Obstructive sleep apnea, hypertension, and their interaction on arterial stiffness and heart remodeling

Serum Biomarkers after Adenotonsillectomy for Pediatric OSA: A Systematic Review and Meta-Analysis

OBJECTIVE

To assess whether adenotonsillectomy improves levels of inflammatory and cardiometabolic markers in children with polysomnographically diagnosed obstructive sleep apnea (OSA).

DATA SOURCES

Two authors independently searched PubMed, Embase, and Cochrane databases up to August 16, 2022, for studies relating to pre- and post-operative levels of serum markers in pediatric patients undergoing adenotonsillectomy.

REVIEW METHODS

Data were extracted from included articles into a structured proforma. Meta-analyses of the standardized mean difference (SMD) were conducted in random-effects models. We calculated the probability of benefit (POB) and number needed to treat (NNT) for outcomes that demonstrated a statistically significant effect after adenotonsillectomy. The primary outcomes were changes in serum markers including C-reactive protein (CRP), high-sensitivity CRP (hs-CRP), Insulin-like growth factor 1 (IGF-1), interleukin-10 (IL-10), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), Brain natriuretic peptide (BNP), insulin, glucose, total cholesterol, triglyceride, low-density lipoprotein (LDL), high-density lipoprotein (HDL).

RESULTS

We screened 1616 studies and included 26 studies with 1331 participants. Meta-analysis was performed on 20 of the included studies. Adenotonsillectomy was associated with a significant decrease in insulin levels (SMD = -0.322, 95% Confidence Interval (CI) = -0.583 to -0.061), CRP (SMD = -0.946, 95% CI = -1.578 to -0.314), and BNP (SMD = -1.416, 95% CI = -2.355 to -0.477) and significant increase in levels of IGF-1 (SMD = 0.691, 95% CI = 0.207 to 1.176). There were no significant changes in levels of triglyceride, total cholesterol, TNF-α, LDL, HDL, glucose, IL-10, and IL-6.

CONCLUSION

In children with polysomnographically diagnosed OSA, adenotonsillectomy was associated with improvements in serum biomarkers, comprising lower CRP, insulin, and BNP, and higher IGF-1. Laryngoscope, 134:3030-3037, 2024.

Machine learning-based detection of sleep-disordered breathing in hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is often concomitant with sleep-disordered breathing (SDB), which can cause adverse cardiovascular events. Although an appropriate approach to SDB prevents cardiac remodelling, detection of concomitant SDB in patients with HCM remains suboptimal. Thus, we aimed to develop a machine learning-based discriminant model for SDB in HCM.

METHODS

In the present multicentre study, we consecutively registered patients with HCM and performed nocturnal oximetry. The outcome was a high Oxygen Desaturation Index (ODI), defined as 3% ODI >10, which significantly correlated with the presence of moderate or severe SDB. We randomly divided the whole participants into a training set (80%) and a test set (20%). With data from the training set, we developed a random forest discriminant model for high ODI based on clinical parameters. We tested the ability of the discriminant model on the test set and compared it with a previous logistic regression model for distinguishing SDB in patients with HCM.

RESULTS

Among 369 patients with HCM, 228 (61.8%) had high ODI. In the test set, the area under the receiver operating characteristic curve of the discriminant model was 0.86 (95% CI 0.77 to 0.94). The sensitivity was 0.91 (95% CI 0.79 to 0.98) and specificity was 0.68 (95% CI 0.48 to 0.84). When the test set was divided into low-probability and high-probability groups, the high-probability group had a higher prevalence of high ODI than the low-probability group (82.4% vs 17.4%, OR 20.9 (95% CI 5.3 to 105.8), Fisher's exact test p<0.001). The discriminant model significantly outperformed the previous logistic regression model (DeLong test p=0.03).

CONCLUSIONS

Our study serves as the first to develop a machine learning-based discriminant model for the concomitance of SDB in patients with HCM. The discriminant model may facilitate cost-effective screening tests and treatments for SDB in the population with HCM.

Implication of sleep apnea for cardiac remodeling in patients with hypertrophic cardiomyopathy

OBJECTIVES

Cardiac remodeling is a life-long process in hypertrophic cardiomyopathy (HCM), and if uncontrolled, would cause substantial morbidity and mortality. Sleep apnea (SA) is a common comorbidity in HCM. This study aimed to investigate the relationship between SA and cardiac remodeling in a large series of patients with HCM.

METHODS

A total of 606 patients with HCM who underwent sleep evaluations at Fuwai Hospital were included. Parameters of cardiac remodeling were evaluated by echocardiographic studies.

RESULTS

SA was present in 363 (59.9%) patients. Left ventricular (LV) end-diastolic diameter (P < 0.001), left atrial (LA) diameter (P = 0.024), ascending aortic diameter (P < 0.001) all increased and maximal end-diastolic wall thickness (P < 0.001) decreased with the severity of SA. After adjustment for sex, age, body mass index, hypertension, hyperlipidemia, diabetes, coronary artery disease and cigarette use, log (apnea-hypopnea index+1) was independently correlated with increasing LV end-diastolic diameter (β = 0.729, P = 0.003) and deceasing maximal end-diastolic wall thickness (β = -0.503, P = 0.009). Log (percentage of total sleep time spent with oxygen saturation<90% + 1) was independently correlated with increasing LV end-diastolic diameter (β = 0.609, P = 0.004) and LA diameter (β = 0.695, P = 0.006). Severity of SA (severe SA with odds ratio, 2.38; 95% CI, 1.20-4.70; P = 0.013), log (apnea-hypopnea index+1) (OR, 1.28; 95% CI, 1.01-1.63; P = 0.045) and log (percentage of total sleep time spent with oxygen saturation<90% + 1) (OR, 1.31; 95% CI, 1.08-1.59; P = 0.006) were also independently associated with LV enlargement.

CONCLUSIONS

Severity of SA is independently associated with cardiac remodeling indicating a trend toward enlarged chamber size and thinned wall. Clinical trials are required to determine whether treatment of SA improves cardiac remodeling and long-term outcomes in patients with HCM.

The pathogenesis of OSA-related hypertension: what are the determining factors?

Sleep-disordered breathing has a relatively high prevalence, which varies from 3-7% in males and from 2-5% in females in the adult population. Studies published in the literature have shown that sleep apnea is closely related to an increased risk of developing various pathologies, among which arterial hypertension stands out. The prevalence of hypertension in patients suffering from obstructive sleep apnea (OSA) ranges from 35-80% and appears to be related to OSA severity. Approximately 40-50% of patients affected by hypertension are also affected by OSA and this association seems to be stronger in young and middle-aged adults (<50 years of age). The primary objective of this narrative review is to provide an update on what are the main contributing comorbidities to the development of a hypertensive state in patients suffering from OSA, an independent risk factor for diurnal hypertension, implicated as a risk factor for the first stroke, recurrent stroke, and post-stroke mortality. There are a lot of factors that contribute to developing a hypertensive state in OSA patients, some more decisive, others less. More evidence from longitudinal studies is needed on the impact of OSA on cardiovascular risk in females, on the causal link between OSA and arterial hypertension or metabolic diseases, like diabetes and glucose intolerance, and the effect of different kinds of OSA treatment.

