Position paper on the management of patients with obstructive sleep apnea and hypertension: joint recommendations by the European Society of Hypertension, by the European Respiratory Society and by the members of European COST (COoperation in Scientific and Technological research) ACTION B26 on obstructive sleep apnea. J Hypertens. 2012;30:633-646. [PMID: 22406463 DOI: 10.1097/hjh.0b013e328350e53b]

Circadian Biology in Obstructive Sleep Apnea-Associated Cardiovascular Disease

A dysregulated circadian system is independently associated with both Obstructive Sleep Apnea (OSA) and cardiovascular disease (CVD). OSA and CVD coexistence is often seen in patients with prolonged untreated OSA. However, the role of circadian dysregulation in their relationship is unclear. Half of the human genes, associated biological pathways, and physiological functions exhibit circadian rhythms, including blood pressure and heart rate regulation. Mechanisms related to circadian dysregulation and heart function are potentially involved in the coexistence of OSA and CVD. In this article, we provide a comprehensive overview of circadian dysregulation in OSA and associated CVD. We also discuss feasible animal models and new avenues for future research to understand their relationship. Oxygen-sensing pathways, inflammation, dysregulation of cardiovascular processes, oxidative stress, metabolic regulation, hormone signaling, and epigenetics are potential clock-regulated mechanisms connecting OSA and CVD.

[Clinical guidelines «Cognitive disorders in the elderly and senile persons»]

Clinical guidelines «Cognitive disorders in the elderly and senile persons».

Renalase rs2296545 variant improve hypertension susceptibility by modifying binding affinity to catecholamines in obstructive sleep apnea

Obstructive sleep apnea (OSA), a condition often linked with hypertension, has an undefined relationship with renalase, a protein known for regulating blood pressure. This study aimed to investigate the relationship between serum renalase levels as well as renalase functional single nucleotide polymorphism (SNP) rs2296545 variant and hypertension in a Han Chinese OSA population. 126 subjects underwent serum renalase detection, with linear regression being performed to evaluate the relationship between serum renalase levels and OSA-related traits. Additional 4275 subjects were obtained rs2296545 genotype information by SNP microarray. And binary logistic regression was used to assess the effect of rs2296545 on hypertension risk. Molecular dynamics simulation and molecular docking were utilized to access the protein structures and the interplay between protein and catecholamines of wild-type and rs2296545 mutant renalase. The results showed that serum renalase levels were significantly higher in the severe OSA group. Further analysis showed renalase levels were positively correlated with blood pressure in the non-OSA group and negatively correlated in the severe OSA group. For rs2296545 polymorphism analysis, the hypertension risk significantly increased for the recessive model CC/GG + CG (OR = 1.211, 95% CI: 1.025-1.431) and the additive model CC/CG (OR = 1.223, 95% CI: 1.025-1.458) in the severe OSA. The rs2296545 polymorphism affected protein structure, and led to increase binding free energy, weakening interactions between renalase and catecholamines. In conclusion, serum renalase levels had independent association with blood pressure. And rs2296545 polymorphism may influence on susceptibility to hypertension by altering protein ability to bind to catecholamines, which might contribute to the intervention of hypertension in the OSA population.

Causal effects of obstructive sleep apnea on chronic kidney disease and renal function: a bidirectional Mendelian randomization study

Background

Observational studies have suggested an association between obstructive sleep apnea (OSA), chronic kidney disease (CKD), and renal function, and vice versa. However, the results from these studies are inconsistent. It remains unclear whether there are causal relationships and in which direction they might exist.

Methods

We used a two-sample Mendelian randomization (MR) method to investigate the bidirectional causal relation between OSA and 7 renal function phenotypes [creatinine-based estimated glomerular filtration rate (eGFRcrea), cystatin C-based estimated glomerular filtration rate (eGFRcys), blood urea nitrogen (BUN), rapid progress to CKD, rapid decline of eGFR, urinary albumin to creatinine ratio (UACR) and CKD]. The genome-wide association study (GWAS) summary statistics of OSA were retrieved from FinnGen Consortium. The CKDGen consortium and UK Biobank provided GWAS summary data for renal function phenotypes. Participants in the GWAS were predominantly of European ancestry. Five MR methods, including inverse variance weighted (IVW), MR-Egger, simple mode, weighted median, and weighted mode were used to investigate the causal relationship. The IVW result was considered the primary outcome. Then, Cochran's Q test and MR-Egger were used to detect heterogeneity and pleiotropy. The leave-one-out analysis was used for testing the stability of MR results. RadialMR was used to identify outliers. Bonferroni correction was applied to test the strength of the causal relationships (p < 3.571 × 10-3).

Results

We failed to find any significant causal effect of OSA on renal function phenotypes. Conversely, when we examined the effects of renal function phenotypes on OSA, after removing outliers, we found a significant association between BUN and OSA using IVW method (OR: 2.079, 95% CI: 1.516-2.853; p = 5.72 × 10-6).

Conclusion

This MR study found no causal effect of OSA on renal function in Europeans. However, genetically predicted increased BUN is associated with OSA development. These findings indicate that the relationship between OSA and renal function remains elusive and requires further investigation.

