Characteristics of hypertension in obstructive sleep apnea: An Asian experience

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.

Factors influencing new-onset hypertension in elderly patients with obstructive sleep apnea: A multicenter cohort study

Investigating the influencing factors of new-onset hypertension in the elderly with obstructive sleep apnea (OSA). 450 Chinese older patients with OSA who were non-hypertensive at baseline were enrolled. All patients had undergone polysomnography monitoring in the multicenter study. The primary endpoint was incident hypertension. Kaplan-Meier survival analysis was performed, and multivariate Cox proportional hazards models were generated to determine the factors influencing new-onset hypertension. A total of 176 (39.1%) patients developed hypertension. The hypertension group had older age, higher hemoglobin (Hb) level and apnea-hypopnea index (AHI) values than the non-hypertension group (all p < 0.05). During the median 33-month follow-up period, multivariate Cox analysis showed age (hazard ratio (HR) = 1.039, 95% confidence interval (95% CI): 1.016-1.062), AHI (HR = 1.015, 95% CI: 1.007-1.023) and Hb level (HR = 1.016, 95% CI: 1.008-1.025) were independent predictors of new-onset hypertension. However, continuous positive airway pressure (CPAP; HR = 0.508, 95% CI: 0.271-0.951) reduced the risk of developing hypertension. Notably, the subgroup analysis demonstrated that the plasma glucose level (HR = 1.168, 95% CI: 1.029-1.326) was a risk factor for male patients. Besides length of time with the pulse oxygen saturation less than 90% (Tsat90; HR = 1.005, 95% CI: 1.003-1.007), body mass index (BMI; HR = 1.170, 95% CI: 1.043-1.311), and dyslipidemia (HR = 2.335, 95% CI: 1.144-4.766) had statistically significant effects on the incidence of hypertension in certain subgroups. Although this study lacked analysis of items such as living habits and medication, it did show age, AHI, Hb and CPAP affected the development of hypertension in elderly OSA patients. These findings suggested that targeted interventions in specific populations may be more effective in preventing hypertension.

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.

[Cerebral microangiopathy in men with obstructive sleep apnea syndrome]

OBJECTIVE

To determine factors associated with the development of small vessel disease (SVD) in patients with obstructive sleep apnea syndrome (OSA).

MATERIAL AND METHODS

One hundred and fifty-two patients with risk factors for the development of cerebrovascular diseases were examined. Based on the results of polysomnography, patients were divided into groups with- (n=84) and without (n=68) OSA. The groups were matched by age, prevalence of arterial hypertension and diabetes mellitus. SVD was diagnosed using brain MRI. Laboratory tests included an assessment of parameters of lipid metabolism, glucose metabolism, concentration of C-reactive protein (CRP), levels of homocysteine and creatinine with the calculation of glomerular filtration rate (GFR).

RESULTS

Patients with OSA, compared with those without OSA, were characterized by a statistically significant number of gliosis foci, with their large sizes, more frequent changes on the Fazekas scales and the Hassan scale. The most severe degree of damage according to the Hassan scale in patients with OSA was detected more often (55 (66%) and 27 (39%) OR=2.89, 95% CI 1.47-5.67, p=0.002). More pronounced atrophic changes in the brain, an increase in the size of the III ventricle and the index of the anterior horns, significantly lower GFR and higher levels of CRP were noted in the OSA group. Patients with OSA and duration of nocturnal hypoxia for more than 2 minutes were more likely to have hyperintensity of subcortical regions. In patients with OSAS, pronounced manifestations of SMD were associated with a significantly higher level of morning systolic blood pressure (MAP): 140 [120; 150] vs. 127 [120; 130] p=0.029; increased levels of blood homocysteine: 14 [11; 17.8] vs. 13 [9.7; 12.5] p=0.049; a decrease in GFR: 79 [71; 87.3] vs. 89.8 [80.3; 94] p=0.002, respectively.

CONCLUSION

OSA and intermittent nocturnal hypoxia are independent risk factors for SMD. A more severe micro-focal vascular lesion in OSA is associated with a decrease in renal filtration function, an increase in morning blood pressure and an elevation in homocysteine level.

Self-reported sleep-disordered breathing and insomnia in association with hypertension: a community-based study in Eastern China

OBJECTIVE

We aimed to explore the associations of self-reported sleep-disordered breathing (SDB) and insomnia with hypertension based on a community-based survey among adults in Suzhou, Eastern China.

METHODS

The Suzhou Food Consumption and Health Survey was conducted from 2018 to 2019. A multistage random sampling method was used to recruit potential participants. Associations of SDB and insomnia with hypertension were examined by multivariable logistic regression models with adjustment for covariates. In addition, sensitivity analysis was used to reinforce our findings.

RESULTS

A total of 2728 participants were included in the final analysis. SDB (OR, 1.83; 95% CI, 1.44-2.34; P < 0.001) and insomnia (OR, 1.31; 95% CI, 1.04-1.65; P < 0.001) were significantly associated with prevalent hypertension after multivariable adjustments. In the subgroup analysis by age groups and sex, the association between SDB and hypertension persisted in all groups, whereas the association between insomnia and hypertension remained significant in males and different age groups. In addition, SDB was positively correlated with DBP. Notably, participants with comorbid SDB and insomnia had the highest risk for hypertension (OR, 1.95; 95% CI, 1.40-2.72; P < 0.001).

