OSA, Short Sleep Duration, and Their Interactions With Sleepiness and Cardiometabolic Risk Factors in Adults

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.

Association Between Augmentation Index and Total Sleep Time in Night Shift Workers

Augmentation index and pulse wave velocity are markers of vascular compromise and independent predictors of cardiovascular risk and mortality. While the link between shift work and heightened cardiovascular risk is established, the intricate genesis of early cardiovascular outcomes in shift workers remains incompletely understood. However, there is evidence that sleep duration plays a role in this regard. Here we evaluate the association of total sleep time with pulse wave velocity, augmentation index, and central blood pressure in night shift workers. This study cross-sectionally evaluated the association of total sleep time evaluated by 10-day monitoring actigraphy with augmentation index, pulse wave velocity, and brachial and central blood pressure evaluated by oscillometry in nursing professionals, 63 shift workers (89% women; age = 45.0 ± 10.5 years), and 17 (100% women; age = 41.8 ± 15.6) day workers. There were no differences in the studied variables between shift workers and day workers. Results of correlation analysis demonstrated that pulse wave velocity, central systolic blood pressure, central diastolic blood pressure, brachial systolic blood pressure, and brachial diastolic blood pressure tended to have significant correlation with each other, while these measures did not have a significant relationship with augmentation index in both groups. However, results of adjusted restricted cubic spline analysis showed a U-shaped-curve association between total sleep time and augmentation index (p < 0.001 for trend) with a nadir at 300-360 min of total sleep time in shift workers. The present study showed that total sleep time, assessed by actigraphy, had a U-shaped association with augmentation index in shift workers, which indicated better characteristics of vascular functionality when sleep time was 5-6 h in the workers studied.

Incident Coronary Calcium Score in Patients With OSA With and Without Excessive Sleepiness: Brazilian Longitudinal Study of Adult Health

BACKGROUND

Uncertainty exists about the impact of OSA and its phenotypes on cardiovascular disease.

RESEARCH QUESTION

Are OSA and clinical features such as daytime sleepiness associated with incident subclinical coronary atherosclerosis?

STUDY DESIGN AND METHODS

In this prospective community-based cohort study, we administered a sleepiness questionnaire, actigraphy, and home sleep studies at baseline. Coronary artery calcium (CAC; 64-slice multidetector CT scan imaging) was measured at two different time points throughout the study (baseline, between 2010 and 2014, and follow-up, between 2016 and 2018). Incidence of subclinical atherosclerosis was defined as baseline CAC of 0 followed by CAC of > 0 at a 5-year follow-up visit. The association of incident CAC outcome was assessed using logistic regression. Stratified analyses based on excessive daytime sleepiness (EDS) were performed.

RESULTS

We analyzed 1,956 participants with available CAC scores at baseline (mean age, 49 ± 8 years; 57.9% female; 32.4% with OSA). In covariate-adjusted analyses (n = 1,247; mean follow-up, 5.1 ± 0.9 years), we found a significant association between OSA and incidence of subclinical atherosclerosis (OR, 1.26; 95% CI, 1.06-1.48), with stronger effects among those reporting EDS (OR, 1.66; 95% CI, 1.30-2.12; P = .028 for interaction). Interestingly, EDS per se was not associated with any CAC outcome. An exploratory analysis of the square root of CAC progression (baseline CAC > 0 followed by a numerical increase in scores at follow-up; n = 319) showed a positive association for both OSA (β = 1.084; 95% CI, 0.032-2.136; P = .043) and OSA with EDS (β = 1.651; 95% CI, 0.208-3.094; P = .025).

INTERPRETATION

OSA, particularly with EDS, predicts the incidence and progression of CAC. These results support biological plausibility for the increased cardiovascular risk observed among patients with OSA with excessive sleepiness.

The Cardiovascular Impact of Obstructive Sleep Apnea in Women: Current Knowledge and Future Perspectives

Overall, cardiovascular diseases have many sex-related differences in prevalence, clinical presentation, and outcomes. A considerable amount of evidence suggests that obstructive sleep apnea (OSA) increases the risk for several cardiovascular diseases. Only recently, the sex-related differences in cardiovascular outcomes gained interest in the literature. In this review, the authors discuss the current evidence addressing the cardiovascular impact of OSA in women. Particular attention is devoted to hypertension, target-organ damage, heart failure, atrial fibrillation, and cardiovascular events (including mortality). A research agenda is proposed to increase the understanding of the relevance of OSA in women from the Cardiology perspective.

Emergence of different dimensions of sleepiness in a general population sample: An EPISONO study

INTRODUCTION

Recent evidence supports the idea that sleepiness has several dimensions, comprising psychophysiological phenomena, such as sleep propensity and sleepiness perception. The Epworth Sleepiness Scale (ESS) is among one of the most used sleepiness assessment tools, but recent data suggest that it might not detect problematic impairments in sleep health. More research is warranted investigating sleepiness dimensions with large sample sizes, using both objective and subjective methods of analyzing sleep.

METHODS

We used data from the Epidemiological Sleep Study (EPISONO), a major study carried out in Brazil using a representative sample of 1042 participants of the general population of Sao Paulo city, who completed questionnaires and underwent type I polysomnography. Sleepiness was measured by the ESS (sleep propensity) and the UNIFESP Sleep Questionnaire, which asked about the frequency of feeling sleepy during the day (sleepiness perception). The participants were distributed into 4 groups in respect of excessive daytime sleepiness (EDS) according to the following criteria: 1) having an ESS score >10 (ESS group). 2) feeling sleepy ≥3 times per week (Frequent EDS group). 3) the combined criteria (Combined EDS group). 4) having no evidence of EDS (no EDS group). The UNIFESP Sleep Questionnaire was used to obtain self-reported sleep duration, sleep debt, and sleep duration variability. Participants also completed the Pittsburgh Sleep Quality Index, the Insomnia Severity Index, and a pre-polysomnography sleep questionnaire.

RESULTS

After removing participants with missing data, there were 620 participants with no EDS, 255 individuals in the ESS group, 68 in the Frequent EDS group, and 73 in the Combined EDS group. Compared to the no EDS group, the ESS and Combined EDS groups had significantly increased sleep efficiency, diminished sleep latency, wake after sleep onset, and self-reported weekly sleep duration. The Frequent and Combined EDS groups had significantly higher scores in the Insomnia Severity Index and Pittsburgh Sleep Quality Index. All EDS groups had an increased likelihood of nonrestorative sleep. EDS frequency and the ESS scores were significantly correlated.

CONCLUSIONS

Participants with a high sleep propensity had a profile suggesting prior sleep deprivation, while high sleepiness perception was associated with impaired sleep quality. These findings indicated that, in the general population, these instruments evaluated separate sleepiness dimensions with different associations, highlighting that screening using a combination of instruments might be more effective in detecting impairments in sleep health.

Comorbid association of obstructive sleep apnea (OSA) and thrombotic primary antiphospholipid syndrome (tPAPS): A more severe phenotype?

OBJECTIVE

We aimed to evaluate the frequency of obstructive sleep apnea (OSA) in patients with thrombotic primary antiphospholipid syndrome (tPAPS), to investigate the performance of screening tools for OSA in this scenario and to compare clinical/laboratorial differences in tPAPS patients with and without OSA.

METHODS

We consecutively enrolled patients with tPAPS to undergo sleep studies using a portable monitor. OSA was defined as apnea-hypopnea index ≥15 events/h. Frequency of OSA in tPAPS was evaluated and compared with age-, gender-, and BMI-matched controls (1:3 ratio) from the Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil). Next, we tested the performance of three different screening tools for assessing OSA in patients with tPAPS. Finally, patients with tPAPS were stratified according to OSA status comparing their clinical and laboratory characteristics (including damage burden measured by Damage Index for Antiphospholipid Syndrome [DIAPS] and biomarkers associated with thrombosis) using standard statistical procedures.

