Effect of intensified diuretic therapy on overnight rostral fluid shift and obstructive sleep apnoea in patients with uncontrolled hypertension

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

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

Effect of antihypertensive agents on sleep apnea and ambulatory blood pressure in patients with hypertension: A randomized controlled trial

BACKGROUND

Obstructive sleep apnea (OSA) and hypertension are common conditions that may be linked through sympathetic activation and water retention. We hypothesized that diuretics, which reduce the body water content, may be more effective than amlodipine, a blood pressure (BP)-lowering agent implicated with edema, in controlling OSA in patients with hypertension. We also aimed to compare the effects of these treatments on ambulatory blood pressure monitoring (ABPM).

METHODS

In a randomized, double-blind clinical trial, we compared the effects of chlorthalidone/amiloride 25/5 mg with amlodipine 10 mg on OSA measured by portable sleep monitor and BP measured by ABPM. The study included participants older than 40 who had moderate OSA (10-40 apneas/hour of sleep) and BP within the systolic range of 140-159 mmHg or diastolic range of 90-99 mmHg.

RESULTS

The individuals in the experimental groups were comparable in age, gender, and other relevant characteristics. Neither the combination of diuretics nor amlodipine alone reduced the AHI after 8 weeks of treatment (AHI 26.3 with diuretics and 25.0 with amlodipine. P = 0.713). Both treatments significantly lowered office, 24-h, and nighttime ABP, but the two groups had no significant difference.

CONCLUSION

Chlorthalidone associated with amiloride and amlodipine are ineffective in decreasing the frequency of sleep apnea episodes in patients with moderate OSA and hypertension. Both treatments have comparable effects in lowering both office and ambulatory blood pressure. The notion that treatments could offer benefits for both OSA and hypertension remains to be demonstrated. TRIAL REGISTRATION CLINICALTRIALS.

GOV IDENTIFIER

NCT01896661.

Who needs to be screened for primary aldosteronism?

The prevalence of patients with primary aldosteronism (PA) is about 5%-15% in hypertensive patients, and it is common cause of secondary hypertension in clinical practice. Two major causes of PA are noted, namely bilateral adrenal hyperplasia and aldosterone-producing adenoma, and the general diagnosis is based on three steps: (1) screening, (2) confirmatory testing, and (3) subtype differentiation (Figure 1). The recommendation for screening patients is at an increased risk of PA, here we focus on which patients should be screened for PA, not only according to well-established guidelines but for potential patients with PA. We recommend screening for 1) patients with resistant or persistent hypertension, 2) hypertensive patients with hypokalemia (spontaneous or drug-induced), 3) young hypertensive patients (age <40 years), and 4) all hypertensive patients with a history of PA in first-degree relatives. Moreover, we suggest screening for 1) hypertensive patients themselves or first-degree relatives with early target organ damage, such as stroke and other diseases, 2) all hypertensive patients with a concurrent adrenal incidentaloma, 3) hypertensive patients with obstructive sleep apnea, 4) hypertensive patients with atrial fibrillation unexplained by structural heart defects and/or other conditions resulting in the arrhythmia, 5) hypertensive patients with anxiety and other psychosomatic symptoms, and 6) hypertensive patients without other comorbidities to maintain cost-effectiveness.

Resistant hypertension: consensus document from the Korean society of hypertension

Although reports vary, the prevalence of true resistant hypertension and apparent treatment-resistant hypertension (aTRH) has been reported to be 10.3% and 14.7%, respectively. As there is a rapid increase in the prevalence of obesity, chronic kidney disease, and diabetes mellitus, factors that are associated with resistant hypertension, the prevalence of resistant hypertension is expected to rise as well. Frequently, patients with aTRH have pseudoresistant hypertension [aTRH due to white-coat uncontrolled hypertension (WUCH), drug underdosing, poor adherence, and inaccurate office blood pressure (BP) measurements]. As the prevalence of WUCH is high among patients with aTRH, the use of out-of-office BP measurements, both ambulatory blood pressure monitoring (ABPM) and home blood pressure monitoring (HBPM), is essential to exclude WUCH. Non-adherence is especially problematic, and methods to assess adherence remain limited and often not clinically feasible. Therefore, the use of HBPM and higher utilization of single-pill fixed-dose combination treatments should be emphasized to improve drug adherence. In addition, primary aldosteronism and symptomatic obstructive sleep apnea are quite common in patients with hypertension and more so in patients with resistant hypertension. Screening for these diseases is essential, as the treatment of these secondary causes may help control BP in patients who are otherwise difficult to treat. Finally, a proper drug regimen combined with lifestyle modifications is essential to control BP in these patients.

Blood pressure control in hypertensive sleep apnoea patients of the European Sleep Apnea Database cohort - effects of positive airway pressure and antihypertensive medication

Aims

We analysed longitudinal blood pressure (BP) data from hypertensive obstructive sleep apnoea (OSA) patients in the European Sleep Apnea Database cohort. The study investigated the interaction between positive airway pressure (PAP)-induced BP change and antihypertensive treatment (AHT).

Methods and results

Hypertensive patients with AHT [monotherapy/dual therapy n = 1283/652, mean age 59.6 ± 10.7/60.6 ± 10.3 years, body mass index (BMI) 34.2 ± 6.5/34.8 ± 7.0 kg/m2, apnoea-hypopnoea index 46 ± 25/46 ± 24 n/h, proportion female 29/26%, respectively] started PAP treatment. Office BP at baseline and 2- to 36-month follow-up were assessed. The interaction between AHT drug classes and PAP on BP was quantified and the influences of age, gender, BMI, co-morbidities, BP at baseline, and study site were evaluated. Following PAP treatment (daily usage, 5.6 ± 1.6/5.7 ± 1.9 h/day), systolic BP was reduced by -3.9 ± 15.5/-2.8 ± 17.7 mmHg in mono/dual AHT and diastolic BP by -3.0 ± 9.8/-2.7 ± 10.8 mmHg, respectively, all P < 0.0001. Systolic and diastolic BP control was improved following PAP treatment (38/35% to 54/46% and 67/67% to 79/74%, mono/dual AHT, respectively). PAP treatment duration predicted a larger BP improvement in the monotherapy group. Intake of renin-angiotensin blockers [angiotensin converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB)] alone or in any AHT combination was associated with better BP control. The AHT-dependent BP improvement was independent of confounders.