CONCLUSION

Both SDB and insomnia were associated with the prevalence of hypertension among the Chinese adults, whereas the comorbid conditions conveyed the highest risk for hypertension. Our findings provide a new insight for the potential pathogenesis of hypertension and a prevention strategy of hypertension among community adults.

Prevalence and associated factors of obstructive sleep apnea in refractory hypertension

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Associations of the Cardiometabolic Index with the Risk of Cardiovascular Disease in Patients with Hypertension and Obstructive Sleep Apnea: Results of a Longitudinal Cohort Study

Purpose

We aimed to explore the relationship between the cardiometabolic index (CMI) and cardiovascular disease (CVD) and its subtypes (coronary artery disease and stroke) in patients with hypertension and obstructive sleep apnea (OSA).

Methods

We conducted a retrospective cohort study enrolling 2067 participants from the Urumqi Research on Sleep Apnea and Hypertension study. The CMI was calculated as triglyceride to high‐density lipoprotein cholesterol ratio × waist‐to‐height ratio. Participants were divided into three groups (T1, T2, and T3) according to the tertile of CMI. The Kaplan-Meier method helped to calculate the cumulative incidence of CVD in different groups. We assessed the association of CMI with the risk of CVD and CVD subtypes by estimating hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox models.

Results

During a median follow-up of 6.83 years (interquartile range: 5.92-8.00 years), 326 incident CVD were identified, including 121 incident stroke and 205 incident coronary heart disease (CHD). Overall, after adjusting for confounding variables, CMI was positively associated with the risk of new-onset CVD (per SD increment, adjusted HR: 1.31; 95% CI: 1.20, 1.43), new-onset CHD (per SD increment, adjusted HR: 1.33; 95% CI: 1.20, 1.48), and new-onset stroke (per SD increment, adjusted HR: 1.27; 95% CI: 1.10, 1.47). Similar results were obtained in various subgroup and sensitivity analyses. Adding CMI to the baseline risk model for CVD improved the C-index (P < 0.001), continuous net reclassification improvement (P < 0.001), and integrated discrimination index (P < 0.001). Similar results were observed for CHD and stroke.

Conclusion

There was a positive association between CMI levels and the risk of new-onset CVD in patients with hypertension and OSA. This finding suggests that CMI may help identify people at high risk of developing CVD.

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.

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

The impact of obstructive sleep apnea (OSA) on arterial stiffness is less studied. We aimed to investigate the prevalence and covariates of increased pulse pressure (PP), a surrogate marker of arterial stiffness, in the entire study population as well as in separate analyses in normotensive and hypertensive patients. Further, we also explored the impact of smoking on brachial BP in hypertensive patients. Between 2012 and 2019, a total of 6408 participants with suspected OSA underwent a standard out-of-center respiratory polygraphy. OSA was defined by an apnea-hypopnea index (AHI) ≥15/h regardless of symptoms. PP ≥60 mmHg was used as a surrogate marker of increased arterial stiffness. Mean age was 49.3±13.7 years, 69.4% were male, and 34.5% had OSA. The prevalence of hypertension was 70.8% in OSA and 46.7% in No-OSA (AHI < 15/h) controls (P < .0001). Hypertension was controlled (clinic BP < 140/90 mmHg) in 45.5% and uncontrolled in 54.5% (P < .001). Mean PP was 50±12 mmHg in smokers and 52±12 mmHg in non-smokers (P = .001). Increased PP was found in 24.2% of the entire study population and was higher in patients with OSA compared to No-OSA group (27.5% vs 22.4%, P < .0001). In an unadjusted logistic regression model, OSA was associated with a 1.3-fold higher risk of having increased PP (95% CI 1.16-1.48, P < .001). In a multivariable-adjusted model, higher age, male sex, and history of hypertension, but not OSA (OR 0.89; 95% CI 0.77-1.02, P = .104) were associated with increased PP. In this large study of nearly 6500 participants who were referred with suspected OSA, one-third were diagnosed with OSA and a quarter had increased arterial stiffness by elevated brachial PP. Hypertension but not OSA per se was associated with increased arterial stiffness. Hypertension was highly prevalent and poorly controlled.

Seasonal variation in blood pressure: current evidence and recommendations for hypertension management

Blood pressure (BP) exhibits seasonal variation, with an elevation of daytime BP in winter and an elevation of nighttime BP in summer. The wintertime elevation of daytime BP is largely attributable to cold temperatures. The summertime elevation of nighttime BP is not due mainly to temperature; rather, it is considered to be related to physical discomfort and poor sleep quality due to the summer weather. The winter elevation of daytime BP is likely to be associated with the increased incidence of cardiovascular disease (CVD) events in winter compared to other seasons. The suppression of excess seasonal BP changes, especially the wintertime elevation of daytime BP and the summertime elevation of nighttime BP, would contribute to the prevention of CVD events. Herein, we review the literature on seasonal variations in BP, and we recommend the following measures for suppressing excess seasonal BP changes as part of a regimen to manage hypertension: (1) out-of-office BP monitoring, especially home BP measurements, throughout the year to evaluate seasonal variations in BP; (2) the early titration and tapering of antihypertensive medications before winter and summer; (3) the optimization of environmental factors such as room temperature and housing conditions; and (4) the use of information and communication technology-based medicine to evaluate seasonal variations in BP and provide early therapeutic intervention. Seasonal BP variations are an important treatment target for the prevention of CVD through the management of hypertension, and further research is necessary to clarify these variations.