Adverse Events with Hypoglossal Nerve Stimulation in the Treatment of Obstructive Sleep Apnea-A Systematic Review of Clinical Trials and Real-World Data

Background/Objectives: Hypoglossal nerve stimulation (HNS) emerged as an alternative treatment for patients with obstructive sleep apnea (OSA) a decade ago. Long-term clinical trials and real-world data show that HNS treatment provides significant and sustained improvements in both OSA disease control and quality-of-life measures over time. Given the nature of HNS treatment, with the requirement of using an implantable neurostimulation system, patient safety is a critical domain in the assessment of this technology. The objective of this review was to evaluate adverse events (AEs) and complications with HNS therapy in a systematic review of published evidence. Methods: Medline, Cochrane, and Web of Science were systematically searched to identify randomized controlled and real-world observational studies reporting relevant outcomes with HNS therapy for treatment of OSA that included procedure-, device-, and treatment-related AEs. Results: Out of 418 articles screened, 27 were reviewed for eligibility, and 17 studies, the majority found to have low-to-moderate risk of bias, with data on 1962 patients were included for further analysis. Across included studies, reporting of AEs was heterogeneous with regard to the classifications used and the extent of reporting. Over an average follow-up duration of 17.5 ± 16.9 months, the pooled mortality rate was 0.01% (95% CI = 0.0 to 0.2%), with all reported deaths being unrelated to HNS treatment. The HNS system survival probability over the follow-up time of 60 months was 0.9834 (95% CI = 0.9768 to 0.9882), with infections and request for removal by patients being the most common indications. The pooled surgical revision rate was 0.08% (95% CI 0.0 to 0.2%). Most reported treatment-related side effects were transient stimulation-related discomfort (0.08%, 95% CI = 0.0 to 0.2%) and tongue abrasions (0.07%, 95% CI = 0.0 to 0.2%). Based on the systematic review, a standardized set of endpoints was defined, aiming to harmonize safety data relevant to HNS therapy. Conclusions: In this systematic review, HNS therapy for treatment of OSA is associated with a positive patient safety profile. AEs occur mainly at device implantation and during the treatment acclimatization period. Due to a lack of available evidence, partially implantable HNS systems are underrepresented in this review, which limits the generalizability of the results. Significant heterogeneity was found for adverse event reporting. A framework for reporting HNS outcomes that includes AEs and side effects is proposed to facilitate comparability of the reported data.

Obstructive sleep apnea and vitamin D level: Has the dust settled?

Obstructive sleep apnea and vitamin D deficiency are associated with multiple complications with increased morbidity and mortality. However, the relationship between these two entities remains unclear, with clinical studies demonstrating contradictory results. This narrative review aims to present the current evidence and understanding of this relationship and discuss the possible mechanisms linking these two disease entities. Finally, we summarize and propose areas of opportunity for future research.

The mediating effect of sleep disturbance on the association between hypertension and depression: a national data analysis

BACKGROUND

Sleep disturbance is a common among people with hypertension. However, the mediating role of sleep disturbance in the association between hypertension and depression remains unclear. This study aims to investigate the mediating role of sleep disturbance in the association between hypertension and depression.

MATERIALS AND METHODS

This was cross-sectional study. The data were derived from the Indonesian Family Life Survey Fifth Wave (2014-2015). We include a total of 19,138 adults' participants with age range from 18 to 65 years old who completed response on the variable of hypertension, sleep disturbance, and depression. The mediating model analysis was processed using the PROCESS macro ins SPSS from Hayes model.

RESULTS

Depression was reported by 22% of total respondents. The group with hypertension showed a substantially higher prevalence of depression than non-hypertension group (P < 0.001). Hypertension had a significant overall effect on depression (β = 0.682; 95%CI 0.489 to 0.875, P < 0.001). The direct effect of hypertension on depression was significant (β = 0.418; 95%CI 0.244 to 0.592, P < 0.001) and the indirect effect that mediated by sleep disturbance was also significant (β = 0.264, 95%CI 0.174 to 0.356, P < 0.001). It is worth noting that sleep disturbance partially mediated the association between hypertension and depression.

CONCLUSION

The findings of this study indicated that sleep disturbance contributed to the etiology of depression and hypertension in adult populations. Nurses should be involved in managing sleep disturbances, such as using behavioral therapy, as it may serve as both a treatment and primary prevention measure for depression and hypertension.

Secondary hypertension as a cause of treatment resistance

In secondary hypertension, elevated blood pressure is caused by a known and/or potentially treatable underlying disease.Although the prevalence of secondary hypertension depends on the patient population and the thoroughness of applied diagnostic approaches, arterial hypertension is classified in 90 to 95% as primary in nature. In young patients, individuals without a family history of hypertension, late onset of hypertension or worsening of a previous well-controlled hypertension as well as in patients who have a difficult to treat hypertension, the prevalence of secondary hypertension is significantly higher.Because the identification and the specific therapy of secondary hypertension may result in normalisation or improvement of elevated blood pressure in many cases, a targeted diagnostics is of great importance.

Management of Obstructive Sleep Apnea in Patients With Heart Failure

Sleep apnea is traditionally classified as obstructive sleep apnea (OSA), which occurs when the upper airway collapses due to the relaxation of oropharyngeal musculature, and central sleep apnea occurs when the brainstem cannot stimulate breathing. Most sleep apnea in patients with heart failure (HF) results from coexisting OSA and central sleep apnea (CSA), or complex sleep apnea syndrome. OSA and CSA are common in HF and can be involved in its progression by exposure to the heart to intermittent hypoxia, increased preload and afterload, activating sympathetic, and decreased vascular endothelial function. A majority of treatments have been investigated in patients with CSA and HF; however, less or short-term randomized trials demonstrated whether treating OSA in patients with HF could improve morbidity and mortality. OSA could directly influence the patient's recovery. This review will focus on past and present studies on the various therapies for OSA in patients with HF and summarize CSA treatment options for reasons of reference and completeness. More specifically, the treatment covered include surgical and non-surgical treatments and reported the positive and negative consequences for these treatment options, highlighting possible implications for clinical practice and future research directions.

Socioeconomic status impacts blood pressure response to positive airway pressure treatment

STUDY OBJECTIVES

Positive airway pressure (PAP) treatment of obstructive sleep apnea (OSA) reduces blood pressure (BP). Retrospective data suggest that African Americans (AA), a group at high-risk for hypertensive organ dysfunction, may have a greater BP response to PAP therapy than European Americans (EA). We examined the difference in 24-hour BP response to three months of PAP treatment between AA and EA.