Conclusion

In this pan-European OSA patient cohort, BP control improved following initiation of PAP. Longer PAP treatment duration, was associated with a favourable effect on BP. Our study suggests that ACEI/ARB, alone or in combination with other drug classes, provides a particularly strong reduction of BP and better BP control when combined with PAP in OSA.

Sleep and Breathing Conference highlights 2023: a summary by ERS Assembly 4

This paper presents some of the highlights of the Sleep and Breathing Conference 2023 https://bit.ly/46MxJml.

Positive Airway Pressure Therapy Adherence and Health Care Resource Use in Patients With Obstructive Sleep Apnea and Heart Failure With Preserved Ejection Fraction

Background Obstructive sleep apnea (OSA) is common in heart failure with preserved ejection fraction (HFpEF). However, current evidence is equivocal regarding the potential benefits of treating OSA with positive airway pressure (PAP) therapy in HFpEF. This study assessed the association between adherence to PAP therapy and health care resource use in patients with OSA and HFpEF. Methods and Results Administrative insurance claims data linked with objective PAP therapy usage data from patients with OSA and HFpEF were used to determine associations between PAP adherence and a composite outcome including hospitalizations and emergency room visits. One-year PAP adherence was based on an adapted US Medicare definition. Propensity score methods were used to create groups with similar characteristics across PAP adherence levels. The study cohort included 4237 patients (54.0% female, mean age 64.1 years); 40% were considered adherent to PAP therapy (30% intermediate adherent, 30% nonadherent). In the matched cohort, PAP-adherent patients had fewer health care resource use visits than nonadherent patients, a 57% decrease in hospitalizations, and a 36% decrease in emergency room visits versus the year before PAP initiation. Total health care costs were lower in adherent patients than nonadherent patients ($12 732 versus $15 610, P<0.001). Outcomes for intermediately adherent patients were most similar to those for nonadherent patients. Conclusions Treating OSA with PAP therapy in patients with HFpEF was associated with a reduction in health care resource use. These data highlight the importance of managing concomitant OSA in patients with HFpEF, and the need for strategies to enhance PAP adherence in this population.

Pharmacotherapy for obstructive sleep apnea: targeting specific pathophysiological traits

INTRODUCTION

The pathophysiology of obstructive sleep apnea (OSA) is multi-factorial and complex. Varying OSA's pathophysiological traits have been identified, including pharyngeal collapsibility, upper airway muscle reactivity, arousal threshold, and regulation of the ventilatory drive. Being CPAP of difficult tolerance and other interventions reserved to specific subpopulations new pharmacological treatments for OSA might be resolutive.

AREAS COVERED

Several existing and newly developed pharmacological drugs can impact one or more endotypes and could therefore be proposed as treatment options for sleep disordered breathing. With this review we will explore different pathophysiological traits as new targets for OSA therapy. This review will summarize the most promising pharmacological treatment for OSA accordingly with their mechanisms of action on upper airway collapsibility, muscle responsiveness, arousal threshold, and loop gain.

EXPERT OPINION

Only understanding the pathophysiological traits causing OSA in each patient and placing the disease in the framework of patient comorbidities, we will be able to evolve interventions toward OSA. The development of new drug's combinations will permit different approaches and different choices beside conventional treatments. In the next future, we hope that sleep specialists will select the treatment for a specific patient on the base of its pathophysiology, defining a precision medicine for OSA.

Effects of Antihypertensive Treatment on Left and Right Ventricular Global Longitudinal Strain and Diastolic Parameters in Patients with Hypertension and Obstructive Sleep Apnea: Randomized Clinical Trial of Chlorthalidone plus Amiloride vs. Amlodipine

Hypertension is highly prevalent in patients with obstructive sleep apnea (OSA), and fluid retention with its nighttime rostral distribution is one potential mechanism. We tested whether or not diuretics differ from amlodipine in their impact on echocardiographic parameters. Patients with moderate OSA and hypertension were randomized to receive diuretics (chlorthalidone plus amiloride) or amlodipine daily for 8 weeks. We compared their effects on left and right ventricular global longitudinal strain (LV-GLS and RV-GLS, respectively), on LV diastolic parameters, and on LV remodeling. In the 55 participants who had echocardiographic images feasible for strain analysis, all echocardiographic parameters were within normal ranges. After 8 weeks, the 24 h blood pressure (BP) reduction values were similar, while most echocardiographic metrics were kept unchanged, except for LV-GLS and LV mass. In conclusion, the use of diuretics or amlodipine had small and similar effects on echocardiographic parameters in patients with moderate OSA and hypertension, suggesting that they do not have important effects on mediating the interaction between OSA and hypertension.

Impact of Body Composition on Sleep and Its Relationship with Sleep Disorders: Current Insights

Sleep is involved in many physiological processes and is essential for both physical and mental health. Obesity and sleep deprivation due to sleep disorders are major public health issues. Their incidence is increasing, and they have a wide range of adverse health-related consequences, including life-threatening cardiovascular disease. The impact of sleep on obesity and body composition is well-known, and many studies have shown an association between insufficient or excessive sleep duration and obesity, body fat percentage, and weight gain. However, there is growing evidence of the effects of body composition on sleep and sleep disorders (particularly sleep disordered breathing) through anatomical and physiological mechanisms (nocturnal fluid shift, core body temperature, or diet). Although some research has been conducted on the bidirectional effects of sleep-disordered breathing and body composition, the specific effects of obesity and body composition on sleep and the underlying mechanisms that explain these effects remain unclear. Therefore, this review summarizes the findings on the effects of body composition on sleep and draws conclusions and proposals for future research in this field.

Hypertension treatment in patients with sleep apnea from the European Sleep Apnea Database (ESADA) cohort - towards precision medicine

We recruited 5,970 hypertensive patients with obstructive sleep apnea (OSA) on current antihypertensive treatment from the European Sleep Apnea Database (ESADA) cohort. The group was subdivided into those receiving monotherapy (n = 3,594) and those receiving dual combined therapy (n = 2,376). We studied how major OSA confounders like age, gender, and body mass index as well as the degree of sleep apnea modified office systolic and diastolic blood pressure. Beta-blockers alone or in combination with a diuretic were compared with other antihypertensive drug classes. Monotherapy with beta-blocker was associated with lower systolic blood pressure, particularly in non-obese middle-aged males with hypertension. Conversely, the combination of a beta-blocker and a diuretic was associated with lower systolic and diastolic blood pressure in hypertensive patients with moderate-severe OSA. Systolic blood pressure was better controlled in female patients using this combined treatment. Our cross-sectional data suggest that specific clinical characteristics and type of antihypertensive medication influence the degree of blood pressure control in hypertensive OSA patients. Controlled trials are warranted.

