

Hypertension is the leading cause of death in the cardiovascular system. Indeed, untreated hypertension can affect one's general health, but medicine can help hypertensive people reduce their chance of developing high blood pressure. However, secondary hypertension remains an unresolved illness.

Areas covered

This review will go through the typical and unusual device-based therapies for resistant hypertension that have arisen in recent years. Further to that, the innovations developed in device-based RH treatment will be covered, as well as the research and studies assessing these novel technologies.

Expert opinion

The innovative device-based techniques that target resistant hypertension provide a potential therapy that has been backed by a number of studies and clinical trials, whereas pharmacological non-adherence and increased sympathetic activity are recognized to be the primary causes of resistant hypertension. Nevertheless, some limitations will be critical for the future of these RH systems, with the device's design and larger RCTs playing a significant role in determining whether a position in routine treatment could be warranted.

Recommended assessment and management of sleep disordered breathing in patients with atrial fibrillation, hypertension and heart failure: Taiwan Society of Cardiology/Taiwan Society of sleep Medicine/Taiwan Society of pulmonary and Critical Care Medicine joint consensus statement

Sleep disordered breathing (SDB) is highly prevalent and may be linked to cardiovascular disease in a bidirectional manner. The Taiwan Society of Cardiology, Taiwan Society of Sleep Medicine and Taiwan Society of Pulmonary and Critical Care Medicine established a task force of experts to evaluate the evidence regarding the assessment and management of SDB in patients with atrial fibrillation (AF), hypertension and heart failure with reduced ejection fraction (HFrEF). The GRADE process was used to assess the evidence associated with 15 formulated questions. The task force developed recommendations and determined strength (Strong, Weak) and direction (For, Against) based on the quality of evidence, balance of benefits and harms, patient values and preferences, and resource use. The resulting 11 recommendations are intended to guide clinicians in determining which the specific patient-care strategy should be utilized by clinicians based on the needs of individual patients.

Sleep-Disordered Breathing and Prevalent Hypertension in Men With and Without HIV

BACKGROUND

Sleep-disordered breathing (SDB) is a known risk factor for hypertension. Despite the well-established link between HIV infection and hypertension, it remains to be determined whether HIV infection modifies the association between SDB and hypertension.

SETTING

The Multicenter AIDS Cohort Study.

METHODS

SDB was assessed using in-home polysomnography in 779 men (436 with and 343 without HIV). The apnea-hypopnea index (AHI) based on oxyhemoglobin desaturation threshold of ≥3% or arousal (AHI 3a ) and ≥4% (AHI 4 ) along with oxygen desaturation index (ODI) were used to quantify SDB severity. Hypertension was defined as a blood pressure ≥140/90 mm Hg, use of antihypertensive medication, or self-report of a clinical diagnosis. The associations between HIV, SDB, and hypertension were characterized using multivariable logistic regression.

RESULTS

The prevalence of hypertension and SDB (AHI 3a ≥ 5 events/hr) was high, with estimates of 53.8% and 82.8%, respectively. Among men without SDB, HIV was independently associated with hypertension, with an adjusted odds ratio (OR) of 3.05 [95% confidence interval (CI): 1.33 to 7.01]. In men without HIV, SDB was associated with hypertension (OR: 2.93; 95% CI: 1.46 to 5.86). No significant increase in the odds of hypertension was noted in men with both HIV and SDB compared with men with either factor alone, with an OR of 3.24 (95% CI: 1.62 to 6.47). These results were consistent across different measures used to define SDB (AHI 3a , AHI 4 , ODI 3 , and ODI 4 ).

CONCLUSIONS

Predictors of hypertension differed by HIV status. SDB was associated with hypertension in men without HIV, but not in men with HIV. Among men with HIV, SDB did not affect the odds of hypertension.

