Effect of Obstructive Sleep Apnea on Cardiovascular Function in Obese Youth

Heart Failure with Preserved Ejection Fraction in Children

Diastolic dysfunction (DD) refers to abnormalities in the mechanical function of the left ventricle (LV) during diastole. Severe LVDD can cause symptoms and the signs of heart failure (HF) in the setting of normal or near normal LV systolic function and is referred to as diastolic HF or HF with preserved ejection fraction (HFpEF). Pediatric cardiologists have long speculated HFpEF in children with congenital heart disease and cardiomyopathy. However, understanding the risk factors, clinical course, and validated biomarkers predictive of the outcome of HFpEF in children is challenging due to heterogeneous etiologies and overlapping pathophysiological mechanisms. The natural history of HFpEF varies depending upon the patient's age, sex, race, geographic location, nutritional status, biochemical risk factors, underlying heart disease, and genetic-environmental interaction, among other factors. Pediatric onset HFpEF is often not the same disease as in adults. Advances in the noninvasive evaluation of the LV diastolic function by strain, and strain rate analysis with speckle-tracking echocardiography, tissue Doppler imaging, and cardiac magnetic resonance imaging have increased our understanding of the HFpEF in children. This review addresses HFpEF in children and identifies knowledge gaps in the underlying etiologies, pathogenesis, diagnosis, and management, especially compared to adults with HFpEF.

Risk Factors for Post-Tonsillectomy Respiratory Events in Children With Severe Obstructive Sleep Apnea

OBJECTIVES/HYPOTHESIS

To identify risk factors for postoperative respiratory events in pediatric patients with severe obstructive sleep apnea (OSA).

METHODS

Retrospective single-institution retrospective cohort study of pediatric patients with severe OSA who were admitted postoperatively after tonsillectomy. Patients who experienced respiratory events after surgery were identified and differences between the respiratory event and no event groups were compared.

RESULTS

There were 887 patients included in this study. 14.8% (n = 131) experienced a documented respiratory event. The following risk factors were found to be most significant: %sleep time with O₂  < 90% (tb90) (95% CI = 1.07-1.14, OR = 1.10, p < 0.001), Black race (95% CI = 1.53-3.58, OR = 2.34, p < 0.001), primary neurologic co-morbidity (1.67-6.32, OR = 3.27, p < 0.001), Down syndrome (1.25-5.94, OR = 2.72, p = 0.01), and age (0.84-0.94, OR = 0.88, p < 0.001). Regression modeling demonstrated that the rate of respiratory events increased with tb90.

CONCLUSIONS

Our results demonstrate that there are other potential risk factors outside of AHI and O₂ nadir that are associated with respiratory events after tonsillectomy. Black race and prolonged desaturations during polysomnography (PSG) are independent risk factors. Measures of abnormal gas exchange on PSG may be better at identifying at risk patients.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

Therapeutic Approaches in Heart Failure with Preserved Ejection Fraction (HFpEF) in Children: Present and Future

For a long time, pediatric heart failure (HF) with preserved systolic function (HFpEF) has been noted in patients with cardiomyopathies and congenital heart disease. HFpEF is infrequently reported in children and instead of using the  HFpEF terminology the HF symptoms are attributed to diastolic dysfunction. Identifying HFpEF in children is challenging because of heterogeneous etiologies and unknown pathophysiological mechanisms. Advances in echocardiography and cardiac magnetic resonance imaging techniques have further increased our understanding of HFpEF in children. However, the literature does not describe the incidence, etiology, clinical features, and treatment of HFpEF in children. At present, treatment of HFpEF in children is extrapolated from clinical trials in adults. There are significant differences between pediatric and adult HF with reduced ejection fraction, supported by a lack of adequate response to adult HF therapies. Evidence-based clinical trials in children are still not available because of the difficulty of conducting trials with a limited number of pediatric patients with HF. The treatment of HFpEF in children is based upon the clinician's experience, and the majority of children receive off-level medications. There are significant differences between pediatric and adult HFpEF pharmacotherapies in many areas, including side-effect profiles, underlying pathophysiologies, the β-receptor physiology, and pharmacokinetics and pharmacodynamics. This review describes the present and future treatments for children with HFpEF compared with adults. This review also highlights the need to urgently test new therapies in children with HFpEF to demonstrate the safety and efficacy of drugs and devices with proven benefits in adults.