Effect of antihypertensive medications on sleep status in hypertensive patients

Purpose

Antihypertensive medication is an effective way to control blood pressure. However, some studies reported that it may affect patients' sleep quality during the treatment. Due to the inconsistency of present results, a comprehensive systematic review and network meta-analysis are needed.

Methods

Electronic databases (MEDLINE, EMBASE, WEB OF SCIENCE, PUBMED) were searched up to April 10th, 2021 including no restriction of publication status. Randomized controlled trials (RCTs) or quasi-experimental studies or cohort studies were eligible. The network meta-analysis was used within a Bayesian framework.

Results

Finally, 16 publications (including 12 RCTs and 4 quasi-experimental studies) with 404 subjects were included in this study. Compared to placebo, the results of the network meta-analysis showed that diuretics were effective in improving sleep apnea with a mean difference (MD) of - 15.47 (95% confidence interval [CI]: - 23.56, - 6.59) which was consistent with the direct comparison result (MD: - 17.91; 95% CI - 21.60, - 14.23). In addition, diuretics were effective in increasing nocturnal oxygen saturation with an MD of 3.64 (95% CI 0.07, 7.46). However, the effects of β-blockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, and the others on sleep apnea were not statistically significant. Additionally, the effects of antihypertensive medication on the total sleep time (min), rapid eye movement (%), and sleep efficiency (%) were not statistically significant.

Conclusion

Our study found that diuretics could effectively reduce the severity of sleep apnea in hypertensive patients. However, the effects of antihypertensive drugs on sleep characteristics were not found.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-022-00391-8.

Turning Over a New Leaf-Pharmacologic Therapy in Obstructive Sleep Apnea

Despite extensive research, there is currently no approved drug for obstructive sleep apnea (OSA) treatment. OSA is a heterogeneous condition that involves multiple dominating pathophysiological traits. Drug development in this field needs to address both pathophysiological mechanisms and associated comorbid conditions in order to meet requirements for long-term therapy in OSA. Several drug candidates have been proposed and ongoing phase II trials that target various forms of sleep-disordered breathing have been initiated. The field is moving toward tailored therapeutic approaches in patients with OSA.

Obstructive Sleep Apnea and Hypertension: Updates to a Critical Relationship

Purpose of Review

Obstructive sleep apnea (OSA) is an underdiagnosed illness linked to essential hypertension (HTN), resistant hypertension (r-HTN), and cardiovascular disease (CVD). This review provides updates on the epidemiology, pathophysiology, and treatments of OSA-associated HTN.

Recent Findings

Mild sleep apnea increases the risk for HTN. Eighty-nine percent of young patients aged 18–35 with HTN not attributed to secondary causes have underlying OSA. Home sleep studies are noninferior to formal polysomnography for OSA diagnosis. Nocturnal oxygen desaturation rate is positively correlated with HTN severity. Gut microbiome neo-colonization in response to high-fat diet cravings in patients with OSA alters immune function and worsens HTN. Carbonic anhydrase inhibitors and probiotics show newfound potential for OSA-associated HTN treatment. OSA recognition improves hospital outcomes after a STEMI. Hypoxia-inducible factor (HIF) transcription increases in a dose-dependent manner to hypoxia, and HIFs are strongly linked to cancer growth.

Summary

OSA and HTN are comorbid conditions with adversely connected pathophysiology including sympathetic hyperactivity, gut dysbiosis, proinflammation, endothelial damage, rostral fluid shifts, pharyngeal collapse, intravascular fluid retention, nocturnal energy expenditure, and metabolic derangements. The dose–response effect of OSA on HTN severity challenges blood pressure (BP) control, so those with refractory HTN should be screened for OSA.

Association of Obstructive Apnea with Thoracic Fluid Shift and Small Airways Narrowing in Asthma During Sleep

RATIONALE

Obstructive sleep apnea (OSA) is highly prevalent among patients with asthma, suggesting a pathophysiological link between the two, but a mechanism for this has not been identified.

HYPOTHESIS

Among patients with asthma, those with OSA will have greater overnight increases in thoracic fluid volume and small airways narrowing than those without OSA.

METHODS

We enrolled 19 participants with asthma: 9 with OSA (apnea-hypopnea index (AHI) ≥10) and 10 without OSA (AHI <10). All participants underwent overnight polysomnography. Before and after sleep, thoracic fluid volume was measured by bioelectrical impedance and small airways narrowing was primarily assessed by respiratory system reactance at 5Hz using oscillometry.

RESULTS

Patients with asthma and OSA (OSA group) had a greater overnight increase in thoracic fluid volume by 120.5 mL than patients without OSA (non-OSA group) (164.4 ± 44.0 vs 43.9 ± 47.3 mL, p=0.006). Compared to the non-OSA group, the OSA group had greater overnight decrease in reactance at 5Hz (-1.08 ± 0.75 vs 0.21 ± 0.27 cmH₂O/L/s, p=0.02), and overnight increase in reactance area (14.81 ± 11.09 vs -1.20 ± 2.46 cmH₂O/L, p=0.04), frequency dependence of resistance (1.02 ± 0.68 vs 0.05 ± 0.18 cmH₂O/L/s, p=0.04), and resonance frequency (2.80 ± 4.14 vs -1.42 ± 2.13 cmH₂O/L/s, p=0.04).

CONCLUSION

Patients with asthma and co-existing OSA had greater overnight accumulation of fluid in the thorax in association with greater small airways narrowing than those without OSA. This suggests OSA could contribute to worsening of asthma at night by increasing fluid accumulation in the thorax.