METHODS

Participants (N=259, 161 AA and 98 EA) with apnea-hypopnea index (AHI) ≥15/hour from two prospective cohorts were included. T-tests and multiple linear regression were used to examine BP outcomes in AA vs. EA, adjusting for PAP adherence, socioeconomic status (SES), and baseline characteristics.

RESULTS

Participants were middle-aged (mean ± standard deviation, 53.8±9.3 years), 86% (227) men, AHI 35.6±19.2/hour, and PAP adherence of 3.36±2.24 hours/day. The reductions in 24-hour systolic and diastolic BP (mm Hg) were not different in AA vs. EA (systolic=-1.13±12.1 vs. -0.61±12.8, p=0.80 and diastolic=-0.74±7.9 vs. -0.80±7.4, p=0.96), and race was not a predictor of 24-hour systolic or diastolic BP reduction (p=0.75 and 0.54). SES and PAP adherence demonstrated a significant interaction; low SES was associated with an increase in 24-hour systolic BP (β=19.3, p=0.03) in the absence of PAP use but a greater reduction in 24-hour systolic BP with higher PAP adherence (β=-3.96, p=0.03).

CONCLUSIONS

24-hour BP response to PAP treatment is similar in AA and EA. Adherence to PAP treatment is more effective in improving 24-hour systolic BP in those with low SES.

The study was a clinical trial. Clinical Trial Registration: NCT01960465 and NCT01578031.

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.

Effects of Obstructive Sleep Apnea and CPAP on Cognitive Function

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA) is characterized by repetitive episodes of complete or partial upper airway obstruction during sleep. Studies indicate that OSA is an independent risk factor for cognitive decline in older patients. The purpose of this paper is to critically review the recent literature on the cognitive effects of untreated OSA and the benefits of treatment across cognitive domains.

RECENT FINDINGS

OSA's greatest impact appears to be on attention, vigilance, and information processing speed. Furthermore, the presence of OSA seems to have a significant impact on development and progression of mild cognitive impairment (MCI). Impact of OSA treatment, particularly with CPAP, appears to mitigate and slow the rate of cognitive decline and may reduce the risk of dementia. Larger properly controlled studies, of a prospective nature, are required to further elucidate the degree of treatment effect. More studies are needed on other treatments for OSA such as oral mandibular devices and hypoglossal nerve stimulation.

Characteristics of hypertension in obstructive sleep apnea: An Asian experience

Obstructive sleep apnea (OSA) is a risk of hypertension and is associated with cardiovascular disease (CVD) incidence. In Asian countries, the prevalence of OSA is high, as in Western countries. When blood pressure (BP) is evaluated in OSA individuals using ambulatory BP monitoring (ABPM), the BP phenotype often indicates abnormal BP variability, such as increased nighttime BP or abnormal diurnal BP variation, that is, non‐dipper pattern, riser pattern, and morning BP surge, and all these conditions have been associated with increased CVD events. Asians have a higher prevalence of increased nighttime BP or morning BP surge than Westerners. Therefore, this review paper focused on OSA and hypertension from an Asian perspective to investigate the importance of the association between OSA and hypertension in the Asian population. Such abnormal BP variability has been shown to be associated with progression of arterial stiffness, and this association could provoke a vicious cycle between abnormal BP phenotypes and arterial stiffness, a phenomenon recognized as systemic hemodynamic atherothrombotic syndrome (SHATS). OSA may be one of the background factors that augment SHATS. An oxygen‐triggered nocturnal oscillometric BP measurement device combined with a pulse oximeter for continuous SpO₂ monitoring could detect BP variability caused by OSA. In addition to treating the OSA, accurate and reliable detection and treatment of any residual BP elevation and BP variability caused by OSA would be necessary to prevent CVD events. However, more detailed detection of BP variability, such as beat‐by‐beat BP monitoring, would further help to reduce CV events.

Obstructive Sleep Apnea-Induced Neurogenic Nocturnal Hypertension: A Potential Role of Renal Denervation?

There is a bidirectional, causal relationship between obstructive sleep apnea (OSA) and hypertension. OSA-related hypertension is characterized by high rates of masked hypertension, elevated nighttime blood pressure, a nondipper pattern of nocturnal hypertension, and abnormal blood pressure variability. Hypoxia/hypercapnia-related sympathetic activation is a key pathophysiological mechanism linking the 2 conditions. Intermittent hypoxia also stimulates the renin-angiotensin-aldosterone system to promote hypertension development. The negative and additive cardiovascular effects of OSA and hypertension highlight the importance of effectively managing these conditions, especially when they coexist in the same patient. Continuous positive airway pressure is the gold standard therapy for OSA but its effects on blood pressure are relatively modest. Furthermore, this treatment did not reduce the cardiovascular event rate in nonsleepy patients with OSA in randomized controlled trials. Antihypertensive agents targeting sympathetic pathways or the renin-angiotensin-aldosterone system have theoretical potential in comorbid hypertension and OSA, but current evidence is limited and combination strategies are often required in drug resistant or refractory patients. The key role of sympathetic nervous system activation in the development of hypertension in OSA suggests potential for catheter-based renal sympathetic denervation. Although long-term, randomized controlled trials are needed, available data indicate sustained and relevant reductions in blood pressure in patients with hypertension and OSA after renal denervation, with the potential to also improve respiratory parameters. The combination of lifestyle interventions, optimal pharmacological therapy, continuous positive airway pressure therapy, and perhaps also renal denervation might improve cardiovascular risk in patients with OSA.

