Superior hypertension control with betablockade in the European Sleep Apnea Database

Quality of sleep among hypertensive patients attending a rural health training centre

Introduction

Sleep is a vital biological, reparative, and restorative phenomenon, and poor sleep has a serious detrimental effect on health. Poor sleep quality is a serious problem as it adversely affects a person's ability to function physically and socially, as well as their potential for profession and quality of life. The degree of hypertension directly affects sleep quality, and poor sleep can exacerbate hypertensive symptoms. This study assesses hypertension patients' sleep quality in a rural health training centre in Chennai.

Objectives

1. To study the prevalence of poor sleep quality among hypertensive patients. 2. To determine the association between selected socio-demographic factors and sleep quality among these patients.

Materials and Methods

Hypertensives attending the outpatient department of a rural health and training centre were selected in a systematic manner and administered a semi-structured interview schedule and the Pittsburgh Sleep Quality Index (PSQI) questionnaire followed by a basic clinical examination. Using the PSQI, they were categorised as having either poor or good sleep quality and the association between selected socio-demographic factors and sleep quality was assessed.

Results

Out of the 179 study participants, there were almost equal numbers of male and female participants. The mean age of participants was 57.80 years (standard deviation (SD) = 9.8 yrs.). Among the study participants, 44.13% had completed secondary level of school as an education qualification and 6.70% were illiterate. By the modified BG Prasad classification 2022, most of the study participants (34.08%) came under the class II socioeconomic classification. A large proportion (78.8%) of study participants had poor sleep quality. The difference in sleep quality was observed with respect to gender, socio-economic class, alcohol consumption and body mass index (BMI).

Conclusion

This observational study shows that individuals with hypertension suffer significantly from poor sleep. A poor quality of sleep was reported by 78.77% of the patients in this study. Statistically significant factors that influenced sleep quality were gender, alcohol consumption and BMI.

Sympathetic overactivity and nocturnal diuresis in obstructive sleep apnea alter the response to hypertension therapy

BACKGROUND

Obstructive sleep apnea (OSA) is associated with high blood pressure that responds poorly to usual antihypertensive therapy.

METHODS AND RESULTS

Forty-one subjects with OSA had 25% higher plasma norepinephrine and 42% higher epinephrine measured every 2 h over 24 h than 20 control subjects. They also excreted more sodium during sleep. This suggested that that a sympatholytic would be a more successful antihypertensive than a diuretic. To test this hypothesis we treated a second group of 23 hypertensive apneics with placebo, 6 weeks of the sympatholytic guanfacine and 6 weeks of hydrochlorothiazide in a crossover study. Guanfacine lowered 24-hour blood pressure by 9.6/6.7 mmHg, more than the 5.4/2.9 mmHg effect of hydrochlorothiazide (P < 0.05). Nighttime systolic blood pressure dipping was poor at 6.6 ± 1.8%. Hydrochlorothiazide did not alter blood pressure dipping but guanfacine improved dipping to 9.1 ± 1.2%, a better result (P = 0.03) than from the diuretic. Central aortic pressure by pulse wave analysis was 120/84 mmHg on hydrochlorothiazide and 109/72 on guanfacine, (P < 0.05). Guanfacine, but not hydrochlorothiazide, improved baroreflex sensitivity, heart rate variability and flow mediated vascular dilation, suggesting that decreasing the elevated sympathetic nerve activity of obstructive sleep apnea returned vascular function toward normal.

CONCLUSIONS

OSA is the most common condition associated with antihypertensive treatment failure. It increased sympathetic nerve activity day and night. Drugs that block sympathetic nerve function are not among the 4 most commonly recommended classes of antihypertensives but diuretics are. Sympatholytic therapy was superior to diuretic treatment for hypertension associated with sleep apnea.

TRIAL REGISTRATION

NCT, NCT02699125, Registered 26 February 2016 - Retrospectively registered, https://clinicaltrials.gov/study/NCT02699125 .

