Obstructive sleep apnea syndrome and the nocturnal blood pressure profile

Clinical and life style factors related to the nighttime blood pressure, nighttime dipping and their phenotypes in Korean hypertensive patients

BACKGROUND

Non-dipping or reverse dipping patterns are known to be associated with adverse cardiovascular prognosis among the general population and clinical cohort. Few large sized studies have explored factors including sleep duration and sleep quality related to nighttime blood pressure (BP) and nocturnal dipping patterns.

METHODS

Among 5,360 patients enrolled  in Korean multicenter nationwide prospective Registry of ambulatory BP monitoring (KORABP), 981 subjects with complete data on sleep duration, sleep quality assessed using a 4-point Likert scale, and clinical variables were included in the analysis. Phenotypes of nighttime BP pattern were categorized as extreme dipper, dipper, non-dipper, and reverse dipper. Hypertension was defined as a 24-h ambulatory BPs were 130/80 mmHg or higher.

RESULTS

Among 981 subjects, 221 were normotensive, 359 were untreated hypertensive, and 401 were treated hypertensive. Age of the participants were 53.87 ± 14.02 years and 47.1% were female. In overall patients, sleep duration was 431.99 ± 107.61 min, and one to four points of sleep quality were observed in 15.5%, 30.0%, 30.4%, and 24.2%, respectively. Of the 760 hypertensive patients, extreme dipper, dipper, non-dipper, and reverse dipper were observed in 58 (7.63%), 277 (36.45%), 325 (42.76%), and 100 (13.16%), respectively. In multiple linear regression analysis, sleep duration (β = 0.0105, p < 0.001) and sleep quality (β = -0.8093, p < 0.001) were associated with nighttime systolic BP and sleep quality was associated with extent of nighttime systolic BP dipping (β = 0.7622, p < 0.001) in hypertensive patients. In addition, sleep quality showed positive association with dipper pattern (odds ratio [OR] = 1.16, 95% confidence interval [CI] = 1.03-1.30) and showed negative association with reverse dipper pattern (OR = 0.73, 95% CI = 0.62-0.86) in multiple logistic regression analyses.

CONCLUSION

When adjusted covariates, less sleep duration and poor sleep quality were positively associated with nighttime systolic BP. Additionally, sleep quality was the independent associated factor for dipper and reverse dipper phenotypes. The study also found that male sex, low estimated glomerular filtration rate, high ambulatory BP, low office BP, and poor sleep quality were associated with blunted nighttime SBP dipping.

Can biomarkers predict the risk of cardiovascular disease in patients with obstructive sleep apnea syndrome?

Background/Aim: Obstructive sleep apnea syndrome (OSAS) is a clinical syndrome characterized by recurrent partial or total obstruction of the upper airway. Cardiovascular disease (CVD) is more common in OSAS patients. Biomarkers can predict the progression of OSAS disease and the occurrence of CVD. Here we investigate the effects of age, gender, body mass index (BMI), comorbidities, neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte ratio (PLR), systemic inflammatory index (SII), atherogenic index of plasma (AIP), C-reactive protein-to-albumin ratio (CAR) and monocyte to HDL cholesterol (MHR) on the severity of OSAS and the occurrence of CVD in OSAS patients. Method: This cross-sectional study included 172 OSAS patients presenting to Erzincan Binali Yildirim University Mengucek Gazi Training and Research Hospital, Sleep Service between 01.01.2021 and 31.08.2022. Polysomnography (PSG) was applied to patients participating in the study, and routine complete blood and biochemistry tests were performed. Comorbidities and demographic data of the participants were recorded. Results: The frequency of CVD, chronic pulmonary disease (CPD) and hyperlipidemia increased as the severity of OSAS increased (P=0.005, P<0.001, P=0.016, respectively). As the severity of OSAS disease increased, only the MHR indices increased (P=0.009). When OSAS groups with and without CVD were examined, OSAS patients with CVD were older and had higher BMI (P<0.001, P=0.001, respectively). In addition, tended to be females with hyperlipidemia, diabetes mellitus (DM) and high Charlson Comorbidity Index (CCI) scores (all P<0.001). When the polysomnography of OSAS patients with CVD was evaluated, apnea-hypopnea index (AHI), non-rapid eye movement (NREM)-AHI (NREM-AHI), respiratory disorder index (RDI) and oxygen desaturation index (ODI) values were higher and sleep efficiency (SE) values were lower than patients with OSAS without CVD (P=0.002, P=0.002, P=0.003, P<0.001, P<0.001, respectively). Conclusion: CVD is common in OSAS patients. As the severity of OSAS increases, the risk of developing CVD increases. Elderly female OSAS patients with hyperlipidemic, DM, high BMI, and Charlson Comorbidity Index (CCI) constitute a relatively risky group for CVD. OSAS patients with high AHI, NREM-AHI, RDI, ODI, and low SE values should be monitored more closely for CVD.

