Comparisons of Office and 24-Hour Ambulatory Blood Pressure Monitoring in Children with Obstructive Sleep Apnea

Associations of Obstructive Sleep Apnea Risk with Obesity, Body Composition and Metabolic Abnormalities in School-Aged Children and Adolescents

The objective of this study is to explore the associations between obesity, body composition, and the self-reported risk of obstructive sleep apnea (OSA) and to examine whether the risk of OSA is related to metabolic abnormalities in children and adolescents aged 6-17 years. Utilizing data from the 2022 to 2023 Beijing Children and Adolescents Health Cohort baseline survey, 5000 school-aged participants were analyzed. OSA risk was assessed via the Pediatric Sleep Questionnaire, with anthropometric and body composition measurements taken. Metabolic markers included blood pressure, lipid levels, blood glucose, and uric acid. Associations were analyzed using logistic regression and generalized linear models. Results showed that 88.6% were low-risk and 11.4% were high-risk for OSA. Overweight (aOR 1.53, 95% CI 1.22-1.92), obesity (aOR 1.94, 95% CI 1.57-2.40), and abdominal obesity (aOR 1.59, 95% CI 1.31-1.93) significantly increased OSA risk. High fat mass was a critical factor, while muscle mass was not, especially in those who were overweight and obese. Associations of OSA risk with metabolic abnormalities were non-significant after adjusting for BMI. Our research highlights the significant associations of obesity and body composition with OSA risk, with child BMI influencing the relationship between OSA and metabolic abnormalities. Future research should explore causative relationships and the enduring impacts of OSA on metabolic health in children.

Efficacy of adenotonsillectomy on pediatric obstructive sleep apnea and related outcomes: A narrative review of current evidence

This review summarizes the current evidence in systematic reviews, meta-analysis and randomized controlled trials regarding adenotonsillectomy outcomes in pediatric obstructive sleep apnea (OSA). Adenotonsillectomy is effective in treating OSA in children without co-morbidities, despite postoperative residual OSA remained in roughly half of these children. For children with comorbidities such as Down syndrome, Prader-Willi syndrome, sickle cell disease, or cerebral palsy, adenotonsillectomy is less effective and associated with more postoperative complications than that in children without comorbidities. For other OSA-related outcomes, evidence from meta-analyses and randomized controlled trials confirm adenotonsillectomy results in improvement of subjective OSA-related outcomes (e.g. symptoms, behaviors, and quality of life), but the results in objective OSA-related outcomes (e.g. cardiometabolic parameters or neurocognitive functions) are inconsistent. Future studies should focus on randomized controlled trials comparing objective OSA-related outcomes and the long-term effects of adenotonsillectomy in children with OSA.

Pediatric obstructive sleep apnea diagnosis: leveraging machine learning with linear discriminant analysis

Objective

The objective of this study was to investigate the effectiveness of a machine learning algorithm in diagnosing OSA in children based on clinical features that can be obtained in nonnocturnal and nonmedical environments.

Patients and methods

This study was conducted at Beijing Children's Hospital from April 2018 to October 2019. The participants in this study were 2464 children aged 3-18 suspected of having OSA who underwent clinical data collection and polysomnography(PSG). Participants' data were randomly divided into a training set and a testing set at a ratio of 8:2. The elastic net algorithm was used for feature selection to simplify the model. Stratified 10-fold cross-validation was repeated five times to ensure the robustness of the results.

Results

Feature selection using Elastic Net resulted in 47 features for AHI ≥5 and 31 features for AHI ≥10 being retained. The machine learning model using these selected features achieved an average AUC of 0.73 for AHI ≥5 and 0.78 for AHI ≥10 when tested externally, outperforming models based on PSG questionnaire features. Linear Discriminant Analysis using the selected features identified OSA with a sensitivity of 44% and specificity of 90%, providing a feasible clinical alternative to PSG for stratifying OSA severity.

Conclusions

This study shows that a machine learning model based on children's clinical features effectively identifies OSA in children. Establishing a machine learning screening model based on the clinical features of the target population may be a feasible clinical alternative to nocturnal OSA sleep diagnosis.

Diagnosis of obstructive sleep apnea in children based on the XGBoost algorithm using nocturnal heart rate and blood oxygen feature

PURPOSE

Obstructive sleep apnea (OSA) is a serious type of obstructive sleep-disordered breathing (SDB) that can cause a series of adverse effects on children's cardiovascular, growth, cognition, etc. The gold standard for diagnosis is polysomnography (PGS), which is used to assess the prevalence of OSA by obtaining the apnea-hypopnea index (AHI), but this diagnosis method is expensive and needs to be performed in a specialized laboratory, making it difficult to be of benefit to children with suspected OSA on a large scale. Our goal was to use a machine learning method to identify children with OSA of varying severity using data on children's nighttime heart rate and blood oxygen data.

METHODS

This study included 3139 children who received diagnostic PSG with suspected OSA. Age, sex, BMI, 3 % oxygen depletion index (ODI), average nighttime heart rate and fastest heart rate were used as predictive features. Data sets were established with AHI ≥ 1, AHI ≥ 5, and AHI ≥ 10 as the diagnostic criteria for mild, moderate and severe OSA, and the samples of each data set were randomly divided into a training set and a test set at a ratio of 8:2. An OSA diagnostic model was established based on the XGBoost algorithm, and the ability of the machine learning model to diagnose OSA children with different severities was evaluated through different classification ability evaluation indicators. As a comparison, traditional classifier Logistic Regression was used to perform the same diagnostic task. The SHAP algorithm was used to evaluate the role of these features in the classification task.

RESULTS

We established a diagnostic model of OSA in children based on the XGBoost algorithm. On the test set, the AUCs of the model for diagnosing mild, moderate, and severe OSA were 0.95, 0.88, and 0.88, respectively, and the classification accuracy was 90.45 %, 85.67 %, and 89.81 %, respectively, perform better than Logistic Regression classifiers. ODI is the most important feature in all classification tasks, and a higher fastest heart rate and ODI make the model tend to classify samples as positive. A high BMI value caused the model to tend to classify samples as positive in the mild and moderate classification tasks and as negative in the classification task with severe OSA.

CONCLUSION

Using heart rate and blood oxygen data as the main features, a machine learning diagnostic model based on the XGBoost algorithm can accurately identify children with OSA at different severities. This diagnostic modality reduces the number of signals and the complexity of the diagnostic process compared to PSG, which could benefit children with suspected OSA who do not have the opportunity to receive a diagnostic PSG and provide a diagnostic priority reference for children awaiting a diagnostic PSG.

Effect of Preoperative Weight Status and Disease Presentation on Postoperative Elevated Blood Pressure After Childhood Adenotonsillectomy

OBJECTIVE

To investigate the risk factors of postoperative elevated blood pressure (BP) in children with childhood obstructive sleep apnea syndrome (OSAS) after adenotonsillectomy (AT).

STUDY DESIGN

Case series with planned data collection.

SETTING

Tertiary referral center.

METHODS

Two hundred forty-five consecutive children (180 boys and 65 girls, median age 6.6 years) with polysomnography-diagnosed OSAS who underwent AT between January 2010 and August 2019. Clinical, polysomnographic, and evening BP data were assessed preoperatively and postoperatively (≥3 months after AT). Changes in the variables before and after AT and between individuals with and without hypertension were compared.

RESULTS

Postoperatively, the median (interquartile range) apnea-hypopnea index significantly decreased from 10.4 (5.3-22.6) to 2.2 (1.0-3.8) events/h. In addition, the mean (standard deviation) evening diastolic BP z-score significantly decreased from 0.7 (0.94) to 0.5 (0.81) in the overall cohort, and both systolic (2.1 [0.94]-1.0 [1.31]) and diastolic BP z-scores (1.6 [0.98]-0.7 [0.85]) significantly decreased in the preoperative elevated BP subgroup. Multivariate logistic regression analysis showed that preoperative obesity (adjusted odds ratio = 4.36, 95% confidence interval = 2.24-8.49) and mean peripheral oxygen saturation <95% during sleep (adjusted odds ratio = 2.73, 95% confidence interval = 1.29-5.79) were independently associated with postoperative elevated BP.