Diagnostic and Therapeutic Approach to Sleep Disorders, High Blood Pressure and Cardiovascular Diseases: A Consensus Document by the Italian Society of Hypertension (SIIA)

Hypertension is a major contributor to fatal/nonfatal cardiovascular diseases, and timely identification and appropriate management of factors affecting hypertension and its control are mandatory public health issues. By inducing neurohormonal alterations and metabolic impairment, sleep disorders have an impact on a variety of cardiovascular risk factors, including hypertension, and ultimately increase the risk of cardiovascular events. There is evidence that qualitative and quantitative sleep disorders are associated with resistant hypertension and with impaired circadian blood pressure variations. However, sleep disturbances are often unrecognized, or heterogeneity exists in their management by non-specialists in the field. This document by the Italian Society of Hypertension summarizes the updated evidence linking sleep disorders to hypertension and cardiovascular diseases, the major underlying mechanisms, and the possible management strategies. A simplified, evidence-based diagnostic and therapeutic algorithm for comorbid hypertension and common sleep disorders, namely obstructive sleep apnoea and insomnia, is proposed.

Treatment of Obstructive Sleep Apnea: Choosing the Best Positive Airway Pressure Device

Positive airway pressure (PAP) remains primary therapy for most patients with obstructive sleep apnea (OSA). CPAP, APAP, and BPAP are all reasonable therapies that can be used for patients with uncomplicated OSA across the spectrum of disease severity. BPAP should be considered for patients who are nonadherent to CPAP or APAP therapy because of pressure intolerance. Several additional factors should be considered when choosing the type of PAP device for a given patient, including associated symptoms and comorbid medical problems, cost, access to online data management and patient portals, and the portability for the device for patients who travel frequently.

How common is obstructive sleep apnea in young hypertensive patients?

Obstructive sleep apnea (OSA) has been reported to be a cause of hypertension in 40-80% of hypertensive patients. However, there are limited data available on the prevalence and predictors of OSA in young hypertensive patients. This study was conducted between October 2017 and October 2018. The inclusion criteria were (1) age over 18 and under 35 years (2) diagnosis with hypertension and (3) available respiratory polysomnography results. Patients with other causes of secondary hypertension were excluded. Predictors for OSA were analyzed using multivariate logistic regression analysis. There were 593 consecutive young patients who were diagnosed with hypertension during the study period. Of those, 475 (80.10%) were excluded due to their hypertension having renal causes (429; 90.32%), endocrine-related causes (40; 8.42%), or cardiovascular causes (6; 1.26%). Of the remaining patients (118 patients) who were eligible for the study, 105 (88.98%) of whom were diagnosed with OSA. The median age of the patients with OSA did not differ from those without OSA (29 vs 23 years; p value 0.065). There were two independent predictors for OSA: age and body mass index with adjusted odds ratios (95% confidence interval) of 1.280 (1.049, 1.562) and 1.258 (1.083, 1.462), respectively. In conclusion, after excluding other possible causes of hypertension, we found OSA to be highly prevalent in hypertensive patients younger than 35 years old. Increasing age and high body mass index were predictors for OSA in young hypertensive patients.

Alternations of Blood Pressure Before and After OSA Surgery

OBJECTIVE

To investigate the changes of blood pressure (BP) on patients with obstructive sleep apnea/hypopnea syndrome (OSA) before and after upper airway surgery.

DESIGN

Case series with chart review.

SETTING

Tertiary academic medical center.

SUBJECTS AND METHODS

Patients with OSA who underwent upper airway surgery were enrolled. We retrospectively investigated the nighttime and daytime BP before and at least 3 months after OSA surgery. Paired t test was used to compare the changes of BP before and after surgery. Generalized estimating equation was used to examine the prognostic significance of the variables in predicting the changes of postoperative BP.

RESULTS

In total, 176 patients with OSA (149 men, 27 women; mean age, 42.9 years; mean apnea/hypopnea index, 43.1/h) were enrolled in this study. The overall nighttime and daytime BP decreased significantly before and after OSA surgery (daytime systolic BP was reduced from 137.3 ± 14.0 mm Hg to 132.7 ± 17.0 mm Hg, P < .01; nighttime systolic BP was reduced from 138.7 ± 16.0 mm Hg to 133.7 ± 15.3 mm Hg, P < .01; daytime diastolic BP was reduced from 87.7 ± 14.7 mm Hg to 84.9 ± 10.6 mm Hg, P = .01; nighttime diastolic BP was reduced from 85.4 ± 12.9 mm Hg to 83.1 ± 11.1 mm Hg, P = .02). The changes of nighttime systolic and diastolic BP were significantly associated with the improvement of percentage of O₂ saturation <90% during polysomnography.

CONCLUSION

Surgical modifications of the upper airways for patients with OSA could benefit blood pressure.

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.

Ambulatory blood pressure monitoring over 24 h: A Latin American Society of Hypertension position paper-accessibility, clinical use and cost effectiveness of ABPM in Latin America in year 2020

Accurate office blood pressure measurement remains crucial in the diagnosis and management of hypertension worldwide, including Latin America (LA). Office blood pressure (OBP) measurement is still the leading technique in LA for screening and diagnosis of hypertension, monitoring of treatment, and long-term follow-up. Despite this, due to the increasing awareness of the limitations affecting OBP and to the accumulating evidence on the importance of ambulatory BP monitoring (ABPM), as a complement of OBP in the clinical approach to the hypertensive patient, a progressively greater attention has been paid worldwide to the information on daytime and nighttime BP patterns offered by 24-h ABPM in the diagnostic, prognostic, and therapeutic management of hypertension. In LA countries, most of the Scientific Societies of Hypertension and/or Cardiology have issued guidelines for hypertension care, and most of them include a special section on ABPM. Also, full guidelines on ABPM are available. However, despite the available evidence on the advantages of ABPM for the diagnosis and management of hypertension in LA, availability of ABPM is often restricted to cities with large population, and access to this technology by lower-income patients is sometimes limited by its excessive cost. The authors hope that this document might stimulate health authorities in each LA Country, as well as in other countries in the world, to regulate ABPM access and to widen the range of patients able to access the benefits of this technique.