RESULTS

Fifty-two patients were included for analysis (females: 82.7%; mean age: 48 ± 14 years; body-mass index: 31.1 ± 6.5 Kg/m2; 25% with moderate-severe OSA). When compared to matched controls from ELSA-Brasil (n = 115), there was no significant differences in the frequencies of OSA (tPAPS: 12/42 [28.6%] vs. controls: 35/115 [30.4%], p = 0.821). Among screening tools, NoSAS had the highest area under ROC curve (AUC 0.806, CI 95% 0.672-0.939, p = 0.001), followed by STOP-Bang (AUC 0.772, CI 95% 0.607-0.938, p = 0.004). Patients with comorbid tPAPS and OSA presented higher levels of von Willebrand factor (vWF) (median 38.9 vs. 32.6, p = 0.038) and DIAPS (median 5 vs. 2, p = 0.020), when compared to those without OSA. OSA remained statistically associated with higher DIAPS, even after controlling for age, disease duration and BMI.

CONCLUSION

OSA is common in patients with tPAPS, with rates comparable to a non-referred population. Both NoSAS and STOP-Bang scores seems to be useful for screening OSA in these patients. Patients with tPAPS+OSA had higher damage burden and higher levels of vWF, which might suggest a more severe phenotype of tPAPS in this scenario.

Obstructive sleep apnea and hypertension-mediated organ damage in nonresistant and resistant hypertension

The potential role of obstructive sleep apnea (OSA) in hypertension-mediated organ damage (HMOD) may be influenced by the presence of resistant hypertension (RH). Herein, we enrolled patients with hypertension from a tertiary center for clinical evaluation and performed a sleep study to identify OSA (apnea-hypopnea index ≥15 events/h) and a blinded analysis of four standard HMOD parameters (left ventricular hypertrophy [LVH], increased arterial stiffness [≥10 m/s], presence of retinopathy, and nephropathy). RH was diagnosed based on uncontrolled blood pressure (BP) (≥140/90 mmHg) despite concurrent use of at least three antihypertensive drug classes or controlled BP with concurrent use of ≥4 antihypertensive drug classes at optimal doses. To avoid the white-coat effect, ambulatory BP monitoring was performed to confirm RH diagnosis. One-hundred patients were included in the analysis (mean age: 54 ± 8 years, 65% females, body mass index: 30.4 ± 4.5 kg/m²). OSA was detected in 52% of patients. Among patients with non-RH (n = 53), the presence of OSA (52.8%) was not associated with an increased frequency of HMOD. Conversely, among patients with RH, OSA (51.1%) was associated with a higher incidence of LVH (RH-OSA,61%; RH + OSA,87%; p = 0.049). Logistic regression analysis using the total sample revealed that RH (OR:7.89; 95% CI:2.18-28.52; p = 0.002), systolic BP (OR:1.04; 95% CI:1.00-1.07; p = 0.042) and OSA (OR:4.31; 95% CI:1.14-16.34; p = 0.032) were independently associated with LVH. No significant association was observed between OSA and arterial stiffness, retinopathy, or nephropathy. In conclusion, OSA is independently associated with LVH in RH, suggesting a potential role of OSA in RH prognosis.

Obstructive Sleep Apnea in Adults with Treacher Collins Syndrome is Related with Altered Anthropometric Measurements, Increased Blood Pressure and Impaired Quality of Life

Objectives  This study aimed at evaluating the risk for obstructive sleep apnea (OSA) and its frequency in adults with Treacher Collins syndrome (TCS). The association of OSA with excessive daytime sleepiness (EDS), respiratory symptoms, and clinical variables was also assessed. Material and Methods  The subjects were prospectively screened for OSA through the Berlin Questionnaire and type I polysomnography. The Epworth Sleepiness Scale and the Respiratory Symptoms Questionnaire were used for assessing OSA-related symptoms. Quality of life was assessed by means of the Short Form 36 Health Survey. Results  The sample comprised 20 adults with TCS (55.0% female), aged 22.6 ± 5.8 years. Mean values of systemic blood pressure (113.0 ± 12.6/68.0 ± 9.5mmHg), body mass index (22.9 ± 5.9kg/m ² ), neck (34.1 ± 4.3cm), and waist circumference (80.4 ± 13.6cm) characterized the sample. A high risk for OSA was detected in 35% of the sample. Polysomnography results indicated an OSA frequency of 44.4%, with a median apnea-hypopnea index (AHI) value of 3.8 events/hour (minimum = 0.2; maximum = 77.5). Snoring (75.0%), nasal obstruction (70.0%) and EDS (20.0%) were the reported OSA-related symptoms. Quality of life median scores were 72.3 points (minimum = 45.0; maximum = 91.1). Strong positive correlations between AHI versus waist circumference and AHI versus systolic blood pressure were found. Moderate positive correlations between AHI versus body mass index and AHI versus neck circumference were detected. Negative correlation between AHI versus vitality were also observed. Conclusion  Adults with TCS are at high risk for OSA, which is associated with respiratory symptoms, altered anthropometric measurements, increased systolic pressure and impairment of quality of life.

Association between objective sleep measures and cognitive performance: a cross-sectional analysis in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) study

Sleep disturbances often co-exist, which challenges our understanding of their potential impact on cognition. We explored the cross-sectional associations of insomnia and objective measures of sleep with cognitive performance in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) study stratified by middle-aged and older adults. Participants aged ≥55 years underwent cognitive evaluations, polygraphy for 1 night, and actigraphy for 7 days. Insomnia was evaluated using the Clinical Interview Scheduled Revised. Obstructive sleep apnea (OSA) and short sleep duration (SSD) were defined by an apnea-hypopnea index (AHI) of ≥15 events/h and <6 h/ night, respectively. In 703 participants (mean [SD] age 62 [6] years, 44% men), cognition was evaluated using a 10-word list, verbal fluency, and trail-making tests. The frequencies of insomnia, SSD, and OSA were 11%, 24%, and 33%, respectively. In all, 4% had comorbid OSA and insomnia, and 11% had both OSA and SSD. Higher wake after sleep onset (β = -0.004, 95% confidence interval [CI] -0.008, -0.001) and the number of awakenings (β = -0.006, 95% CI -0.012, -0.001) were associated with worse verbal fluency performance. Compared to those without insomnia, older participants with insomnia had worse global performance (β = -0.354, 95% CI -0.671, -0.038). Insomnia was an effect modifier in the associations between AHI and executive function performance (p for the interaction between insomnia and AHI = 0.004) and between oxygen saturation <90% and memory performance (p for the interaction between insomnia and oxygen saturation = 0.02). Although some associations between sleep measures and cognition were significant, they should be considered with caution due to the large sample size and multiple testing performed in this study.

Sleep irregularity and the association with hypertension and blood pressure levels: the ELSA-Brasil study

OBJECTIVE

To evaluate the associations of sleep irregularity with hypertension (HTN) and blood pressure (BP) levels.

METHODS

Adult participants from the ELSA-Brasil performed a clinical evaluation including objective sleep duration (actigraphy), insomnia, and a sleep study for defining obstructive sleep apnoea (OSA). To quantify sleep irregularity, we used two parameters obtained through actigraphy: 7-day standard deviation (SD) of sleep duration and 7-day SD of sleep-onset timing. A multivariate analysis was used to determine the independent associations of sleep irregularity with HTN and SBP/DBP values.