Identification of Patients at Risk of Obstructive Sleep Apnea in Dental Settings

Objectives This study aims to assess the risk of obstructive sleep apnea (OSA) in the Saudi Arabian population at a dental hospital using the Berlin Questionnaire (BQ) and investigate the association of gender, age, neck circumference, systolic blood pressure (SBP), diastolic blood pressure (DBP), and smoking habits with the risk of OSA. Methodology Participants were recruited through random selection from walk-in patients aged between 18 and 80 years. BQ was used to screen for OSA. In addition, age, gender, smoking habits, neck circumference, and blood pressure were collected. Data were analyzed using descriptive statistics, Student's t-test, and chi-square test. Results In this study, 55 participants were screened for OSA using BQ. Of the participants, 44 (80%) were considered to be at low risk of OSA. Age, neck circumference, BMI, SBP, and DBP were statistically significantly associated with high risk of OSA (P < 0.05). Age and neck circumference were found to be statistically significant predictors of OSA, even after controlling for gender and smoking status (P < 0.05). Conclusions BQ is a reliable tool for assessing the risk of OSA in the Saudi Arabian population. Age, neck circumference, BMI, SBP, and DBP are all significant factors of OSA, while age and neck circumference are significant predictors of OSA. Dental practitioners can play a valuable role in the early detection and referral of patients at high risk of OSA.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

The Belun sleep platform to diagnose obstructive sleep apnea in patients with hypertension and high cardiovascular risk

STUDY OBJECTIVE

Current hypertension guidelines recommend that at-risk individuals be screened for obstructive sleep apnea (OSA). The Belun Ring is a wearable OSA diagnostic device worn on the palmar side of the proximal phalanx of the index finger.

METHODS

We recruited 129 participants (age: 60 ± 8 years, male sex: 88%, BMI: 27 ± 4 kg/m 2 ) with hypertension and high cardiovascular risk for a simultaneous polysomnography and Belun Ring monitoring for one night. Epworth Sleepiness Scale score more than 10 was detected in 27 (21.0%) participants.

RESULTS

In the 127 participants who completed the study, the apnea-hypopnea index (AHI) derived from polysomnography was 18.1 (interquartile range: 33.0) events/h and that derived from the Belun Ring was 19.5 (interquartile range: 23.3) events/h [intraclass correlation coefficient: 0.882, 95% confidence interval (95% CI): 0.837-0.916]. A Bland-Altman plot showed the difference between the Belun Ring and polysomnography AHIs to be -1.3 ± 10.4 events/h. Area under the receiver operating characteristic for the Belun Ring AHI was 0.961 (95% CI: 0.932-0.990, P  < 0.001). When the Belun Ring AHI of at least 15 events/h was used to diagnose OSA, the sensitivity, specificity, positive predictive value, and negative predictive value were 95.7, 77.6, 85.3, and 93.8%, respectively. The overall accuracy was 87.4%. The Cohen's kappa agreement was 0.74 ± 0.09 ( P  < 0.001). Similar results were obtained when the oxygen desaturation index was used to diagnose OSA.

CONCLUSION

A high prevalence of OSA was detected in patients with hypertension and high cardiovascular risk. The Belun Ring is a reliable device for OSA diagnosis similar to polysomnography.

Prognostic importance of obstructive sleep apnea and CPAP treatment for cardiovascular and mortality outcomes in patients with resistant hypertension: a prospective cohort study