The current position of β-blockers in hypertension: guidelines and clinical practice

The benefits of improved clinical outcomes through blood pressure (BP) reduction have been proven in multiple clinical trials and meta-analyses. The new (2023) guideline from the European Society of Hypertension (ESH) includes β-blockers within five main classes of antihypertensive agents suitable for initiation of antihypertensive pharmacotherapy and for combination with other antihypertensive agents. This is in contrast to the 2018 edition of ESH guidelines that recommended β-blockers for use primarily in patients with compelling indications such as cardiovascular comorbidities, e.g. coronary heart disease, heart failure. This change was based on the fact that the magnitude of BP reduction is the most important factor for adverse cardiovascular outcomes, over and above the precise manner in which reduced BP is achieved. The ESH guideline also supports the use of β-blockers for patients with resting heart rate (>80 bpm); high resting heart rate is a sign of sympathetic overactivity, an important driver of adverse cardiac remodelling in the setting of hypertension and heart failure. Hypertension management guidelines support for the use of combination therapies for almost all patients with hypertension, ideally within a single-pill combination to optimise adherence to therapy. Where a β-blocker is prescribed, the inclusion of a dihydropyridine calcium channel blocker within a combination regimen is rational. These agents together reduce both peripheral and central BP, which epidemiological studies have shown is important for reducing the burden of premature morbidity and mortality associated with uncontrolled hypertension, especially strokes.

Adaptive responses to chronic intermittent hypoxia: contributions from the European Sleep Apnoea Database (ESADA) Cohort

Obstructive sleep apnoea (OSA) is a common disease in the general population, and is associated with increased cardiovascular risk and several comorbidities. Obesity favours upper airway collapsibility, but other pathophysiological traits have been identified, i.e. upper airway muscle activity, modulation of the respiratory drive, and the arousal threshold. OSA causes chronic intermittent hypoxia, inflammatory activation and autonomic imbalance with diurnal and nocturnal sympathetic hyperactivity. Disentangling so many components to investigate the pathogenesis of OSA's consequences is very hard clinically. However, albeit imperfect, clinical medicine constitutes a major source of inspiration for basic research, and a mutual exchange of information is essential between clinicians and physiologists to improve our understanding of disease states. OSA is no exception, and this narrative review will summarize the results of clinical studies performed over the years by the European Sleep Apnoea Database (ESADA) Study Group, to explore the variables linked to markers of intermittent hypoxia as opposed to the traditional assessment of OSA severity based on the frequency of respiratory events during sleep (the Apnoea Hypopnoea Index). The results of the clinical studies indicate that intermittent hypoxia variables are associated with several comorbidities, although evidence of a cause-effect relationship is still missing in many cases. It is also possible that adaptive rather than maladaptive responses could be evoked by intermittent hypoxia. The intensity, duration and frequency of intermittent hypoxia episodes causing adaptive rather than maladaptive responses, and their clinical implications, deserve further investigation.

Chronic intermittent hypoxia-induced cardiovascular and renal dysfunction: from adaptation to maladaptation

Chronic intermittent hypoxia (CIH) is the dominant pathological feature of human obstructive sleep apnoea (OSA), which is highly prevalent and associated with cardiovascular and renal diseases. CIH causes hypertension, centred on sympathetic nervous overactivity, which persists following removal of the CIH stimulus. Molecular mechanisms contributing to CIH-induced hypertension have been carefully delineated. However, there is a dearth of knowledge on the efficacy of interventions to ameliorate high blood pressure in established disease. CIH causes endothelial dysfunction, aberrant structural remodelling of vessels and accelerates atherosclerotic processes. Pro-inflammatory and pro-oxidant pathways converge on disrupted nitric oxide signalling driving vascular dysfunction. In addition, CIH has adverse effects on the myocardium, manifesting atrial fibrillation, and cardiac remodelling progressing to contractile dysfunction. Sympatho-vagal imbalance, oxidative stress, inflammation, dysregulated HIF-1α transcriptional responses and resultant pro-apoptotic ER stress, calcium dysregulation, and mitochondrial dysfunction conspire to drive myocardial injury and failure. CIH elaborates direct and indirect effects in the kidney that initially contribute to the development of hypertension and later to chronic kidney disease. CIH-induced morphological damage of the kidney is dependent on TLR4/NF-κB/NLRP3/caspase-1 inflammasome activation and associated pyroptosis. Emerging potential therapies related to the gut-kidney axis and blockade of aryl hydrocarbon receptors (AhR) are promising. Cardiorenal outcomes in response to intermittent hypoxia present along a continuum from adaptation to maladaptation and are dependent on the intensity and duration of exposure to intermittent hypoxia. This heterogeneity of OSA is relevant to therapeutic treatment options and we argue the need for better stratification of OSA phenotypes.