RESULTS

We studied 1720 participants (age 49 ± 8 years; 43.4% men) and 27% fulfilled the HTN diagnosis. After adjustments for age, gender, race, BMI, excessive alcohol consumption, physical activity intensity, urinary sodium excretion, insomnia, objective sleep duration and OSA (apnoea-hypopnoea index ≥15 events/h), we found that the continuous analysis of 7-day SD of sleep duration was modestly associated with prevalent HTN. However, 7-day SD of sleep duration more than 90 min was independently associated with SBP [ β : 1.55; 95% confidence interval (CI) 0.23-2.88] and DBP ( β : 1.07; 95% CI 0.12-2.01). Stratification analysis excluding participants with OSA revealed that a 7-day SD of sleep duration greater than 90 min was associated with a 48% higher chance of having HTN (OR: 1.48; 95% CI: 1.05-2.07). No significant associations were observed for the SD of sleep-onset timing.

CONCLUSION

Objective measurement of sleep irregularity, evaluated by SD of sleep duration for 1 week, was associated with HTN and higher BP levels, especially in participants without OSA.

Association between glycolipids and risk of obstructive sleep apnea: A population-based study

Background

This study aimed to investigate the associations between multiple glycolipid biomarkers and the risk of obstructive sleep apnea (OSA).

Methods

Participants (10,286) aged from 35 to 74 years old were included in this cross-sectional study from the baseline survey of the Guangzhou Heart Study. OSA was ascertained using both Berlin Questionnaire and STOP-BANG Questionnaire. Fasting blood samples were collected from each participant; fasting blood glucose (FBG) and serum concentrations of high-density lipoprotein cholesterol (HDL-CH), low-density lipoprotein cholesterol (LDL-CH), total cholesterol (TC), and triglyceride (TG) were determined. Odds ratio (OR) with 95% confidence interval (CI) was calculated using the multivariate logistic regression model after adjustment for covariates.

Results

Of the participants included, 15.56% were categorized into the pre-OSA group, and 8.22% into the OSA group. When comparing the highest with the lowest quartiles, HDL-HC was associated with a 22% (OR: 0.78, 95% CI: 0.65–0.94) and 41% (OR: 0.59, 95% CI: 0.45–0.78) reduced risk of pre-OSA and OSA, triglyceride was associated with a 32% (OR 1.32, 95% CI 1.08–1.60) and a 56% (OR 1.56, 95% CI 1.18–2.07) increased risk of pre-OSA and OSA, and FBG was associated with a 1.37-fold (95% CI 1.13–1.67) risk of pre-OSA and 1.38-fold (95% CI 1.03–1.85) risk of OSA. A significant exposure-response trend was observed for HDL-HC, TG, and FBG with both OSA and Pre-OSA (all p &lt; 0.05). No significant association of LDL-CH and TC with the risk of both pre-OSA and OSA was observed.

Conclusion

The findings suggest that serum HDL-CH was inversely associated with OSA risk, while elevated serum TG and FBG could increase the risk of OSA. Healthy glycolipid metabolism warrants more attention in the field of OSA prevention.

Excessive daytime sleepiness, but not sleep apnea, sleep duration or insomnia, was associated with poor adherence to anti-hypertensive treatment: The ELSA-Brasil study

Hypertension is the leading risk factor for cardiovascular mortality. Poor adherence may partially explain this scenario. Beyond traditional factors, it is conceivable that sleep conditions such as Obstructive Sleep Apnea (OSA), Sleep Duration (SDUR), sleepiness and insomnia may contribute to impair adherence but the evidence is scanty. Consecutive participants with hypertension from the ELSA-Brasil study performed a home sleep monitoring and 7-days actigraphy to determine OSA (apnea-hypopnea index ≥15 events/hour) and SDUR, respectively. Excessive daytime sleepiness (EDS) and insomnia were evaluated by Epworth Sleepiness Scale (ESS) and Clinical Interview Scheduled Revised (CIS-R), respectively. The 4-itens Morisky questionnaire was used to evaluate adherence to anti-hypertensive therapy. A total of 411 patients were including in the analysis (mean age: 54 ± 8 years, 47% men). Medium/low adherence to anti-hypertensive therapy was observed in 62%. Compared to the high adherence group, the participants with medium/low adherence had lower frequencies of Whites (64.1 vs. 47.8%), high-degree education (50.6 vs. 40%), and monthly per-capita income ($1021.90 vs. $805.20). In contrast, we observed higher frequency of EDS (35.9 vs. 46.1%). No differences were observed for OSA, short SDUR (<6 h) and insomnia. Logistic regression analysis showed that race other than White (OR: 1.80; 95% IC:1.15-2.82), lower monthly income (OR: 1.74; 95% IC:1.01-3.0) and EDS (OR: 1.63; 95% IC:1.05-2.53) were independently associated with medium/low adherence to the anti-hypertensive treatment. Interestingly, EDS mediated the abdominal obesity-adherence outcome. In conclusion, among sleep-related parameters, EDS, but not OSA, short SDUR or insomnia, were associated to impaired adherence to anti-hypertensive therapy.

Sleep Apnea and Cardiovascular Risk in Patients with Prediabetes and Type 2 Diabetes

Obstructive sleep apnea (OSA) is a common but largely undiagnosed clinical condition, which is turning into a serious public health issue. Of note is that its prevalence is gradually increasing in parallel with the obesity and type 2 diabetes mellitus (T2DM) epidemics. The aim of this article is to comprehensively review the literature in order to evaluate the cardiovascular (CV) risk among patients with OSA and prediabetes or T2DM. OSA seems to be an independent risk factor for the development as well as the progression of T2DM, whereas it is associated with T2DM-related macrovascular and microvascular complications. OSA may also act as a potential risk factor for the presentation and development of CV disease, such as hypertension, coronary artery disease, heart failure, pulmonary hypertension, atrial fibrillation and other cardiac arrythmias, as well as stroke. OSA and T2DM also share common pathophysiological mechanisms leading to atherosclerosis. Considering that the coexistence of OSA and T2DM is an independent and cumulative risk factor for CV mortality, more so than the two diseases separately, clinicians and healthcare professionals should be aware of and screen for OSA in patients with T2DM. Notably, targeted therapy for both conditions seems to substantially improve CV prognosis.

Multiple Machine Learning Methods Reveal Key Biomarkers of Obstructive Sleep Apnea and Continuous Positive Airway Pressure Treatment

Obstructive sleep apnea (OSA) is a worldwide health issue that affects more than 400 million people. Given the limitations inherent in the current conventional diagnosis of OSA based on symptoms report, novel diagnostic approaches are required to complement existing techniques. Recent advances in gene sequencing technology have made it possible to identify a greater number of genes linked to OSA. We identified key genes in OSA and CPAP treatment by screening differentially expressed genes (DEGs) using the Gene Expression Omnibus (GEO) database and employing machine learning algorithms. None of these genes had previously been implicated in OSA. Moreover, a new diagnostic model of OSA was developed, and its diagnostic accuracy was verified in independent datasets. By performing Single Sample Gene Set Enrichment Analysis (ssGSEA) and Counting Relative Subsets of RNA Transcripts (CIBERSORT), we identified possible immunologic mechanisms, which led us to conclude that patients with high OSA risk tend to have elevated inflammation levels that can be brought down by CPAP treatment.

Prevalence of obstructive sleep apnoea syndrome in hospitalized patients with type 2 diabetes in Beijing, China

Aims/Introduction

To estimate the prevalence, and patient clinical and demographic profile, as well as risk factors associated with obstructive sleep apnea syndrome (OSAS) in hospitalized patients with type 2 diabetes mellitus in Beijing, China.

Materials and Methods

Hospitalized adult patients with type 2 diabetes mellitus were consecutively screened and invited for an overnight polysomnography from four hospitals in Beijing, China, from May 2016 to February 2017. We used the American Academy of Sleep Medicine 2012 polysomnography recording techniques and scoring criteria to identify the type of apnea and the severity of OSAS. The χ²‐test was used to evaluate differences between groups regarding the prevalence, and demographic and other clinical parameters.