The prognostic importance of obstructive sleep apnea (OSA) severity and other polysomnographic parameters in patients with resistant hypertension (RHT) has never been evaluated. We aimed to assess it in a prospective cohort of 422 individuals with RHT. OSA presence/severity was ascertained by complete polysomnography (PSG) at baseline. Multivariable Cox regressions assessed the risks associated with OSA severity and other PSG parameters (apnea-hypopnea index, sleep duration, nocturnal hypoxemia and periodic limb movements) for the primary (total cardiovascular events [CVEs] and all-cause mortality) and secondary outcomes (major CVEs). In the subgroup of patients with moderate/severe OSA, the risks associated with CPAP treatment were also estimated in relation to untreated individuals. One-hundred and eighty-six participants (44%) had no/mild OSA and 236 (56%) had moderate/severe OSA, and 67 of them were CPAP-treated. Over a mean follow-up of 5 years, there were 46 CVEs (37 major ones) and 44 all-cause deaths. Neither the presence of moderate/severe or severe OSA, nor being untreated during follow-up, was associated with significant excess risks for any outcome in relation to the subgroup with no/mild OSA. Similarly, no other PSG-derived parameter predicted any adverse outcome. Otherwise, CPAP treatment was associated with non-significant risk reductions of 37% for total CVEs, 49% for major CVEs and 63% for all-cause mortality in relation to those who remained untreated during follow-up. In conclusion, the presence/severity of OSA and its related PSG parameters were not associated with worse cardiovascular/mortality prognosis in patients with RHT. However, CPAP treatment might be protective in individuals with moderate/severe OSA.

Association between arterial stiffness and sleep apnoea in patients with resistant hypertension

Resistant Hypertension (RHT) is associated with a higher risk of Obstructive Sleep Apnoea (OSA). OSA and aortic stiffness (AS) measured by Pulse Wave Velocity (PWV) are independent risk factors for cardiovascular events. We assessed, in a cross-sectional study, the association between AS measured by PWV and OSA severity in patients with RHT. All patients were submitted to polysomnography, PWV measure and 24 h ABPM. Bivariate analysis compared patients with and without moderate/severe OSA. Multivariate analysis was performed to assess the independent correlates of moderate/severe OSA. A total of 376 patients were included, 31% were men with a mean age of 63 ± 10 years. Moderate/severe OSA was diagnosed in 214 patients (57%), 63 patients (17%) presented AS. Uncontrolled ABPM (true RHT) was found in 215 patients (57.2%) and among them 113 were diagnosed with moderate/severe OSA. Evaluating AS in patients with mild, moderate and severe apnoea, we observed a progressive increase in PWV (8.19 ± 1.55, 8.51 ± 1.84, 8.67 ± 1.68, respectively). Classifying them in 2 groups: (1) without apnoea/mild apnoea and (2) moderate/severe apnoea, we found higher values in group 2 (8.21 ± 1.52 m/s vs. 8.60 ± 1.75 m/s, p = 0.02), especially among true RHT patients (8.28 ± 1.62 vs. 8.81 ± 1.86, p = 0.029), women (8.13 ± 1.49 vs. 8.55 ± 1.73, p = 0.036), and uncontrolled nocturnal systolic BP (8.49 ± 1.63 vs. 8.58 ± 1.78, p = 0.04). In conclusion, in this RHT cohort, although with borderline results, the more severe the apnoea, the greater the arterial stiffness, mainly among women, true RHT and patients with an adverse nocturnal BP profile.

Higher Hospital Frailty Risk Score Is an Independent Predictor of In-Hospital Mortality in Hospitalized Older Adults with Obstructive Sleep Apnea

Background: Frailty predisposes individuals to stressors, increasing morbidity and mortality risk. Therefore, this study examined the impact of frailty defined by the Hospital Frailty Risk Score (HFRS) and other characteristics in older hospitalized patients with Obstructive Sleep Apnea (OSA). Methods: We conducted a retrospective study using the National Inpatient Sample 2016 in patients ≥65 years old with OSA. Logistic regression was used to evaluate the impact of frailty on inpatient mortality. A Kaplan-Meier curve with a log-rank test was used to estimate survival time between frailty groups. Results: 182,174 discharge records of elderly OSA were included in the study. 54% of the cohort were determined to be a medium/high frailty risk, according to HFRS. In multivariable analysis, frailty was associated with a fourfold (medium frailty, adjusted odd ratio (aOR): 4.12, 95% Confidence Interval (CI): 3.76−4.53, p-value < 0.001) and sixfold (high frailty, OR: 6.38, 95% CI: 5.60−7.27, p-value < 0.001) increased odds of mortality. Hospital survival time was significantly different between the three frailty groups (Log-rank test, p < 0.0001). Comorbidity burden defined by Charlson comorbidity Index (CCI) was associated with increased mortality (p < 0.001). Conclusion: More than half of the whole cohort was determined to be at medium and high frailty risk. Frailty was a significant predictor of in-hospital deaths in hospitalized OSA patients. Frailty assessment may be applicable for risk stratification of older hospitalized OSA patients.