CONCLUSION

Preoperative obesity and mean peripheral oxygen saturation <95% during sleep were significantly associated with postoperative elevated BP in the children with OSAS, further indicating the importance of careful BP monitoring in this subgroup despite AT treatment.

Ambulatory Blood Pressure Variability after Adenotonsillectomy in Childhood Sleep Apnea

OBJECTIVE

To investigate the influence of adenotonsillectomy (T&A) on ambulatory blood pressure (BP) variability in children with obstructive sleep apnea (OSA).

STUDY DESIGN

Prospective, interventional study.

METHODS

Children with OSA symptoms were recruited from a tertiary center. After OSA diagnosis was confirmed (ie, apnea-hypopnea index [AHI] > 1), these children underwent T&A for treatment. We performed polysomnography and 24-hour recordings of ambulatory BP before and 3 to 6 months postoperatively. Ambulatory BP variability was presented as the standard deviation of mean blood pressure in the 24-hour monitoring of ambulatory BP. Differences in BP variability among different subgroups were tested using a multivariable linear mixed model.

RESULTS

A total of 190 children were enrolled (mean age: 7.8 ± 3.3 years; 73% were boys; 34% were obese). The AHI significantly decreased from 12.3 ± 17.0 to 2.7 ± 5.5 events/hr after T&A. Overall, daytime, and nighttime ambulatory BP did not significantly change postoperatively, and overall, daytime, and nighttime ambulatory BP variability did not differ significantly preoperatively and postoperatively. In the subgroup analysis, children aged <6 years demonstrated a significantly greater decrease in ambulatory BP variability postoperatively than those aged >6 years (nighttime diastolic BP variability: 9.9 to 7.7 vs. 8.9 to 9.4). Children with hypertension also showed a significantly greater decrease in ambulatory BP variability than those without hypertension.

CONCLUSIONS

We concluded that overall ambulatory BP variability does not significantly change after T&A in children with OSA. Moreover, young-aged and hypertensive children demonstrate a significant decrease in BP variability after T&A.

LEVEL OF EVIDENCE

4 Laryngoscope, 132:2491-2497, 2022.

Sleep-related breathing disorders and cardiometabolic risk factors in pediatric kidney transplant recipients

BACKGROUND

SRBDs have been shown to increase the risk of cardiovascular disease, which is a significant cause of mortality in kidney transplant recipients. Few studies have investigated the association between SRBDs and cardiometabolic risk factors in pediatric kidney transplant recipients.

METHODS

This was a cross-sectional study of pediatric kidney transplant recipients using baseline cardiometabolic data from a previous clinical trial (NCT01007994). Parents/guardians of pediatric kidney transplant recipients filled out 22-item PSQ. A score greater than 33% was defined as a diagnosis of a SRBD. Fisher's exact test, Mann-Whitney U test, and regressions were used to determine associations.

RESULTS

Among the 58 transplant recipients enrolled, 14.80% (n = 8) of participants identified as Black and 40.7% (n = 22) were male. The median age was 13 (IQR 8.25, 17) years and median number of years post-transplant for participants was 2 (IQR 1, 4). The prevalence of SRBDs was 26% (n = 14). The presence of a SRBD was associated with abnormalities in multiple cardiometabolic risk factors including total cholesterol level (β = 23.63; 95% CI 3.58-43.67), LDL level (β = 24.94; 95% CI 6.37-43.50), triglyceride level (β = 54.62; 95% CI 8.74-100.50), and LVH (OR = 5.12; 95% CI 1.12-23.45) when adjusted for age, sex, and race.

CONCLUSIONS

Similar to associations reported in the general pediatric and general CKD populations, SRBD is associated with increased cardiometabolic risk in pediatric kidney transplant recipients.

Night-to-night variability in respiratory sleep parameters to diagnose obstructive sleep apnea in children: A systematic review and meta-analysis

PURPOSE

This systematic review aims to assess the night-to-night variability (NtNV) in respiratory sleep parameters in children and the accuracy of diagnosing obstructive sleep apnea (OSA) in children based on a single-night sleep study.

METHODS

The PubMed, EMBASE, and Cochrane Library databases were searched until March 8, 2021. This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42021239838).

RESULTS

Our study included 395 patients from 5 articles. The mean (SD) age of all included patients was 11.78 (4.05) years. AHI was reported for 325 participants in 4 studies, and the mean change between two consecutive nights was -0.13 [95% CI: -0.40, 0.14] events per hour. The mean change in OAI was -0.07 [95% CI: -0.27, 0.12] events per hour in 187 participants across 3 studies. Based on the diagnostic criteria used, three studies reported that the diagnostic rates of OSA patients in a single-night sleep study were 83%, 84.6%, and 91%. The NtNV in AHI in children with severe and moderate OSA was greater than that in children with mild OSA (3.35 [95% CI: 0.07, 6.62] events per hour vs -0.15 [95% CI: -0.42, 0.12] events per hour), and these children with more severe OSA may have shown a higher AHI on the first night.

CONCLUSIONS

The NtNV in AHI was not statistically significant in the group sample of children. However, there were significant differences in NtNV in AHI between children with mild and moderate-to-severe OSA. Individual NtNV in respiratory sleep parameters may cause children to be misdiagnosed by single-night diagnostic sleep studies.

Prevalence of sleep disorders in children with chronic kidney disease: a meta-analysis

BACKGROUND

The reported prevalence of sleep disorders in children with chronic kidney disease (CKD) varies greatly. A quantitative meta-analysis to estimate the prevalence of sleep disorders among pediatric CKD patients may provide further information.

OBJECTIVES

The objective of this study is to estimate the prevalence of sleep disorders in children with CKD. The study protocol was registered on PROSPERO (registration number CRD42021268378).

DATA SOURCES

Two authors independently searched the PubMed, MEDLINE, EMBASE, and Cochrane review databases up to June 2021.

STUDY ELIGIBILITY CRITERIA

Eligible studies include data of prevalence of sleep disorders in children with CKD.

STUDY APPRAISAL AND SYNTHESIS METHODS

The prevalence of restless legs syndrome, sleep-disordered breathing, pediatric obstructive sleep apnea (i.e., apnea-hypopnea index &gt; 1 event/h in polysomnography), excessive daytime sleepiness, and insomnia/insufficient sleep was estimated using a random-effects model. Subgroup analyses were conducted to compare the prevalence of sleep disorders between children on dialysis and not on dialysis. This meta-analysis included 12 studies with 595 children (mean age: 12.9 years; gender ratio: 55.6% boys; mean sample size: 49.6 patients).

RESULTS

The prevalence of restless legs syndrome in children with CKD was 21% (95% confidence interval [CI], 14-30%). The prevalence of sleep-disordered breathing, pediatric obstructive sleep apnea, excessive daytime sleepiness, and insomnia/insufficient sleep was 22% (95% CI, 12-36%), 34% (95% CI, 19-53%), 27% (95% CI, 17-41%), and 14% (95% CI, 7-27%), respectively. Subgroup analysis revealed the pooled prevalence of excessive daytime sleepiness was significantly higher in children on dialysis than in children not on dialysis (43.3% vs. 11.2%; P = 0.018). Children on dialysis also had a high prevalence of other sleeping disorders, although the differences did not reach statistical significance. Children with CKD exhibited a 3.9-fold (95% CI, 1.37 to 10.93) increased risk of restless legs syndrome and a 9.6-fold (95% CI, 3.57 to 25.76) increased risk of excessive daytime sleepiness compared with controls.

LIMITATIONS

The selected papers are of small sample size, lack of a control group, and exhibit substantial heterogeneity.

CONCLUSIONS

Sleep disorders are common in children with CKD. Our results indicate that while the prevalence rates of various sleep disorders were higher in children on dialysis than in children not on dialysis, the prevalence of excessive daytime sleepiness was statistically significant in children on dialysis. A higher resolution version of the Graphical abstract is available as Supplementary information.

