Characteristics of hypertension and arterial stiffness in obstructive sleep apnea: A Scandinavian experience from a prospective study of 6408 normotensive and hypertensive patients

Symptom and comorbidity burden in hypertensive patients with obstructive sleep apnea

Background

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

Methods

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

Results

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

Conclusion

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

Different Home Blood Pressure Thresholds to Predict Perfect 24-Hour Ambulatory Blood Pressure Control in Treated Hypertension Based on an "All-in-One" Device

BACKGROUND

Home blood pressure (BP) is an important component of digital strategies for hypertension management. However, no studies have used the same device to investigate 24-hour BP control status in relation to different home BP control thresholds.

METHODS

Participants in the general practitioner-based, multicenter HI-JAMP study (Home-Activity Information and Communication Technology-Based Japan Ambulatory Blood Pressure Monitoring Prospective) underwent office BP measurement, then 24-hour ambulatory BP monitoring, then home BP monitoring for 5 days. A validated all-in-one BP monitoring device was used to measure office, home, and ambulatory BP. Baseline data were used to investigate ambulatory BP control status in individuals with well-controlled home BP based on the different guideline thresholds (125/75 mm Hg, 130/80 mm Hg, and 135/85 mm Hg).

RESULTS

Data from 2269 patients were analyzed. For individuals with well-controlled home BP <135/85 mm Hg (59.5% of the total population), the prevalence of uncontrolled 24-hour (≥130/80 mm Hg), daytime (≥135/85 mm Hg), and nighttime ambulatory BP (≥120/70 mm Hg) was 19.9%, 18.5%, and 33.6%, respectively. Corresponding prevalence rates in the 42.7% of participants with well-controlled home BP <130/80 mm Hg were 13.4%, 12.9%, and 26.0%, and when well-controlled home BP was strictly defined as <125/75 mm Hg (23.9% of the population), prevalence of rates of uncontrolled 24-hour, daytime, and nighttime ambulatory BP were 7.0%, 9.0%, and 15.3%, respectively.

CONCLUSIONS

Home BP control status defined using different thresholds could predict 24-hour ambulatory BP control status in treated hypertension. One-third of individuals still had uncontrolled nocturnal hypertension when home BP was controlled to <135/85 mm Hg, but ambulatory BP was quite well controlled when home BP was <125/75 mm Hg.

Gender Modulated the Association of Sleep Apnea and Sleep Duration with Arterial Stiffness: The ELSA-Brasil Study

Increased arterial stiffness is independently associated with cardiovascular risk. Obstructive sleep apnea (OSA) and sleep duration (SDUR) may contribute to increased arterial stiffness, but it is unclear whether this association is modulated by gender. We aimed to evaluate the potential impact of gender in modulating the association of OSA and SDUR with arterial stiffness. Participants from the ELSA-Brasil study performed sleep assessments with portable polygraph to define OSA severity and SDUR by 1-week wrist actigraphy. Pulse wave velocity (PWV) was measured using a standard technique without access to the sleep data. We studied 1863 participants (42.2% male, age: 49±8 years, respiratory disturbance index (RDI): 9.9 (4.5-19.4) events/h, SDUR: 6.5 (5.9-7.1) hours, mean PWV: 7.3 ± 1.2 m/s). We found that men had higher PWV, higher frequency of diabetes, and higher blood pressure when compared to women. The regression analysis showed an independent association between increased RDI and PWV in men (ß: 0.007; 95% CI: 0.001-0.012), but not in women. In contrast, an independent association between SDUR and increased arterial stiffness was observed only in women (ß: 0.068; 95% CI: 0.002-0.134). In conclusion, the association of sleep disorders with arterial stiffness showed a distinct gender pattern depending on the sleep variable studied.

Vascular function in hypertension: does gender dimension matter?

Blood pressure and vascular ageing trajectories differ between men and women. These differences develop due to sex-related factors, attributable to sex chromosomes or sex hormones, and due to gender-related factors, mainly related to different sociocultural behaviors. The present review summarizes the relevant facts regarding gender-related differences in vascular function in hypertension. Among sex-related factors, endogenous 17ß-estradiol plays a key role in protecting pre-menopausal women from vascular ageing. However, as vascular ageing (preceding and inducing hypertension) has a steeper increase in women than in men starting already from the third decade, it is likely that gender-related factors play a prominent role, especially in the young. Among gender-related factors, psychological stress (including that one related to gender-based violence and discrimination), depression, some psychological traits, but also low socioeconomic status, are more common in women than men, and their impact on vascular ageing is likely to be greater in women. Men, on the contrary, are more exposed to the vascular adverse consequences of alcohol consumption, as well as of social deprivation, while "toxic masculinity" traits may result in lower adherence to lifestyle and preventive strategies. Unhealthy diet habits are more prevalent in men and smoking is equally prevalent in the two sexes, but have a disproportional negative effect on women's vascular health. In conclusion, given the major and complex role of gender-related factors in driving vascular alterations and blood pressure patterns, gender dimension should be systematically integrated into future research on vascular function and hypertension and to tailor cardiovascular prevention strategies.