Sleep apnea is associated with the increase of certain genera of Ruminococcaceae and Lachnospiraceae in the gut microbiome of hypertensive patients

BACKGROUND

Obstructive sleep apnea (OSA) and hypertension are interrelated diseases linked to gut dysbiosis. This study aimed to investigate the effect of OSA on the gut microbiome in the context of hypertension and vice versa.

RESEARCH DESIGN AND METHODS

Of 211 consecutively screened patients, 52 completed polysomnography study, medical history questionnaires, and fecal sample collection. 16S rRNA gene sequencing was performed on fecal samples, and diversity, richness, and microbial taxa were analyzed using bioinformatics.

RESULTS

Alpha diversity showed slightly decreased diversity in OSA and hypertension groups without significant difference, and the hypoxia burden index (HBI) showed a weak positive correlation with Chao1 index (r = 0.342, p < 0.05) in OSA patients. Firmicutes-to-Bacteroidetes ratio was higher in patients with than without OSA. In hypertensive patients, those with OSA had higher Ruminococcus_1, Lachnoclostridium, Lachnospira, [Ruminococcus]_torques_group, and unidentified Lachnospiraceae levels than those without OSA. Conversely, in OSA patients, hypertensive patients had lower Faecalibacterium and Lachnospiraceae_NK4A136_group levels.

CONCLUSION

The present study suggests a possible compensatory mechanism for gut microbiome changes in sleep apnea pathophysiology. The positive correlation between HBI and alpha diversity, and increase in certain genera of Ruminococcaceae and Lachnospiraceae in OSA patients may represent an adaptive response to hypoxia.

Resistant Hypertension in Patients With Type-2 Diabetes Mellitus: A Single-Center, Cross-Sectional Study

Background The prevalence of resistant hypertension in Saudi patients with type-2 diabetes mellitus (T2DM) has not been previously estimated. Therefore, our objective was to assess the prevalence and characteristics of resistant hypertensive patients with T2DM at King Abdulaziz Medical City, Jeddah, Saudi Arabia. Methods This cross-sectional study included patients with hypertension and T2DM who presented to our center in 2018. We examined 1960 patients with T2DM during the study period; 809 were hypertensives. We compared T2DM patients with controlled hypertension versus resistant hypertension. Results The prevalence of resistant hypertension in patients with T2DM was 137/809 (16.93%). The mean age was 66.38±10.80 years, and females presented 56% of the study population (n= 451). Obstructive sleep apnea (OSA; OR: 2.60 [1.15- 5.87]; P=0.02) and ischemic heart disease (IHD; OR: 3.01 [2.04- 4.45]; P˂0.001) were significantly associated with resistant hypertension. The most common medications used with resistant hypertension were calcium channel blockers (CCBs; 89.05%), β-blockers (76.64%), and angiotensin-2 receptor blockers (ARBs; 62.77%). Conclusions Resistant hypertension in patients with T2DM is common in Saudi Arabia. Resistant hypertension could be associated with OSA and IHD. Further studies are required to evaluate the temporal relationship between resistant hypertension and risk factors.

Association Between Smoking Behavior and Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis

INTRODUCTION

To systematically review the association between smoking behavior and obstructive sleep apnea (OSA).