Office Blood Pressure Monitoring in Children with Obesity and Obstructive Sleep Apnea

OBJECTIVE

To investigate the relative contributions of obesity and obstructive sleep apnea (OSA) to unfavorable blood pressure in children.

STUDY DESIGN

Children aged 3-18 years with OSA-related symptoms were recruited. All children underwent office blood pressure (BP) monitoring and full-night polysomnography. Obesity was defined as a body mass index ≥95th percentile. OSA severity was divided into primary snoring (apnea-hypopnea index [AHI] <1), mild OSA (5> AHI ≥1), and moderate to severe OSA (AHI ≥5). Age- and sex-adjusted logistic regression analysis was performed to determine the associations among OSA, obesity, and elevated BP.

RESULTS

This cross-sectional study enrolled 1689 children (66% boys), with a mean age of 7.9 years. Compared with children with primary snoring, children with moderate to severe OSA had significantly higher systolic BP (108.1 mmHg vs 105.6 mmHg), diastolic BP (75.0 mmHg vs 70.4 mmHg), systolic BP percentile (75.0 vs 70.4), and diastolic BP percentile (74.0 vs 69.2). The rate of unfavorable BP (ie, elevated BP or hypertension level BP) also was significantly higher in children with more severe OSA. Children with obesity had higher BP and BP percentile. Logistic regression analysis revealed that children with obesity and moderate to severe OSA have a 3-fold greater risk of unfavorable BP compared with children without obesity and primary snoring.

CONCLUSIONS

We identified a 3-fold greater risk of unfavorable BP in children with obesity and moderate to severe OSA.

Changes in Cone-Beam Computed Tomography Pediatric Airway Measurements After Adenotonsillectomy in Patients With OSA

Importance

Early intervention using cone-beam computed tomography (CBCT) and adenotonsillectomy for children with obstructive sleep apnea (OSA) may prevent impaired growth, adverse cardiovascular consequences, learning deficits, and poor quality of life.

Objective

To assess changes in CBCT airway measurements and polysomnography (PSG) parameters that occur after adenotonsillectomy in children with OSA and to determine whether CBCT changes are correlated with apnea-hypopnea index (AHI) reduction.

Design, Setting, and Participants

This prospective cohort study was conducted at a tertiary medical center from 2013 to 2016. Children aged 7 to 13 years with PSG-confirmed OSA (ie, AHI ≥1) were recruited. Data analysis was performed from March to July 2021.

Exposures

All participants underwent CBCT and PSG before and after adenotonsillectomy.

Main Outcomes and Measures

Changes in PSG and CBCT parameters after adenotonsillectomy were analyzed.

Results

A total of 49 children (mean [SD] age, 9.5 [1.8] years; 34 boys [69.4%]) were recruited. Eighteen participants (36.7%) had obesity. After adenotonsillectomy, AHI significantly decreased from 11.4 to 1.2 events per hour (mean difference, -10.24 events per hour; 95% CI, -13.84 to -6.64 events per hour). The following CBCT parameters significantly increased: total airway volume (from 11 265 to 15 161 mm3; mean difference, 3896.6 mm3; 95% CI, 2788.0 to 5005.2 mm3), nasopharyngeal volume (from 2366 to 3826 mm3; mean difference, 1459.7 mm3; 95% CI, 1122.9 to 1796.5 mm3), minimal nasopharyngeal airway area (from 128 to 191 mm2; mean difference, 63.1 mm2; 95% CI, 47.4 to 78.8 mm2), mean nasopharyngeal airway area (from 144 to 231 mm2; mean difference, 86.8 mm2; 95% CI, 67.0 to 106.5 mm2), oropharyngeal volume (from 8898 to 11 335 mm3; mean difference, 2436.9 mm3; 95% CI, 1477.0 to 3396.8 mm3), minimal oropharyngeal airway area (from 82 to 158 mm2; mean difference, 76.2 mm2; 95% CI, 57.0 to 95.4 mm2), and mean oropharyngeal airway area (from 182 to 234 mm2; mean difference, 52.5 mm2; 95% CI, 33.6 to 71.4 mm2). Among all parameters, only body mass index percentile showed large effect size between the group with residual OSA (postoperative AHI ≥1) and the group with resolved disease, with the residual OSA group having a higher body mass index percentile (87.8 vs 61.4; mean difference, 26.33; 95% CI, 10.00 to 42.66). A quantile regression model revealed that total airway volume and minimal oropharyngeal airway area were significantly correlated with reductions in AHI.

Conclusions and Relevance

These findings suggest that in children undergoing adenotonsillectomy, improvements in total airway volume and oropharyngeal minimal airway area were correlated with reduction of AHI. Future studies are needed to assess whether CBCT has a role in the evaluation of children with OSA who are being considered for adenotonsillectomy.

Obstructive sleep apnea in children with non-syndromic cleft palate: a systematic review

STUDY OBJECTIVES

To characterize obstructive sleep apnea (OSA) in children with non-syndromic cleft palate based on polysomnographic parameters relative to primary palatoplasty.

METHODS

A systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The following databases were searched: PubMed, Scopus, CINAHL, and Cochrane. Studies were only considered for inclusion if they examined exclusively non-syndromic cleft palate patients and reported polysomnogram data.

RESULTS

Seven studies met inclusion criteria, providing information on a total of 151 patients with a weighted mean age of 5.2 ± 5.0 years old (range 0.1- 12 years). Five studies presented data from either the pre- or post-operative period. Two studies investigated both pre- and post-palatoplasty polysomnogram data, and neither observed a significant change in apnea hypopnea index (AHI) values following surgery (mean pre-operative AHI of 2.7, mean improvement of 0.6 events/hour). The entire cohort had a pre-palatoplasty weighted mean AHI of 11.4 (range 1.5 -16.1) and post-palatoplasty AHI of 1.5 (range 0.2 - 5.2). Interpretation of polysomnographic data was limited by heterogeneity; however, the AHI values of children with non-syndromic cleft palate largely demonstrated mild to moderate OSA following palatoplasty.

CONCLUSIONS

The full effect of cleft palate repair on OSA in children with non-syndromic cleft palate remains understudied. While published data are heterogenous, few studies support the worsening of obstructive AHI after palatoplasty in children with non-syndromic cleft palate. Further studies with standardized polysomnographic parameters are needed to provide guidance for management of this population.

Overweight/Obese Status Synergistically Worsens Nocturnal Time-to-Time Blood Pressure in Children with Obstructive Sleep Apnea

OBJECTIVE

To investigate the influence of obstructive sleep apnea (OSA) severity and weight on blood pressure (BP) during nighttime sleep in children.

METHODS

Habitually snoring children who were 3-14 years old and from Beijing Children's Hospital between 1 January 2018 and 31 December 2020 were recruited. All participants completed polysomnography (PSG) and BP monitoring during different sleep stages using pulse transit time analysis. Subjects were divided into three groups based on the obstructive apnea-hypopnea index (OAHI), ie, primary snoring (PS), mild-to-moderate OSA, and severe OSA group.

RESULTS

Totally, 284 habitually snoring children were enrolled, including 85 with PS, 152 with mild-to-moderate OSA, and 47 with severe OSA. The differences of age and sex ratio among groups were not statistically significant (all P>0.05). For the normal weight group, compared with those in the PS group, children in the severe OSA group had higher BP, mainly in N2 and R stages, and children in the mild-to-moderate OSA group had lower BP in all sleep and wake stages (all P<0.01). For the overweight/obese group, compared with the PS group, children in the severe OSA group had higher BP in all sleep and wake stages, and children in the mild-to-moderate group had higher BP mainly in sleep stages (all P<0.01). Compared with normal weight children, those who were overweight/obese and had OSA had higher BP in all sleep and wake stages (all P<0.01). There was a synergistic effect of OSA and weight status on BP (P<0.01).

CONCLUSION

The influence of OSA on both systolic and diastolic pediatric BP differs between children with normal weight and overweight/obese status. Overweight/obese status synergistically worsens nocturnal blood pressure in children with OSA. Early diagnosis and risk stratification are more important in overweight/obese children with OSA to achieve timely initiation of treatment.