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.

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.

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.

Comorbidity Profile and Predictors of Obstructive Sleep Apnea Severity and Mortality in Non-Obese Obstructive Sleep Apnea Patients

Backgrounds and Objectives: Obstructive sleep apnea (OSA) is associated with increased morbidity and mortality. OSA is an independent risk factor for many different conditions, especially cardiovascular diseases. The purpose of this study was to ascertain the comorbidity profile of non-obese patients with newly diagnosed OSA and evaluate the risk for cardiovascular disease and mortality. The present study also aimed to establish predictors for OSA severity. Materials and Methods: This study included 138 newly diagnosed patients who underwent polysomnographic analysis. The 10-year risk for cardiovascular disease was assessed using a newly validated prediction model: Systematic Coronary Risk Evaluation (SCORE-2). In addition, the Charlson Comorbidity Index (CCI) was assessed as a widely-used example of a mortality comorbidity index. Results: The study population included 138 patients: 86 males and 52 females. Patients were stratified, according to AHI (apnea/hypopnea index), into four groups: 33 patients had mild OSA (5 ≤ AHI < 15), 33 patients had moderate OSA (15 ≤ AHI < 30), 31 patients had severe OSA (AHI ≥ 30), and 41 individuals had AHI < 5, which were a part of the control group. SCORE-2 increased in line with OSA severity and was higher in OSA groups compared to the control group (H = 29.913; DF = 3; p < 0.001). Charlson Index was significantly higher in OSA patients compared to controls (p = 0.001), with a higher prevalence of total comorbidities in the OSA group of patients. Furthermore, CCI 10-year survival score was significantly lower in the OSA group, suggesting a shorter survival of those patients with a more severe form of OSA. We also examined the prediction model for OSA severity. Conclusions: Determining the comorbidity profile and estimation of the 10-year risk score of OSA patients could be used to classify these patients into various mortality risk categories and, according to that, provide them with adequate treatment.

Effect of continuous positive airway pressure on atrial remodeling and diastolic dysfunction of patients with obstructive sleep apnea and metabolic syndrome: a randomized study

OBJECTIVE

The aim of this study was to evaluate the role of obstructive sleep apnea (OSA) treatment on heart remodeling and diastolic dysfunction in patients with metabolic syndrome (MS).

METHODS

This study is a prespecified analysis of a randomized placebo-controlled trial that enrolled patients with a recent diagnosis of MS and moderate-to-severe OSA to undergo continuous positive airway pressure (CPAP) or nasal dilators (placebo) for 6 months. Patients were invited to perform a transthoracic echocardiogram by a single investigator blinded to treatment assignment.

RESULTS

A total of 99 (79% men; mean [SD], age: 48 [9] years; BMI: 33 [4] kg/m² ) completed the study. At follow-up, in the placebo group, patients had a significant increase in atrial diameter: from 39.5 (37.0-43.0) mm to 40.5 (39.0-44.8) mm (p = 0.003). CPAP prevented atrial enlargement: from 40.0 (38.0-44.0) to 40.0 (39.0-45.0) mm (p = 0.194). In patients with diastolic dysfunction at baseline, almost half had diastolic dysfunction reversibility with CPAP (in comparison with only two patients in the placebo group, p = 0.039). In the regression analysis, the chance of diastolic dysfunction reversibility by CPAP was 6.8-fold (95% CI: 1.48-50.26, p = 0.025) compared with placebo.

CONCLUSIONS

In patients with MS and OSA, 6 months of CPAP therapy prevented atrial remodeling and increased the chance of diastolic dysfunction reversibility.

The Metabolic Score for Insulin Resistance (METS-IR) Predicts Cardiovascular Disease and Its Subtypes in Patients with Hypertension and Obstructive Sleep Apnea

Objective

We aimed to evaluate the METS-IR (metabolic score for insulin resistance) index for the prediction of incident cardiovascular disease (CVD) and its subtypes (coronary artery disease and stroke) in patients with hypertension and obstructive sleep apnea (OSA).

Methods

A retrospective cohort study was conducted with 2031 adults with hypertension and OSA, participants from the Urumqi Research on Sleep Apnea and Hypertension study (UROSAH). The hazard ratios and 95% CIs (credibility interval) for CVD and its subtypes were estimated using multivariate Cox proportional hazards regression models.

Results

After a median follow-up of 6.80 years (interquartile range: 5.90-8.00 years), a total of 317 (15.61%) participants developed new-onset CVD, including 198 (9.75%) incident coronary heart disease (CHD) and 119 (5.86%) incident stroke. After adjusting for as many relevant confounding factors as possible, each SD increase in METS-IR was associated with a 30% increased risk of new onset overall CVD events, a 32% increased risk of new onset CHD, and a 27% increased risk of new onset stroke. When METS-IR was assessed as tertiles, after adjustment for fully confounding factors, the highest tertiles versus the lowest tertiles were associated with a greater hazard of CVD (HR 2.05; 95% CI 1.52,-2.77), CHD (HR 1.96; 95% CI 1.35-2.84), and stroke (HR 2.24; 95% CI 1.35-3.72). The results of various subgroups and sensitivity analyses were similar. When METS-IR was added, CVD predictions were reclassified and identified more accurately than baseline models for the C-index, continuous net reclassification improvement, and integrated discrimination index. CHD and stroke showed similar results.

Conclusion

METS-IR is a powerful predictor of CVD and its subtypes in patients with hypertension and OSA, which can facilitate the identification of high-risk individuals and provide individualized CVD prevention.

Echocardiographic parameters in French Bulldogs, Pugs and Boston Terriers with brachycephalic obstructive airways syndrome

BACKGROUND

In this prospective study, we hypothesized that dogs with signs of brachycephalic obstructive airway syndrome (BOAS) would show differences in left and right heart echocardiographic parameters compared with brachycephalic dogs without signs of BOAS and non-brachycephalic dogs.

RESULTS

We included 57 brachycephalic (30 French Bulldogs 15 Pugs, and 12 Boston Terriers) and 10 non-brachycephalic control dogs. Brachycephalic dogs had significantly higher ratios of the left atrium to aorta and mitral early wave velocity to early diastolic septal annular velocity; smaller left ventricular (LV) diastolic internal diameter index; and lower tricuspid annular plane systolic excursion index, late diastolic annular velocity of the LV free wall, peak systolic septal annular velocity, late diastolic septal annular velocitiy, and right ventricular global strain than non-brachycephalic dogs. French Bulldogs with signs of BOAS had a smaller diameter of the left atrium index and right ventricular systolic area index; higher caudal vena cava at inspiration index; and lower caudal vena cava collapsibility index, late diastolic annular velocity of the LV free wall, and peak systolic annular velocity of the interventricular septum than non-brachycephalic dogs.