AIMS AND METHODS

PubMed, Medline, the Cochrane Library, EMBASE, and Scopus databases were used to conduct this review. The two researchers independently screened the literatures, conducted the quality assessment, and data extraction according to the inclusion and exclusion criteria. The RevMan 5.3 was used to analysis the apnea hypopnea index (AHI) index, min saturation of oxyhemoglobin (SaO2), Epworth Sleepiness Scale (ESS) score, and oxygen desaturation index (DOI) and publication bias analysis to assess the effect of smoking on OSA patients. Furthermore, we performed subgroup of the severity of OSA, different countries of sample origin (western countries or eastern countries), and pack-years (PYs < 10 or PYs ≥ 20) to analyze the heterogeneity.

RESULTS

Thirteen studies were included in this analysis that conformed to inclusion criteria and exclusion criteria. Totally 3654 smokers and 9796 non-smokers have participated. The meta-analysis of 13 studies demonstrated that AHI levels were significantly higher in smoker group compared with non-smoker, ESS scores were also significantly higher in smoker group compared with non-smoker, min SaO2 levels were obviously lower in smoker group compared with non-smoker, however, DOI levels hadn't significantly different between two groups. The subgroup analysis showed that there was an association between severe OSA, eastern countries, pack-years, and smoking.

CONCLUSIONS

Smoking behavior is a significant association with OSA. Heavy smokers with histories of more than 20 PYs were at a higher risk of OSA. Moreover, patient with severe OSA exhibited a significantly association with smoking compared with patients with mild or moderate OSA.

IMPLICATIONS

The relationship between smoking and OSA was controversial, especially, whether smoking increase or aggravate the risk of OSA. In our review and meta-analysis, we demonstrated that smoking behavior is a significant association with OSA. Heavy smokers with histories of more than 20 PYs were at a higher risk of OSA. Moreover, patient with severe OSA exhibited a significant association with smoking compared with patients with mild or moderate OSA. More prospective long-term follow-up studies about effect of quit smoking on OSA are recommended to establish the further relationship.

Prevalence and associated factors of obstructive sleep apnea in refractory hypertension

BACKGROUND

Refractory hypertension (RfHT) and obstructive sleep apnea (OSA) share common pathophysiological mechanisms and probably are intrinsically associated, but their prevalence, clinical profile, and polysomnography (PSG) pattern remain misunderstood.

OBJECTIVE

To describe OSA prevalence and PSG pattern of patients with RfHT in a large cohort of resistant hypertension (RHT).

METHODS

This is a cross-sectional study involving 418 RHT patients (30.9% male; mean age of 62.5 ± 9.9 years) who were submitted to full-night PSG. RfHT was defined as uncontrolled ambulatory blood pressure monitoring using five or more antihypertensive drugs, including spironolactone. Bivariate analysis compared RHT and RfHT and multivariate analysis was performed to assess the independent correlates of OSA.

RESULTS

A total of 90 patients (21.5%) were diagnosed with RfHT (26.7% male; mean age of 58.5 ± 8.3 years). In comparison with resistant ones, RfHT patients were younger, with higher smoking and previous cardiovascular diseases prevalence, especially stroke. There was no difference regarding anthropometric measures. OSA prevalence (80.0 vs. 82.9%) and moderate/severe OSA (51.1 vs. 57.0%) were similar in both groups as well as apnea-hypopnea index. In its turn, refractory hypertensive patients presented better sleep efficiency (78 vs. 71%), with higher total sleep time (315 vs. 281 min) and lower sleep latency (11 vs. 17 min). There was no difference regarding rapid eye movement sleep, oxygen saturation, microarousals index, and periodic limb movement.

CONCLUSION

In this large RHT cohort, resistant and refractory hypertensive patients have similar OSA prevalence, although refractory ones, which by definition use spironolactone, are younger and apparently have a better sleep pattern.

The Burden of Resistant Hypertension Across the World

PURPOSE OF REVIEW

Resistant hypertension (R-HTN) is related to worse cardiovascular, renal outcomes, and death compared to non R-HTN. We aimed to review the burden of R-HTN across the world, focusing on its prevalence, associated factors and outcomes, and the impact of treatment.