Right ventricular diastolic dysfunction in patients with obstructive sleep apnea syndrome

BACKGROUND AND OBJECTIVES

This study aimed to assess right ventricular (RV) diastolic dysfunction in patients with obstructive sleep apnea syndrome (OSAS) using velocity vector imaging (VVI) and to evaluate the application of VVI technology.

METHODS

According to the apnea-hypopnea index (AHI), 69 patients with OSAS were divided into three groups: mild, moderate, and severe. A total of 35 cases of healthy subjects were enrolled as the control group. Digital images of apex four-chamber views were acquired to measure the peak early diastolic strain rate (RV-SRe), late diastolic strain rate(RV-SRa), and RV-SRe/RV-SRa using VVI.

RESULTS

RV-SRe, RV-Sra, and RV-SRe/RV-SRa were decreasing along with the disease severity. RV-SRe, RV-SRe/RV-SRa in moderate and severe OSAS group showed lower than control and mild OSAS groups. RV-SRa in severe OSAS group showed lower than control group. RV-SRe had the best correlation with AHI than other parameters.

CONCLUSIONS

Right ventricular diastolic dysfunction starts before the development of heart failure and pulmonary hypertension in patients with OSAS. RV-SRe was the parameter that may reflect subclinical myocardial dysfunction and can better reflect RV diastolic dysfunction.

Efficacy and adherence of auto-CPAP therapy in patients with obstructive sleep apnea: a prospective study

Introduction

The use of auto-continuous positive airway pressure (auto-CPAP) therapy has been recommended for subjects with moderate-to-severe obstructive sleep apnea (OSA) without significant comorbidities. This study is aimed at evaluating the efficacy and adherence of auto-CPAP therapy in subjects with OSA.

Methods

It was a perspective and descriptive study. All study subjects who had apnea-hypopnea index (AHI) > 30/h, measured by polysomnography, were included. They were treated with auto-CPAP and followed-up for 6 months for evaluating the effect of CPAP-therapy on clinical and biological features and treatment adherence.

Results

One hundred and thirty-nine subjects with severe OSA were accepted for auto-CPAP therapy at inclusion. BMI was 28.4±3.8 kg/m²; neck and abdomen circumferences were 38.2±6.4 and 85.7±11.6. Epworth and Pichot scores were 18.4±6.3 and 28.3±4.5, respectively; AHI was 39±7/h and arousal index was 39±13/h. At 6^th month, 96.4% of study subjects continued to use auto-CPAP-therapy within 6.5±2.4 h/night. There was a significant correlation between the modification (Δ) of Epworth scores and (Δ) AHI after 3 and 6 months of auto-CPAP-therapy (R=0.568 and p=0.003; R=0.745 and p=0.002; respectively). At 6^th month follow up, the main side effects of auto-CPAP were difficult sleeping, dry mouth or nose, skin marks or rashes, discomfort when breathing, and nasal congestion (36.1%, 32.0%, 20.8%, 16.0%, and 11.9%, respectively).

Conclusion

Auto-CPAP is effective in treatment of Vietnamese patients with severe OSA in short term follow up.

A Review of Current Tools Used for Evaluating the Severity of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a common and heterogeneous disease characterized by episodic collapse within the upper airways, which leads to reduced ventilation and adverse consequences, including hypoxia, hypercapnia, sleep fragmentation, and long-term effects such as cardiovascular comorbidities. The clinical diagnosis of OSA and its severity classification are often determined based on the apnea-hypopnea index (AHI), defining the number of apneic and hypopnea events per hour of sleep. However, the limitations of the AHI to assess disease severity have necessitated the exploration of other metrics for additional information to reflect the complexity of OSA. Novel parameters such as the hypoxic burden have the potential to better capture the main features of OSA by maximizing the information available from the polysomnogram. These emerging measures have described multidimensional qualities of sleep-disordered breathing events and breathing irregularity and will ultimately result in better management of OSA.

Sleep-disordered breathing and effectiveness of cardiac resynchronization therapy in heart failure patients: gender differences?

OBJECTIVES

This study evaluated heart failure (HF) patients who underwent cardiac resynchronization therapy (CRT) and who had device-documented sleep-disordered breathing (SDB). We found gender differences in acute changes in SDB due to CRT impact.

BACKGROUND

SDB typically occurs in HF patients. However, the role of SDB and its response to CRT in HF patients, as well as the relation with gender are currently not fully researched.

METHODS

Among 63 consecutive patients who received CRT with an SDB algorithm, 23 patients documented SDB at one-month cardiac device interrogation and represented our population. We defined a Sleep apnoea Severity SCore(SSSC), and consequently, patients were categorized to have mild, moderate, and severe sleep apnoea syndrome divided into two groups: Group-1: 18 males (78%); Group-2: 5 females (22%). We evaluated the variation of apnoea burden and CRT response based on gender differences.

RESULTS

A significantly higher proportion of patients in the male group were non-responders to CRT at 12-months follow-up (p = 0.076) while in the female population 5/5 patients (100%) were responders to CRT at the same follow-up time (p = 0.021). Among Group-2 subjects, we documented a significant linear decrease in SSSC(p > 0,01) while in Group-1 the CRT effect on SSSC was variable. At 12-months follow-up, the difference in SSSC between the two groups was statistically significant (p < 0.001).

CONCLUSIONS

Our study reports a correlation between CRT response and sleep apnoea burden considering gender differences. In particular, HF-women responders to CRT demonstrate a significant linear decrease in sleep apnoea burden determined through a device algorithm, when compared to a similar male population. Further research is needed to confirm these findings.