Sleep Efficiency is Inversely Associated with Brachial Artery Diameter and Morning Blood Pressure in Midlife Adults, with a Potential Sex-Effect

PURPOSE

Sleep efficiency is inversely associated with cardiovascular risk. Brachial artery diameter and flow-mediated dilation (FMD) are noninvasive cardiovascular disease markers. We assessed the associations between sleep efficiency and these vascular markers in midlife adults, including people with sleep apnea.

PATIENTS AND METHODS

Thirty (18 males) participants completed an in-laboratory 8-hour sleep opportunity beginning at their habitual bedtimes. Polysomnography was used to assess sleep patterns and sleep efficiency (time asleep/time in bed). We measured systolic and diastolic blood pressure, heart rate, and baseline diameter, and FMD immediately upon awakening in the morning. Mixed model analyses, adjusting for apnea-hypopnea and body mass indices, were used to assess the relationship between overnight sleep efficiency and cardiovascular markers. We also explored sex differences.

RESULTS

Sleep efficiency was negatively associated with baseline brachial artery diameter (p = 0.005), systolic BP (p = 0.01), and diastolic BP (p = 0.02), but not flow-mediated dilation or heart rate (p > 0.05). These relationships were confirmed with correlations between sleep efficiency and baseline diameter (r = -0.52, p = 0.004), systolic BP (r = -0.43, p = 0.017), and diastolic BP (r = -0.43, p = 0.019). There was a sex-specific interaction trend for sleep efficiency and arterial diameter (p = 0.07) and a significant sex-specific interaction (p < 0.05) for BP, such that the relationships between sleep efficiency and cardiovascular markers were significant in women but not in men.

CONCLUSION

In midlife adults, poor sleep efficiency is associated with increased brachial artery diameter and blood pressure, effects that were primarily driven by significant associations in women. These associations could underlie the observed increase in cardiovascular risk in adults with poor sleep and cardiovascular disease.

Clinical Characteristics of Hypertensive Patients with Obstructive Sleep Apnoea Syndrome Developing Different Types of Left Ventricular Geometry

Objective

The objective of the study was to compare polygraphic parameters and selected laboratory parameters in patients with obstructive sleep apnoea (OSA) who develop various types of left ventricular (LV) geometry. Material and Methods. The research covered 122 patients with obstructive sleep apnoea and coexisting effectively treated systemic hypertension (95 men, 27 women, average age: 54 ± 10.63). Overnight polygraphy, echocardiography, carotid artery ultrasonography, and laboratory measurements were performed. The patients were classified into four groups, depending on LV geometry. Group 1 comprised patients with normal LV geometry, group 2 included those with LV concentric remodelling. Group 3 and group 4 were patients with LV hypertrophy, concentric or eccentric, respectively.

Results

The most frequent type of LV geometry in the examined population was eccentric hypertrophy (36%). The highest average values of BMI and T-Ch were observed in the group of patients with concentric remodelling (group 2). The most severe respiratory disorders were found in the group of patients developing LV concentric hypertrophy (group 3); however, these differences were not statistically significant in comparison to other groups. Patients with LV eccentric hypertrophy had significantly decreased LV ejection fraction (p = 0.0008).

Conclusions

LV eccentric hypertrophy is the most frequent type of LV geometry in OSA patients. Patients with severe sleep-disordered breathing are more likely to develop concentric hypertrophy, while concentric remodelling occurs more frequently among OSA patients with other coexisting conditions, such as obesity or lipid-related disorders.

Quantification of Nocturnal Blood Pressure Oscillations Induced by Sleep Disordered Breathing

We present an approach to quantifying nocturnal blood pressure (BP) variations that are elicited by sleep disordered breathing (SDB). A sample-by-sample aggregation of the dynamic BP variations during normal breathing and BP oscillations prompted by apnea episodes is performed. This approach facilitates visualization and analysis of BP oscillations. Preliminary results from analysis of a full night study of 7 SDB subjects (5 Male 2 Female, 52±5.6 yrs., Body Mass Index 36.4±7.4 kg/m², Apnea-Hypopnea Index 69.1±26.8) are presented. Aggregate trajectory and quantitative values for changes in systolic blood pressure (SBP) and diastolic blood pressure (DBP) concomitant with obstructive apnea episodes are presented. The results show 19.4 mmHg (15.3%) surge in SBP and 9.4 mmHg (13.6%) surge in DBP compared to their respective values during normal breathing (p<0.05). Further, the peak of the surge in SBP and DBP occurred about 9s and 7s, respectively, post the end of apnea events. The return of SBP and DBP to baseline values displays a decaying oscillatory pattern.