Novel avenues to approach non-CPAP therapy and implement comprehensive OSA care

Recent advances in obstructive sleep apnoea (OSA) pathophysiology and translational research have opened new lines of investigation for OSA treatment and management. Key goals of such investigations are to provide efficacious, alternative treatment and management pathways that are better tailored to individual risk profiles to move beyond the traditional, continuous positive airway pressure (CPAP)-focused, "one size fits all", trial and error approach which is too frequently inadequate for many patients. Identification of different clinical manifestations of OSA (clinical phenotypes) and underlying pathophysiological phenotypes (endotypes), that contribute to OSA have provided novel insights into underlying mechanisms and have underpinned these efforts. Indeed, this new knowledge has provided the framework for precision medicine for OSA to improve treatment success rates with existing non-CPAP therapies such as mandibular advancement devices and upper airway surgery, and newly developed therapies such as hypoglossal nerve stimulation and emerging therapies such as pharmacotherapies and combination therapy. These concepts have also provided insight into potential physiological barriers to CPAP adherence for certain patients. This review summarises the recent advances in OSA pathogenesis, non-CPAP treatment, clinical management approaches and highlights knowledge gaps for future research. OSA endotyping and clinical phenotyping, risk stratification and personalised treatment allocation approaches are rapidly evolving and will further benefit from the support of recent advances in e-health and artificial intelligence.

Associations of ambient air pollution with overnight changes in body composition and sleep-related parameters

This study aims to investigate the association of air pollution with overnight change in 4body composition and sleep-related parameters. Body composition of 197 subjects in New Taipei city was measured before and after sleep by bioelectric impedance analysis. Air pollutant data were collected from Taiwan Environmental Protection Administration. Sleep parameters were examined by polysomnography. We observed fine particulate matter (PM_2.5) decreased arterial oxygen saturation (SaO₂) and increased apnea-hypopnea index (AHI); NO₂ increased arousal, AHI, and decreased mean SaO₂; and O₃ inmcreased mean SaO₂. We observed 0.99-μg/m³ increase in PM_2.5 was associated with 18.8% increase in changes of right arm fat percentage (95% confidence interval (CI): 0.004, 0.375) and 0.011-kg increase in changes of right arm fat mass (95% CI: 0.000, 0.021). 2.45-ppb increase in NO₂ was associated with 0.181-kg decrease in changes of muscle mass (95% CI: -0.147, -0.001), 0.192-kg decrease in changes of fat free mass (95% CI: -0.155, -0.001), 21.1% increase in changes of right leg fat percentage (95% CI: 0.012, 0.160), and 21.3% increase in changes of left leg fat percentage (95% CI: 0.006, 0.168). 1.56-ppb increase in O₃ was associated with 29.3% decrease in changes of right leg fat percentage (95% CI: -0.363, -0.013), 0.058-kg increase in changes of right leg fat free mass (95% CI: 0.008, 0.066), and 0.059-kg increase in changes of right leg muscle mass (95% CI: 0.010, 0.066). We observed AHI was associated with overnight changes in fat percentage, total fat mass, muscle mass, bone mass, fat free mass, extracellular water, basal metabolic rate, leg fat percentage, leg fat mass, and trunk fat percentage (p < 0.05). In conclusion, exposure to air pollutants was associated with overnight body composition changes and sleep-related parameters. Nocturnal changes in total muscle mass and leg fat percentage likely contribute to the relationship between air pollution and obstructive sleep apnea.

Positionspapier „Schlafmedizin in der Kardiologie“, Update 2021

Es hat sich viel getan in der Welt der Schlafmedizin in der Kardiologie, weshalb eine vollwertige Überarbeitung des Positionspapiers „Schlafmedizin in der Kardiologie“ erforderlich wurde. In der aktuellen neuartigen Version finden sich nicht nur alle verfügbaren Studien, Literaturstellen und Updates zu Pathophysiologie, Diagnostik- und Therapieempfehlungen, sondern auch Ausblicke auf neue Entwicklungen und zukünftige Forschungserkenntnisse. Dieses überarbeitete Positionspapier gibt Empfehlungen für Diagnostik und Therapie von Patienten mit kardiovaskulären Erkrankungen mit schlafassoziierten Atmungsstörungen und erteilt darüber hinaus einen fundierten Überblick über verfügbare Therapien und Evidenzen, gibt aber ebenso Ratschläge wie mit Komorbiditäten umzugehen ist. Insbesondere enthält dieses überarbeitete Positionspapier aktualisierte Stellungnahmen zu schlafassoziierten Atmungsstörungen bei Patienten mit koronarer Herzerkrankung, Herzinsuffizienz, arterieller Hypertonie, aber auch für Patienten mit Vorhofflimmern. Darüber hinaus finden sich erstmals Empfehlungen zur Telemedizin als eigenes, neues Kapitel. Dieses Positionspapier bietet Kardiologen sowie Ärzten in der Behandlung von kardiovaskulären Patienten die Möglichkeit einer evidenzbasierten Behandlung der wachsend bedeutsamen und mit zunehmender Aufmerksamkeit behafteten Komorbidität schlafassoziierter Atmungsstörungen. Und nicht zuletzt besteht mit diesem neuen Positionspapier eine enge Verknüpfung mit dem neuen Curriculum Schlafmedizin der Deutschen Gesellschaft für Kardiologie, weshalb dieses Positionspapier eine Orientierung für die erworbenen Fähigkeiten des Curriculums im Umgang von kardiovaskulären Patienten mit schlafassoziierten Atmungsstörungen darstellt.