Tissue Doppler echocardiography in children with OSA before and after tonsillectomy and adenoidectomy: A systematic review and meta-analysis

BACKGROUND

When to order an echocardiogram in children with obstructive sleep apnea (OSA) is debated. Studies evaluating the utility of pre-operative standard echocardiography are inconsistent. Tissue Doppler imaging (TDI) is an additional technique that quantifies the velocity of myocardial motion to assess cardiac function. The utility of TDI in pediatric OSA remains unclear.

METHODS

A systematic review and meta-analysis were performed in accordance with PRISMA guidelines using PubMed, Scopus, CINAHL, and Cochrane Library databases. Studies of echocardiographic findings using TDI in children with polysomnogram confirmed OSA before and after tonsillectomy and adenoidectomy (T&A) were included. 1,423 studies were screened, and 4 studies met inclusion criteria. Meta-analysis of echocardiographic findings was performed.

RESULTS

Data from 560 children were analyzed. Study groups included pre- and post-T&A children with OSA and non OSA controls. Pre-T&A S' wave at the tricuspid annulus (S' RV) was decreased with a mean difference of -1.04 [95% CI -1.57, -0.52, p < 0.001] and E'/A' ratio at the mitral annulus (E'/A' LV) was decreased with a mean difference of -0.74 [95% CI -0.85, -0.64, p < 0.001] when compared to controls. These variables were not statistically different when comparing post-T&A to controls.

CONCLUSIONS

TDI appears to successfully detect subclinical changes in cardiac function in children with OSA. However, echocardiography parameters of post-T&A and non OSA control children were similar. Further prospective studies stratified by OSA severity are needed with both TDI and standard echocardiography to define the utility of pre-operative cardiac imaging.

The effect of overweight/obesity on diastolic function in children and adolescents: A meta-analysis

Left ventricular diastolic function (LVDF) is an important marker of early cardiovascular remodelling, which has not been well summarized in young people with overweight/obesity. Weighted, random-effects regression was used to determine the strength of associations of both body mass index (BMI) and homeostatic model assessment of insulin resistance (HOMA-IR) with LVDF measures, adjusting for age and sex. Six databases were searched after PROSPERO registration (CRD42020177470) from inception to July 2020 for studies that compared LVDF between overweight/obesity and control groups aged ≤24 years, yielding 70 studies (9983 individuals). Quality and risk of bias were assessed using NHLBI tools, with scores of good, fair, and poor for 6, 48, and 16 studies, respectively. Increased BMI was associated with worse LVDF in all measures except early mitral inflow deceleration time, with septal early diastolic tissue peak velocity to late diastolic tissue peak velocity ratio having the strongest association (n = 13 studies, 1824 individuals; r = -0.69; P < 0.001). Elevated HOMA-IR was also associated with worse LVDF. Although we could not determine the causality of reduced LVDF in young people, our findings should aid the development of paediatric guidelines for the assessment of LVDF and support further work to address the longitudinal consequences of childhood obesity and IR on LVDF.

Echocardiographic findings in children with obstructive sleep apnea: A systematic review

OBJECTIVE

To systematically review the incidence of cardiac abnormalities in pediatric patients with obstructive sleep apnea (OSA) in order to assess the utility of preoperative echocardiographic evaluation for patients undergoing surgery.

STUDY DESIGN

A systematic literature review was performed following the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines. Data sources were searched from January 1, 1980 to March 25, 2020. Studies that examined echocardiographic findings and polysomnographic data for patients between birth and 18 years of age with polysomnogram-confirmed OSA were included. Studies that included patients with preexisting cardiac, metabolic, or hematologic disorders that could affect hemodynamic parameters were excluded. Included studies were assessed for quality and risk of bias using the U.S. National Institute of Health's Quality Assessment Tools.