Validation of novel automatic ultra-wideband radar for sleep apnea detection

Background

To validate the accuracy of ultra-wideband (UWB) wireless radar for the screening diagnosis of sleep apnea.

Methods

One hundred and seventy-six qualified participants were successfully recruited. Apnea-hypopnea index (AHI) results from polysomnography (PSG) were reviewed by physicians, while the radar device automatically calculated AHI values with an embedded chip. All results were statistically analyzed.

Results

A UWB radar-based AHI algorithm was successfully developed according to respiratory movement and body motion signals. Of all 176 participants, 63 exhibited normal results (AHI <5/hr) and the remaining 113 were diagnosed with obstructive sleep apnea. Significant correlation was detected between radar AHI and PSG AHI (Intraclass correlation coefficient 0.98, P<0.001). Receiver operating characteristic curve (ROC) analysis revealed high sensitivity and specificity. High concordance in participants with varying gender, age, BMI, and PSG AHI was reached.

Conclusions

The UWB radar may be a portable, convenient, and reliable device for obstructive sleep apnea screening.

Effect of hypertension status on the association between sleep duration and stroke among middle-aged and elderly population

We aimed to examine whether hypertension status modified the association between sleep duration and stroke among middle-aged and elderly population. This cross-sectional study included 10 516 participants aged ≥45 years from the China Hypertension Survey study. Sleep duration and history of stroke were assessed by questionnaires. Multivariate logistic regression analyses, a generalized additive model (GAM) and smooth curve fitting (penalized spline method) and a two-piecewise logistic regression models were performed to evaluate the association between sleep duration and stroke in different status of hypertension. 95% confidence interval (CI) for turning point was obtained by bootstrapping. Multiple logistic analyses showed that per 1 hour increase in sleep duration was associated with a 37% increased prevalence of stroke among participants without hypertension and associated with a 8% increased prevalence of stroke among hypertensive participants (without hypertension: odds ratio [OR] = 1.37, 95% CI 1.09-1.71; with hypertension: OR = 1.08, 95% CI 0.95-1.21; P_Interaction  = .029). The fully adjusted smooth curves presented a linear association between sleep duration and stroke among participants without hypertension, but a threshold, nonlinear association among hypertensive participants. The turning point for the curve was found at a sleep duration of 8 (95% CI 5-9) h among hypertensive patients. The ORs (95% CIs) for stroke were 0.92 (0.79, 1.06) and 1.60 (1.23, 2.08) to the left and right of the turning point, respectively. In conclusion, we found a linear association between sleep duration and stroke among middle-aged and elderly participants without hypertension, but a threshold, nonlinear association among hypertensive participants.

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

Background

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

Methods

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

Results

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

Conclusions

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

Peripapillary Retinal Nerve Fiber Layer Thickness in Patients with Alzheimer's Disease: A Comparison of Eyes of Patients with Alzheimer's Disease, Primary Open-Angle Glaucoma, and Preperimetric Glaucoma and Healthy Controls

BACKGROUND The aim of this study was to assess and compare peripapillary retinal nerve fiber layer (RNFL) thickness in patients with Alzheimer's disease (AD), primary open-angle glaucoma (POAG), preperimetric glaucoma (PPG), and healthy controls with the use of Spectral Domain Optical Coherence Tomography (SD-OCT). MATERIAL AND METHODS Thirty patients with AD, 30 patients with POAG, 30 patients with PPG, and 30 healthy controls were enrolled in this cross-sectional study. Only 1 randomly selected eye of each patient was analyzed. Every subject underwent a thorough ophthalmological examination and OCT of the optic disc. The peripapillary RNFL thickness in each of the 6 sectors and globally was analyzed. RESULTS The RNFL was thinnest in patients with POAG. The mean RNFL thickness value was 60.97±12.97 µm and it was significantly lower than in healthy controls (106.30±8.95 µm), patients with PPG (93.20±12.04 µm), and AD patients (95.73±13.52 µm). Mean RNFL thickness in patients with AD was significantly lower when compared to healthy controls, and was higher compared to eyes with POAG, while there were no significant differences compared to patients with PPG. CONCLUSIONS Neuronal damage in the central nervous system (CNS) also affects to retinal axons. A major problem is to distinguish the cause for a moderate decrease in the RNFL thickness. This is particularly true for patients with glaucoma who have not been diagnosed with changes in the visual field. It is not possible to distinguish the cause of a mild decrease in the RNFL thickness based on the SD-OCT. This may result in misdiagnosis of glaucoma, unnecessary use of anti-glaucoma eye drops, and a delayed diagnosis of AD.