CONCLUSIONS

The differences in echocardiographic parameters between brachycephalic and non-brachycephalic dogs, brachycephalic dogs with signs of BOAS and non-brachycephalic dogs, and brachycephalic dogs with and without signs of BOAS indicate higher right heart diastolic pressures affecting right heart function in brachycephalic dogs and those with signs of BOAS. Most changes in cardiac morphology and function can be attributed to anatomic changes in brachycephalic dogs alone and not to the symptomatic stage.

Association of obstructive sleep apnea with endothelial function and heart remodeling in hypertension: A cross-sectional study

BACKGROUND

This study aims to analyze the association of obstructive sleep apnea (OSA) with endothelial function and heart structure in patients with hypertension and lay a clinical foundation for preventing and treating endothelial dysfunction and heart remodeling in patients with hypertension.

METHODS

A cross-sectional study design was adopted in this study. From April 2020 to April 2021, 143 patients with hypertension were included and classified into two groups according to the severity of OSA: 81 patients with hypertension without OSA [apnea-hypopnea index (AHI) < 5 events/hour] serving as the control group; 62 patients with hypertension with moderate-severe OSA (AHI ≥ 15 events/hour) serving as the OSA group. The endothelial function and heart structure were assessed by flow-mediated vasodilation (FMD) and transthoracic echocardiography. Logistic regression analyses were conducted to identify factors associated with endothelial dysfunction and heart remodeling.

RESULTS

Compared with the control group, patients with OSA had significantly greater interventricular septal thickness (IVST) and left ventricular posterior wall thickness (LVPWT) (P < 0.05), and FMD exhibited a significant decrease (P < 0.05). Logistic regression analyses demonstrated that gender and AHI were associated with FMD (P < 0.05), and FMD was associated with LVMI (P < 0.05).

CONCLUSIONS

OSA was associated with endothelial dysfunction and heart remodeling in patients with hypertension. Endothelial dysfunction may be crucial for the development of heart remodeling in patients with hypertension with OSA.

Impact of obstructive sleep apnea on platelet activation and development of silent brain infarctions

Background

Obstructive sleep apnea (OSA) is a unique potent predictor for stroke compared to other predictors. By aiding in the adherence of leukocytes and platelets, soluble P-selectin (sP-selectin) contributes to the development of ischemic stroke. The objective of this study was to investigate the independent impact of OSA on platelet activation and development of silent brain infarction. Twenty-four OSA patients and 24 controls were studied in a case–control study, who underwent one-night polysomnography, magnetic resonance imaging for evaluation of silent brain infarctions (SBI), measurement of serum (sP-selectin) levels for assessment of increased platelet activation and C-reactive protein (CRP) serum levels.

Results

Out of 24 patients, 5 (20.8%) had mild OSA and 8 (33.3%) had moderate and 11 (45.8%) had severe OSA. Serum levels of sP-selectin were statistically significantly higher in moderate and severe groups (p < 0.001). Eleven (57.9%) patients in moderate and severe OSA had SBI. Fifty percent of patients with moderate OSA had elevated serum sP-selectin and 25.0% of them had SBI and 81.8% of severe OSA patients had elevated serum sP-selectin and 81.8% of them had SBI. Patients with mild OSA and controls had no SBI and normal serum sP-selectin level. CRP was statistically significantly higher in moderate and severe OSA groups (16.6% and 45.8%) than the mild and control groups (4.1% and 0%) (p < 0.001).

Conclusion

Moderate and severe obstructive sleep apnea were associated independently with elevated serum sP-selectin reflecting increased platelet function, elevated inflammatory marker CRP and an increased risk of silent brain infarctions.

Sleep-disordered breathing in high-risk pregnancies is associated with elevated arterial stiffness and increased risk for preeclampsia

BACKGROUND

Impaired vascular function is a central feature of pathologic processes preceding the onset of preeclampsia. Arterial stiffness, a composite indicator of vascular health and an important vascular biomarker, has been found to be increased throughout pregnancy in those who develop preeclampsia and at the time of preeclampsia diagnosis. Although sleep-disordered breathing in pregnancy has been associated with increased risk for preeclampsia, it is unknown if sleep-disordered breathing is associated with elevated arterial stiffness in pregnancy.

OBJECTIVE

This prospective observational cohort study aimed to evaluate arterial stiffness in pregnant women, with and without sleep-disordered breathing and assess the interaction between arterial stiffness, sleep-disordered breathing, and preeclampsia risk.

STUDY DESIGN

Women with high-risk singleton pregnancies were enrolled at 10 to 13 weeks' gestation and completed the Epworth Sleepiness Score, Pittsburgh Sleep Quality Index, and Restless Legs Syndrome questionnaires at each trimester. Sleep-disordered breathing was defined as loud snoring or witnessed apneas (≥3 times per week). Central arterial stiffness (carotid-femoral pulse wave velocity, the gold standard measure of arterial stiffness), peripheral arterial stiffness (carotid-radial pulse wave velocity), wave reflection (augmentation index, time to wave reflection), and hemodynamics (central blood pressures, pulse pressure amplification) were assessed noninvasively using applanation tonometry at recruitment and every 4 weeks from recruitment until delivery.

RESULTS

High-risk pregnant women (n=181) were included in the study. Women with sleep-disordered breathing (n=41; 23%) had increased carotid-femoral pulse wave velocity throughout gestation independent of blood pressure and body mass index (P=.042). Differences observed in other vascular measures were not maintained after adjustment for confounders. Excessive daytime sleepiness, defined by Epworth Sleepiness Score >10, was associated with increased carotid-femoral pulse wave velocity only in women with sleep-disordered breathing (P_interaction=.001). Midgestation (first or second trimester) sleep-disordered breathing was associated with an odds ratio of 3.4 (0.9-12.9) for preeclampsia, which increased to 5.7 (1.1-26.0) in women with sleep-disordered breathing and hypersomnolence, whereas late (third-trimester) sleep-disordered breathing was associated with an odds ratio of 8.2 (1.5-39.5) for preeclampsia.

CONCLUSION

High-risk pregnant women with midgestational sleep-disordered breathing had greater arterial stiffness throughout gestation than those without. Sleep-disordered breathing at any time during pregnancy was also associated with increased preeclampsia risk, and this effect was amplified by hypersomnolence.

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

INTRODUCTION

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

AREA COVERED

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

EXPERT COMMENTARY

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

The impact of the Adenotonsillectomy on cardiac functions and oxidative stress

OBJECTIVE

Obstructive sleep apnea syndrome (OSAS) causes cardiovascular comorbidities and increased oxidative stress. Adenotonsillectomy is the first treatment option for OSAS secondary to adenotonsillar hypertrophy (ATH). This study evaluated the presence of cardiovascular changes, hypertension and oxidative stress before and after adenotonsillectomy in patients with OSAS secondary to ATH.