Results

A total of 735 patients were found eligible for the study, of whom 309 patients completed the overnight polysomnography. The mean age of the patients was 58.2 ± 10.9 years, and most (67.3%) were men. The prevalence of overall (apnea hypopnea index ≥5/h), moderate‐to‐severe (apnea hypopnea index ≥15/h) and severe (apnea hypopnea index ≥30/h) OSAS was 66.3% (95% confidence interval 60.8–71.6%), 35.6% (95% confidence interval 30.3–41.2%) and 16.5% (95% confidence interval 12.5–21.1%), respectively. Central and mixed apnea contributed 12% to all sleep‐disordered breathing. With the aggravation of OSAS, the combined prevalence for central, mixed and obstructive apnea increased from 57% to 70%. We found OSAS to be associated with older age, obesity, self‐reported snoring and apnea, and diabetes complications.

Conclusions

Guidelines on screening and treatment of OSAS among hospitalized patients with diabetes are needed to direct the routine practice for diabetes endocrinologists for optimal clinical care of such patients.

Independent Association Between Oxygen Desaturation Index and Cardiovascular Disease in Non-Sleepy Sleep-Disordered Breathing Subtype: A Chinese Community-Based Study

PURPOSE

Non-sleepy sleep-disordered breathing (SDB) is increasingly recognized as an important clinical subtype. The association between non-sleepy SDB and cardiovascular disease (CVD) is not well understood. Our objectives were to investigate the relationship between non-sleepy SDB and CVD and determine which nocturnal hypoxia parameter most strongly reflects this association in a large community population.

PATIENTS AND METHODS

Cross-sectional data from 3626 randomly-selected Chinese community-dwelling participants who underwent overnight type IV sleep monitoring were analyzed. Parameters of nocturnal hypoxemia were extracted from sleep monitoring devices, including mean nocturnal oxygen saturation, lowest oxygen saturation, oxygen desaturation index (ODI), and time with oxygen saturation <90%. An ODI ≥7.0 events/h was considered to signify SDB. An Epworth Sleepiness Scale score of 10 or less indicated no sleepiness.

RESULTS

The SDB rate was 30.7% (1114/3626), of which 96.5% (1075/1114) were considered the non-sleepy SDB subtype. ODI, typical nocturnal intermittent hypoxia indicator for SDB, was independently related to CVD, regardless of whether excessive daytime sleepiness was present. After adjusting for confounders, ODI most strongly reflected the association between non-sleepy SDB and CVD (OR:1.023; 95% CI:1.003-1.043). We observed a nonlinear association between ODI and the prevalence of CVD, where the likelihood of CVD increased with ODI≥10 events/h and a markedly increasing trend was observed with ODI ≥20 events/h (reference ODI = 7.0 events/h). Metabolic parameters, Pittsburgh Sleep Quality Index, and inflammatory marker did not mediate the association between ODI and CVD in the non-sleepy SDB subtype.

CONCLUSION

In the Chinese community-dwelling population, non-sleepy SDB was highly prevalent. ODI, an easily extracted indicator from a type IV sleep monitor, most strongly reflected the association between non-sleepy SDB and CVD.

Sleep Disorder Symptoms Among Adults in 8 States and the District of Columbia, 2017

Sleep disorder symptoms (trouble falling asleep or staying asleep, unintentionally falling asleep, snoring loudly, and episodes of having stopped breathing) among US adults (N = 59,108) from 8 states and the District of Columbia were analyzed by using data from the 2017 Behavioral Risk Factor Surveillance System. We conducted a multivariable logistic regression to assess the association between the 4 symptoms and sociodemographic characteristics, risk behaviors, and chronic conditions. The 4 symptoms were prevalent and more likely to be reported among adults with any chronic condition(s) than their counterparts without symptoms and among those who slept fewer than 7 hours compared with those who slept 7 to 9 hours.

Self-reported versus actigraphy-assessed sleep duration in the ELSA-Brasil study: analysis of the short/long sleep duration reclassification

PURPOSE

This study was aimed to determine the magnitude and predictors of self-reported short/long sleep duration (SDUR) reclassifications using objective measurements.

METHODS

Adult participants from the ELSA-Brasil study performed self-reported SDUR, 7-day wrist actigraphy, and a portable sleep study. We explored two strategies of defining self-reported SDUR reclassification: (1) short and long SDUR defined by <6 and ≥8h, respectively; (2) reclassification using a large spectrum of SDUR categories (<5, 5-6, 7-8, 8-9, and >9 h).

RESULTS

Data from 2036 participants were used in the final analysis (43% males; age: 49±8 years). Self-reported SDUR were poorly correlated (r=0.263) and presented a low agreement with actigraphy-based total sleep time. 58% of participants who self-reported short SDUR were reclassified into the reference (6-7.99 h) or long SDUR groups using actigraphy data. 88% of participants that self-reported long SDUR were reclassified into the reference and short SDUR. The variables independently associated with higher likelihood of self-reported short SDUR reclassification included insomnia (3.5-fold), female (2.5-fold), higher sleep efficiency (1.35-fold), lowest O₂ saturation (1.07-fold), higher wake after sleep onset (1.08-fold), and the higher number of awakening (1.05-fold). The presence of hypertension was associated with a 3.4-fold higher chance of self-reported long SDUR reclassification. Analysis of five self-reported SDUR categories revealed that the more extreme is the SDUR, the greater the self-reported SDUR reclassification.

CONCLUSION

In adults, we observed a significant rate of short/long SDUR reclassifications when comparing self-reported with objective data. These results underscore the need to reappraise subjective data use for future investigations addressing SDUR.

Association of Craniofacial and Upper Airway Morphology with Cardiovascular Risk in Adults with OSA

BACKGROUND AND OBJECTIVE

Clinical and population-based studies have demonstrated a strong association between obstructive sleep apnea (OSA) and cardiovascular disease (CVD). Anatomical abnormalities of the craniofacial region and upper airway are important risk factors for OSA. The objective of this study was to investigate the association of craniofacial and upper airway morphology with CVD risk biomarkers.

METHODS

One hundred and sixty-nine male patients with OSA underwent in-laboratory polysomnography (PSG) and upper airway computed tomography (CT) scanning. Ten-year Framingham CVD risk score (FRS) was calculated and categorized into low- and moderate-to-high-risk groups. N-terminal pro B-type natriuretic peptide (NT-proBNP) was measured as a biomarker of increased myocardial wall stress.

RESULTS

Compared to the low-risk group, total sleep time (TST), the proportion of N3 (N3%) and mean oxygen saturation (SpO2mean) were lower, while the arousal index of non-rapid eye movement (NREM) sleep, apnea index (AI) of NREM sleep, apnea hypopnea index (AHI) of NREM sleep, oxygen desaturation index (ODI) and percentage of total sleep time spent with oxyhemoglobin saturation below 90% (TST90) were higher in the moderate-to-high risk group. The corrected upper airway length (UAL), ANB angle and gonion-gnathion-hyoid angle were larger for subjects in the moderate-to-high risk group than those in the low-risk group. In multiple regression analysis, TST, AINREM and adjusted UAL were independently associated with moderate-to-high CVD risk. Plasma NT-proBNP levels were higher in patients in the moderate- to high-risk group, and among the PSG and CT scan parameters, only SPO2mean was marginally associated with NT-proBNP (r=0.183, P=0.054).

CONCLUSION

Craniofacial and upper airway features may contain valid cues about CVD risk, and sleep duration, obstructive event type and occurrence phase may be closely related to CVD risk for patients with OSA.