RESULTS

Thirteen studies met inclusion criteria. Five studies were categorized as high risk of bias, three were categorized as medium risk, and five were categorized as low risk. Study design varied considerably between studies, including heterogeneous classifications of OSA severity, discrepant reporting of echocardiographic parameters, and differing estimations of pulmonary hemodynamics. Significant disagreement regarding the effect of OSA on cardiac function was found between all included studies.

CONCLUSION

Data demonstrating significant associations between OSA and cardiac abnormalities in children is inconsistent. Echocardiographic abnormalities are inconsistently found and, when present, their clinical significance remains poorly understood. Assessing the utility of preoperative echocardiography in children with OSA requires further investigation with prospective studies utilizing standardized classifications of OSA severity, reporting of echocardiographic parameters, and estimations of pulmonary hemodynamics.

Cardiopulmonary Testing before Pediatric Adenotonsillectomy for Severe and Very Severe Obstructive Sleep Apnea Syndrome

OBJECTIVES/HYPOTHESIS

Adenotonsillectomy is first-line treatment for pediatric obstructive sleep apnea syndrome (OSAS) when not otherwise contraindicated. There is concern severe OSAS increases risk of comorbid cardiopulmonary abnormalities, such as ventricular hypertrophy or pulmonary hypertension, which preoperative testing could detect. Our objective is to determine if there is a severity of pediatric OSAS where previously undetected cardiopulmonary comorbidities are likely.

STUDY DESIGN

Retrospective chart review.

METHODS

We performed a retrospective review of 358 patients ≤21 years with severe OSAS who underwent adenotonsillectomy at a tertiary hospital June 1, 2016 to June 1, 2018. We extracted demographics, comorbidities, polysomnography, and preoperative tests. Wilcoxon rank-sum and logistic regression estimated associations of OSAS severity (based on obstructive apnea-hypopnea index [OAHI], hypoxia, hypercarbia) with preoperative echocardiograms and chest X-rays (CXRs).

RESULTS

Mean age was 5.9 (±3.6) years and 52% were male. Mean OAHI and oxygen saturation nadir were 30.3 (±23.8) and 80.7% (±9.2), respectively. OAHI ≥60 was associated with having a preoperative echocardiogram (OR, 3.8; 95% CI, 1.7-8.5) or CXR (OR, 3.0; 95% CI, 1.4-6.8) compared to OAHI 10-59. There were no significant associations between OSAS severity and test abnormalities. The presence of previously diagnosed cardiopulmonary comorbidities was associated with abnormalities on echocardiogram (OR, 36; 95% CI, 4.1-320.1) and CXR (OR, 4.1; 95% CI, 1.2-14.4).

CONCLUSIONS

Although pediatric patients with very severe OSAS (OAHI ≥60) underwent more pre-adenotonsillectomy cardiopulmonary tests, OSAS severity did not predict abnormal findings. Known cardiopulmonary comorbidities may be a better indication for cardiopulmonary testing than polysomnographic parameters, which could streamline pre-adenotonsillectomy evaluation and reduce cost.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

Correlation between OSAHS and Early Peripheral Atherosclerosis Indices in Patients with Type 2 Diabetes Mellitus in China: A Cross-Sectional Inpatient Study