METHODS

Patients with ATH diagnosed with OSAS by polysomnography (PSG) were included. All participants received an Echocardiography (ECHO) and 24-h ambulatory blood pressure measurement (ABPM). Serum malonyldialdehyde (MDA) and total oxidant activity (TOS) levels of oxidant parameters; total antioxidant activity (TAS), catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH) levels of antioxidant parameters were measured. All patients received an adenotonsillectomy. Postoperative evaluation was performed at the 6th month. In the postoperative period, PSG, ECHO, ABPM and the oxidant-antioxidant parameter levels in the serum was repeated.

RESULTS

Twenty-eight patients (13 males, 15 females; mean age 8.2 ± 2.06 years) were included in the study. In the preoperative period, concentric remodeling was observed in 14,8% of the patients, although they had no cardiovascular system complaints. The apnea-hypopnea index (AHI) scores were classified as mild in 39.3% (n = 11), moderate in 21.4% (n = 6) and severe in 39.3% (n = 11) preoperatively. In the postoperative period, 22 patients were evaluated. It was observed that the severity of OSAS decreased, ventricular functions improved, oxidant parameters decreased and antioxidant parameters increased postoperatively.

CONCLUSION

Adenotonsillectomy provides a positive change in cardiovascular system parameters and an antioxidant change in the oxidative balance in patients with OSAS.

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

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

Obstructive sleep apnea and cardiovascular comorbidity: common pathophysiological mechanisms to cardiovascular disease

Obstructive sleep apnea (OSA) is associated with many cardiovascular and metabolic diseases. Sleep apnea causes intermittent hypoxemia, chest pressure fluctuations and a reaction from the cerebral cortex in the form of a short awakening during sleep (EEG-activation). The consequences of pathological pathways are studied in experimental models involving cell cultures, animals, and healthy volunteers. At present, the negative impact of intermittent hypoxemia on a variety of pathophysiological disorders of the heart and blood vessels (vascular tone fluctuations, thickening of the intimamedia complex in the vascular wall, direct damaging effect on the myocardium) has a great evidence base. Two other pathological components of OSA (pressure fluctuations and EEG-activation) can also affect cardiovascular system, mainly affecting the increase in blood pressure and changing cardiac hemodynamics. Although these reactions are considered separately in the review, with the development of sleep apnea they occur sequentially and are closely interrelated. As a result, these pathological pathways trigger further pathophysiological mechanisms acting on the heart and blood vessels. It is known that these include excessive sympathetic activation, inflammation, oxidative stress and metabolic dysregulation. In many respects being links of one process, these mechanisms can trigger damage to the vascular wall, contributing to the formation of atherosclerotic lesions. The accumulated data with varying degrees of reliability confirm the participation of OSA through these processes in the formation of cardiovascular disorders. There are factors limiting direct evidence of this interaction (sleep deprivation, causing similar changes, as well as the inability to share the contribution of other risk factors for cardiovascular diseases, in particular arterial hypertension, obesity, which are often associated with OSA). It is necessary to continue the study of processes that implement the pathological effect of OSA on the cardiovascular system.

Obstructive Sleep Apnea and Cardiac Arrhythmias: A Contemporary Review

Obstructive sleep apnea (OSA) is a highly prevalent disorder with a growing incidence worldwide that closely mirrors the global obesity epidemic. OSA is associated with enormous healthcare costs in addition to significant morbidity and mortality. Much of the morbidity and mortality related to OSA can be attributed to an increased burden of cardiovascular disease, including cardiac rhythm disorders. Awareness of the relationship between OSA and rhythm disorders is variable among physicians, a fact that can influence patient care, since the presence of OSA can influence the incidence, prevalence, and successful treatment of multiple rhythm disorders. Herein, we provide a review of this topic that is intentionally broad in scope, covering the relationship between OSA and rhythm disorders from epidemiology and pathophysiology to diagnosis and management, with a particular focus on the recognition of undiagnosed OSA in the general clinical population and the intimate relationship between OSA and atrial fibrillation.

Integrating the precision, sleep, and aerospace medicine fields: a systematic review of the genetic predisposition for obstructive sleep apnea in military aviation

PURPOSE

Obstructive sleep apnea (OSA) is the most common pathologic sleep disorder with an estimated prevalence in the USA of up to 25% of adult males. With military aviation being heavily comprised of adult men, the impact of OSA on flying operations is concerning as OSA is disqualifying for all flying classes in the US Air Force. In order to minimize the impact of OSA on operations, early identification of at-risk patients is critical in disease management. Individuals could be identified for whom regular polysomnography testing may reveal OSA while mild or sub-clinical, at which point treatment may be initiated in order to promote continued medical qualification for duty and career retention.

METHODS

We performed a keyword search of PubMed, EMBASE, and Google Scholar along with searches in the NHGRI/EBI GWAS Catalogue and the Atlas of GWAS Summary Statistics. We included primary research from candidate gene, GWAS, and meta-analyses. We also included other review articles in our search to confirm interpretations and implications of any genetic associations with OSA. Only studies related to OSA susceptibility or risk were included.

RESULTS

We identified 134 publications reporting or reviewing genetic associations with OSA risk. These papers reported 301 variants, of which 195 were unique and 33 were replicated in at least two papers. With respect to the strength of association, 43 variants exhibited odds ratios greater than 2. Finally, there were 84 null results reported, 51 of which were in conflict with reported associations.

CONCLUSION

There is ample evidence in the literature to confirm that genetics provide an important contribution to OSA development. The high number of strongly associated variants suggests that a polygenic risk model could be created with high predictive value for prognostic screening.

Beat-to-beat blood pressure variability in patients with obstructive sleep apnea

STUDY OBJECTIVES

Cardiovascular comorbidities in obstructive sleep apnea (OSA) are difficult to treat, perhaps due to autonomic dysfunction. We assessed beat-to-beat blood pressure (BP) variability (BPV) in OSA while considering other markers derived from electrocardiogram and continuous BP signals.

METHODS

We studied 66 participants (33 participants with OSA: respiratory event index [mean ± SEM]: 21.1 ± 2.7 events/h; 12 females, aged 51.5 ± 2.4 years; body mass index: 32.8 ± 1.4 kg/m²; 33 healthy controls: 20 females; aged 45.3 ± 2.4 years; body mass index: 26.3 ± 0.7 kg/m²). We collected 5-minute resting noninvasive beat-to-beat BP and electrocardiogram values. From BP, we derived systolic, diastolic, and mean BP values, and calculated variability as standard deviations (systolic BPV, diastolic BPV, BPV). We also calculated diastole-to-systole time (time to peak). From the electrocardiogram, we derived QRS markers and calculated heart rate and heart rate variability. We performed a multivariate analysis of variance based on sex and group (OSA vs control), with Bonferroni-corrected post hoc comparisons (P ≤ .05) between groups. We calculated correlations of BPV with biological variables.

