Relationship between sleep apnea, fat distribution, and insulin resistance in obese children

Obstructive sleep related breathing disorders and cardiometabolic risk factors - A Portuguese birth cohort

BACKGROUND

Pediatric obstructive sleep related breathing disorders (SRBD) are an important under-diagnosed health problem with associated cardiometabolic comorbidities, demonstrated with polysomnographic studies in selected samples. Our main goal was to assess the prevalence of SRBD in a population-based cohort and to analyze its association with cardiometabolic risk factors, in general and by sex.

METHODS

Pediatric Sleep Questionnaire (PSQ) was applied to parents of 7-years-old children evaluated in the birth cohort, Generation XXI. Sex, anthropometrics, blood pressure (BP), lipid profile, glucose, insulin, HOMA-IR, and high-sensitivity C-reactive protein were compared among children with/without SRBD, using Chi-square, Mann-Whitney tests and logistic regression models.

RESULTS

A total of 1931 children (51.2 % boys) were included; 17.5 % were overweight and 15.7 % obese. The prevalence of SRBD was 13.4 %, more frequent among boys (15.7 % vs.10.9 %, p = 0.002) and in overweight/obese children (22.0 % vs.13.6 % vs.11.3 % in obese, overweight and normal weight group, respectively, p < 0.001). Children with SRBD had higher systolic BP (107 ± 8 vs.105±9 mmHg; p = 0.001) and lower HDL-cholesterol levels (54 ± 11 vs.56 ± 11 mg/dL; p = 0.04) than children without SRBD. After adjustment for sex, age, birthweight-for-gestational age and maternal age, children with SRBD had higher BMI-z-score, systolic BP, insulin and HOMA-IR levels, and lower HDL-cholesterol, when compared to those without SRBD, but these associations were lost when adjusting to BMI z-score. Analyzing obese children with the same regression model, those with SRBD presented lower HDL-cholesterol than those without SRBD.

CONCLUSIONS

Our results identified a male predominance of SRBD in pre-pubertal children and highlighted the potential contribution of SRBD to cardiovascular risk in obese children.

Food Intake and Sleep Disorders in Children and Adolescents with Obesity

Over the last few decades, numerous scientific studies have investigated the possible association between sleep duration and adiposity during childhood, since it has been reported that sleep deprivation causes a related increase in caloric intake. Even though the underlying pathogenetic mechanisms are still under study and not completely known, the effect of dietetic habits and nutrient intake on sleep quality and patterns has been reported. The aim of this study is to explore the intricate interplay between food intake/diet patterns and pediatric sleep disturbances in children and adolescents with obesity, emphasizing the importance of not underestimating this aspect in the prevention and treatment of this complex disease. Recent evidence supports a high correlation between specific diet patterns and foods with sleep disturbances in children at all ages. Diets rich in fiber, fruit, vegetables, and anti-inflammatory nutrients and low in saturated fats seem to promote better sleep quality. Sleep disturbances are, in turn, risk factors for the development of obesity. Therefore, food strategies should be applied to counteract this harmful process. Unraveling the complex links between dietary habits, sleep patterns, and obesity is essential for developing effective strategies to combat this critical public health issue.

Sleep Patterns, Eating Behavior and the Risk of Noncommunicable Diseases

Sleep is extremely important for the homeostasis of the organism. In recent years, various studies have been carried out to address factors related to sleep patterns and their influence on food choices, as well as on the onset of chronic noncommunicable diseases. The aim of this article is to provide a scientific literature review on the possible role of sleep patterns on eating behavior and the risk of noncommunicable diseases. A search was performed on Medline (PubMed interface) using several keywords (e.g., "Factors Influencing Sleep" OR "Sleep and Chronic Diseases"). Articles published between 2000 and the present date that relate sleep to cyclic metabolic processes and changes in eating behavior were selected. Changes in sleep patterns are increasingly detected today, and these modifications are mainly caused by work and lifestyle conditions as well as a growing dependence on electronic devices. Sleep deprivation and the resultant short sleep duration lead to an increased appetite via an increase in the hunger hormone (ghrelin) and a decrease in the satiety hormone (leptin). Nowadays, sleep is undervalued, and thus often impaired, with consequences for the performance of various body systems. Sleep deprivation alters physiological homeostasis and influences eating behavior as well as the onset of chronic diseases.