Impact of obstructive sleep apnea complicated with type 2 diabetes on long-term cardiovascular risks and all-cause mortality in elderly patients

BACKGROUND

The prognostic significance of obstructive sleep apnea (OSA) in elderly patients with type 2 diabetes is unclear. The aim of this study was to determine the risk of cardiovascular disease (CVD) and mortality in elderly patients with OSA complicated with type 2 diabetes compared to patients with OSA without type 2 diabetes.

METHODS

From January 2015 to October 2017, 1113 eligible elderly patients with OSA, no history of cardiovascular, ≥60 years of age, and complete follow-up records were enrolled in this consecutive multicentre prospective cohort study. All patients had completed polysomnography (PSG) examinations. An apnoea-hypopnoea index of ≥5 events per hour recorded by polysomnography was defined as the diagnostic criterion for OSA. We collected baseline demographics, clinical characteristics, sleep parameters and follow-up outcomes. The primary aim of this study was to identify the risk of incident major adverse cardiovascular events (MACE). Secondary outcomes were all-cause mortality, components of MACE and a composite of all events. Kaplan-Meier survival analysis and Cox proportional hazards models were used to evaluate whether type 2 diabetes was associated with incident events.

RESULTS

A total of 266 (23.9%) patients had OSA complicated with type 2 diabetes. MACE occurred in 97 patients during the median 42-month follow-up. Kaplan-Meier survival curves indicated a significant relationship between type 2 diabetes and MACE (log-rank P = 0.003). Multivariable Cox regression analysis showed that type 2 diabetes increased the risk of MACE (HR = 1.64, 95% CI:1.08-2.47, P = 0.019), hospitalisation for unstable angina (HR = 2.11, 95% CI:1.23-3.64, P = 0.007) and a composite of all events in elderly patients with OSA (HR = 1.70, 95% CI:1.17-2.49, P = 0.007). However, there were no significant differences in the incidence of cardiovascular death, all-cause mortality, MI and hospitalisation for heart failure between patients with and without diabetes (P > 0.05). The subgroup analysis demonstrated that females (AHR = 2.46, 95% CI:1.17-5.19, P = 0.018), ≥ 70 years (AHR = 1.95, 95% CI:1.08-3.52, P = 0.027), overweight and obese (AHR = 2.04, 95% CI:1.29-3.33, P = 0.002) with mild OSA (AHR = 2.42, 95% CI: 1.03-5.71, P = 0.044) were at a higher risk for MACE by diabetes.

CONCLUSION

OSA and type 2 diabetes are interrelated and synergistic with MACE, hospitalisation for unstable angina and a composite of all events development. Overweight and obese females, ≥ 70 years with mild OSA combined with type 2 diabetes presented a significantly high MACE risk.

Is self-reported short sleep duration associated with obesity? A systematic review and meta-analysis of cohort studies

CONTEXT

A possible association between self-reported short sleep duration and risk of obesity has been studied.

OBJECTIVE

To analyze the association between sleep duration and obesity.

METHODS

The LILACS, Medline, Central, Embase, and OpenGrey databases were searched from inception until July 2020. Two authors screened the studies independently according to the PECO strategy, as follows: participants: > 18 years old; exposure: short sleep duration; control: regular sleep; outcome: obesity). Only cohort studies were included. A total of 3286 studies were retrieved with the search strategy, but only 36 were included. Disagreements were resolved by a third author. The quality of studies was assessed with Newcastle-Ottawa Quality Assessment Form for Cohort Studies. The certainty of the evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation.

RESULTS

Thirty-six studies were included, and 22 contributed quantitative data. Most of the studies (n = 27) assessed sleep by self-report. The meta-analysis showed a significant association between self-reported short sleep and development of obesity, and the chances of developing obesity increased when self-reported sleep duration decreased.

CONCLUSIONS

Self-reported short sleep was significantly associated with a higher incidence of obesity, with moderate quality of evidence.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42019130143.

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.

Physical activity is associated with reduced prevalence of self-reported obstructive sleep apnea in a large, general population cohort study

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is a common condition with significant symptoms and long-term adverse cognitive, mental health, vascular, and respiratory sequelae. Physical activity has been recognized as a key determinant for good health and has been associated with lower risk of these sequelae. We hypothesized that increased physical activity may be associated with a decreased prevalence of OSA.

METHODS

This cross-sectional study used baseline questionnaire data from the Ontario Health Study, a population-based cohort of residents of Ontario, Canada. Participants were adults who provided lifestyle, medical, socio-demographic, and sleep health information. The study sample consisted of 155,448 men (39.8%) and women (60.2%). The prevalence of physician-diagnosed OSA in this cohort was 6.9%. Logistic regression models were used to investigate the association of OSA with physical activity. Missing data were imputed using a multiple imputation by chained equation approach.

RESULTS

In multivariable analyses adjusted for potential confounding factors, increased total physical activity (metabolic equivalent [h/wk]) (odds ratio [OR] = .98, 95% confidence interval [CI] = .96 to 1.00), vigorous-intensity activity (OR = .98, 95% CI = .97 to 1.00), and walking (OR = .98, 95% CI = .96 to 1.00) were all associated (all P ≤ .045) with decreased prevalence of OSA. Moderate-intensity activity was not associated with risk of OSA (P = .826).

CONCLUSIONS

Independent of known risk factors for OSA, including body mass index, increased levels of physical activity, including walking, were associated with a prevalence of OSA. Our results highlight the importance of physical activity as a preventive measure for sleep apnea.

Obstructive sleep apnea, sleep duration and chronic kidney disease in patients with coronary artery disease

BACKGROUND

Limited evidence is available addressing the potential role of sleep disorders on renal function. Here, we aimed to explore the associations of obstructive sleep apnea (OSA) and sleep duration (SD) with renal function in subjects with high cardiovascular risk.

METHODS

Consecutive subjects with coronary artery disease (CAD) underwent clinical evaluation, sleep study to define OSA and one-week wrist actigraphy to objectively measure SD. OSA was defined by an apnea-hypopnea index (AHI) of ≥15 events/hour. The estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation. We analyzed the associations of OSA and SD with continuous eGFR values and according to the presence of CKD (eGFR<60 mL/min/1.73 m²) after adjusting for multiple confounding factors.

RESULTS

We studied 242 subjects (62.8% men). The frequency of OSA was 55.4% and the median SD was 412.8 (363.4-457.25) min. There was no difference in the eGFRs between participants with and without OSA (69.3 ± 19.1 vs. 74.6 ± 19.3 mL/min/1.73 m², p = 0.72) and the rate of eGFR <60 mL/min/1.73 m² (34.3% vs. 25.9%; p = 0.21). Similarly, we did not find differences in patients in eGFR for those with SD ≥ 6 h versus SD < 6 h (72.5 ± 20.3 vs. 71.4 ± 19.1 mL/min/1.73 m², p = 0.72). In the linear regression analysis, AHI was independently associated with an eGFR<60 mL/min/1.73 m² in the unadjusted model [-0.15 (-0.27 to -0.04)], (P = 0.01), but not in the adjusted models. Analyses of continuous SD or the stratification in SD ≥ 6 h or <6 h also revealed neutral results on eGFR.

CONCLUSION

OSA severity and SD were not independently associated with CKD in subjects with CAD.

Contribution of sleep characteristics to the association between obstructive sleep apnea and dyslipidemia

OBJECTIVES/BACKGROUND

Little information is available about the association of obstructive sleep apnea (OSA) with atherogenic dyslipidemia and the contribution of sleep characteristics to lipid alterations. We compare dyslipidemia prevalence among non-apneic subjects and mild-severe OSA patients to identify the sleep characteristics that are independently associated with dyslipidemia and serum lipid levels in OSA patients.