RESULTS

Multivariate analysis of variance showed effects of diastolic BPV and BPV in OSA; post hoc comparisons revealed high diastolic BPV and BPV only in female participants with OSA vs controls. QRS duration was higher in OSA, with post hoc comparisons showing the effect only in males. BPV correlated positively with heart rate variability in controls but not in participants with OSA. BPV correlated positively with time to peak in females with OSA and OSA combined, whereas there was no BPV-time-to-peak correlation in healthy participants.

CONCLUSIONS

The findings show sex-specific autonomic dysfunction reflected in beat-to-beat BP in OSA. The higher BPV may reflect poor baroreflex control or vascular damage in OSA, which are potential precursors to cardiovascular complications.

Association of arterial stiffness with left atrial structure and phasic function: a community-based cohort study

OBJECTIVES

Increased arterial stiffness is currently recognized as an independent risk factor for atrial fibrillation, although the pathophysiological mechanisms remain unclear. This study aimed to investigate the association of arterial stiffness with left atrial (LA) volume and phasic function in a community-based cohort.

METHODS

We included 1156 participants without overt cardiovascular disease who underwent extensive cardiovascular examination. Arterial stiffness was evaluated by cardio-ankle vascular index (CAVI). Speckle-tracking echocardiography was employed to evaluate LA phasic function including reservoir, conduit, and pump strain as well as left ventricular global longitudinal strain (LVGLS).

RESULTS

CAVI was negatively correlated with reservoir and conduit strain (r = -0.37 and -0.45, both P < 0.001), whereas weakly, but positively correlated with LA volume index and pump strain (r = 0.12 and 0.09, both P < 0.01). In multivariable analysis, CAVI was significantly associated with reservoir and conduit strain independent of traditional cardiovascular risk factors and LV morphology and function including LVGLS (standardized β = -0.22 and -0.27, respectively, both P < 0.001), whereas there was no independent association with LA volume index and pump strain. In the categorical analysis, the abnormal CAVI (≥9.0) carried the significant risk of impaired reservoir and conduit strain (adjusted odds ratio = 2.61 and 3.73 vs. normal CAVI, both P < 0.01) in a fully adjusted model including laboratory and echocardiographic parameters.

CONCLUSION

Arterial stiffness was independently associated with LA phasic function, even in the absence of overt cardiovascular disease, which may explain the higher incidence of atrial fibrillation in individuals with increased arterial stiffness.

Circulating Levels of the Heparan Sulfate Proteoglycan Syndecan-4 Positively Associate with Blood Pressure in Healthy Premenopausal Women

Syndecans (SDCs) are transmembrane proteins that are present on most cell types where they play a role in multiple physiological processes, including cell-matrix adhesion and inflammation. Growing evidence suggests that elevated levels of both shed SDC1 and SDC4 are associated with hypertension and cardiovascular diseases, but their relationships with cardiovascular risk factors in healthy individuals are unknown. The primary objective of this study was to investigate whether serum levels of SDC4 and SDC1 were associated with body composition, hemodynamic parameters, pro-inflammatory cytokine concentrations, and urinary noradrenaline and dopamine levels in healthy women (17 African American and 20 European American) between the ages of 20 and 40 years old. Univariate analyses revealed only a significant (p < 0.05) inverse correlation between serum SDC1 and body fat percentage. On the other hand, serum SDC4 was positively correlated with systolic blood pressure, diastolic blood pressure, and urinary levels of noradrenaline and dopamine. Serum SDC4 was also a significant predictor of systolic blood pressure in a multivariate regression model that included fat-free mass and urinary dopamine levels as significant independent variables. The result did not change even adjusting for race. Our findings indicate that SDC4 has an important role in the physiological regulation of blood pressure.

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.

Recent Advances in Studies on the Role of Neuroendocrine Disorders in Obstructive Sleep Apnea-Hypopnea Syndrome-Related Atherosclerosis

Cardiovascular disease is a common cause of death worldwide, and atherosclerosis (AS) and obstructive sleep apnea-hypopnea syndrome (OSAHS) critically contribute to the initiation and progression of cardiovascular diseases. OSAHS promotes endothelial injury, vascular smooth muscle cell (VSMC) proliferation, abnormal lipid metabolism, and elevated arterial blood pressure. However, the exact OSAHS mechanism that causes AS remains unclear. The nervous system is widely distributed in the central and peripheral regions. It regulates appetite, energy metabolism, inflammation, oxidative stress, insulin resistance, and vasoconstriction by releasing regulatory factors and participates in the occurrence and development of AS. Studies showed that OSAHS can cause changes in neurophysiological plasticity and affect modulator release, suggesting that neuroendocrine dysfunction may be related to the OSAHS mechanism causing AS. In this article, we review the possible mechanisms of neuroendocrine disorders in the pathogenesis of OSAHS-induced AS and provide a new basis for further research on the development of corresponding effective intervention strategies.

Targeting subclinical organ damage in obstructive sleep apnea: a narrative review

Subclinical abnormalities in cardiac and vascular structure reflect the adverse effects triggered by a variety of risk factors on the cardiovascular (CV) system thereby representing an intermediate step in the cardiovascular continuum; such alterations are recognized as reliable markers of increased cardiovascular risk in different clinical settings including obstructive sleep apnea (OSA). The mechanisms underlying subclinical organ damage (OD) in the OSA setting are multifactorial. Hypoxemia and hypercapnia, induced by repeated collapses of upper airways, have been suggested to trigger a cascade of events such as activation of the sympathetic tone, renin-angiotensin-aldosterone system leading to endothelial dysfunction, vasoconstriction, myocardial and vascular remodeling, and hypertension. Furthermore, coexisting non-haemodynamic alterations such as increased oxidative stress, release of inflammatory substances, enhanced lipolysis and insulin resistance have been reported to play a role in the pathogenesis of both cardiac and extra-cardiac OD. In this article we reviewed available evidence on the association between OSA and subclinical cardiac (i.e., left and right ventricular hypertrophy, left atrial dilatation) and extra-cardiac organ damage (i.e., carotid atherosclerosis, arterial stiffness, microvascular retinal changes, and microalbuminuria). This association is apparently stronger for cardiac and carotid subclinical damage than for other markers (i.e., arterial stiffness and retinal changes) and mostly evident in the setting of severe OSA.

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.

Impact of CPAP on arterial stiffness in patients with obstructive sleep apnea: a meta-analysis of randomized trials

PURPOSE

This study aimed to perform a systematic review and meta-analysis of randomized trials investigating the effect of continuous positive airway pressure (CPAP) on non-invasive markers of arterial stiffness in patients with OSA.