RECENT FINDINGS

R-HTN prevalence among hypertensive individuals varies around 10-20%, depending on the population and definition applied. R-HTN consistently relates to older age, chronic kidney disease, obesity, and obstructive sleep apnea - which are increasing in prevalence with global population aging. As such, R-HTN prevalence is also expected to rise. Infrequent use of ambulatory blood pressure monitoring to identify at higher risk individuals and poor adherence to treatment are still barriers in the approach of R-HTN. Available evidence suggests that 10-20% of patients with hypertension have R-HTN. However, the prevalence of true R-HTN using contemporaneous standardized definitions is still unknown. Novel strategies to address clinicians, patients and health system barriers to treatment inertia and adherence are fundamental to reduce the burden of R-HTN.

Effect of CPAP treatment on BP in resistant hypertensive patients according to the BP dipping pattern and the presence of nocturnal hypertension

High heterogeneity in the blood pressure (BP) response to continuous positive airway pressure (CPAP) exists in patients with resistant hypertension (RH). Only nondipper normotensive and hypertensive patients exhibited BP reductions when treated with CPAP; the baseline BP dipping pattern has been proposed as a predictor of BP response to CPAP but has never been explored in patients with RH. This study aimed to assess the effect of CPAP on BP in subjects with RH with respect to BP dipping pattern or nocturnal hypertension. This is an ancillary study of the SARAH study. RH subjects with an apnea/hypopnea index (AHI) ≥ 15/h and who received CPAP treatment for 1 year were included. Subjects underwent a sleep study and ambulatory BP monitoring (ABPM) at baseline and at the 1-year follow-up. Eighty-nine RH subjects were included. The subjects were mainly male (77.5%) and obese, with a mean age of 66 years (25th-75th percentile; 59.0; 70.0) and an AHI of 32.7/h (25th-75th percentile; 25.0; 54.7). A total of 68.5% of participants were nondippers, and 71.9% had nocturnal hypertension. After 1 year of CPAP, no significant differences in ABPM parameters were observed between dippers and nondippers. According to nighttime BP, subjects with nocturnal normotension did not show significant changes in ABPM parameters, while nocturnal hypertensive subjects achieved a significant reduction in mean nighttime BP of -4.38 mmHg (-7.10 to -1.66). The adjusted difference between groups was 3.04 (-2.25 to 8.34), which was not significant. This study shows that the BP response to CPAP in patients with RH does not differ according to the BP dipping pattern (dipper and nondipper) and suggests a differential response according to the presence of nocturnal hypertension (ClinicalTrials.gov: NCT03002558).

Obstructive sleep apnea and associated factors among hypertensive patients attending a tertiary cardiac center in Tanzania: a comparative cross-sectional study

Background

There is mounting evidence for a reciprocal yet bidirectional association between sleep-disordered breathing and hypertension. Obstructive sleep apnea (OSA), a common cause of systemic hypertension is an independent risk factor for hypertension-related cardiovascular morbidity and mortality. In this comparative hospital-based cross-sectional study, we sought to explore the burden of obstructive sleep apnea and its associated risk factors among hypertensive patients attending Jakaya Kikwete Cardiac Institute.

Methodology

A total of 1974 individuals (i.e. 1289 hypertensive and 685 normotensives) were consecutively enrolled in this study. The Berlin questionnaire and Epworth Sleepiness Scale were utilized in the assessment of OSA and excessive daytime sleepiness (EDS) respectively. Logistic regression analyses were employed in the determination of associated factors for OSA.