Hour-to-hour variability of respiratory sleep indices and ambulatory blood pressure

STUDY OBJECTIVES

Respiratory sleep indices are traditionally reported on the basis of the average total sleep time. The relationship between the hour-to-hour variability of these parameters and blood pressure (BP) has not been reported.

METHODS

We evaluated the associations of the hour-to-hour variability of the apnea-hypopnea index (AHI), oxygen desaturation index (ODI), and lowest oxygen saturation with the 24-h ambulatory BP in patients with hypertension and newly diagnosed obstructive sleep apnea. A total of 147 patients underwent polysomnography, based on which obstructive sleep apnea was diagnosed in 106 patients; these patients underwent 24-h ambulatory BP monitoring within the next 30 days. Each polysomnogram was divided into hourly reports to calculate the variability of the respiratory sleep indices. Variability independent of the mean was considered the primary measure of variability.

RESULTS

The median number of hourly polysomnogram reports was 7 (range, 4-8). The hour-to-hour variability of both AHI and ODI, but not of the lowest oxygen saturation, was correlated with the 24-h pulse pressure, 24-h systolic BP, and awake systolic BP (p < 0.05 for all). The fully adjusted linear regression analysis indicated that the hour-to-hour variability of AHI and ODI remained associated with the 24-h pulse pressure (AHI: β coefficient, 0.264 [95% CI = 0.033-0.495], p = 0.026; ODI: β coefficient, 0.450 [95% CI = 0.174-0.726], p = 0.002).

CONCLUSIONS

The hour-to-hour variability of AHI and ODI is independently associated with the 24-h pulse pressure. Further investigations are warranted to evaluate the clinical relevance of this new-found association.

Exercise Intolerance in Untreated OSA: Role of Pulmonary Gas Exchange and Systemic Vascular Abnormalities

BACKGROUND

Reduced exercise capacity has been reported previously in patients with OSA hypopnea syndrome (OSAHS), although the underlying mechanisms are unclear.

RESEARCH QUESTION

What are the underlying mechanisms of reduced exercise capacity in untreated patients with OSAHS? Is there a role for systemic or pulmonary vascular abnormalities?

STUDY DESIGN AND METHODS

This was a cross-sectional observational study in which 14 patients with moderate to severe OSAHS and 10 control participants (matched for age, BMI, smoking history, and FEV1) underwent spirometry, incremental cycle cardiopulmonary exercise test (CPET) with arterial line, resting echocardiography, and assessment of arterial stiffness (pulse wave velocity [PWV] and augmentation index [AIx]).

RESULTS

Patients (age, 50 ± 11 years; BMI, 30.5 ± 2.7 kg/m2; smoking history, 2.4 ± 4.0 pack-years; FEV1 to FVC ratio, 0.78 ± 0.04; FEV1, 85 ± 14% predicted, mean ± SD for all) had mean ± SD apnea hypopnea index of 43 ± 19/h. At rest, PWV, AIx, and mean pulmonary artery pressure (PAP) were higher in patients vs control participants (P < .05). During CPET, patients showed lower peak work rate (WR) and oxygen uptake and greater dyspnea ratings compared with control participants (P < .05 for all). Minute ventilation (V·E), ventilatory equivalent for CO2 output (V·E/V·CO2), and dead space volume (VD) to tidal volume (VT) ratio were greater in patients vs control participants during exercise (P < .05 for all). Reduction in VD to VT ratio from rest to peak exercise was greater in control participants compared with patients (0.24 ± 0.08 vs 0.04 ± 0.14, respectively; P = .001). Dyspnea intensity at the highest equivalent WR correlated with corresponding values of V·E/V·CO2 (r = 0.65; P = .002), and dead space ventilation (r = 0.70; P = .001). Age, PWV, and mean PAP explained approximately 70% of the variance in peak WR, whereas predictors of dyspnea during CPET were rest-to-peak change in VD to VT ratio and PWV (R2 = 0.50; P < .001).

INTERPRETATION

Patients with OSAHS showed evidence of pulmonary gas exchange abnormalities during exercise (in the form of increased dead space) and resting systemic vascular dysfunction that may explain reduced exercise capacity and increased exertional dyspnea intensity.