METHODS

The purpose of the study was to evaluate the effect of CPAP on markers of arterial stiffness (pulse wave velocity (PWV) and augmentation index (Aix)) in patients with OSA. The study adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We systematically reviewed MEDLINE, EMBASE, CENTRAL/CCTR, SciELO, and LILACS databases for randomized trials (RT) evaluating the changes in markers of arterial stiffness (pulse wave velocity (PWV) and augmentation index (Aix) comparing CPAP vs. controls in patients with OSA. Reviewer Manager version 5.3 (R Foundation for Statistical Computing, Vienna, Austria) was used to perform meta-analysis. Risk of bias analysis was performed using the Cochrane tool.

RESULTS

Of the 464 studies initially retrieved, 9 relevant studies with 685 participants were included in the analysis. The studies presented moderate risk of bias. CPAP did not significantly reduce Aix (mean difference, - 1.96 (95% confidence interval (CI) - 5.25 to 1.33), p = 0.24), whereas it significantly changed PWV (mean difference, - 0.44 (95% confidence interval (CI) - 0.76 to - 0.12), p = 0.00).

CONCLUSION

CPAP treatment was effective in improving arterial stiffness by reducing PWV in patients with OSA. Additional randomized trials, however, should be performed to confirm these findings.

Evaluation of late atrial enhancement by cardiac magnetic resonance imaging in patients with obstructive sleep apnea

INTRODUCTION

Atrial fibrillation (AF) is a growing public health problem especially due to its association with thromboembolic phenomena. Among its risk factors, obstructive sleep apnea (OSA) has increased in incidence and is often under diagnosed. OSA increases the risk of AF by mechanisms not fully known, but it may lead to remodeling and structural alteration of the atria. Cardiac magnetic resonance (CMR), in addition to assessing heart morphology, allows the identification of areas of fibrosis, including the atrium, by the late gadolinium enhancement technique (LGE) and could identify cases of OSA with potential atrial instability.

OBJECTIVE

To evaluate the relationship of LGE atrial by CMR in patients with atrial fibrillation with OSA.

METHODS

We selected 81 patients who were divided into four groups: Group 1: 20 OSA patients without AF, Group 2: 20 OSA and AF patients, Group 3: 21 patients with only atrial fibrillation without OSA and Group 4: 20 healthy patients without associated comorbidities. All underwent CMR for morphofunctional evaluation and LGE research.

RESULTS

The average age was 57.1+-10.59 years. Clinical variables such as hypertension (p = 0.24) and Diabetes Mellitus (p = 0.20) were not predictors of AF in OSA patients. Of the 40 cases with OSA, 18, 45% had severe obstructive disorder, and in this group AF was more prevalent. The mean left ventricular ejection fraction was 62.9% (+-7.46) and it did not differ between groups (p = 0.2). Patients with concomitant OSA and AF had significantly larger left atria (p < 0.001). Cases of OSA with AF showed significantly more atrial LGE (95% vs. 30%, p < 0.001), being an independent predictor in multivariate analysis (P < 0,001).

CONCLUSION

Atrial LGE is independently associated with the presence of AF in patients with OSA. These elements may help to identify cases of higher risk for developing AF in OSA patients in clinical practice.

Long-term variations of arterial stiffness in patients with obesity and obstructive sleep apnea treated with continuous positive airway pressure

BACKGROUND

Obstructive sleep apnea (OSA) is associated with cardiovascular co-morbidities and mortality. Arterial stiffness is an independent predictor of cardiovascular risk and mortality, and is influenced by the presence of OSA and related comorbidities. There is a paucity of data regarding long-term evolution of arterial stiffness in CPAP-treated OSA patients. We aimed to prospectively study long term PWV variations and determinants of PWV deterioration.

METHODS

In a prospective obese OSA cohort, at time of diagnosis and after several years of follow-up we collected arterial stiffness measured by carotid-femoral pulse wave velocity (PWV), clinical and metabolic parameters, and CPAP adherence. Univariate and multivariate analyses were performed in order to determine contributing factors.

RESULTS

Seventy two OSA patients (men: 52.8%, median age: 55.8 years and median BMI of 38.5 kg/m2) with a prevalence of hypertension: 58.3%, type 2 diabetes: 20.8%, hypercholesterolemia: 33.3%, current or past smoking: 59.7%, were evaluated after a median follow-up of 7.4 [5.8; 8.3] years. Over the period of follow-up, the median increase in PWV was 1.34 [0.10; 2.37] m/s. In multivariate analysis, the increase in PWV was associated with older age (10 extra years was associated with a 5.24 [1.35; 9.12] % increase in PWV) and hypertension (a significant increase in PWV of 8.24 [1.02; 15.57] %). No impact of CPAP adherence on PWV evolution was found.

CONCLUSION

PWV progression in CPAP-treated OSA patients is mainly related to pre-existing cardio-metabolic comorbidities and not influenced by CPAP adherence. In this high cardiovascular risk population, it is crucial to associated weight management and exercise with CPAP treatment.

Implication of Apnea-Hypopnea Index, a Measure of Obstructive Sleep Apnea Severity, for Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy

Background

Obstructive sleep apnea (OSA) is common and independently associated with atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM). This study aimed to investigate the relationship between apnea‐hypopnea index (AHI), a measure of OSA severity, and prevalence of AF in a large series of patients with HCM.

Methods and Results

A total of 555 patients with HCM who underwent sleep evaluations were retrospectively included. Data from polysomnography studies, echocardiography, and baseline clinical characteristics were collected. OSA was present in 327 patients (58.9%). Patients with OSA or higher AHI quartiles were older, more often male, had a higher body mass index, and more clinical comorbidities. The prevalence of AF increased in patients with OSA (23.9% versus 13.6%, P=0.003) or across AHI quartiles (9.4%, 17.3%, 26.6%, and 25.2%, respectively; P for trend <0.001). After adjustment for age, sex, body mass index, New York Heart Association class, left atrial diameter, hypertension, oxygen desaturation index, and obstructive HCM, highest AHI quartile (odds ratio, 4.42; 95% CI, 1.35–14.52 [P=0.014]) or moderate to severe OSA (odds ratio, 3.03; 95% CI, 1.28–7.20 [P=0.012]) but not presence of OSA (odds ratio, 1.58; 95% CI, 0.84–2.97 [P=0.153]) were significantly associated with AF. Higher AHI levels were also factors associated with persistent or permanent AF (highest AHI quartile with odds ratio, 10.96; 95% CI, 1.07–111.85).

Conclusions

Severity of AHI level is independently associated with AF in patients with HCM. Clinical trials are required to determine the benefits of OSA treatment on AF in patients with HCM.