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.

Impact of beta-blockers on mortality and cardiovascular disease outcomes in patients with obstructive sleep apnoea: a population-based cohort study in target trial emulation framework

Background

There is no real-world evidence regarding the association between beta-blocker use and mortality or cardiovascular outcomes in patients with obstructive sleep apnoea (OSA). We aimed to investigate the impact of beta-blocker use on all-cause mortality and cardiovascular diseases (CVDs) in patients with OSA.

Methods

We conducted a target trial emulation study of 37,581 patients with newly diagnosed OSA from 1st January 2000 to 30th November 2021 using the IMRD-UK database (formerly known as the THIN database). We compared the treatment strategies of initiating beta-blocker treatment within one year versus non-beta-blocker treatment through the method of clone-censor-weight. Covariates, including patients' demographics, lifestyle, comorbidities, and recent medications, were measured and controlled. Patients were followed up for all-cause mortality or composite CVD outcomes (angina, myocardial infarction, stroke/transient ischaemic attack, heart failure, or atrial fibrillation). We estimated the five-year absolute risks, risk differences and risk ratio with 95% confidence intervals (CIs) with standardised, weighted pooled logistic regression, which is a discrete-time hazard model for survival analysis. Several sensitivity analyses were performed, including multiple imputation addressing the missing data.

Findings

The median follow-up time was 4.1 (interquartile range, 1.9-7.8) years. The five-year absolute risk of all-cause mortality and CVD outcomes were 4.9% (95% CI, 3.8-6.0) and 13.0% (95% CI, 11.4-15.0) among beta-blocker users, and 4.0% (95% CI, 3.8-4.2) and 9.4% (95% CI, 9.1-9.7) among non-beta-blocker users, respectively. The five-year absolute risk difference and risk ratio between the two groups for all-cause mortality and CVD outcomes were 0.9% (95% CI, -0.2 to 2.1) and 1.22 (95% CI, 0.96-1.54), and 3.5% (95% CI, 2.1-5.5) and 1.37 (95% CI, 1.22-1.62), respectively. Findings were consistent across the sensitivity analyses.

Interpretation

Beta-blocker treatment was associated with an increased risk of CVD and a trend for an increased risk of mortality among patients with OSA. Further studies are needed to confirm our findings.

Funding

Innovation and Technology Commission of the Hong Kong Special Administration Region Government.

Management of hypertension in obstructive sleep apnea

Obstructive sleep apnea (OSA) plays an important role in the development of hypertension. Thus, this review summarizes pharmacological and non-pharmacological approaches to blood pressure (BP) control in patients with OSA. Current treatments for OSA, such as continuous positive airway pressure, are effective at lowering BP. However, they only provide a modest BP reduction, and pharmacological treatment remains important for achieving optimal BP control. Furthermore, current guidelines for the treatment of hypertension do not make specific recommendations on pharmacological treatment protocols for controlling BP in patients with OSA. Moreover, the BP-lowering effects of various classes of antihypertensives may be different in hypertensive patients with OSA than in those without OSA due to the underlying mechanisms that promote hypertension in OSA. The acute and chronic increase in sympathetic nerve activity in patients with OSA explain the effectiveness of beta blockers in controlling BP in these patients. As activation of the renin-angiotensin-aldosterone system may also promote hypertension in OSA, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers have generally been found effective for lowering BP in hypertensive patients with OSA. The aldosterone antagonist spironolactone also produces a good antihypertensive response in patients with OSA and resistant hypertension. However, there are limited data available that compare the effects of various classes of antihypertensive medication on BP control in those with OSA, and most data have been obtained from small-scale studies. This demonstrates the need for large-scale randomized controlled trials to evaluate a range of BP-lowering regimens in patients with OSA and hypertension.

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.