Risk factors for obstructive sleep apnea-related hypertension in police officers in Southern China

Background

Obstructive sleep apnea (OSA) is an independent risk factor for hypertension. OSA-related hypertension is common and treatment of OSA can reduce blood pressure (BP). However, few studies have been conducted on this type of hypertension in the Chinese occupational population.

Methods

We conducted a field investigation of a team of police officers who underwent an annual health check-up in 2017 in the city of Guangzhou, in southern China. Participants were screened with the Berlin Questionnaire and those at high risk for OSA performed a home sleep apnea test (HSAT). BP over 140/90 mmHg or taking antihypertensive drugs is considered hypertension.

Results

Of the 1,036 individuals (799 males and 237 females) included in our study, the mean age was 40.7±9.1 years (range, 22-63 years), 228 (22.0%) were at high risk for OSA, and 103 (9.9%) were diagnosed with OSA. Of the 103 diagnosed with OSA, none had ever been diagnosed with and treated for OSA, and 49 (47.6%) were also diagnosed with hypertension; of these 49, 15 (30.6%) had not been diagnosed with hypertension before, and 27 (55.1%) had never been treated for hypertension. Age [odds ratio (OR) =5.81, 95% confidence interval (CI): 1.78-18.98, P<0.01] and severity of OSA (OR =5.07, 95% CI: 1.72-14.89, P<0.01) were associated with increased risk of OSA-related hypertension. After mood (depression and anxiety) status adjustment, age (adjusted OR =5.81, 95% CI: 1.80-18.80, P<0.01) and severity of OSA (adjusted OR =4.56, 95% CI: 1.49-13.93, P<0.01) were still risk factors for OSA-related hypertension.

Conclusions

Among the policemen of southern China, a higher prevalence was detected not only of OSA but also of OSA-related hypertension which was associated with higher OSA severity and age.

Impact of obstructive sleep apnea on cardiac organ damage in patients with acute ischemic stroke

BACKGROUND AND PURPOSE

Both obstructive sleep apnea (OSA) and cardiac organ damage have a crucial role in acute ischemic stroke. Our aim is to explore the relationship between OSA and cardiac organ damage in acute stroke patients.

METHODS

A total of 130 consecutive patients with acute ischemic stroke were enrolled. Patients underwent full multichannel 24-h polysomnography for evaluation of OSA and echocardiography to evaluate left ventricle (LV) mass index (LV mass/BSA, LV mass/height), thickness of interventricular septum (IVS) and posterior wall (LVPW), LV ejection fraction and left atrium enlargement. Information on occurrence of arterial hypertension and its treatment before stroke was obtained from patients' history.

RESULTS

61.9% (70) of patients, mostly men (67.1%), with acute stroke had OSA (AHI > 10). Patients with acute stroke and OSA showed a significant increase (P < 0.05) of LV mass index, IVS and LVPW thickness and a significant left atrial enlargement as compared with patients without OSA. LV ejection fraction was not significantly different in stroke patients with and without OSA and was within normal limits. No relationship was found among cardiac alterations, occurrence of OSA and history of hypertension.

CONCLUSION

Acute stroke patients with OSA had higher LV mass and showed greater left atrial enlargement than patients without OSA. This study confirms the high prevalence of OSA in stroke patients, suggesting also an association between OSA and cardiac target organ damage. Our finding of structural LV abnormalities in acute stroke patients with OSA suggests a potential role of OSA as contributing factor in determining both cerebrovascular and cardiac damage, even in absence of clear link with a history of blood pressure elevation.

The Pathophysiology and Treatment of Hypertension in Patients With Cushing's Syndrome

When hypertension, a pathology that is frequently found in the general population, presents in a young patient, secondary causes such as Cushing's syndrome (CS), a rare disease characterized by long-term elevated cortisol levels, should be considered. Present in ~80% of CS patients independently of their age and sex, hypertension is one of the pathology's most prevalent, alarming features. Its severity is principally associated with the duration and intensity of elevated cortisol levels. Prompt diagnosis and rapid initiation of treatment are important for reducing/delaying the consequences of hypercortisolism. Glucocorticoid excess leads to hypertension via a variety of mechanisms including mineralocorticoid mimetic activity, alterations in peripheral and renovascular resistance, and vascular remodeling. As hypertension in CS patients is caused by cortisol excess, treating the underlying pathology generally contributes to reducing blood pressure (BP) levels, although hypertension tends to persist in approximately 30% of cured patients. Surgical removal of the pituitary tumor remains the first-line treatment for both adrenocorticotropin hormone (ACTH) dependent and independent forms of the syndrome. In light of the fact that surgery is not always successful in curing the underlying disease, it is essential that other treatments be considered and prescribed as needed. This article discusses the mechanisms involved in the pathogenesis of CS and the pros and the cons of the various antihypertensive agents that are presently available to treat these patients.

Obstructive Sleep Apnea and Hypertension: Why Treatment Does Not Consistently Improve Blood Pressure

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA) and hypertension are two phenomena deeply linked together and, although a causal relationship has been suggested, a recent meta-analysis showed only a very modest effect of OSA treatment on blood pressure (BP). However, a vast number of randomized controlled trials published so far share some limitations, mainly of methodological nature: neither OSA nor BP is always assessed in a standardized way. Moreover, compliance with OSA treatment is often sub-optimal making the results of these trials difficult to interpret.

RECENT FINDINGS

Recent studies have shown that antihypertensive drugs can reduce BP more than OSA treatment, showing a better compliance profile and very few side effects. Considering the importance of reducing the overall cardiovascular risk of OSA patients, a more careful management of patient's antihypertensive medication could allow a better BP control also in this condition. In addition, greater efforts should be made to improve patient's acceptance of OSA treatment with the aim of improving their compliance.