Potential Role of mRNAs and LncRNAs in Chronic Intermittent Hypoxia Exposure-Aggravated Atherosclerosis

Atherosclerosis is the pathological basis of cardiovascular disease. Obstructive sleep apnea (OSA) aggravates atherosclerosis, and chronic intermittent hypoxia (CIH) as a prominent feature of OSA plays an important role during the process of atherosclerosis. The mechanisms of CIH in the development of atherosclerosis remain unclear. In the current study, we used microarray to investigate differentially expressed mRNAs and long non-coding RNAs (lncRNAs) in aorta from five groups of ApoE^–/– mice fed with a high-fat diet and exposed to various conditions: normoxia for 8 weeks, CIH for 8 weeks, normoxia for 12 weeks, CIH for 12 weeks, or CIH for 8 weeks followed by normoxia for 4 weeks. Selected transcripts were validated in aorta tissues and RT-qPCR analysis showed correlation with the microarray data. Gene Ontology analysis and pathway enrichment analysis were performed to explore the mRNA function. Bioinformatic analysis indicated that short-term CIH induced up-regulated mRNAs involved in inflammatory response. Pathway enrichment analysis of lncRNA co-localized mRNAs and lncRNA co-expressed mRNAs were performed to explore lncRNA functions. The up-regulated mRNAs, lncRNA co-localized mRNAs and lncRNA co-expressed mRNAs were significantly associated with protein processing in endoplasmic reticulum pathway in atherosclerotic vascular tissue with long-term CIH exposure, suggesting that differentially expressed mRNAs and lncRNAs play important roles in this pathway. Moreover, a mRNA-lncRNA co-expression network with 380 lncRNAs, 508 mRNAs and 3238 relationships was constructed based on the correlation analysis between the differentially expressed mRNAs and lncRNAs. In summary, our study provided a systematic perspective on the potential function of mRNAs and lncRNAs in CIH-aggravated atherosclerosis, and may provide novel molecular candidates for future investigation on atherosclerosis exposed to CIH.

Sleep Disordered Breathing in Hypertrophic Cardiomyopathy-Current State and Future Directions

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy and sleep disordered breathing (SDB) is a treatable risk factor that has been seen to occur concurrently, and is known to propagate mortality and morbidity in a number of cardiovascular disease states including heart failure, and indeed hypertrophic cardiomyopathy. In this review, we summarize past studies that explored the simultaneous occurrence of HCM and SDB, and the pathophysiology of SDB in relation to heart failure, arrhythmias, cardiac ischemia and pulmonary hypertension in HCM. The current therapeutic modalities, with the effect of obstructive sleep apnea (OSA) treatment on HCM, are then discussed along with potential future directions.

The Effects of Eplerenone on the Circadian Blood Pressure Pattern and Left Ventricular Hypertrophy in Patients with Obstructive Sleep Apnea and Resistant Hypertension-A Randomized, Controlled Trial

The obstructive sleep apnea (OSA) is highly associated with various significant cardiovascular outcomes such as resistant hypertension (RAH). Despite this, as of now the relationship between high night-time blood pressure (BP) and left ventricular hypertrophy (LVH) in patients with OSA and RAH is not fully understood. The aim of this study was to assess the influence of the addition of eplerenone to a standard antihypertensive therapy on parameters of 24-h ambulatory blood pressure measurement (ABPM) as well as on the results of echocardiography and polysomnography in patients with OSA and RAH. The patients were randomly assigned to one of the two study groups: the treatment group, receiving 50 mg/d eplerenone orally for 6 months (n = 51) and the control group, remaining on their standard antihypertensive therapy (n = 51). After that period, a significant reduction in the night-time BP parameters in the treatment group including an increased night blood pressure fall from 4.6 to 8.9% was noted. Additionally, the number of non-dipper patients was reduced by 45.1%. The treatment group also revealed a decrease in left ventricular hypertrophy and in the apnea-hypopnea index (AHI) with a positive correlation being observed between these two parameters. This study is the first to report the improvement of the circadian BP profile and the improvement of the left ventricle geometry in patients with OSA and RAH following the addition of selective mineralocorticoid receptor antagonists to antihypertensive therapy.

Sleep Apnea and Cardiovascular Disease: An Enigmatic Risk Factor

Synchronization of molecular, metabolic, and cardiovascular circadian oscillations is fundamental to human health. Sleep-disordered breathing, which disrupts such temporal congruence, elicits hemodynamic, autonomic, chemical, and inflammatory disturbances with acute and long-term consequences for heart, brain, and circulatory and metabolic function. Sleep apnea afflicts a substantial proportion of adult men and women but is more prevalent in those with established cardiovascular diseases and especially fluid-retaining states. Despite the experimental, epidemiological, observational, and interventional evidence assembled in support of these concepts, this substantial body of work has had relatively modest pragmatic impact, thus far, on the discipline of cardiology. Contemporary estimates of cardiovascular risk still are derived typically from data acquired during wakefulness. The impact of sleep-related breathing disorders rarely is entered into such calculations or integrated into diagnostic disease-specific algorithms or therapeutic recommendations. Reasons for this include absence of apnea-related symptoms in most with cardiovascular disease, impediments to efficient diagnosis at the population level, debate as to target, suboptimal therapies, difficulties mounting large randomized trials of sleep-specific interventions, and the challenging results of those few prospective cardiovascular outcome trials that have been completed and reported. The objectives of this review are to delineate the bidirectional interrelationship between sleep-disordered breathing and cardiovascular disease, consider the findings and implications of observational and randomized trials of treatment, frame the current state of clinical equipoise, identify principal current controversies and potential paths to their resolution, and anticipate future directions.

Cross-Sectional Study of Arterial Stiffness in Adolescents with Down Syndrome

OBJECTIVES

To test whether youth with Down syndrome have aortic stiffness indices, as measured by pulse wave velocity (PWV), that differ from youth without Down syndrome and to compare reference-based age-adjusted (age-PWV-Z) and height-adjusted (Ht-PWV-Z) in youth with and without Down syndrome.

STUDY DESIGN

Cross-sectional study of PWV in 129 adolescents with Down syndrome and 97 youth of comparable age, sex, race/ethnicity, and body mass index (BMI). PWV, age-PWV-Z, and Ht-PWV-Z were compared. Regression models were developed to test for associations with PWV.

RESULTS

Youth with Down syndrome and controls were comparable in BMI-Z (1.4 [-1.5 to 2.8] vs 1.2 [-2.0 to 2.8], P = .57) but not Ht-Z (-2.3 [-4.7 to 0.8] vs 0.4 [-2.0 to 2.6], P < .0001). PWV (m/s, 5.0 [3.1-7.9] vs 5.0 [3.6-8.0], P = .5) and mean arterial pressure (MAP, mm Hg) (78 [61-102] vs 74 [64-97], P = .09) were not different between groups. In adjusted analyses confined to Down syndrome, PWV was associated only with BMI, but not age, black race, or MAP (R2 = 0.11). In contrast, BMI, age, black race, and MAP were all positively associated with and better explained PWV in controls (R2 = 0.50). PWV was not associated with height in youth with or without Down syndrome. Although age-PWV-Z was not different in Down syndrome (-0.36 [-2.93 to 3.49]) vs -0.15 [-2.32 to 3.22]), Ht-PWV-Z was greater in Down syndrome (0.32 [-2.28 to 4.07] vs -0.08 [-2.64 to 2.64], P = .002), and Ht-PWV-Z was greater than age-PWV-Z in Down syndrome (P < .0001).