Association of Sodium with Obstructive Sleep Apnea. The ELSA-Brasil Study

Rationale: Excessive sodium may have a role in the pathogenesis of obstructive sleep apnea (OSA) for patients with hypervolemic conditions, but it is unclear whether this is valid for all patients with OSA, including those with no significant comorbidities.Objectives: To test the association of urinary sodium and OSA in a large sample of participants from the ELSA-Brasil (Estudo Longitudinal de Saúde do Adulto-Brasil) Study. In addition, we stratified the analysis participants according to the presence of hypertension.Methods: In this cross-sectional study, OSA was defined by an apnea-hypopnea index ≥15 events/h. A validated 12-hour urine collection as representative of the 24-hour period was obtained from all participants to measure sodium excretion. We performed a logistic regression analysis to test the association of urinary sodium excretion with OSA (dependent variable) adjusting for age, sex, race and income, glomerular filtration rate, diabetes, physical activity, and antihypertensive classes related to sodium excretion. To address potential residual factors that may influence sodium excretion, we performed additional analysis replacing sodium excretion for salt intake (food frequency questionnaire) using the same models.Results: We studied 1,946 participants (age 49 ± 8 yr; 43.4% men). A third of them had OSA. Compared with those with no OSA, participants with OSA presented with higher sodium excretion (1.66 [1.19-2.29] vs. 1.99 [1.44-2.69] g/12 h; P < 0.001). After adjustments for confounding factors, we found no overall significant associations of sodium excretion with OSA (odds ratio [OR], 1.09; 95% confidence interval [CI], 0.97-1.23; P = 0.150). Regardless of the OSA status, the sodium excretion was higher in hypertensive than in normotensive participants (1.93 [1.35-2.64] vs. 1.71 [1.22-2.37] g/12 h). An independent association of sodium excretion with OSA was observed in patients with hypertension only (OR, 1.326; 95% CI, 1.067-1.648; P = 0.011), but the interaction of urinary sodium with hypertension was not significant (P = 0.37). The analysis of salt intake revealed consistent findings.Conclusions: The potential role of sodium in the pathogenesis of OSA seems to be modest and limited for those with higher salt intake and, consequently, higher fluid retention such as observed in patients with hypertension.

New frontiers in pharmacologic obstructive sleep apnea treatment: A narrative review

Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing characterized by intermittent partial or complete closure of the upper airway during sleep. If left untreated, OSA is associated with adverse cardiovascular outcomes such as hypertension, coronary heart disease, heart failure, cardiac arrhythmia, stroke, and death. Positive airway pressure (PAP) is often considered the first-line treatment for OSA. While PAP can be very effective in reducing the number of obstructive apneas and hypopneas, its impact on prevention of adverse cardiovascular consequences remains controversial, and treatment adherence is often poor. Hence, the necessity for novel treatment options to help those who cannot adhere to positive airway pressure treatment. Different classes of medications have been tested with regards to their effect on OSA severity. This review 1) provides an update on the epidemiology and pathophysiology of OSA, 2) outlines the mechanistic rationale for medication classes tested as OSA treatment and 3) discusses the effects of these medications on OSA. Several wake-promoting medications are approved for management of persistent sleepiness despite OSA treatment; discussion of these symptomatic treatments is outside the scope of this review. Herein, the authors review the current evidence for pharmacological management of OSA and provide future directions.

Effects of Exercise in Patients with Obstructive Sleep Apnoea

Obstructive sleep apnoea (OSA) constitutes a public health problem, with various systemic consequences that can increase cardiovascular morbidity and mortality as well as increase healthcare expenditure. This review discusses the rationale and effects of using general physical exercise, oropharyngeal exercises, and respiratory muscle training as an adjunctive treatment for patients with sleep apnoea. The recommended treatment for OSA is the use of continuous positive airway pressure, which is a therapy that prevents apnoea events by keeping the airways open. In the last decade, coadjuvant treatments that aim to support weight loss (including diet and physical exercise) and oropharyngeal exercises have been proposed to lower the apnoea/hypopnoea index among patients with OSA. Based on the available evidence, health professionals could decide to incorporate these therapeutic strategies to manage patients with sleep apnoea.

Sleep Apnea as a Cardiorenal Risk Factor in CKD and Renal Transplant Patients

BACKGROUND

Chronic kidney disease (CKD) is a public health priority of increasing concern worldwide. Sleep apnea (SA) of moderate-to-severe degree has a 3-9% prevalence in women and 10-17% in men in the general population.

SUMMARY

In CKD patients, the prevalence of SA parallels the decline of the GFR being 27% in CKD patients with a GFR of >60 mL/min/1.73 m2 and 57% in patients with end-stage kidney disease (ESKD). In the early CKD stages, fluid overload is probably the sole risk factor for SA in this population. At more severe CKD stages, disturbed central and peripheral chemosensitivity and the accumulation of uremic toxins might contribute to SA. Still, there is no direct evidence supporting this hypothesis in human studies. Observational studies coherently show that SA is a risk factor for CKD incidence and CKD progression as well as for cardiovascular disease and death in this population. However, there is no randomized clinical trial testing continuous positive airway pressure or other interventions documenting that attenuation of SA may have a favorable effect on renal and cardiovascular outcomes in CKD and ESKD patients. However, most likely, the causal nature of the association between SA and cardiorenal outcomes remains unproven. Renal transplantation is the most effective treatment of SA in patients with ESKD, but this disturbance re-emerges on long-term observation in this population. However, after renal transplantation, SA does not seem to be a predictor of adverse health outcomes.

The Role of Aldosterone in OSA and OSA-Related Hypertension

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

Superior hypertension control with betablockade in the European Sleep Apnea Database

AIMS

Arterial hypertension is highly prevalent and difficult to control in patients with obstructive sleep apnea (OSA). High sympathoadrenergic activity is a hallmark physiological phenomenon in OSA. We hypothesized that an antihypertensive drug with inhibitory properties on this activity, such as beta blockers (BBs), may be particularly efficacious in OSA patients.

METHODS

Hypertensive OSA patients receiving blood pressure-lowing treatment in the European Sleep Apnea Database (ESADA) (n = 5818, 69% men, age 58 ± 11 years, body mass index 33 ± 7 kg/m2, apnea hypopnea index 34 ± 26 events/h) were analyzed. Reported medications [BB, diuretic, renin-angiotensin blocker (RAB), calcium channel blocker (CCB), and centrally acting antihypertensive (CAH)] were classified according to ATC code. Office blood pressure was compared in patients with monotherapy or combination therapy controlling for confounders.

RESULTS

Poorly controlled SBP according to the ESC/ESH guidelines was found in 66% of patients. Patients receiving monotherapy with RAB, CCB or CAH had 2.2 (95% CI 1.4-3.0), 3.0 (1.9-4.1) and 3.0 (1.7-4.7) mmHg higher SBP compared with those on BB (adjusted model, P = 0.007, 0.008 and 0.017, respectively). In those with a combination of two antihypertensive drugs, SBP was 5.5 (4.0-7.1), 5.1 (3.7-6.6), 4.3 (2.5-6.1) and 3.1 (1.6-4.6) mmHg higher in those on CCB/RAB, BB/RAB, BB/CCB or diuretic/RAB compared with those on BB/diuretic (adjusted model, P < 0.001, <0.001, 0.018 and 0.036, respectively).