PATIENTS/METHODS

We recruited 809 consecutive patients who had been referred for polysomnography study by OSA suspicion. Anthropometric characteristics, body composition and comorbidities were recorded. Spirometry and 24-h ambulatory blood pressure monitoring were performed the same day of the sleep study. The day after attended polysomnography, fasting blood samples were drawn to measure the lipid profile.

RESULTS

Dyslipidemia prevalence increased with the presence of OSA, from non-OSA subjects to mild, moderate and severe OSA patients (31%, 33%, 42% and 51%, respectively; p < 0.001). After adjusting for sex, age, body mass index and smoking habit, only severe OSA had an independent association with dyslipidemia when compared to non-OSA subjects (adjusted odds ratio 1.71, 95%CI 1.09 to 2.69, p = 0.019). In OSA patients, multivariate logistic regression identified active smoking, apnea-hypopnea index (AHI) and mean nocturnal saturation as variables independently associated with dyslipidemia. However, in these patients, arousal index, slow wave sleep duration and REM latency were also independently associated with cholesterol and low-density lipoprotein levels.

CONCLUSIONS

The association between dyslipidemia and OSA is limited to severe patients, with high AHI and nocturnal hypoxemia. However, sleep fragmentation and increased sympathetic activity could also contribute to OSA-related lipid dysregulation.

Adherence with positive airway pressure therapy for obstructive sleep apnea in developing vs. developed countries: a big data study

STUDY OBJECTIVES

Minimal focus has been placed on variations in health care delivery for obstructive sleep apnea (OSA). This study compared positive airway pressure usage in developing countries (Brazil and Mexico) vs. a developed country (United States) and investigated the impact of a patient engagement tool (myAir; ResMed, San Diego, CA) on adherence.

METHODS

Deidentified data from the AirView database (ResMed) for patients receiving positive airway pressure therapy with wirelessly connected Air10 (AirSense and AirCurve) devices in Brazil, Mexico, and the United States were analyzed. Adherence was defined using US Center for Medicare and Medicaid Services (CMS) criteria (usage ≥ 4 h/night on ≥ 70% of nights in the first 90 days).

RESULTS

The analysis included 4,181,490 patients (Brazil: 31,672; Mexico 16,934; United States: 4,132,884). CMS adherence over 90 days was slightly lower in Latin America vs. the United States (Brazil: 71.7%; Mexico: 66.4%; United States: 74.0%). Significantly fewer patients were using the patient engagement tool in Brazil (8.1%) and Mexico (2.8%) vs. the United States (26%; both P < .001). Patients registered to use an engagement tool had a higher rate of CMS adherence and were twice as likely to achieve CMS adherence. Average daily usage and days with usage > 4 hours in the first week were the strongest predictors of CMS adherence. Across all countries, > 80% of patients meeting CMS criteria at 3 months were still using positive airway pressure therapy at 1 year, with 1-year adherences rates of > 75%.

CONCLUSIONS

Short-term and long-term positive airway pressure adherence rates in Brazil and Mexico were similar to those achieved in the United States. Patients who registered to use an engagement tool consistently had better adherence than those who did not.

Effect of Sleep Disturbances on Blood Pressure

This review summarizes recent literature addressing the association of short sleep duration, shift work, and obstructive sleep apnea with hypertension risk, blood pressure (BP) levels, and 24-hour ambulatory BP. Observational studies demonstrate that subjectively assessed short sleep increases hypertension risk, though conflicting results are observed in studies of objectively assessed short sleep. Intervention studies demonstrate that mild and severe sleep restriction are associated with higher BP. Rotating and night shift work are associated with hypertension as shift work may exacerbate the detrimental impact of short sleep on BP. Further, studies demonstrate that shift work may increase nighttime BP and reduce BP control in patients with hypertension. Finally, moderate to severe obstructive sleep apnea is associated with hypertension, particularly resistant hypertension. Obstructive sleep apnea is also associated with abnormal 24-hour ambulatory BP profiles, including higher daytime and nighttime BP, nondipping BP, and a higher morning surge. Continuous positive airway pressure treatment may lower BP and improve BP dipping. In conclusion, efforts should be made to educate patients and health care providers about the importance of identifying and treating sleep disturbances for hypertension prevention and management. Empirically supported sleep health interventions represent a critical next step to advance this research area and establish causality.

Obstructive sleep apnea is associated with lower adiponectin and higher cholesterol levels independently of traditional factors and other sleep disorders in middle-aged adults: the ELSA-Brasil cohort

PURPOSE

Obstructive sleep apnea (OSA) may contribute to metabolic and inflammatory deregulation but previous studies failed to consider sleep duration, sleep fragmentation, insomnia, and daytime sleepiness as potential confounders.

METHODS

Consecutive non-diabetic middle-aged participants from the ELSA-Brasil cohort were invited to perform a clinical evaluation, home sleep study for 1 night, and wrist actigraphy for 7 days. OSA was defined by an apnea-hypopnea index ≥ 15 events/h. Participants were stratified according to the presence of OSA measuring the following markers: fasting glucose, glucose tolerance test, homeostatic model assessment of insulin resistance (HOMA-IR) index, fasting insulin, insulin after 2 h of glucose load, glycated hemoglobin, total cholesterol and their fractions, triglycerides, C-reactive protein, TNF-alpha, interleukin-6, interleukin-10, leptin, adiponectin, E-selectin, ADMA, MCP-1, TGF, apolipoprotein B, fibrinogen, and lipoprotein(a). Differences between groups were identified by chi-square test and ANOVA.

RESULTS

We studied 708 participants (mean age: 46 ± 5 years, men: 44%, BMI 26.1 ± 4.1 kg/m²). Compared to no OSA, participants with OSA presented higher levels while fasting and after 2 h glucose load of insulin, HOMA-IR, cholesterol, triglycerides, and C-reactive protein (all p < 0.001). After linear regression analysis adjusting for traditional risk factors plus sleep duration, fragmentation, insomnia, and daytime sleepiness, OSA was negatively associated with adiponectin (β = - 0.271 CI 95% - 0.456 - 0.085) and positively associated with cholesterol (β = 9.707 CI 95% 2.737 16.678). Sex-stratification revealed that these associations were significant for men but not women.

CONCLUSIONS

In non-diabetic middle-age adults, men with OSA presented with lower adiponectin and higher cholesterol levels independently of sleep duration, sleep fragmentation, insomnia, and daytime sleepiness.

Three-year effects of bariatric surgery on obstructive sleep apnea in patients with obesity grade 1 and 2: a sub-analysis of the GATEWAY trial

BACKGROUND

Most of the evidence on bariatric surgery on obstructive sleep apnea (OSA) is based on observational studies and/or short-term follow-up in patients with obesity grade 3.

SUBJECTS/METHODS

This randomized study compared the effects of roux-en-Y gastric bypass (RYGB) or usual care (UC) on OSA severity in patients with obesity grade 1-2. Mild, moderate, and severe OSA was defined by the apnea-hypopnoea index (AHI): 5-14.9; 15-29.9, and ≥30 events/h, respectively. OSA remission was defined by converting any form of OSA into normal AHI (<5 events/h).

RESULTS

After 3-year of follow-up, the body-mass index increased in the UC while decreased in the RYGB group: +1.7 (-1.9; 2.7) versus -10.6 (-12.7; -9.2) kg/m², respectively. The AHI increased by 5 (-4.2; 12.7) in the UC group while reduced in the RYGB group to -13.2 (-22.7; -7) events/h. UC significantly increase the frequency of moderate OSA (from 15.4 to 46.2%). In contrast, RYGB had a huge impact on reaching no OSA status (from 4.2 to 70.8%) in parallel to a decrease of moderate (from 41.7 to 8.3%) and severe OSA (from 20.8 to 0%).