CONCLUSIONS

The lack of relationship of PWV, an independent predictor of adult cardiovascular events, with its traditional determinants including MAP suggests Down syndrome-specific phenomena may alter such relationships in this population. In youth with Down syndrome, Ht-adjusted PWV may overestimate aortic stiffness.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT01821300.

Impact of obstructive sleep apnea on cardiac organ damage in patients with acute ischemic stroke

BACKGROUND AND PURPOSE

Both obstructive sleep apnea (OSA) and cardiac organ damage have a crucial role in acute ischemic stroke. Our aim is to explore the relationship between OSA and cardiac organ damage in acute stroke patients.

METHODS

A total of 130 consecutive patients with acute ischemic stroke were enrolled. Patients underwent full multichannel 24-h polysomnography for evaluation of OSA and echocardiography to evaluate left ventricle (LV) mass index (LV mass/BSA, LV mass/height), thickness of interventricular septum (IVS) and posterior wall (LVPW), LV ejection fraction and left atrium enlargement. Information on occurrence of arterial hypertension and its treatment before stroke was obtained from patients' history.

RESULTS

61.9% (70) of patients, mostly men (67.1%), with acute stroke had OSA (AHI > 10). Patients with acute stroke and OSA showed a significant increase (P < 0.05) of LV mass index, IVS and LVPW thickness and a significant left atrial enlargement as compared with patients without OSA. LV ejection fraction was not significantly different in stroke patients with and without OSA and was within normal limits. No relationship was found among cardiac alterations, occurrence of OSA and history of hypertension.

CONCLUSION

Acute stroke patients with OSA had higher LV mass and showed greater left atrial enlargement than patients without OSA. This study confirms the high prevalence of OSA in stroke patients, suggesting also an association between OSA and cardiac target organ damage. Our finding of structural LV abnormalities in acute stroke patients with OSA suggests a potential role of OSA as contributing factor in determining both cerebrovascular and cardiac damage, even in absence of clear link with a history of blood pressure elevation.

The effect of high evening blood pressure on obstructive sleep apnea-related morning blood pressure elevation: does sex modify this interaction effect?

PURPOSE

Obstructive sleep apnea (OSA) can lead to increased morning blood pressure (BP). We hypothesized that high evening BP may aggravate OSA-related morning BP elevation. Additionally, this interactional effect may be modified by sex.

METHODS

This retrospective, cross-sectional study included newly diagnosed OSA patients with an apnea-hypopnea index (AHI) ≥ 5 per hour on a full-night polysomnography. An analysis of covariance (ANCOVA) was used to determine whether severe OSA (AHI ≥ 30) was associated with higher morning BP than mild-to-moderate OSA (5 ≤ AHI < 30) and whether there was an interaction between apnea severity and evening BP on morning BP. To identify the sex effects, analyses were performed separately in each sex group.

RESULTS

A total of 1445 patients with an average age of 51.9 years (SD 11.7) (male 77.9% vs. female 22.1%; high evening BP group 22.4% vs. normal evening BP group 59.6%) were included in the study. Based on the ANCOVA, patients with severe OSA had significantly higher morning systolic BP (SBP) (p = 0.003), diastolic BP (DBP) (p < 0.001), and mean BP (MBP) (p < 0.001) than the mild-to-moderate group in male subjects. A significant interaction between apnea severity and evening BP was identified on morning DBP and MBP in male subjects. However, there were no differences in morning BP between severe and mild-to-moderate OSA groups in female subjects.

CONCLUSIONS

In male subjects, severe OSA contributed to higher morning BP than mild-to-moderate OSA. OSA-associated morning BP elevation was more prominent in the high evening BP group than in the normal BP group. Such relations were not found in female subjects.

Obstructive Sleep Apnea is Common and Associated with Heart Remodeling in Patients with Chagas Disease

BACKGROUND

Chagas Disease (CD) is an important cause of morbimortality due to heart failure and malignant arrhythmias worldwide, especially in Latin America.

OBJECTIVE

To investigate the association of obstructive sleep apnea (OSA) with heart remodeling and cardiac arrhythmias in patients CD.

METHODS

Consecutive patients with CD, aged between 30 to 65 years old were enrolled. Participants underwent clinical evaluation, sleep study, 24-hour Holter monitoring, echocardiogram and ambulatory blood pressure monitoring.

RESULTS

We evaluated 135 patients [age: 56 (45-62) years; 30% men; BMI: 26 ± 4 kg/m2, Chagas cardiomyopathy: 70%]. Moderate to severe OSA (apnea-hypopnea index, AHI, ≥ 15 events/h) was present in 21% of the patients. OSA was not associated with arrhythmias in this population. As compared to patients with mild or no OSA, patients with moderate to severe OSA had higher frequency of hypertension (79% vs. 72% vs. 44%, p < 0.01) higher nocturnal systolic blood pressure: 119 ± 17 vs. 113 ± 13 vs. 110 ± 11 mmHg, p = 0.01; larger left atrial diameter [37 (33-42) vs. 35 (33-39) vs. 33 (30-36) mm, p < 0.01]; and a greater proportion of left ventricular dysfunction [LVEF < 50% (39% vs. 28% vs. 11%), p < 0.01], respectively. Predictor of left atrial dimension was Log10 (AHI) (b = 3.86, 95% CI: 1.91 to 5.81; p < 0.01). Predictors of ventricular dysfunction were AHI > 15 events/h (OR = 3.61, 95% CI: 1.31 - 9.98; p = 0.01), systolic blood pressure (OR = 1.06, 95% CI: 1.02 - 1.10; p < 0.01) and male gender (OR = 3.24, 95% CI: 1.31 - 8.01; p = 0.01).

CONCLUSIONS

OSA is independently associated with atrial and ventricular remodeling in patients with CD.

The Bidirectional Relationship Between Obstructive Sleep Apnea and Metabolic Disease

Obstructive sleep apnea (OSA) is a common sleep disorder, effecting 17% of the total population and 40-70% of the obese population (1, 2). Multiple studies have identified OSA as a critical risk factor for the development of obesity, diabetes, and cardiovascular diseases (3-5). Moreover, emerging evidence indicates that metabolic disorders can exacerbate OSA, creating a bidirectional relationship between OSA and metabolic physiology. In this review, we explore the relationship between glycemic control, insulin, and leptin as both contributing factors and products of OSA. We conclude that while insulin and leptin action may contribute to the development of OSA, further research is required to determine the mechanistic actions and relative contributions independent of body weight. In addition to increasing our understanding of the etiology, further research into the physiological mechanisms underlying OSA can lead to the development of improved treatment options for individuals with OSA.