CONCLUSION

Poorly controlled blood pressure was common in OSA patients with antihypertensive medication. Treatment with BB alone or BB in combination with a diuretic was associated with the lowest systolic pressure in this large clinical cohort.

Managements for Obstructive Sleep Apnea in Adults: Review

Obstructive sleep apnea (OSA) is characterized by recurrent obstruction of the pharyngeal airway during sleep, with resultant hypoxia and sleep fragmentation. It is more common in middle-aged obese men and prevalence is higher in most obese people. However, prevalence is high in African-Americans. OSA is associated with major comorbidities including excessive daytime sleepiness and increased risk of cardiovascular diseases. First and foremost, OSA management starts from educating patients about short-term consequences like motor vehicle accidents, behavioral modifications, long term consequences like cardiopulmonary disease, and resistant high blood pressure. Various types of management options are available for OSA such as weight loss, CPAP, oral appliances, and surgery. The review aims to explain the pathophysiology and cause of the obstruction of the airway in order to choose proper management carefully to decrease the symptoms and cure the disease.

Sleep disturbances: one of the culprits of obesity-related cardiovascular risk?

Growing evidence suggested that Sleep Disorders (SD) could increase the risk of developing obesity and could contribute to worsen obesity-related cardiovascular risk. Further, obesity per se has been reported to blunt sleep homeostasis. This happens through several mechanisms. First of all, the excessive adipose tissue at neck and chest levels could represent a mechanical obstacle to breathe. Moreover, the visceral adipose tissue is known to release cytokines contributing to low-grade chronic inflammation that could impair the circadian rhythm. Also, nutrition plays an important role in sleep homeostasis. High fat and/or high carbohydrate diets are known to have a negative impact on both sleep quality and duration. In addition, obesity predisposes to a condition called "obstructive sleep apnea" that has a detrimental effect on sleep. SD could increase the risk and/or could contribute to worsen cardiovascular risk usually associated with obesity. The chronic low grade inflammation associated with obesity has been reported to increase the risk of developing hypertension, type 2 diabetes and dyslipidemia. In turn, improving quality of sleep has been reported to improve the management of these cardiovascular risk factors. Thus, the aim of this manuscript is to provide evidence on the association of obesity and SD and on how they could contribute to the risk of developing cardiovascular risk factors such as hypertension, dyslipidemia and type 2 diabetes in obesity.

Primary Aldosteronism and Obstructive Sleep Apnea: Casual Association or Pathophysiological Link?

The coexistence of aldosterone oversecretion and obstructive sleep apnea is frequently observed, especially in patients with resistant hypertension, obesity, and metabolic syndrome. Since aldosterone excess and sleep apnea are both independently associated with an increased risk of cardiovascular disease, to investigate whether their coexistence might be attributed to common predisposing conditions, such as metabolic disorders, or to an actual pathophysiological interconnection appears of great importance. Fluid overload and metabolic abnormalities relating to aldosterone oversecretion may be implicated in obstructive sleep apnea development. Nocturnal intermittent hypoxia may in turn exacerbate renin-angiotensin-aldosterone system activity, thus leading to hyperaldosteronism. Furthermore, fat tissue excess and adipocyte secretory products might predispose to both sleep apnea and aldosterone oversecretion in subjects with obesity. Consistent with these evidences, obstructive sleep apnea frequently affects patients with primary aldosteronism. Conversely, whether primary aldosteronism is more prevalent in individuals affected by obstructive sleep apnea compared to the general population remains controversial.

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

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

Effect of dapagliflozin on obstructive sleep apnea in patients with type 2 diabetes: a preliminary study

Objective

The aim of this case-control study was to assess the efficacy of dapagliflozin combined with metformin for type-2 diabetes mellitus (T2DM) with obstructive sleep apnea hypopnea syndrome (OSAHS).

Methods

A total of 36 patients with newly-diagnosed T2DM and OSAHS were randomized divided into two groups. Eighteen OSAHS patients with T2DM, who were treated with dapagliflozin and metformin, were assigned as the dapagliflozin group. These patients were given dapagliflozin and metformin for 24 weeks between February 2017 and February 2018. Another 18 OSAHS patients with T2DM, who were treated with glimepiride and metformin for 24 weeks, were assigned as the control group. Fasting plasma glucose (FPG) level, postprandial blood glucose (PPG), hemoglobin A1C (HbA1c), fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), blood lipids, body mass index (BMI), blood pressure, apnea-hypopnea index (AHI), minimum oxygen saturation (LSpO₂), and Epworth Somnolence Scale (ESS) score were measured before and at 24 weeks after the initiation of treatment.

Results

In the dapagliflozin group, triglyceride (TG), systolic pressure (SBP) and diastolic pressure (DBP) significantly decreased following treatment, while high-density lipoprotein cholesterol (HDL-C) significantly increased (P < 0.05). Furthermore, a reduction in AHI, an increase in LSpO₂ and a decrease in ESS score were observed in the dapagliflozin group (P < 0.05), but not in the control group. Moreover, blood glucose, HbA1c, HOMA-IR, and BMI significantly decreased in these two groups, and the decrease was more significant in the dapagliflozin group.

Conclusion

These present results indicate that dapagliflozin can significantly reduce glucose, BMI, blood pressure and AHI, and improve hypoxemia during sleep and excessive daytime sleepiness, which thereby has potential as an effective treatment approach for OSAHS.

Primary Aldosteronism and Obstructive Sleep Apnea: A Cross-Sectional Multi-Ethnic Study

The association between primary aldosteronism (PA) and obstructive sleep apnea (OSA) has been a matter of debate. 2016 Endocrine Society guideline recommends screening for PA all hypertensive patients with OSA. We designed a multicenter, multiethnic, cross-sectional study to evaluate the prevalence of PA in patients with OSA and the prevalence of OSA in unselected patients with PA. Two hundred and three patients with OSA (102 whites and 101 Chinese) were screened for PA, and 207 patients with PA (104 whites, 100 Chinese, and 3 of African descent) were screened for OSA by cardiorespiratory polygraphy. Eighteen patients with OSA (8.9%) had PA (11.8% of white and 5.9% of Chinese ethnicity). In patients without other indications for PA screening, the prevalence of PA dropped to 1.5%. The prevalence of OSA in patients with PA was 67.6%, consistent in both white and Chinese patients. A correlation between aldosterone levels and apnea/hypopnea index was observed in white patients with PA (R²=0.225, P=0.016) but not in Chinese patients. Multinomial logistic regression confirmed a significant and independent association between plasma aldosterone levels and moderate to severe OSA diagnosis in white patients (odds ratio, 1.002; P=0.002). In conclusion, aldosterone levels may contribute to the severity of OSA in white patients with hyperaldosteronism, but patients with OSA are not at high risk of PA. Results of the present study challenge the current recommendation of the Endocrine Society guideline that all patients with OSA should be screened for PA, irrespective of the grade of hypertension.