Role of obstructive sleep apnea on the response to cardiac resynchronization therapy and all-cause mortality

BACKGROUND

The role of obstructive sleep apnea (OSA) on the response to cardiac resynchronization therapy (CRT) and all-cause mortality in patients with advanced heart failure (HF) is unknown.

OBJECTIVE

We assessed the association between OSA, response to CRT, and all-cause mortality in patients with HF.

METHODS

We analyzed records of 548 consecutive patients (mean age 65 ± 13 years; 216 (39%) women; mean follow-up period 76 ± 17 months) who received a CRT-defibrillator device from January 15, 2007 to March 30, 2016 at our tertiary care referral center.

RESULTS

A total of 180 patients (33%) had OSA. Fewer patients in the OSA group (109 [61%]) had improvement in left ventricular ejection fraction (EF) than did those in the non-OSA group (253 [69%]) (P = .001). A total of 144 patients (27%) died by the end of follow-up (OSA group: 61 [33%]; non-OSA group 83 [23%]; P < .001). OSA diagnosis was associated with a lower chance of improvement in EF (hazard ratio 0.71; 95% confidence interval 0.60-0.89) and a higher risk of all-cause mortality (hazard ratio 3.7; 95% confidence interval 2.5-6.8). This was true in continuous positive airway pressure-compliant patients and in patients with nonischemic cardiomyopathy. However, among patients with ischemic cardiomyopathy, the chance of improvement in EF and all-cause mortality was similar in patients with OSA and those without OSA.

CONCLUSION

OSA is associated with a decreased response to CRT and an increase in all-cause mortality in patients with HF. The differential effect of OSA on CRT response in patients with ischemic cardiomyopathy and nonischemic cardiomyopathy needs further study.

Rhinological interventions for obstructive sleep apnoea - a systematic review and descriptive meta-analysis

OBJECTIVES

Obstructive sleep apnoea is a common chronic sleep disorder characterised by collapse of the upper airway during sleep. The nasal airway forms a significant part of the upper airway and any obstruction is thought to have an impact on obstructive sleep apnoea. A systematic review was performed to determine the role of rhinological surgical interventions in the management of obstructive sleep apnoea.

METHODS

A systematic review of current literature was undertaken; studies were included if they involved comparison of a non-surgical and/or non-rhinological surgical intervention with a rhinological surgical intervention for treatment of obstructive sleep apnoea.

RESULTS

Sixteen studies met the selection criteria. The pooled data suggest that there are reductions in the apnoea/hypopnea index and respiratory disturbance index following nasal surgery. However, the current body of studies is too heterogeneous for statistically significant meta-analysis to be conducted.

CONCLUSION

Nasal surgery may have limited benefit for a subset of patients based on current evidence.

Systemic hypertension in obstructive sleep apnea

There is consistent epidemiological evidence that sleep disordered breathing and systemic arterial hypertension are deeply associated, being linked through a bidirectional complex interaction among multiple mechanisms including autonomic nervous system alterations, inflammation, hormonal and hemodynamic components, sleep alterations. However there are several unanswered questions not only from a pathophysiological perspective, but also regarding the effects of obstructive sleep apnea (OSA) treatment on arterial blood pressure values. At present, while many studies have supported the possibility to obtain at least a small blood pressure reduction with OSA treatment, in particular in hypertensive patients, large trials have not clearly confirmed a significant anti-hypertensive effect, nor a beneficial effect of this intervention on cardiovascular endpoints including cardiovascular mortality. Aim of the present review article is to address the relationship between OSA and hypertension in the light of the latest evidence in the field. Moreover we will discuss research topics which need to be investigated in the future, in order to better clarify still pending issues with the aim of obtaining an early diagnosis, a more suitable phenotyping including comorbidities, and better strategies to improve patients' compliance and adherence to treatment.

Screening obstructive sleep apnea-hypopnea syndrome in hypertensive patients: a comparative study of the efficiency of the Epworth sleepiness scale

Background

Untreated Obstructive Sleep Apnea Hypnopnea Syndrome (OSAHS) is a known factor contributing to resistant hypertension (HT). Continuous Positive Airways Pressure (CPAP) is effective to decrease blood pressure (BP) in severe OSAHS. In our clinical practice, hypertensive patients seem less symptomatic with regard to severe OSAHS than normotensive patients, leading to a risk of underdiagnosis when OSAHS is screened with Epworth Sleepiness Scale (ESS). We aimed to confirm that severe OSAHS is less symptomatic in HT patients than normotensive patients using ESS.

Methods

We retrospectively compared two age, gender-matched groups - 100 hypertensive patients and 100 normotensive patients - with severe OSAHS defined as an AHI (Apnea Hypopnea Index) ≥30. OSAHS was considered symptomatic when ESS > 10.

Results

The two groups of patients did not differ significantly with respect to main characteristics including Body Mass Index (BMI), AHI and ODI (Oxygen Desaturation Index). Systolic and Diastolic BP were higher in HT patients (p < 0.01). HT patients were less symptomatic with regard to severe OSAHS with a lower ESS (10.0 vs 11.9, p < 0.01), and a lower number of patients with an ESS > 10 (30% vs 58%, p < 0.01). In multivariable analysis adjusted on age, gender, Obesity, Systolic BP, Diastolic BP, AHI and ADO, normotension was significantly associated with symptomatic OSAHS (OR = 2.83, [1.298–6.192], p < 0.01).

Conclusions

In our study on patients with severe OSAHS, ESS score was lower in hypertensive patients than in normotensive patients. This discrepancy may lead to an underestimation of severe OSAHS in hypertensive patients.