The Tonsil Lymphocyte Landscape in Pediatric Tonsil Hyperplasia and Obstructive Sleep Apnea

Tonsil hyperplasia is the most common cause of pediatric obstructive sleep apnea (OSA). Despite the growing knowledge in tissue immunology of tonsils, the immunopathology driving tonsil hyperplasia and OSA remains unknown. Here we used multi-parametric flow cytometry to analyze the composition and phenotype of tonsillar innate lymphoid cells (ILCs), T cells, and B cells from pediatric patients with OSA, who had previous polysomnography. Unbiased clustering analysis was used to delineate and compare lymphocyte heterogeneity between two patient groups: children with small tonsils and moderate OSA (n = 6) or large tonsils and very severe OSA (n = 13). We detected disturbed ILC and B cell proportions in patients with large tonsils, characterized by an increase in the frequency of naïve CD27^-CD21^hi B cells and a relative reduction of ILCs. The enrichment of naïve B cells was not commensurate with elevated Ki67 expression, suggesting defective differentiation and/or migration rather than cellular proliferation to be the causative mechanism. Finally, yet importantly, we provide the flow cytometry data to be used as a resource for additional translational studies aimed at investigating the immunological mechanisms of pediatric tonsil hyperplasia and OSA.

C-reactive protein in children with obstructive sleep apnea and effects of adenotonsillectomy

OBJECTIVE

C-reactive protein (CRP) is an important serum marker of inflammation associated with cardiovascular outcomes. This study aims to evaluate the association between CRP and childhood obstructive sleep apnea (OSA) and clarify the effects of adenotonsillectomy on serum CRP levels in children with OSA.

METHODS

Children with symptoms suggestive of OSA who underwent an overnight polysomnography were recruited from a tertiary medical center. Their serum CRP levels were measured. For children who underwent adenotonsillectomy for OSA treatment, polysomnography and serum high-sensitivity CRP (hs-CRP) level measurement were conducted after surgery.

RESULTS

This study included 326 children (mean age: 7.2 ± 3.0 years; boys: 67%). Children with apnea-hypopnea index (AHI) > 5 events/h had significantly higher hs-CRP levels than children with AHI of 1-5 events/h and AHI < 1 event/h [median (interquartile range): 0.08 (0.03-0.25) vs 0.03 (0.02-0.14) vs 0.04 (0.01-0.10), P < 0.001]. Log-transformed hs-CRP levels were positively associated with log AHI values (r = 0.2, P < 0.001). In multiple linear regression analysis, hs-CRP levels were independently associated with AHI; 101 children with OSA (ie, AHI > 1) underwent adenotonsillectomy. In children with OSA in the study cohort, a significant reduction of hs-CRP levels did not occur after surgery [from 0.07 (0.02-0.22) to 0.08 (0.03-0.17), P = 0.716]. In children with OSA having abnormal hs-CRP levels (ie, CRP > 1 mg/dL), hs-CRP levels significantly decreased after surgery [from 1.87 (1.11-2.78) to 0.20 (0.07-1.04), P = 0.043].

CONCLUSION

Children with OSA had increased hs-CRP levels. Children with OSA and abnormal hs-CRP levels exhibited significantly reduced hs-CRP levels following adenotonsillectomy.

Effect of adenotonsillectomy on blood pressure in children with obstructive sleep apnea: a meta-analysis

BACKGROUND

While adenotonsillectomy (T&A) is widely recognized as the first-line therapy for pediatric obstructive sleep apnea (OSA), effects of T&A on blood pressure (BP) remain unclear. This meta-analysis evaluates the associations between T&A and BP in children with OSA.

METHODS

The study protocol was registered on PROSPERO (CRD42020154425). Two authors independently searched the PubMed, Medline, EMBASE, and Cochrane databases. The keywords used were "sleep apnea syndromes," "adenotonsillectomy," and "child." A random-effects model was applied to determine office systolic BP (SBP), diastolic BP (DBP), and ambulatory BP changes.

RESULT

Twelve studies with 1193 children were analyzed (mean age: 7.6 y; 54% boys). The apnea-hypopnea index significantly reduced of 9.4 events/h (95% CI, -12.0 to -6.8) after T&A. Office SBP (-0.24 mmHg; 95% CI, -1.64 to 1.16) and DBP (-1.65 mmHg; 95% CI, -3.47 to 0.17) did not decrease significantly after surgery. No significant decreases were observed in 24-h ambulatory BP after T&A. Subgroup analysis showed a significant postoperative decrease in office SBP (-6.23 mmHg; 95% CI, -7.78 to -4.67) and DBP (-7.93 mmHg; 95% CI, -10.37 to -5.48) among children with hypertension but a slight increase in office SBP (2.50 mmHg; 95% CI, 1.14 to 3.86) and DBP (1.98 mmHg; 95% CI, -0.02 to 3.98) in those without (P for heterogeneity < 0.001).

CONCLUSION

This meta-analysis suggests the office and ambulatory BP changes after T&A in children with OSA are trivial. Moreover, children with hypertension experience a significantly greater decrease in office BP than children without hypertension.

Cardiovascular issues in obstructive sleep apnoea in children: A brief review

Obstructive sleep apnoea (OSA) is a very common disease with a prevalence that ranges from 1% to 6% in children. It is characterized by intermittent partial or complete occlusion of the upper airway during sleep, leading to recurrent arousals and disturbed sleep architecture, to neurocognitive disorders and alterations in homeostatic gas exchange. Cardiovascular complications may develop in children with OSA through various mechanisms including activation and dysregulation of the sympathetic nervous system, induction of pro-inflammatory and pro-oxidant status and increased risk of systemic hypertension. As the deleterious effects of OSA on the cardio-vascular system may start early in life, in this brief review we focused our attention both on early and late cardiological changes induced by apnoeic events in the paediatric population, by reviewing recent findings in the literature.

Surgery for obstructive sleep apnea in young children: Outcome evaluated by polysomnograhy and quality of life

PURPOSE

Hypertrophy of adenoid and tonsils is the most common risk factor for OSA in children, and adenotonsillectomy is considered the first-line treatment. The effect of surgery for OSA in children varies considerably between studies, and few studies have focused on the effect in young children under 5 years of age. Thus, the aim of this study was to: 1) evaluate the effect of surgery for OSA in young children using objective data from polysomnography and parent-reported symptoms using questionnaires, and 2) identify predictors of residual OSA following surgery.

METHODS

This is a prospective cohort study of children aged 2-4 years who were referred for surgery to treat OSA. Measures collected before and after surgery included polysomnography (PSG), Pediatric Sleep Questionnaire (PSQ), OSA-18 and clinical data.

RESULTS

56 children completed a preoperative and postoperative PSG. Their median age was 3.1 (IQR 2.6-3.1) years. After surgery, 63% had an obstructive apnea hypopnea index (OAHI) < 1, 82% had an OAHI < 2 and 95% had an OAHI < 5. Parent-reported OSA-18 and PSQ scores improved significantly after surgery. In logistic regression analyses, higher preoperative OAHI was the only significant clinical predictor of residual OSA after surgery.

CONCLUSION

There was a high resolution rate after surgery for OSA in this group of young children, with significant improvements in both the OAHI measured with PSG and parent-reported symptoms. The only clinical predictor of residual OSA after surgery was higher preoperative OAHI.

Prematurity: A Prognostic Factor for Increased Severity of Pediatric Obstructive Sleep Apnea

OBJECTIVE/HYPOTHESIS

Studies have suggested preterm birth, defined as gestational age (GA) <37 weeks, is a risk factor for obstructive sleep apnea (OSA) in later childhood. However, little is known about the characteristics, severity, and degree of intervention of childhood OSA in former preterm infants compared to term infants. This study compares polysomnographic characteristics and surgical interventions in former preterm and term infants presenting with sleep disordered breathing.

STUDY DESIGN

Retrospective cohort study from 2015 to 2019 at a single tertiary referral center.