Age-stratified sex differences in polysomnographic findings and pharyngeal morphology among children with obstructive sleep apnea

BACKGROUND

Childhood obstructive sleep apnea (OSA) has important implications for growth, learning, behavior, cognition and cardiovascular health as well as snoring and OSA in adulthood. In this study, we elucidated the sex differences in polysomnographic (PSG) findings and pharyngeal radiographic data in pediatric OSA patients.

METHODS

Sixty three children (age between 3 and 15 years old) with OSA [defined as apnea-hypopnea index (AHI) ≥1/h by polysomnography] were enrolled. Lateral neck radiographs were obtained from the patients. All subjects were separated by age: pre-adolescent group (3-8 years old) and adolescent group (9-15 years old).

RESULTS

Overall, 45 patients in the pre-adolescent group (33 boys and 12 girls) and 18 patients in the adolescent group (10 boys and 8 girls) were enrolled, and sex differences were compared in each group. We found sex differences in craniofacial features and severity of OSA in the adolescent group, in which girls with OSA had more upper airway space, in addition to lower AHI, lower 3% oxygen desaturation index (ODI), higher minimum SO2 and better sleep efficiency than the boys.

CONCLUSIONS

The present study found revealed sex differences in pediatric OSA patients in the adolescent group. Girls in the adolescent group had more upper airway space in addition to lower AHI, lower 3% ODI, higher minimum SO2 and better sleep efficiency than boys.

Hematological indices as simple, inexpensive and practical severity markers of obstructive sleep apnea syndrome: a meta-analysis

Background

Clinical detection of inflammatory markers is useful to assess the degree of nocturnal hypoxia and predict the presence of complications in obstructive sleep apnea syndrome (OSAS) patients. Nowadays, some researchers proposed that hematological parameters could be substituted for novel disease-specific biochemical markers (such as C-reactive protein) because they were comparatively cheap, simple and practical. But there was a contradiction whether the hematological parameters were positively correlated with the OSAS severity.

Methods

Medical databases were searched included PubMed, Web of Science, Scopus, Cochrane Library, Clinical Trial, Embase and Google Scholar (up to March 29, 2018). We used weighted mean differences (WMDs) with 95% confidence intervals (CIs) from random-effects model.

Results

Seventeen studies were included in this meta-analysis and results were presented by different hematological parameters. Pooled analysis showed that OSAS was associated with a high level of WBC (white blood cell, 11 studies, 2,206 subjects, WMD: 0.58; 95% CI: 0.31 to 0.85; P<0.0001), NLR (neutrophil-to-lymphocyte ratio, 5 studies, 1416 subjects, WMD: 0.46; 95% CI: 0.13 to 0.80; P=0.007), MPV (mean platelet volume, 8 studies, 1,854 subjects, WMD: 0.63; 95% CI: 0.29 to 0.98; P=0.0004), PDW (platelet distribution width, 6 studies, 1,911 subjects, WMD: 0.76; 95% CI: 0.47 to 1.06; P<0.00001), PLR (platelet-to-lymphocyte ratio, 3 studies, 998 subjects, WMD: 21.76; 95% CI: 8.54 to 34.99; P=0.001), RDW (red cell distribution width, 5 studies, 1,701 subjects, WMD: 0.31; 95% CI: 0.11 to 0.51; P=0.002) and HCT (hematocrit, 3 studies, 662 subjects, WMD: 1.58; 95% CI: 0.52 to 2.64; P=0.003). But OSAS was associated with a low level of LYM (lymphocyte, 5 studies, 1,285 subjects, WMD: -0.27; 95% CI: -0.49 to -0.06; P=0.01). There was a gradual rising trend from mild OSAS to severe OSAS existed in all subgroups.

Conclusions

Hematological indices are comparatively Simple, Inexpensive and Practical Severity Markers of OSAS including WBC, LYM, NLR, MPV, PDW, PLR, RDW and HCT.