OBJECTIVE

To analyze the differences of early atherosclerosis indices in type 2 diabetes mellitus (T2DM) patients with different degrees of obstructive sleep apnea-hypopnea syndrome (OSAHS) and explore the correlation between them, so as to provide a new clinical basis for the prevention and treatment of early atherosclerosis in patients with T2DM and OSAHS. Methods. A prospective study was conducted in 312 patients with T2DM and snoring who were hospitalized in the Department of Endocrinology, Peking University International Hospital from January 2017 to January 2020. According to the monitoring results, 312 patients were divided into 4 groups including the control group (208 cases), mild OSAHS group (18 cases), moderate OSAHS group (38 cases), and severe OSAHS group (48 cases). Multivariate logistic regression analysis was used to analyze the early atherosclerosis indices including brachial-ankle pulse wave velocity (PWV) and ankle-brachial index (ABI) in patients with T2DM coexistence with different degrees of OSAHS. Results. (1) As the degree of OSAHS increased, ABI decreased gradually and was lower than that in the control group, but PWV increased and was higher than that in the control group (p < 0.05, respectively). (2) The apnea-hypopnea index (AHI) positively correlated with PWV (r = 0.36, p < 0.05) and negatively correlated with ABI (r = -0.37, p < 0.05). (3) Multivariate logistic regression showed that after adjusting for age, gender, duration, BMI, blood pressure, blood glucose, blood lipid, and other factors, OSAHS was a risk factor of lower extremity arterial disease (LEAD) in patients with T2DM. With the increase of degree of OSAHS, the risk of lower extremity atherosclerosis gradually increased. Conclusion. OSAHS is an independent risk factor of LEAD in patients with T2DM, and with the increase of AHI, the ABI and PWV have changed, which provides a new clinical basis for the prevention and the treatment of early atherosclerosis in patients with T2DM and OSAHS.

Cardiac function and cognitive function in patients with obstructive sleep apnea

Objectives

This study was designed to evaluate echocardiographic findings in patients with obstructive sleep apnea (OSA) with cognitive impairment and compare it with the control group.

Methods

Sixty-seven OSA patients and 52 group of healthy controls were evaluated prospectively by Mini-Mental State Examination questionnaire and trans-thoracic echocardiography.

Results

The cognitive impairment and diastolic dysfunction were 19.6% (P = .002) and 18.4% (P = .016) more prevalent in OSA group compared to the control group. The mean tricuspid regurgitant gradient, pulmonary artery size, and transmitral A velocity were higher, but mean right ventricular peak systolic velocity, tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), transmitral E/A ratio, and annular E’ velocity were lower in the OSA group than the control group. Comparing the patients with and without cognitive disorders, showed significant differences regarding the size of right atrium, TAPSE and FAC (P < .05).

Conclusions

OSA patients need accurate cardiac examinations, early diagnosis, and interventions to prevent the progression of cardiac dysfunction, especially older male patients with higher BMI and impaired cognition. Further studies are needed to determine the exact link between the OSA, obesity, and cardiac physiology.

Subclinical decrease in cardiac autonomic and diastolic function in patients with metabolic disorders: HSCAA study

Heart failure due to decreased diastolic function, HFpEF, is a growing health concern with rising prevalence. We examined subclinical cardiac autonomic and diastolic functions in 605 patients with metabolic diseases classified as pre-heart failure. Presence of glucose intolerance or diabetes, or visceral adiposity was significantly associated with reduced cardiac autonomic and diastolic functions. Higher autonomic functions were significantly associated with a parameter of better cardiac diastolic function (E/A) (SDNN: r = 0.306, p < 0.01; HF: r = 0.341, p < 0.01), with the association independent of diabetes, body mass index, visceral adiposity and insulin resistance index. Thus, reduced autonomic function may be a potential predictor for decreased cardiac diastolic functions in metabolic disorders.

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Metabolic disorders, including diabetes and obesity, are known risk factors for HFpEF.

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Reduced autonomic function may be involved in pathogenesis of HFpEF.

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Cardiac diastolic function in metabolic disorders in pre-HF phase is not well examined.

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In pre-HF subjects, reduced autonomic function is associated with lower cardiac diastolic functions.

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Our findings provide new insights into HFpEF etiology in metabolic disorders.

Measurement of Visceral Fat, Abdominal Circumference and Waist-hip Ratio to Predict Health Risk in Males and Females

BACKGROUND AND OBJECTIVE

Obesity is a risk factor for a broad range of diseases. This study aimed to estimate association between selected variables (visceral fat, abdominal circumference and waist-hip ratio) and health risk in between male and female.

MATERIALS AND METHODS

The university student based cross-sectional study was conducted among male and female students. The anthropometric measurements were taken through the auto-calibrated digital scale. Bioelectrical impedance analyzer device was used to determine visceral fat area, abdominal circumference and waist-hip ratio. Independent t-test and Pearson Chi-Square was used for statistical analysis. To see the association among the all three variables, scatter plots were also drawn.