METHODS

Electronic Medical Records of pediatric patients ages 0 to 18 presenting with sleep disordered breathing were reviewed for gestational age, polysomnographic findings, clinical characteristics, and OSA surgical interventions. Association between gestational age, polysomnographic characteristics, and surgical interventions for OSA were reported.

RESULTS

A total of 615 patient records were analyzed. Adjusting for covariates, prematurity was associated with a 2.97× higher likelihood of development of severe OSA (aOR (95%CI): 2.97 (1.40-6.32)), increased apneic-hypoxic index (AHI) (mean (SD): 6.5 (9.8) vs. 4.6 (6.4), P < .05), increased end tidal CO₂ (50.5 (5.11) vs. 48.5 (5.8), P < .05), decreased REM latency (116 (64.7) vs. 132.4 (69.9), P < .05), and increased number of surgeries for OSA (0.65 (.95) vs. 0.45 (0.69), P < .05) compared to children born at term. Children born with GA < 32 weeks presented at a significantly later age with sleep disordered breathing (7.04 (.80) vs. 5.1 (0.15), P < .05) than children born at term.

CONCLUSIONS

Prematurity was associated with increased likelihood of severe OSA, increased AHI, as well as increased number of surgical interventions for OSA compared to children born at term. These results suggest an association with preterm birth and increased severity of childhood OSA.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:1909-1914, 2021.

24-Hour Ambulatory Blood Pressure Variability in Children with Obstructive Sleep Apnea

OBJECTIVE

To evaluate blood pressure (BP) variability in 24-hour ambulatory BP monitoring in children with obstructive sleep apnea (OSA).

STUDY DESIGN

Case series study.

METHODS

Children aged 4 to 16 years with clinical symptoms were recruited in a tertiary medical center. Overnight polysomnography and 24-hour recordings of ambulatory BP were performed for each child. The severity of OSA was classified as primary snoring (apnea-hypopnea index [AHI] < 1), mild OSA (1 ≤ AHI < 5), moderate OSA (10 > AHI ≥ 5), and severe OSA (AHI ≥ 10). The standard deviation of mean BP was used as an indicator of BP variability.

RESULTS

A total of 550 children were included (mean age: 7.6 years; 70% were boys; 20% were obese). Compared with the children with primary snoring, children with severe OSA exhibited significantly higher nighttime systolic BP (108.0 vs. 100.5 mmHg, P < .001), nighttime diastolic BP (58.9 vs 55.6 mmHg, P = .002), nighttime mean arterial pressure (75.3 vs. 70.5 mmHg, P < .001), nighttime systolic BP load (40.5% vs. 25.0%, P < .001), nighttime diastolic BP load (25.3% vs. 12.9%, P < .001), and nighttime systolic BP variability (11.4 vs. 9.6, P = .001). Multiple linear regression analyses revealed an independent association between AHI and nighttime systolic BP variability (regression coefficient = 0.31, 95% CI = 0.06-0.56, P = .015) after adjustment for age, gender, adiposity, and hypertensive status.

CONCLUSIONS

OSA in children is associated with increased BP and BP variability.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:2126-2132, 2021.

Obstructive sleep apnea in children with hypothalamic obesity: Evaluation of possible related factors

INTRODUCTION

Hypothalamic obesity (HO) is a type of obesity that is caused by hypothalamic damage. HO can be complicated by obstructive sleep apnea syndrome (OSAS) due to anatomical narrowing of the upper airway and hypothalamic damage-induced dysfunction of the sleep control mechanisms. We aimed to explore the presence and severity of OSAS in children with HO and hypothesized that OSAS is more severe and frequent in HO than exogenous obesity (EO).

METHODS

This cross-sectional study was conducted among children aged 6.6-17.9 years. Subjects with HO (n = 14) and controls with EO (n = 19) were consecutively recruited through an endocrinology clinic. All patients underwent full-night polysomnography. The primary outcomes were obstructive apnea-hypopnea index (OAHI) and the severity of OSAS. We analyzed the polysomnography findings, biochemical parameters, Brodsky and modified Mallampati scores, and blood pressure compared with the controls. We explored the different obesity types and these variables in association with OAHI using multiple linear regression (MLR).

RESULTS

Age and body mass index z scores (BMI-z) were similar between the EO and HO groups. The OAHI of HO (5.8) was higher than that of EO (2.2). In MLR, the predicted OAHI was formulated as an equation using regression coefficients of obesity type (HO), age, and BMI-z (R²  = .41). In the logistic regression analysis, the odds ratio of moderate/severe OSA was 5.6 for HO.

CONCLUSIONS

Children with HO have a higher risk of moderate/severe OSAS than children with EO. Polysomnography should be considered in all patients with HO.

Randomised trial showed no difference in behavioural symptoms between surgical methods treating paediatric obstructive sleep apnoea

AIM

Our previous randomised controlled trial of children with obstructive sleep apnoea (OSA) showed no significant differences between adenotonsillectomy (ATE) and adenotonsillotomy (ATT) in improving nocturnal respiration and quality of life after 1 year. The aim of this report was to evaluate the effects on behavioural symptoms using the Strengths and Difficulties Questionnaire (SDQ).

METHODS

Children between 2 and 6 years with OSA were randomised to ATT or ATE. Parents, blinded to method, answered the SDQ while their child underwent polysomnography before and 1 year after surgery. Differences between the total SDQ scores were analysed between the treatment groups.

RESULTS

The SDQ was filled out in 87% of the cases preoperatively, and in 86% postoperatively. At follow-up, the mean total SDQ score was 9.6 SD ± 5.1 in the ATE group (n = 31), and 8.2 ± 6.7 in the ATT group (n = 37), P = .09. The mean total SDQ score for all was preoperatively 10.6 ± 5.0, and postoperatively 8.8 ± 6.0, P = .0002.

CONCLUSION

There were no significant differences in SDQ scores between the groups at follow-up, indicating that the more conservative ATT is a treatment option in paediatric OSA. The whole group of patients showed a significant improvement after surgery.

Does obstructive sleep apnoea contribute to obesity, hypertension and kidney dysfunction in children? A systematic review protocol

INTRODUCTION

Childhood obstructive sleep apnoea (OSA) is a highly prevalent disorder that may directly contribute to the development of obesity, hypertension and renal injury. Although those associations seem to be clearer in adults, studies in children have revealed conflicting results and updated synthesis of the evidence is lacking. The aim of this systematic review is to summarise the available evidence on the effect of OSA on obesity, systemic blood pressure and kidney function, to help to elucidate whether respiratory interventions to correct OSA would have the potential to improve those outcomes.

METHODS AND ANALYSIS

A systematic literature review search was created by a medical librarian and peer-reviewed by a second librarian prior to running. Ovid Medline, Ovid Embase, CINAHL via EbscoHOST, Wiley Cochrane Library and ProQuest Dissertations and Theses Global were searched on 25 February 2020. Titles and abstracts will be screened by two independent reviewers for inclusion, followed by full-text screening of relevant articles. Studies in children will be included if they report data on OSA and weight, systemic blood pressure or kidney parameters. The extracted data will be combined for analysis and the information subcategorised in groups based on outcome. Risk of bias will be determined using tools specific to study methodology and certainty of the evidence using the Grading of Recommendations, Assessment, Development and Evaluations approach.

ETHICS AND DISSEMINATION

This study will provide essential information for healthcare professionals to better understand the relationship between childhood OSA and changes in body mass index, systemic blood pressure and kidney function indicators. Our findings will be disseminated through conferences and publications. The results of this review may guide the initiation of new strategies and the development of future research studies. This research did not involve human subjects and therefore did not undergo research ethical review.

PROSPERO REGISTRATION NUMBER

CRD42020171186.

Frequency of moderate-to-severe obstructive sleep apnea syndrome among children with snoring and blood pressure in the hypertensive range

BACKGROUND

It is recommended that children with hypertension and loud snoring should be referred for polysomnography. We aimed to compare the frequency of moderate-to-severe obstructive sleep apnea syndrome (OSAS) among snorers with and without hypertension. Thus, it was hypothesized that systolic or diastolic hypertension among children with snoring is a risk factor for moderate-to-severe OSAS.