CONCLUSIONS

RYGB is an attractive strategy for mid-term OSA remission or decrease moderate-to-severe forms of OSA in patients with obesity grade 1-2.

Obstructive Sleep Apnea, Sleep Duration, and Associated Mediators With Carotid Intima-Media Thickness: The ELSA-Brasil Study

[Figure: see text].

Effects of transcranial direct current stimulation on performance and recovery sleep during acute sleep deprivation: a pilot study

BACKGROUND

Previous studies claimed that transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) improves cognition in neuropsychiatric patients with cognitive impairment, schizophrenia, organic hypersomnia, etc, but few studies evaluated the effects of tDCS on cognitive improvement following sleep deprivation. The objective of this study was to determine whether tDCS (anode on the left DLPFC and cathode on the right DLPFC with a 2-mA current for 30 min) improves cognition following sleep deprivation.

METHODS

Seven participants received active tDCS and eight participants received sham tDCS when their cognition declined during at least 30 h of sleep deprivation. All participants completed the psychomotor vigilance task, Trail Making Tests A and B, digit cancellation test, Stroop color word test, the Brief Visuospatial Memory Test-Revised and a procedural game every 2 h during the sleep deprivation and after recovery sleep.

RESULTS

Compared to the sham stimulation, active tDCS (anode on the left DLPFC and cathode on the right DLPFC at a 2-mA current for 30 min) had beneficial effects on attention, memory, executive function, processing speed, and the ability to inhibit cognitive interference, and improved in subjective drowsiness and fatigue following sleep deprivation. The lasting effect of a single tDCS on cognition during sleep deprivation was greater than 2 h. In all participants, tDCS did not disturb recovery sleep, and cognitive performance recovered to the baseline levels after recovery sleep.

CONCLUSIONS

The study results indicate that tDCS can improve cognition following sleep deprivation and does not disturb recovery sleep or cognitive performance after recovery sleep. The possible pathophysiological mechanisms might be related to the modulation of the corticothalamic pathway. We believe that tDCS can be applied in the treatment of sleep disorders involving sleepiness.

TRIAL REGISTRATION NUMBER

ChiCTR2000029420.

DATE OF REGISTRATION

2020-1-31.

What Is the Most Common Cause of Secondary Hypertension?: An Interdisciplinary Discussion

PURPOSE OF REVIEW

Traditional statements in medical textbooks pointed that 90 to 95% of cases of hypertension is essential or primary. However, secondary hypertension seems to be common in those patients with resistant forms of hypertension. Appropriate investigation and treatment may have prognostic impact but frequently hypertension remission did not occur raising concerns about the real meaning of secondary hypertension. Here, we provided an interdisciplinary and critical discussion comprising an endocrinologist, a nephrologist, and a cardiologist with expertise in resistant hypertension. We reviewed the literature approaching each one of the recognizable cause of hypertension.

RECENT FINDINGS

Recent studies pointed that the most common causes of secondary hypertension are those who overall responses to their treatments do not promote hypertension remission including obstructive sleep apnea (OSA), chronic kidney disease, renovascular hypertension and primary aldosteronism. The authors raised concerns regarding the lack of inclusion of obesity by several societies as a formal cause of hypertension considering not only the biologic plausibility but also the huge impact of weight loss therapies such as bariatric surgery on hypertension remission. In contrast, there is no discussion that a very rare condition-namely pheochromocytoma-is the most "typical" cause of hypertension by promoting hypertension remission in the majority of patients after surgical procedure. Hypertension is a complex condition with multiple environmental and genetics interactions. In clinical practice, it is challenging to prove causality in hypertension. Common conditions largely acceptable as causes of hypertension (OSA, chronic kidney disease, renovascular hypertension, and primary aldosteronism) frequently occur in a setting of an established hypertension background and therefore do not promote hypertension remission in a significant proportion of patients. If obesity becomes largely accepted by several societies as a secondary form of hypertension, this pandemic condition will be certainly the most common cause of hypertension.

Understanding the pathophysiological mechanisms of cardiometabolic complications in obstructive sleep apnoea: towards personalised treatment approaches

In January 2019, a European Respiratory Society research seminar entitled "Targeting the detrimental effects of sleep disturbances and disorders" was held in Dublin, Ireland. It provided the opportunity to critically review the current evidence of pathophysiological responses of sleep disturbances, such as sleep deprivation, sleep fragmentation or circadian misalignment and of abnormalities in physiological gases such as oxygen and carbon dioxide, which occur frequently in respiratory conditions during sleep. A specific emphasis of the seminar was placed on the evaluation of the current state of knowledge of the pathophysiology of cardiovascular and metabolic diseases in obstructive sleep apnoea (OSA). Identification of the detailed mechanisms of these processes is of major importance to the field and this seminar offered an ideal platform to exchange knowledge, and to discuss pitfalls of current models and the design of future collaborative studies. In addition, we debated the limitations of current treatment strategies for cardiometabolic complications in OSA and discussed potentially valuable alternative approaches.

The association between sleep duration and hypertension: a meta and study sequential analysis

Hypertension is a global public issue, and sleep duration was regarded as its risk factors, however, the results were inconsistent. This study aims to deeply investigate and assess the association between sleep duration and hypertension. The electronic databases Cochrane Library, Pubmed and Embase updated to April, 30, 2020 were retrieved. Cohort studies that compared the long or short sleep duration versus normal sleep duration for the incidence of hypertension were included. The associations between sleep duration and hypertension were analyzed by meta-analyses, using risk ratio and 95% confidence interval as effect indexes. TSA software was used to assess the reliability of the pooled results and estimate the required sample size. A total of 11 studies (involving 85,838 subjects) were eligible for this meta-analysis. The association between short sleep duration and hypertension had statistical significances (RR = 1.161, 95% CI: 1.058-1.274), while there was no significant difference in ≥8 h group (RR = 1.059, 95% CI: 0.951-1.180). For short sleep hours, the required information size was calculated to be 44,889, and the number of subjects included in the meta-analysis exceeded the required information size. For long sleep hours, the required information size was 92,368, and the number of included subjects was less than that. The short sleep duration was confirmed to be a risk factor of the incidence of hypertension, future research should be conducted for some in-depth exploration. However, the significant association between long sleep duration and hypertension was not found, more studies should be conducted to confirm the pooled results.

Interaction between obstructive sleep apnea and short sleep duration on insulin resistance: a large-scale study : OSA, short sleep duration and insulin resistance

Objectives

Both short sleep duration and obstructive sleep apnea (OSA) seem to be associated with insulin resistance. We aimed to explore whether short sleep duration modifies the relationship between OSA and insulin resistance.

Methods

Participants were consecutively enrolled from our sleep center during the period from 2007 to 2017. The index of homeostasis model assessment insulin resistance (HOMA-IR) was calculated from insulin and glucose. Sleep duration was determined by standard polysomnography. The associations between sleep duration and insulin resistance were estimated by logistic regression analyses.

Results

A total of 5447 participants (4507 OSA and 940 primary snorers) were included in the study. OSA was independently correlated with insulin resistance after adjusting for all potential confounders (OR, 1.319; 95% CI, 1.088–1.599), but not short sleep duration. In stratified analysis by sleep duration, compared with primary snorers, in the OSA group only extremely short sleep duration (< 5 h) was significantly associated with insulin resistance after adjusting for all covariates (OR, 2.229; 95% CI, 1.283–3.874). Rapid eye movement predominant OSA was significantly associated with insulin resistance (OR = 1.355, 95% CI: 1.019–1.802) after adjustment for confounding factors including age, sex and body mass index.