Results

The mean age was 53.4 years and females constituted the large majority (60.4%) of participants. About three quarters (74.1%) of participants had excess body weight, 11.6% had diabetes, 8.0% had asthma and 18.6% had history of recurrent nasal congestion. Positive family history of snoring was reported by 43.1% of participants and 36.9% had a personal history of snoring. Persons with hypertension displayed a higher frequency (42.1%) of OSA compared to their normotensive counterparts (11.8%), p < 0.001. Multivariate logistic regression analyses revealed hypertension (OR 5.1, 95% CI 3.2-8.2, p < 0.001), diabetes mellitus (OR 2.2, 95% CI 1.3-3.5, p < 0.01), chronic nasal congestion (OR 1.6, 95% CI 1.1-2.5, p = 0.01), obesity (OR 2.4, 95% CI 1.8-3.3, p < 0.001), increased neck circumference (OR 2.7, 95% CI 1.2-6.4, p = 0.02), family history of snoring (OR 5.5, 95% CI 4.0-7.5, p < 0.001), and working > 8 h/24 h (OR 0.6, 95% CI 0.4-1.0, p = 0.03) to have an independent association for OSA. Furthermore, participants with hypertension displayed superior odds for OSA compared to their normotensive counterparts across all subgroup analyses.

Conclusion

OSA is considerably common among patients with hypertension in a tertiary health care setting in Tanzania. Positive family history of snoring was the strongest associated factor; however, excess body weight proved to be the strongest modifiable risk factor. In view of its pervasiveness, OSA should be an integral part of the medical evaluation in hypertensive individuals.

Fiberoptic Endoscopic Evaluation of Swallowing in Resistant Hypertensive Patients With and Without Sleep Obstructive Apnea

Resistant arterial hypertension (RAH) is strongly associated with obstructive sleep apnea (OSA). Individuals with OSA may have subclinical swallow impairment, diagnosed by instrumental assessments, such as videofluoroscopy and fiberoptic endoscopic evaluation of swallowing (FEES). However, few studies have evaluated this population and included a control group of individuals without OSA. To evaluate, through FEES, the swallowing characteristics of resistant hypertensive patients with and without OSA and to investigate the association between the signs of swallow impairment and OSA. This was an observational study in which individuals with RAH underwent baseline polysomnography and were diagnosed with and without OSA. All participants underwent an initial assessment with the collection of demographic characteristics and FEES. Individuals were divided into 2 groups based on the presence or absence of OSA. Seventy-nine resistant hypertensive patients were evaluated: 60 with OSA (19 with mild OSA, 21 with moderate OSA, and 20 with severe OSA) and 19 without OSA. The most prevalent swallowing differences between groups with and without OSA were piecemeal deglutition, in 61.7% and 31.6%, respectively (p = 0.022); spillage, in 58.3% and 21.1% (p = 0.005); penetration/aspiration, in 55% and 47.4% (p = 0.561); and pharyngeal residue, in 51.5% and 26.3% (p = 0.053). The prevalence of swallow impairment among the participants in this study was 58.3% and 47.4% in the groups with OSA and without OSA, respectively (p = 0.402). This study shows a high prevalence of swallow impairment both in hypertensive patients with OSA and without OSA. The characteristics of swallowing associated with hypertensive patients with OSA are spillage, piecemeal deglutition, and the onset of the pharyngeal phase in the hypopharynx.

An alternative model in the provision of CPAP in sleep apnea: a comparative cost analysis

BACKGROUND

To conduct a pilot study on an alternative model for the provision of respiratory therapies in sleep apnea-hypopnea syndrome (SAHS) by internalizing the service with the purchase, monitoring and control of continuous positive airway pressure (CPAP) equipment by the hospital.

METHODS

An observational, prospective pilot study of comparative cost analysis by internalizing the service to include all patients up to a budget limit of 5000 euros. The cost of internalizing the service included the acquisition of CPAP equipment and all the necessary accessories in addition to the nursing days necessary to track the patients. Patient satisfaction was assessed by a survey of the hospital service.

RESULTS

Twenty-one patients with 23,046 patient-days of follow-up were included. The cost of the internalized system was 6825.11 €. The cost of the outsourced system over the same period would have been 22,781.18 €; thus, the direct saving was 15,956.07 €. The cost per device per day of the internalized system was 0.30 € versus the 0.99 € that the outsourced system would have cost during the study period. In the satisfaction survey, 12 (70.6%) patients indicated that they preferred the service of the hospital over that of the external company. No patient preferred the outsourced system.