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

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

Targeting autonomic nervous system as a biomarker of well-ageing in the prevention of stroke

Stroke prediction is a key health issue for preventive medicine. Atrial fibrillation (AF) detection is well established and the importance of obstructive sleep apneas (OSA) has emerged in recent years. Although autonomic nervous system (ANS) appears strongly implicated in stroke occurrence, this factor is more rarely considered. However, the consequences of decreased parasympathetic activity explored in large cohort studies through measurement of ANS activity indicate that an ability to improve its activity level and equilibrium may prevent stroke. In support of these observations, a compensatory neurostimulation has already proved beneficial on endothelium function. The available data on stroke predictions from ANS is based on many long-term stroke cohorts. These data underline the need of repeated ANS evaluation for the general population, in a medical environment, and remotely by emerging telemedicine digital tools. This would help uncovering the reasons behind the ANS imbalance that would need to be medically adjusted to decrease the risk of stroke. This ANS unbalance help to draw attention on clinical or non-clinical evidence, disclosing the vascular risk, as ANS activity integrates the cumulated risk from many factors of which most are modifiable, such as metabolic inadaptation in diabetes and obesity, sleep ventilatory disorders, hypertension, inflammation, and lack of physical activity. Treating these factors may determine ANS recovery through the appropriate management of these conditions. Natural aging also decreases ANS activity. ANS recovery will decrease global circulating inflammation, which will reinforce endothelial function and thus protect the vessels and the associated organs. ANS is the whistle-blower of vascular risk and the actor of vascular health. Such as, ANS should be regularly checked to help draw attention on vascular risk and help follow the improvements in response to our interventions. While today prediction of stroke relies on classical cardiovascular risk factors, adding autonomic biomarkers as HRV parameters may significantly increase the prediction of stroke.

Obstructive sleep apnea, chronic obstructive pulmonary disease and hypertensive microvascular disease: a cross-sectional observational cohort study

Hypertensive microvascular disease is associated with an increased risk of diastolic heart failure, vascular dementia and progressive renal impairment. This study examined whether individuals with obstructive sleep apnoea (OSA) had more retinal hypertensive microvascular disease than those with chronic obstructive pulmonary disease (COPD) and hospital controls. This was a single-centre, cross-sectional, observational study of participants recruited consecutively from a general respiratory clinic and a general medical clinic. OSA was diagnosed on overnight polysomnography study (apnoea:hypopnoea index ≥ 5), and controls with COPD had a forced expiratory volume/forced vital capacity (forced expiratory ratio) < 70%. Individuals with both OSA and COPD were excluded. Hospital controls had no COPD on respiratory function testing and no OSA on specialist physician questioning. Study participants completed a medical questionnaire, and underwent resting BP measurement, and retinal photography with a non-mydriatic camera. Images were deidentified and graded for microvascular retinopathy (Wong and Mitchell classification), and arteriole and venular calibre using a semiautomated method at a grading centre. Individuals with OSA (n = 79) demonstrated a trend to a higher mean arterial pressure than other hospital patients (n = 143) (89.2 ± 8.9 mmHg, p = 0.02), and more microvascular retinopathy (p < 0.001), and narrower retinal arterioles (134.2 ± 15.9 μm and 148.0 ± 16.2 μm respectively, p < 0.01). Microvascular retinopathy and arteriolar narrowing were still more common in OSA than hospital controls, after adjusting for age, BMI, mean arterial pressure, smoking history and dyslipidaemia (p < 0.01, p < 0.01, respectively). Individuals with OSA demonstrated a trend to a higher mean arterial pressure than those with COPD (n = 132, 93.2 ± 12.2 mmHg and 89.7 ± 12.8 mmHg respectively, p = 0.07), and more microvascular retinopathy (p = 0.0001) and narrower arterioles (134.2 ± 15.9 and 152.3 ± 16.8, p < 0.01). Individuals with OSA alone had more systemic microvascular disease than those with COPD alone or other hospital patients without OSA and COPD, despite being younger in age.

Cardiovascular remodeling in obstructive sleep apnea: focus on arterial stiffness, left ventricular geometry and atrial fibrillation

INTRODUCTION

Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder that is associated with increased risk of cardiovascular disease. The main interest of this clinical review is to discuss the cardiovascular consequences of OSA with a special focus on left ventricular (LV) function and structure, arterial stiffness and atrial fibrillation.

AREA COVERED

We present an overview of the definition, prevalence, and risk factors of OSA and outline the association between OSA and cardiovascular complications. We then briefly discuss echocardiographic assessment in OSA with focus on the left atrium and LV. Finally, we highlight the importance of adherence to continuous positive airway pressure (CPAP) therapy with regard to reducing the risk of cardiovascular disease.

EXPERT COMMENTARY

Although OSA has a strong association with cardiovascular complications, it is often underdiagnosed and undertreated. Patients with resistant hypertension and atrial fibrillation with poor therapeutic success after cardioversion or catheter ablation should be more often screened for OSA. Patients with nocturnal adverse cardiovascular events (stroke, arrhythmias, angina, coronary events) should be closely assessed with regard to OSA, and if confirmed, timely treated by lifestyle modification, CPAP, and aggressive antihypertensive treatment. Adherence to CPAP in OSA patients is essential in terms of reducing the risk of cardiovascular events.