Conclusions

OSA, but not short sleep duration, was independently associated with insulin resistance. It is worth noting that OSA combined with extremely short sleep duration showed a greater detrimental effect than OSA itself with regard to insulin resistance.

Risk factors of excessive daytime sleepiness in a prospective population-based cohort

Although excessive daytime sleepiness is commonly evaluated in clinical and research settings using the Epworth Sleepiness Scale, few studies have assessed the factors associated with its incidence in the general population. We prospectively investigated the predictors of incident and persistent excessive daytime sleepiness in 2,751 subjects (46.1% men, mean age 56.0 ± 9.8 years) from the CoLaus-PsyCoLaus population-based cohort (Lausanne, Switzerland) over 5 years. Participants completed the Epworth Sleepiness Scale and the Pittsburgh Sleep Quality Index, and underwent a full clinical evaluation at baseline and 5 years afterwards. Ambulatory polysomnography was performed at baseline in a sub-sample of 1,404 subjects. Among the 2,438 subjects without excessive daytime sleepiness (Epworth Sleepiness Scale ≤ 10) at baseline, the 5-year incidence of excessive daytime sleepiness was 5.1% (n = 124). Multivariate logistic regression revealed that male sex, depressive symptoms, reported poor sleep quality and moderate to severe obstructive sleep apnea were independent predictors of incident excessive daytime sleepiness, while older age, moderate coffee consumption, periodic leg movement during sleep and hypertension were independent protective factors. Stratified analysis according to sex and age showed some distinctive associations. Among the 313 patients with excessive daytime sleepiness at baseline, 137 (43.8%) had persistent excessive daytime sleepiness 5 years later. Our findings provide new insights into the predictors of incident excessive daytime sleepiness, but interventional studies are needed to understand the impact of treating these risk factors on the incidence of excessive daytime sleepiness.

Associations of objectively measured sleep characteristics and incident hypertension among police officers: The role of obesity

This study investigated the associations of baseline sleep onset latency, wake after sleep onset, longest wake episode, number of awakenings, sleep efficiency and sleep duration with incident hypertension during a 7-year follow-up (n = 161, 68% men) and the joint effect of insufficient sleep and obesity on incident hypertension. Sleep parameters were derived from 15-day actigraphy data. Relative risks and 95% confidence intervals were estimated using a robust Poisson regression model. Each 10-min increase in sleep onset latency was associated with an 89% higher risk of hypertension (95% confidence interval [CI] = 1.12-3.20). Each 10-min increase in longest wake episode was associated with a 23% higher risk of hypertension (95% CI = 1.01-1.50) and each 10% decrease in sleep efficiency was associated with a 50% higher risk of hypertension (95% CI = 1.02-2.22). These associations were independent of demographic and lifestyle characteristics, depressive symptoms, shift work, sleep duration and body mass index. Having <6 hr of sleep and a body mass index ≥30 kg/m² increased the risk of hypertension (relative risk = 2.81; 95% CI = 1.26-6.25) compared with having ≥6 hr of sleep and a body mass index <30 after controlling for confounders. Relative excess risk due to interaction was 3.49 (95% CI = -1.69-8.68) and ratio of relative risk was 3.21 (95% CI = 0.72-14.26). These results suggest that poor sleep quality is a risk factor for hypertension. Longitudinal studies with larger sample sizes are warranted to examine the joint effect of insufficient sleep and obesity on development of hypertension.

Obstructive sleep apnea and cardiovascular disease, a story of confounders!

Obstructive sleep apnea (OSA) syndrome is increasingly common among middle aged and older adults and is frequently linked to most cardiovascular diseases (CVD). Sleep-disordered breathing and CVD share a number of common risk factors and comorbid conditions including obesity, male gender, advancing age, metabolic syndrome, and hypertension. OSA appears to be associated with worsened CVD outcomes, sleep-related symptoms, quality of life, and risk of motor vehicle accidents. Demonstrating a cause-and-effect relationship between CVD and OSA has been challenging due to shared comorbidities. Strong evidence demonstrating clinically significant benefit for OSA treatments on OSA-related CVD outcomes are limited. In this review, we evaluate potential pathophysiologic mechanisms that link OSA to CVD and focus on specific treatments for OSA, including positive airway pressure (PAP), dental devices, and surgeries with regard to OSA-related CVD outcomes.

Accuracy of global and/or regional anthropometric measurements of adiposity in screening sleep apnea: the ELSA-Brasil cohort

OBJECTIVE

Adiposity is a well-established risk factor for obstructive sleep apnea (OSA) but the existence of a preferable anthropometric measurement is not established or whether the combination of measurements may improve the accuracy to detect OSA. This study aimed to compare the accuracies of body mass index (BMI), several surrogate markers of body fat (in isolation or combined) and validated questionnaires for screening OSA.

METHODS

A total of 2059 participants from the ELSA-Brasil study given anthropometric measurements using standard procedures and a home sleep study. OSA was defined by an apnea-hypopnea index ≥15 events/hour.

RESULTS

The frequency of OSA was 32.3%. Compared with the non-OSA group, all anthropometric measurements were higher in the OSA group. Age and gender-adjusted BMI afforded the highest accuracy to detect OSA [AUC = 0.760 (0.739-0.781)], followed by waist [AUC = 0.753 (0.732-0.775)] and neck [AUC = 0.733 (0.711-0.755)] circumferences, waist-to-hip ratio [AUC = 0.722 (0.699-0.745)] and body shape index [AUC = 0.680 (0.656-0.704)]. The combination of two or more anthropometric measurements did not improve the accuracy of BMI in predicting OSA. The adjusted BMI had similar predictive performance to the NoSAS score [AUC = 0.748 (0.727-0.770)] but a better accuracy than the Berlin Questionnaire [AUC = 0.676 (0.653-0.699)].

CONCLUSIONS

Despite one's intuition, surrogate markers of regional adiposity are not better than BMI in screening OSA. Combining measurements of global and/or regional adiposity did not have additional value in detecting OSA. The merely fair accuracy range of BMI and sleep questionnaires underscore the need for additional tools to improve OSA underdiagnosis.

Pragmatic Validation of Home Portable Sleep Monitor for diagnosing Obstructive Sleep Apnea in a non-referred population: The ELSA-Brasil study

Objective

Polygraphy (PG) is an attractive alternative for diagnosing obstructive sleep apnea (OSA) in patients with high pre-test probability. However, several patients may not present typical symptoms. In this scenario, it is unclear the performance of PG for diagnosing OSA in non-referred populations to sleep laboratories.

Methods

Data from participants of the ELSA-Brasil cohort were used for this analysis. We performed an overnight home PG (Embletta Gold^TM) synchronized with a wrist actigraphy (Actiwatch model 2^TM). The validation strategy comprised three scorings from each participant: 1) Original scoring (PG): Routine scoring using data from the exclamation button mark to define “analysis start” and “analysis stop”; 2) Scoring using actigraphy data (PG+actigraphy): total sleep time defined by the actigraphy data; 3) Scoring using diaries (PG+diary): “analysis start” and “analysis stop” based on the diaries. Bland-Altman plots were generated to assess the agreements (Kappa) between each scoring strategy.

Results

A total of 300 participants were included in the final analysis (45% males, mean age: 48±8 years). The frequency of OSA using the PG score was 27.3%. Despite small differences in the OSA severity index, we obtained a high concordance of AHI comparing the PG vs. PG+actigraphy (Kappa: 0.95) as well as PG+diary vs. PG+actigraphy (Kappa: 0.96). No significant changes in the OSA classification (mild, moderate and severe) were observed in the 3 protocols.

Conclusion

Using a pragmatic approach to address OSA at home, our results suggest that PG is a useful tool for OSA diagnosis even in subjects not referred to sleep studies.