CONCLUSIONS

The internalization of CPAP service represents significant cost savings from a hospital perspective and an improvement in patients' perceptions of the quality of service.

Efficacy of continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea (OSA) and resistant hypertension (RH): Systematic review and meta-analysis

Approximately 70-85% of patients with resistant hypertension (RH) report obstructive sleep apnea (OSA). However, whether therapy with continuous positive airway pressure (CPAP) improves blood pressure (BP) in this population is not clear. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to determine the efficacy of CPAP in patients with OSA and RH. Two reviewers performed the literature search, risk of bias analysis, and data extraction. The pooled data were analyzed in a meta-analysis using the DerSimonian-Laird method. We calculated the mean difference (MD) in systolic blood pressure (SBP) and diastolic blood pressure (DBP) measured at 24 h and in the daytime and nighttime. We also evaluated changes in aortic stiffness and aldosterone excretion. A total of 10 RCTs and 606 participants were included. CPAP was associated with changes in 24-h SBP (-5.06 mmHg; CI, -7.98, -2.13), 24-h DBP (-4.21 mmHg; CI, -6.5, -1.93), daytime SBP (-2.34 mmHg; CI, -6.94, +2.27), daytime DBP (-2.14 mmHg; CI, -4.96, -0.67), nighttime SBP (-4.15 mmHg; CI, -7.01, -1.29), and nighttime DBP (-1.95 mmHg; CI, -3.32, -0.57). We found no benefit for aortic stiffness, but it did lead to a mild reduction in aldosterone secretion. CPAP therapy improved BP, especially nighttime BP, in this population.

Higher Apnea-Hypopnea Index (AHI) and Oxygen Desaturation Index (ODI) Were Independently Associated with Increased Risks of Hypertension in Patients with T2DM: A Cross-Sectional Study

Objective

The current study aimed to explore the relationship between OSAS and hypertension and whether polysomnography (PSG) indices were independently associated with hypertension in patients with type 2 diabetes (T2DM).

Methods

This study recruited 316 T2DM patients. Multivariable logistic regression analyses were performed to determine the independent association of apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) with hypertension with adjustment for potential confounders.

Results

Among 316 patients, 130 (41.1%) and 204 (64.6%) had hypertension and OSAS, respectively. T2DM patients with hypertension showed significantly increased levels of AHI ((median (interquartile range)): 17.2 (5.7–34.9) vs. 5.7 (2.1–17.3) events/hour, p < 0.001), nonrapid eye movement AHI (NREM-AHI) (17.6 (5.5–36.5) vs. 5.2 (2.2–16.6) events/hour, p < 0.001), ODI (48.4 (21.9–78.0) vs. 22.6 (10.8–48.1) events/hour, p < 0.001), and severities of OSAS and decreased levels of lowest SaO₂ ((mean ± standard deviation): 74.0 ± 10.4 vs. 77.3 ± 9.8, p = 0.004). Multivariable logistic regression analysis showed that higher levels of AHI, NREM-AHI, and ODI were significantly associated with increased risks of hypertension, and the adjusted odds ratios (ORs) with 95% CI were 1.026 (1.008–1.044, p = 0.004), 1.026 (1.009–1.044, p = 0.003), and 1.005 (1.001–1.010, p = 0.040), respectively. Compared with non-OSAS, severe OSAS was significantly associated with the risk of hypertension with the adjusted OR (95% CI) of 3.626 (1.609–8.172, p = 0.002), but associations of rapid eye movement AHI (REM-AHI) and lowest SaO₂ with hypertension were not statistically significant.

Conclusion

Increased AHI, NREM-AHI, ODI, and severities of OSAS were significantly associated with higher risks of hypertension in T2DM patients. Detection and treatment of OSAS are needed to prevent hypertension in T2DM patients.