METHODS

Data of children with snoring and adenotonsillar hypertrophy and/or obesity referred for polysomnography were retrospectively analyzed. Blood pressure (BP) was measured three times in the morning after polysomnography and percentiles were calculated for the average of the second and third measurement. Association of systolic or diastolic hypertension with moderate-to severe OSAS (apnea-hypopnea index-AHI > 5 episodes/h) adjusted for age and obesity was assessed by logistic regression.

RESULTS

Data of 646 children with snoring (median age, 6.5 years; 3-14.9 years; 25.7% obese) were analyzed. Prevalence of systolic or diastolic hypertension was 14.1% and 16.1%, respectively and frequency of AHI > 5 episodes/h was 18.3%. Systolic hypertension was a significant predictor of moderate-to-severe OSAS (OR 1.87; 95% CI 1.10 to 3.17; P = 0.02) after adjustment for age and obesity, but diastolic hypertension was not (OR, 0.96; 0.55 to 1.67; P > 0.05). Odds of AHI > 5 episodes/h prior to considering systolic hypertension was 0.25 and after considering its presence, increased to 0.46 (Bayes' theorem), or for every three children with systolic hypertension and snoring tested, one had AHI > 5 episodes/h.

CONCLUSIONS

In the context of systolic hypertension and snoring, referral for polysomnography to rule out moderate-to-severe OSAS is a clinically productive practice.

Evaluation of Upper Airway in Children with Obstructive Sleep Apnea Using Cone-Beam Computed Tomography

OBJECTIVE

Cone-beam computed tomography (CBCT) offers three-dimensional structures in assessing upper airway of patients. This study aims to compare the cone-beam computerized tomography scan measurements between children with obstructive sleep apnea (OSA) and primary snoring.

STUDY DESIGN

Case-control study.

METHODS

This prospective study was conducted in a tertiary referral center. Thirty-six children with moderate-to-severe OSA (with apnea-hypopnea index [AHI] > 5 events/hour) and 36 age-, gender-, and obesity-matched children with primary snoring (AHI <1) were enrolled. The measurements in CBCT parameters were compared between children with moderate-to-severe OSA and primary snorers by conditional logistic regression model.

RESULTS

A total of 72 children (mean age, 7.9 ± 2.8 years; 64% male) were included. Children with moderate-to-severe OSA had a significantly smaller nasopharyngeal (2900 ± 1400 vs. 3800 ± 1800 mm³ , P = .017) and oropharyngeal airway volume (5600 ± 2700 vs. 7400 ± 4000 mm³ , P = .026) than those with primary snoring. Children with moderate-to-severe OSA, as compared to primary snorers, also had a significantly smaller minimal airway area in nasopharynx (77.4 ± 37.7 vs. 107.7 ± 52.0 mm² , P = .006) and oropharynx (66.6 ± 61.9 vs. 101.6 ± 65.8 mm² , P = .023). Moreover, the airway length was not significantly different between children with moderate-to-severe OSA and primary snoring.

CONCLUSIONS

The three-dimensional CBCT airway analysis could be used as a useful tool to evaluate upper airway in children with OSA.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:680-685, 2021.

Cognition After Early Tonsillectomy for Mild OSA

OBJECTIVES

It remains uncertain whether treatment with adenotonsillectomy for obstructive sleep apnea in children improves cognitive function. The Preschool Obstructive Sleep Apnea Tonsillectomy and Adenoidectomy study was a prospective randomized controlled study in which researchers evaluated outcomes 12 months after adenotonsillectomy compared with no surgery in preschool children symptomatic for obstructive sleep apnea.

METHODS

A total of 190 children (age 3-5 years) were randomly assigned to early adenotonsillectomy (within 2 months) or to routine wait lists (12-month wait, no adenotonsillectomy [NoAT]). Baseline and 12-month assessments included cognitive and behavioral testing, medical assessment, polysomnography, and audiology. The primary outcome was global IQ at 12-month follow-up, measured by the Woodcock Johnson III Brief Intellectual Ability (BIA). Questionnaires included the Pediatric Sleep Questionnaire, Parent Rating Scale of the Behavioral Assessment System for Children-II, and Behavior Rating Inventory of Executive Function, Preschool Version.

RESULTS

A total of 141 children (75.8%) attended baseline and 12-month assessments, and BIA was obtained at baseline and 12-month follow-up for 61 and 60 participants in the adenotonsillectomy versus NoAT groups, respectively. No cognitive gain was found after adenotonsillectomy compared with NoAT, adjusted for baseline; BIA scores at 12-month follow-up were as follows: adenotonsillectomy, 465.46 (17.9) versus NoAT, 463.12 (16.6) (mean [SD]). Improvements were seen for polysomnogram arousals and apnea indices and for parent reports of symptoms (Pediatric Sleep Questionnaire), behavior (Behavior Assessment System for Children behavioral symptoms, P = .04), overall health, and daytime napping.

CONCLUSIONS

Structured testing showed no treatment-attributable improvement in cognitive functioning of preschool children 12 months after adenotonsillectomy compared with NoAT. Improvements were seen after adenotonsillectomy in sleep and behavior by using polysomnogram monitoring and parental questionnaires.

Adenotonsillectomy for the Treatment of Obstructive Sleep Apnea in Children with Prader-Willi Syndrome: A Meta-analysis

Objective

Adenotonsillectomy outcomes in obstructive sleep apnea (OSA) treatment among children with Prader-Willi syndrome (PWS) remain unclear. This study aimed to elucidate the effectiveness of adenotonsillectomy in OSA treatment among children with PWS.

Data Source

PubMed, MEDLINE, Embase, and Cochrane Review up to February 2019.

Review Methods

The registry number of the protocol published on PROSPERO was CRD42015027053. Two authors independently searched the relevant database. Polysomnography outcomes in these children were examined, including net postoperative changes in the apnea-hypopnea index (AHI), net postoperative changes in the minimum and mean oxygen saturation, the overall success rate for a postoperative AHI <1, and the overall success rate for a postoperative AHI <5.

Results

Six studies with 41 patients were analyzed (mean age, 5.0 years; 55% boys; mean sample size, 6.8 patients). All children had PWS and received adenotonsillectomy for the treatment of OSA. The AHI was 13.1 events per hour (95% CI, 11.0-15.1) before surgery and 4.6 events per hour (95% CI, 4.1-5.1) after surgery. The mean change in the AHI was a significant reduction of 8.0 events per hour (95% CI, −10.8 to −5.1). The overall success rate was 21% (95% CI, 11%-38%) for a postoperative AHI <1 and 71% (95% CI, 54%-83%) for a postoperative AHI <5. Some patients developed velopharyngeal insufficiency postoperatively.

Conclusion

Adenotonsillectomy was associated with OSA improvement among children with PWS. However, residual OSA was frequently observed postoperatively in these patients.

Are there gender differences in the severity and consequences of sleep disordered in children?

OBJECTIVES

In adults there is a distinct gender difference in the prevalence and severity of sleep disordered breathing (SDB), however there have been limited studies examining the effects of gender in children with SDB. We aimed to compare the effects of gender on severity of SDB, blood pressure, sleep and respiratory characteristics, quality of life, behavior and executive function.

METHODS

We included 533 children aged 3-18 years, who underwent standard pediatric overnight polysomnography (PSG) between 2004 and 2016. Blood pressure was recorded prior to each study. Quality of life, behavior and executive function were assessed with parental questionnaires. Children were grouped by gender and SDB severity based on their obstructive apnea hypopnea index (OAHI) into non-snoring controls, Primary Snoring (PS) (OAHI≤1 event/h), Mild obstructive sleep apnea (OSA) (OAHI>1-≤5 events/h) and moderate/severe (MS) OSA (OAHI>5 events/h) and data compared with 2-way ANOVA.