Evaluation of Intensity of Sleep Bruxism in Arterial Hypertension

Sleep bruxism (SB) is a masticatory muscle activity during sleep that is characterized as rhythmic (phasic) or non-rhythmic (tonic). The recent hypothesis on the etiology of SB supports the role of the central and autonomic nervous systems. Therefore, in this study, we aimed to assess the intensity of SB in patients with arterial hypertension. A total of 70 adults participated in this study: 35 patients with hypertension (study group) and 35 normotensive subjects (control group). Data were recorded using home portable cardiorespiratory polygraphy. The bruxism episode index (BEI) in the study group was found to be significantly higher compared to the control group (3.4 ± 3.25 vs. 2.35 ± 2.29, p = 0.04). Hypertension, higher body mass index (BMI), lower values of mean oxygen saturation (SpO₂), and a higher percentage of SpO₂ < 90% constituted independent risk factors for increased BEI. These results suggest the need for special oral care in hypertensive patients, patients with higher BMI, lower values of SpO₂ and a higher percentage of SpO₂ < 90%.

Patterns of ambulatory blood pressure: clinical relevance and application

Ambulatory blood pressure measurement (ABPM) is now recommended in all patients suspected of having hypertension. However, in practice, the mean daytime pressures are often used to make diagnostic and therapeutic decisions, and the information from abnormal patterns of blood pressure behavior is often overlooked. This paper presents daytime patterns (eg, white coat hypertension and siesta dipping), nocturnal patterns (eg, dipping, non-dipping, reverse dipping, and the morning surge), and discusses ambulatory hypotension, and abnormal patterns and indices of related hemodynamic parameters (eg, heart rate, pulse pressure, and blood pressure variability).

Managing comorbid cardiovascular disease and sleep apnea with pharmacotherapy

INTRODUCTION

Highly prevalent sleep disordered breathing (SDB) has been recognized as an independent cardiovascular disease (CVD) risk factor. Although these two entities often coexist, there is a shortage of sufficiently-powered studies testing the interplay between the course of sleep apnea and CVD pharmacotherapy. The mutual relationship between treated/untreated obstructive sleep apnea (OSA) with ongoing cardiovascular pharmacotherapies is an evident gap in clinical expertise.

AREAS COVERED

In this article, the authors review the available evidence and outline future research directions concerning the reciprocal relationship between the pharmacological treatment of CVD and SDB. Several attempts have been made to identify the most efficacious hypotensive agents for patients with both OSA and hypertension. Various cardiovascular drugs are also evaluated in terms of their influence on sleep apnea severity.

EXPERT OPINION

The question of whether OSA should be included in cardiovascular pharmacotherapy individualization algorithms is a matter of debate and more evidence is needed. Cautious intensification of diuretics with the use of aldosterone receptor antagonists deserves attention when both high blood pressure and sleep apnea coexist.

Continuous Positive Airway Pressure Reduces Night-Time Blood Pressure and Heart Rate in Patients With Obstructive Sleep Apnea and Resistant Hypertension: The RHOOSAS Randomized Controlled Trial

Objective

Most patients with resistant hypertension (RH) have obstructive sleep apnea (OSA). We aimed to determine the impact of OSA and continuous positive airway pressure (CPAP) treatment on the leptin profile and blood pressure (BP) in patients with RH.

Methods

After an initial case-control study (RH with and without OSA), we performed a randomized, single blind study in OSA + RH patients receiving either sham CPAP (3 months) followed by active CPAP (6 months) or 6 months of active CPAP. The primary outcome was the comparison of leptin levels between groups of RH patients with or without OSA. Secondary outcomes were the comparison of metabolic parameters, biomarkers of sympathetic activity, and BP indices between the two groups of RH patients with or without OSA. The same outcomes were then evaluated and compared before and after sham and effective CPAP intervention.

Results

Sixty-two patients (60 ± 10 years; 77% men) with RH (24-h daytime systolic BP (SBP)/diastolic BP: 145 ± 13/85 ± 10 mmHg, 3.7 antihypertensive drugs) were included. The 37 RH patients exhibiting OSA (60%) were predominantly men (87 vs 64% for non-OSA patients), with a greater prevalence of metabolic syndrome and higher creatininemia. Their leptin concentrations were significantly lower than in non-OSA patients [9 (6; 15) vs 17 (6; 29) ng/mL] but increased after 6 months of CPAP. Three months of effective CPAP significantly decreased night-time SBP by 6.4 mmHg and heart rate (HR) by 6.0 bpm, compared to sham CPAP.

Conclusion

The association between OSA and RH corresponds to a specific, predominately male phenotype with a higher burden of metabolic syndrome and higher creatininemia but there was no significant difference between OSA and non-OSA patients regarding BP indices, and the number of antihypertensive drugs used. Active CPAP could be efficient at decreasing night-time BP and HR, but there was no difference between CPAP and sham CPAP groups for all metabolic and SNS markers (NCT00746902 RHOOSAS).

The association between different features of sleep-disordered breathing and blood pressure: A cross-sectional study

Sleep disordered breathing (SDB) is highly prevalent in patients with high blood pressure (BP). Severity of SDB can be evaluated by the number of apneas and hypopneas per hour (AHI) or by measures of hypoxia. The objective of this study was to assess the association between different measures of SDB and BP. In 134 consecutive patients, polygraphy was performed to determine the AHI. Pulse oximetry was used to determine hypoxemic burden (time below 90% oxygen saturation [T90] and hypoxia load [HL], representing the integrated area above the curve of desaturation). AHI did not correlate with systolic and diastolic BP or pulse pressure. In contrast, HL correlated with pulse pressure during the day (P = .01) and night (P = .0034) before and after adjustment for body mass index. The correlation between systolic BP and HL at night disappeared following adjustment for body mass index. This study generates the hypothesis that nocturnal hypoxemic burden may represent a suitable marker of BP pattern and a potential treatment target in hypertensive patients.

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

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