Targeting Endotypic Traits with Medications for the Pharmacological Treatment of Obstructive Sleep Apnea. A Review of the Current Literature

Obstructive sleep apnea (OSA) is a highly prevalent condition with few therapeutic options. To date there is no approved pharmacotherapy for this disorder, but several attempts have been made in the past and are currently ongoing to find one. The recent identification of multiple endotypes underlying this disorder has oriented the pharmacological research towards tailored therapies targeting specific pathophysiological traits that contribute differently to cause OSA in each patient. In this review we retrospectively analyze the literature on OSA pharmacotherapy dividing the medications tested on the basis of the four main endotypes: anatomy, upper airway muscle activity, arousal threshold and ventilatory instability (loop gain). We show how recently introduced drugs for weight loss that modify upper airway anatomy may play an important role in the management of OSA in the near future, and promising results have been obtained with drugs that increase upper airway muscle activity during sleep and reduce loop gain. The lack of a medication that can effectively increase the arousal threshold makes this strategy less encouraging, although recent studies have shown that the use of certain sedatives do not worsen OSA severity and could actually improve patients' sleep quality.

The Effects of Eplerenone on the Circadian Blood Pressure Pattern and Left Ventricular Hypertrophy in Patients with Obstructive Sleep Apnea and Resistant Hypertension-A Randomized, Controlled Trial

The obstructive sleep apnea (OSA) is highly associated with various significant cardiovascular outcomes such as resistant hypertension (RAH). Despite this, as of now the relationship between high night-time blood pressure (BP) and left ventricular hypertrophy (LVH) in patients with OSA and RAH is not fully understood. The aim of this study was to assess the influence of the addition of eplerenone to a standard antihypertensive therapy on parameters of 24-h ambulatory blood pressure measurement (ABPM) as well as on the results of echocardiography and polysomnography in patients with OSA and RAH. The patients were randomly assigned to one of the two study groups: the treatment group, receiving 50 mg/d eplerenone orally for 6 months (n = 51) and the control group, remaining on their standard antihypertensive therapy (n = 51). After that period, a significant reduction in the night-time BP parameters in the treatment group including an increased night blood pressure fall from 4.6 to 8.9% was noted. Additionally, the number of non-dipper patients was reduced by 45.1%. The treatment group also revealed a decrease in left ventricular hypertrophy and in the apnea-hypopnea index (AHI) with a positive correlation being observed between these two parameters. This study is the first to report the improvement of the circadian BP profile and the improvement of the left ventricle geometry in patients with OSA and RAH following the addition of selective mineralocorticoid receptor antagonists to antihypertensive therapy.

Sleep Apnea and Cardiovascular Disease: An Enigmatic Risk Factor

Synchronization of molecular, metabolic, and cardiovascular circadian oscillations is fundamental to human health. Sleep-disordered breathing, which disrupts such temporal congruence, elicits hemodynamic, autonomic, chemical, and inflammatory disturbances with acute and long-term consequences for heart, brain, and circulatory and metabolic function. Sleep apnea afflicts a substantial proportion of adult men and women but is more prevalent in those with established cardiovascular diseases and especially fluid-retaining states. Despite the experimental, epidemiological, observational, and interventional evidence assembled in support of these concepts, this substantial body of work has had relatively modest pragmatic impact, thus far, on the discipline of cardiology. Contemporary estimates of cardiovascular risk still are derived typically from data acquired during wakefulness. The impact of sleep-related breathing disorders rarely is entered into such calculations or integrated into diagnostic disease-specific algorithms or therapeutic recommendations. Reasons for this include absence of apnea-related symptoms in most with cardiovascular disease, impediments to efficient diagnosis at the population level, debate as to target, suboptimal therapies, difficulties mounting large randomized trials of sleep-specific interventions, and the challenging results of those few prospective cardiovascular outcome trials that have been completed and reported. The objectives of this review are to delineate the bidirectional interrelationship between sleep-disordered breathing and cardiovascular disease, consider the findings and implications of observational and randomized trials of treatment, frame the current state of clinical equipoise, identify principal current controversies and potential paths to their resolution, and anticipate future directions.

Diuretic or sodium-restricted diet for obstructive sleep apnea-a randomized trial

Study Objectives

Interventions that decrease leg fluid retention reduce obstructive sleep apnea (OSA) severity in nonrandomized experiments. We aimed to investigate in a randomized trial the effect of interventions that reduce fluid volume on OSA severity.

Methods

Men diagnosed with severe OSA were randomized to receive daily spironolactone 100 mg + furosemide 20 mg or nutritional counseling to sodium-restricted diet plus placebo pill or placebo pill. All participants underwent home sleep apnea testing at baseline and after 1 week follow-up. The change in apnea-hypopnea index (AHI) was the primary outcome.

Results

The study included 54 participants and all were assessed at follow-up. The average baseline value of the AHI was similar among groups and from baseline to follow-up the AHI reduced 14.4 per cent (δ value -7.3 events per hour; 95% confidence interval, -13.8 to -0.9) in the diuretic group, 22.3 per cent (-10.7; 95% CI, -15.6 to -5.7) in the diet group, and 0.8 per cent (0.4; 95% CI, -2.5 to 3.2) in the placebo group (p = .001 for time × group interaction). None of the patients had their AHI returned to normal. The reduction in the total body water was 2.2 ± 2.2 L in the diuretic group (p < .001) and 1.0 ± 1.6 l in the low salt diet group (p = .002). Sleepiness and neck circumference were significantly reduced only in the diet group (p = .007 and p < .001 for the time × group interactions, respectively).

Conclusions

Interventions to reduce bodily fluid content in men with severe OSA promoted a limited decrease of apnea frequency. This finding suggests that rostral fluid displacement affects only partially the OSA severity and/or that other factors prevail in determining pharyngeal collapsibility.