RESULTS

The results showed that 28.3% male and 9.4% female at risk for visceral fat, for the abdominal circumference 16.9% male and 6% female at risk and for waist-hip ratio 27.5% male and 6% female fell under risk category. There was a significant relationship among all variable for male and female.

CONCLUSION

Findings suggested that visceral fat area, abdominal circumference and waist-hip ratio were strong predictors of health risk. Male were more prone to health risk than female participants.

Childhood and Adolescent Obesity: A Review

Obesity is a complex condition that interweaves biological, developmental, environmental, behavioral, and genetic factors; it is a significant public health problem. The most common cause of obesity throughout childhood and adolescence is an inequity in energy balance; that is, excess caloric intake without appropriate caloric expenditure. Adiposity rebound (AR) in early childhood is a risk factor for obesity in adolescence and adulthood. The increasing prevalence of childhood and adolescent obesity is associated with a rise in comorbidities previously identified in the adult population, such as Type 2 Diabetes Mellitus, Hypertension, Non-alcoholic Fatty Liver disease (NAFLD), Obstructive Sleep Apnea (OSA), and Dyslipidemia. Due to the lack of a single treatment option to address obesity, clinicians have generally relied on counseling dietary changes and exercise. Due to psychosocial issues that may accompany adolescence regarding body habitus, this approach can have negative results. Teens can develop unhealthy eating habits that result in Bulimia Nervosa (BN), Binge- Eating Disorder (BED), or Night eating syndrome (NES). Others can develop Anorexia Nervosa (AN) as they attempt to restrict their diet and overshoot their goal of "being healthy." To date, lifestyle interventions have shown only modest effects on weight loss. Emerging findings from basic science as well as interventional drug trials utilizing GLP-1 agonists have demonstrated success in effective weight loss in obese adults, adolescents, and pediatric patients. However, there is limited data on the efficacy and safety of other weight-loss medications in children and adolescents. Nearly 6% of adolescents in the United States are severely obese and bariatric surgery as a treatment consideration will be discussed. In summary, this paper will overview the pathophysiology, clinical, and psychological implications, and treatment options available for obese pediatric and adolescent patients.

Echocardiographic screening in children with very severe obstructive sleep apnea

OBJECTIVE

(i) To determine the prevalence of echocardiographic abnormalities in children with very severe OSA defined by an apnea hypopnea index (AHI) ≥ 30 events/hour. (ii) To test the hypothesis that polysomnographic parameters predict echocardiographic variables in this population.

METHODS

Children aged 1-17 years presenting with polysomnography demonstrating an AHI ≥30 and referred for pre-operative echocardiography performed within the 6 months prior to tonsillectomy and adenoidectomy (T&A), over a two-year period (January 1, 2016 to December 31, 2018) were evaluated. The exclusion criteria were the presence of (i) unrepaired congenital cardiac disease, (ii) tracheostomy, (iii) poorly controlled asthma, or (iv) neuromuscular disorder. The prevalence of echocardiographic abnormalities was determined for the study population. The impact of the severity of OSA on echocardiographic parameters was evaluated using Student's t-test. The relationships between polysomnographic variables and biventricular function as well as pulmonary hemodynamics were measured. A penalized regression model was used to identify the contributions of polysomnographic variables to each echocardiographic parameter by mitigating inter-variable relationships. P < .05 was considered significant.

RESULTS

Eighty-nine children were screened, of whom 47 were included for analysis. The mean age was 68.8 months [95% confidence interval, 56.0 to 81.6]. Thirty-three (70.2%) were boys. Twenty (42.6%) were obese. All children had normal echocardiograms. The differences in echocardiographic variables between children grouped by the severity of OSA were not statistically significant (P: 0.18-0.98). Polysomnographic variables predicted only 4 out of 13 studied echocardiographic parameters.

CONCLUSIONS

Pre-operative echocardiography did not identify significant abnormalities in children with very severe OSA. Majority of the echocardiographic variables were not predicted by polysomnographic parameters. This study demonstrates the limited benefit associated with routine echocardiographic screening of children with very severe OSA solely based on polysomnographic indices.