RESULTS

A total of 298 boys and 235 girls were studied. There were no differences in age, BMI z-score, SDB severity sleep characteristics or blood pressure between genders. Diastolic blood pressure was elevated in females with MS OSA compared to males (P < 0.05). Quality of life, behavior and executive function scores were all elevated in the SDB groups compared to controls. Females with MS OSA exhibited more internalizing behavioral problems compared to males (59.2 ± 2.4 vs. 51.4 ± 2.3, P < 0.05).

CONCLUSIONS

In contrast to studies in adults, we identified no gender differences in the severity or consequences of SDB in children, other than females with moderate-severe OSA exhibiting more internalizing problems and higher diastolic blood pressure.

Correlations of Circadian Rhythm Disorder of Blood Pressure with Arrhythmia and Target Organ Damage in Hypertensive Patients

Background

The aim of this study was to investigate the correlations of circadian rhythm disorder of blood pressure with arrhythmia and target organ damage in hypertensive patients.

Material/Methods

A total of 198 patients admitted and treated in our hospital from May 2018 to April 2019 were selected to receive 24-h ambulatory blood pressure monitoring. The nighttime blood pressure decrease rate is 0–10% in people with normal circadian rhythm of blood pressure. In the present study, we divided patients into a normal circadian rhythm group (normal circadian rhythm of blood pressure, n=132) and a circadian rhythm disorder group (circadian rhythm disorder of blood pressure, n=66) according to the circadian rhythm of blood pressure. The systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean pulse pressure (PP) were observed, and dynamic electrocardiography was performed to observe the status of arrhythmia. Finally, the degree of damage to target organs such as heart, brain, and kidney was compared.

Results

The circadian rhythm disorder group had remarkably higher daytime SBP (d-SBP), daytime DBP (d-DBP), and daytime PP (d-PP) but clearly lower nighttime SBP (n-SBP), nighttime DBP (n-DBP), and nighttime PP (n-PP) than in the normal circadian rhythm group (P<0.0001). The detection rate of arrhythmia and the degree of target organ damage were clearly higher in the circadian rhythm disorder group compared with the normal circadian rhythm group (P<0.0001). Moreover, the incidence rates of heart disease, cerebrovascular disease, and nephropathy were higher in the circadian rhythm disorder group than in the normal circadian rhythm group (P<0.0001).

Conclusions

The circadian rhythm disorder of blood pressure in hypertensive patients probably increases the risk of arrhythmia and worsens the target organ damage, so attention should be paid to the adjustment of disordered blood pressure rhythm in hypertensive patients in clinical practice.

Activation of adenosine A2a receptor accelerates and A2a receptor antagonist reduces intermittent hypoxia induced PC12 cell injury via PKC-KATP pathway

Obstructive sleep apnea hypopnea syndrome (OSAHS) is associated with multiple system diseases. Neurocognitive dysfunction resulting from central nervous system complications has been reported, especially in children with OSAHS. Chronic intermittent hypoxia is accepted to be the major pathophysiological mechanism of OSAHS. Adenosine plays an important role in cellular function via interactions with its receptors. A2a receptor has been recognized as a factor involved in neuroprotection. However, the role of adenosine A2a receptor in intermittent hypoxia induced cellular injury is not completely understood. In this study, we aim to investigate the underlying mechanisms of A2a receptor mediated cellular damage caused by intermittent hypoxia in PC12 cells. We found that activated A2a receptor by CGS21680 decreased cellular viability, increased PKC as well as ATP-sensitive potassium channel (KATP) subunits expression Kir6.2 and SUR1. Inhibition of A2a receptor by SCH58261 increased cellular viability, suppressed PKC and SUR1 expression level, ultimately showing a protective role in PC12 cells. Moreover, we observed that CHE, which is an antagonist of PKC, downregulated Kir6.2 and SUR1 expression and increased cellular viability. Additionally, we found that A2a receptor activation induced cell injury was associated with increased Cleaved-Caspase 3 expression, which can be decreased by inhibition of A2a receptor or PKC. In conclusion, our findings indicate that A2a receptor induced KATP expression by PKC activation and plays a role in accelerating PC12 cells injury induced by intermittent hypoxia exposure via A2a-PKC-KATP signal pathway mediated apoptosis.

OSA and Cardiovascular Risk in Pediatrics

OSA occurs in approximately 1% to 5% of children in the United States. Long-term cardiovascular risks associated with OSA in the adult population are well documented. Although changes in BP regulation occur in children with OSA, the pathways leading to chronic cardiovascular risks of OSA in children are less clear. Risk factors associated with cardiovascular disease in adult populations could carry the same future risk for children. It is imperative to determine whether known mechanisms of cardiovascular diseases in adults are like those that lead to pediatric disease. Early pathophysiologic changes may lead to a lifetime burden of cardiovascular disease and early mortality. With this perspective in mind, our review discusses pathways leading to cardiovascular pathology in children with OSA and provides a comprehensive overview of recent research findings related to cardiovascular sequelae in the pediatric population.

Effect of Adenotonsillectomy on Ambulatory Blood Pressure in Pediatric Obstructive Sleep Apnea: 6-Month Follow-up Study

Objective

To investigate 24-hour ambulatory blood pressure changes 6 months after surgery among children with obstructive sleep apnea.

Study Design

Prospective interventional study.

Setting

Tertiary medical hospital.

Subjects and Methods

Children aged 4 to 16 years with symptoms of obstructive sleep apnea (apnea-hypopnea index >1) were recruited. All children underwent adenotonsillectomy and postoperative polysomnography overnight. The 24-hour ambulatory blood pressure was measured before and 6 months after surgery.

Results

The study cohort enrolled 124 children: mean (SD) age, 7.3 (3.1) years; 73% boys. After surgery, the apnea-hypopnea index significantly decreased from 13.3 (18.1) to 3.3 (7.2) events per hour ( P < .001). Overall systolic blood pressure and diastolic blood pressure were not significantly different following surgery, while daytime systolic blood pressure was slightly increased (114.3 to 117.3 mm Hg, P < .01) postoperatively. The hypertensive group (n = 43) exhibited significantly decreased levels of overall diastolic, nighttime systolic, and nighttime diastolic blood pressure ( P < .05), and 54% of hypertensive children became nonhypertensive after surgery. The nonhypertensive group (n = 81) showed slightly increased levels of nocturnal overall systolic, daytime systolic, and nighttime systolic blood pressure. A generalized linear mixed model revealed that children with hypertension had a greater decrease in systolic and diastolic ambulatory blood pressure during the daytime and nighttime (all P < .05) than those without hypertension.

Conclusions

Ambulatory blood pressure changes after adenotonsillectomy among children with obstructive sleep apnea are minimal. The decrease in ambulatory blood pressure after surgery is more prominent for hypertensive children than nonhypertensive children.

Systemic hypertension in obstructive sleep apnea

There is consistent epidemiological evidence that sleep disordered breathing and systemic arterial hypertension are deeply associated, being linked through a bidirectional complex interaction among multiple mechanisms including autonomic nervous system alterations, inflammation, hormonal and hemodynamic components, sleep alterations. However there are several unanswered questions not only from a pathophysiological perspective, but also regarding the effects of obstructive sleep apnea (OSA) treatment on arterial blood pressure values. At present, while many studies have supported the possibility to obtain at least a small blood pressure reduction with OSA treatment, in particular in hypertensive patients, large trials have not clearly confirmed a significant anti-hypertensive effect, nor a beneficial effect of this intervention on cardiovascular endpoints including cardiovascular mortality. Aim of the present review article is to address the relationship between OSA and hypertension in the light of the latest evidence in the field. Moreover we will discuss research topics which need to be investigated in the future, in order to better clarify still pending issues with the aim of obtaining an early diagnosis, a more suitable phenotyping including comorbidities, and better strategies to improve patients' compliance and adherence to treatment.

24-Hour Ambulatory Blood Pressure after Adenotonsillectomy in Childhood Sleep Apnea

OBJECTIVE

To assess the effects of adenotonsillectomy (T&A) on ambulatory blood pressure (ABP) in childhood obstructive sleep apnea (OSA).