Clinical Trial

Sodium-Restricted Diet and Diuretic in the Treatment of Severe Sleep Apnea (DESALT), https://clinicaltrials.gov/ct2/show/NCT01945801 ClinicalTrials.gov number: NCT01945801.

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

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

Effect of calf muscle electrical stimulation on rostral fluid shift, snoring and obstructive sleep apnea

STUDY OBJECTIVES

Overnight fluid shift from the legs into the neck may contribute to the pathogenesis of snoring and obstructive sleep apnea (OSA). The present study investigates the effects of calf muscle electrical stimulation (ES) on reducing leg fluid accumulation while seated, subsequent rostral fluid shift on lying down, and the impact on snoring and OSA.

METHODS

Sixteen non-obese, normotensive men with OSA participated in the study. On the first study day, participants sat for 150 min receiving either active or sham ES through random allocation, then lied supine for 60 min. While seated and supine, leg and neck fluid volumes were measured using bioelectrical impedance to determine the magnitude of fluid shift. On the night of the study day, participants wore a portable sleep apnea diagnostic device overnight to measure snoring and sleep apnea severity. One week later, participants crossed over to the other study condition.

RESULTS

Active calf muscle ES reduced leg fluid accumulation by 46% while seated. Upon lying supine, active ES reduced fluid shift out of the legs by 17% and reduced neck fluid accumulation by 31%. This led to a 15% reduction in snoring index, but did not alleviate OSA.

CONCLUSIONS

One session of calf muscle ES was effective at reducing leg fluid accumulation and rostral fluid shift, which led to a modest reduction in the snoring index, but not OSA. Despite this lack of effect of calf muscle ES in attenuating OSA severity, the reduction in the snoring index suggests that it did have an effect, albeit mild, on upper-airway mechanics.

Chronotherapy for Hypertension

PURPOSE OF REVIEW

Given the emerging knowledge that circadian rhythmicity exists in every cell and all organ systems, there is increasing interest in the possible benefits of chronotherapy for many diseases. There is a well-documented 24-h pattern of blood pressure with a morning surge that may contribute to the observed morning increase in adverse cardiovascular events. Historically, antihypertensive therapy involves morning doses, usually aimed at reducing daytime blood pressure surges, but an absence of nocturnal dipping blood pressure is also associated with increased cardiovascular risk.

RECENT FINDINGS

To more effectively reduce nocturnal blood pressure and still counteract the morning surge in blood pressure, a number of studies have examined moving one or more antihypertensives from morning to bedtime dosing. More recently, such studies of chronotherapy have studied comorbid populations including obstructive sleep apnea, chronic kidney disease, or diabetes. Here, we summarize major findings from recent research in this area (2013-2017). In general, nighttime administration of antihypertensives improved overall 24-h blood pressure profiles regardless of disease comorbidity. However, inconsistencies between studies suggest a need for more prospective randomized controlled trials with sufficient statistical power. In addition, experimental studies to ascertain mechanisms by which chronotherapy is beneficial could aid drug design and guidelines for timed administration.

Does Obstructive Sleep Apnea Influence Blood Pressure and Arterial Stiffness in Response to Antihypertensive Treatment?

Untreated obstructive sleep apnea (OSA) is common in patients with hypertension and may impair blood pressure (BP) and target-organ damage responses to antihypertensive therapy. In this study, we recruited hypertensive patients who underwent treatment with a 30-day regimen of hydrochlorothiazide 25 mg plus enalapril (20 mg BID) or losartan (50 mg BID) and were assessed with a baseline clinical evaluation, polysomnography, 24-hour ambulatory BP monitoring, and carotid-femoral pulse wave velocity. All the examinations except for polysomnography were repeated at 6 and 18 months of follow-up. We studied 94 hypertensive patients (mean age, 55±9 years). The frequency of OSA was 55%. Compared with baseline, we did not observe significant differences between groups in 24-hour BP, daytime systolic and diastolic BPs, or night-time systolic BP at 6 and 18 months. The BP control rate at 24 hours (<130/80 mm Hg) was similar between the groups (baseline, 42.3% versus 45.2%; 6 months, 46.9% versus 57.5%; 18 months, 66.7% versus 61.5%). However, patients with OSA had higher night-time diastolic BP decrease than did the non-OSA group (6 months, -4.9±11.8 versus -0.3±10.3 mm Hg; 18 months, -6.7±11.1 versus -1.2±10.6 mm Hg; P=0.027). There were no differences in the number and class of antihypertensive medications prescribed during follow-up. In terms of arterial stiffness, patients with OSA had higher pulse wave velocity than did patients without OSA at baseline (10.3±1.9 versus 9.2±1.7 m/s; P=0.024), but both groups had similar decreases in pulse wave velocity during follow-up. In conclusion, with combined antihypertensive treatment aimed at controlling BP, hypertensive patients with OSA had similar 24-hour BP and arterial stiffness to those without OSA.

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.

Effect of sodium glucose cotransporter 2 inhibitors on obstructive sleep apnea in patients with type 2 diabetes

Obstructive sleep apnea syndrome (OSAS) is often associated with metabolic disorders such as obesity and type 2 diabetes and may contribute to cardiovascular events. A novel class of antidiabetic drugs, the sodium glucose cotransporter 2 inhibitors (SGLT2i) reduce body weight (BW), although there is limited data on their impact on OSAS. We therefore evaluated the effect of SGLT2i on OSAS in patients with type 2 diabetes. The presented study was a retrospective design in 18 patients with type 2 diabetes with OSAS (4 males, age range 39-81 yr) administrated a SGLT2i. HbA1c, BW, body mass index (BMI), blood pressure (BP) and apnea hypopnea index (AHI) were evaluated before and after SGLT2i administration. The relationships between the reduction in AHI and the other variables were examined using Pearson correlation analysis. We have got result that SGLT2i reduced AHI from 31.9 ± 18.0 to 18.8 ± 11.5 events per hr (p = 0.003). HbA1c, BW and BMI decreased significantly, whereas BP did not. The Pearson correlation analysis showed a significant relationship between the reduction in AHI and pre-administration of AHI. In conclusion, SGLT2i reduced not only HbA1c, BW and BMI but also AHI significantly and therefore has potential as an effective treatment of OSAS.