STUDY DESIGN

From 2012 to 2017, children aged 4-16 years with symptoms and polysomnography-diagnosed OSA (apnea-hypopnea index [AHI] >1) underwent T&A. PSG studies and 24-hour ABP monitoring were performed before and at 3 months after surgery.

RESULTS

In total, 159 children were enrolled (mean age, 7.8 ± 3.3 years; 72% male). T&A significantly reduced the AHI from 12.4 ± 15.9 events/hour to 2.7 ± 5.7 events/hour (P < .001). A decrease was observed in the children's overall diastolic blood pressure (65.1 ± 6.1 mm Hg to 63.8 ± 7.4 mm Hg, P = .04) after surgery. In subgroup analysis, 100 (63%) patients were classified as nonhypertensive, and 59 (37%) were classified as hypertensive. Linear mixed model analysis revealed that compared with the children without hypertension, those with hypertension had superior improvement in systolic and diastolic blood pressure during daytime and nighttime (all P values < .01). The ABP changes after surgery were not correlated with the AHI changes. Finally, preoperative hypertension was an independent risk factor of postoperative hypertension among these children (OR 3.66; 95% CI 1.70-7.86).

CONCLUSIONS

Overall, in children with OSA, the 24-hour ABP change after T&A is small. However, among children with preoperative hypertension, there is significant BP improvement after T&A surgery.

Prevalence of Obstructive Sleep Apnea in Children With Down Syndrome: A Meta-Analysis

STUDY OBJECTIVES

To estimate the prevalence of obstructive sleep apnea (OSA) in children with Down syndrome.

METHODS

Two authors independently searched databases, namely PubMed, MEDLINE, EMBASE, and the Cochrane Review database. The keywords used were "Down syndrome," "Trisomy 21," "OSA," "sleep apnea syndromes," "polysomnography" and "polygraphy." The prevalence of OSA based on apnea-hypopnea index (AHI) greater than 1, 1.5, 2, 5, and 10 event/h was estimated using a random-effects model. Subgroup analyses were conducted for children in different countries, sample size, study year, and risk of bias. Finally, the prevalence of OSA was compared between two types of sleep studies (polysomnography versus polygraphy).

RESULTS

A total of 18 studies (1,200 children) were included (mean age: 7.7 years; 56% boys; mean sample size: 67 patients). Five studies had low risk of bias, and nine and four studies had moderate and high risk of bias, respectively. The OSA was evaluated through polygraphy in 2 studies, and polysomnography in 16 studies. For children who underwent polysomnography, the prevalences of OSA based on AHI > 1, 1.5, 2, 5, and 10 events/h were 69%, 76%, 75%, 50%, and 34%, respectively. Subgroup analyses revealed no significant difference among all subgroups. Meta-regression showed that AHI > 5 events/h was inversely correlated with age (P < .001). Moreover, the prevalence of OSA based on AHI > 1.5 events/h was lower in polygraphy compared with polysomnography (59% versus 76%, P = .037).

CONCLUSIONS

OSA is highly prevalent in children with Down syndrome. Prevalence of moderate to severe OSA is higher in younger age.

Association of Adenotonsillectomy With Blood Pressure Among Hypertensive and Nonhypertensive Children With Obstructive Sleep Apnea

Importance

Hypertension in childhood may continue into adulthood and lead to adverse cardiovascular outcomes. Evidence suggests that adenotonsillectomy for childhood obstructive sleep apnea (OSA) may be associated with blood pressure (BP) improvement. However, how adenotonsillectomy is associated with BP in hypertensive and nonhypertensive children with OSA remains unclear.

Objective

To investigate disparities in BP changes after adenotonsillectomy in hypertensive and nonhypertensive children with OSA.

Design, Setting, and Participants

From January 1, 2010, to April 30, 2016, children (aged <18 years) with symptoms of OSA treated at National Taiwan University Hospital were enrolled in this retrospective case series study.

Interventions

Children underwent polysomnography for diagnosis of OSA (apnea-hypopnea index >1). All children with OSA underwent adenotonsillectomy.

Main Outcomes and Measures

Preoperative and postoperative overnight polysomnographic data were obtained. Office BP was measured in a sleep center before (nocturnal BP) and after (morning) polysomnography.

Results

A total of 240 nonobese children (mean [SD] age, 7.3 [3.0] years; 160 [66.7%] male and 80 [33.3%] female) with OSA were recruited. Postoperatively, the apnea-hypopnea index decreased significantly from 12.1 to 1.7 events per hour (95% CI of difference, -12.3 to -8.4 events per hour). The whole cohort had a significant decrease in nocturnal diastolic BP (66.9 to 64.5 mm Hg; 95% CI of difference, -4.1 to -0.7 mm Hg) and morning diastolic BP (66.9 to 64.4 mm Hg; 95% CI of difference, -4.2 to -0.8 mm Hg). The number (percentage) of patients with diastolic BP in the greater than 95th percentile decreased significantly nocturnally (48 [20.0%] to 33 [13.8%]; 95% CI of difference, -12.1% to -0.4%) and in the morning (52 [21.7%] to 34 [14.2%]; 95% CI of difference, -13.6% to -1.4%). Postoperatively, hypertensive children had a significant decrease in all BP measures, including mean (SD) nocturnal and morning systolic BP (nocturnal: 107.5 [8.6] mm Hg; morning: 106.0 [9.4] mm Hg), systolic BP index (nocturnal: -4.3 [8.6]; morning: -5.7 [8.5]), diastolic BP (nocturnal: 65.1 [11.5] mm Hg; morning: 64.4 [10.1] mm Hg), and diastolic BP index (nocturnal: -10.7 [17.3]; morning: -11.6 [15.7]), whereas the nonhypertensive group had a slight increase in nocturnal systolic BP (103.8 to 105.9 mm Hg; 95% CI of difference, 0.4-3.9 mm Hg). A generalized estimating equation model for subgroup comparisons revealed that children with hypertension, compared with those without, had greater improvement in all BP measures.

Conclusions and Relevance

Hypertensive children with OSA had a significant improvement in BP after adenotonsillectomy. Hypertensive children with OSA should be screened and treated by adenotonsillectomy because proper treatment not only eases OSA symptoms but also potentially prevents future cardiovascular and end-organ disease.

Systolic Blood Pressure Elevation in Children with Obstructive Sleep Apnea Is Improved with Positive Airway Pressure Use

INTRODUCTION

To evaluate the effect of continuous positive airway pressure (CPAP) treatment on blood pressure (BP) in children with obstructive sleep apnea (OSA).

STUDY DESIGN

Retrospective chart review of children aged 7-17 referred to Benioff Children's Hospital Oakland for the evaluation of snoring. Data collected included age, body mass index (BMI), BP, heart rate, apnea-hypopnea index, and oxygen saturation nadir. Children were divided into 3 groups: snorers, untreated OSA, and OSA treated with CPAP. Seventy-five children were identified, 25 in each group.

RESULTS

There was no difference in age or apnea-hypopnea index among the groups. The CPAP group had higher BMI than the snorers and untreated OSA groups. Systolic BP was higher in the 2 OSA groups compared with the snorers. After CPAP treatment, systolic BP decreased. The BP decrease was significantly greater in patients with higher BMI at baseline. There was no significant change in diastolic BP in the 3 groups.

CONCLUSION

Children with OSA have higher systolic BP than habitual snorers. Treatment with CPAP in children with OSA for 6 months reduced their systolic BP despite a small increase in their BMI.

Pediatric Obstructive Sleep Apnea in High-Risk Populations: Clinical Implications

Certain common medical conditions are associated with a higher risk of pediatric obstructive sleep apnea (OSA). A lower threshold for screening is therefore indicated for such patient cohorts. In this article, we briefly discuss the high prevalence of OSA in children born prematurely, and in those with Down syndrome, craniofacial disorders, and neuromuscular disorders. Primary care providers should have an increased index of suspicion for OSA in these children, considering the neurocognitive disability that occurs in these high-risk groups when OSA is left untreated. [Pediatr Ann. 2017;46(9):e336-e339.].