Evaluating symptoms and polysomnographic findings among male and female children with obesity with and without obstructive sleep apnea

OBJECTIVE

Limited data regarding sex-based differences in the presentation and phenotype of obstructive sleep apnea (OSA) exists among children with obesity. The study objectives were to compare reported symptoms and polysomnogram (PSG) findings between children with obesity 1) with and without OSA and 2) males and females with OSA.

PATIENTS/METHODS

This cross-sectional study included children with obesity, aged 8-18 years, with a diagnostic PSG between 2015 and 2021, referred for evaluating sleep-related breathing. Patient demographics, anthropometrics, and PSG data were recorded. Symptoms were evaluated using Epworth Sleepiness Scale and Pediatric Sleep Questionnaire. Pubertal staging was collected using Tanner Stage questionnaire. PSG parameters, symptoms and pubertal stage were compared between sexes with and without OSA.

RESULTS

Of 148 children, 61 (41%) had OSA. Within the OSA group, 41/62 (69%) were male (p = 0.002). Males with OSA reported higher Pediatric Sleep Questionnaire scores compared to males without OSA (0.38 ± 0.2 vs 0.23 ± 0.1; p = 0.002). Males with OSA reported more trouble breathing (p = 0.04) and mouth breathing (p = 0.008) compared to females with OSA. Females with OSA showed longer sleep onset latency (45.8 ± 40.6 min vs 22.4 ± 26.7; p = 0.02) and higher supine obstructive-apnea hypopnea index (32.9 ± 31.1 vs 20.4 ± 18.4 events/hour; p = 0.02) compared to males with OSA. A significant interaction was found between male sex and waist-to-height ratio (β = 15.34, R² = 0.18, p = 0.05).

CONCLUSIONS

Sex differences in symptoms and phenotype of OSA exist among children with obesity. Such information is beneficial for early diagnosis and management to mitigate adverse outcomes and comorbidities.

Serum leptin differs in children with obstructive sleep apnea: A meta-analysis and PRISMA compliant article

BACKGROUND

Obstructive sleep apnea (OSA) as an independent cardiovascular risk factor has been proposed, but the mechanisms underlying cardiovascular disease is far from being completely elucidated. Leptin, an inflammatory cytokine produced by adipocytes, contributes to the modulation of metabolism, respiratory control, and inflammation, which are factors associated with cardiovascular disease. Serum levels of leptin in children with OSA have shown conflicting results in previous studies.

METHODS

We performed a meta-analysis to clarify the correlation between leptin expression of the OSA patients following the PRISMA. PubMed, Embase, and Web of Science were systematically searched for relevant studies, and then independently screened by two researchers, and analyzed the data through STATA version 12.0.

RESULTS

In a total of 5 articles including 469 participants, the data analysis showed that serum leptin levels were elevated in children with OSA (MD, 6.36; 95% CI, 0.24-12.49, P < .001), compared to the control group. Subgroup analysis were performed based on body mass index. The results of subgroup analysis demonstrated that the serum leptin concentration was correlated with body mass index in children with OSA (MD, 9.70; 95% CI, 0.22-11.18, P < .001).

CONCLUSIONS

The serum leptin levels were elevated in children with OSA, compared to the control group. It could add to our developing understanding of the pathogenesis and potential treatments for children with OSA, and help us to recognize the relevance of OSA in determining cardiovascular issues among children.

Visceral adiposity is related to insulin sensitivity and inflammation in adolescents with obesity and mild sleep disordered breathing

OBJECTIVES

To evaluate the relationships between adipose tissue distribution, insulin secretion and sensitivity, sleep-disordered breathing, and inflammation in obese adolescents.

METHODS

Cross-sectional study of 56 obese adolescents who underwent anthropometric measures, dual-energy X-ray absorptiometry, overnight polysomnography, oral glucose tolerance test (OGTT) and frequently sampled intravenous glucose tolerance test. Correlation and regression analyses were used to assess relationships between adiposity, insulin secretion and sensitivity, measures of sleep-disordered breathing (oxyhemoglobin nadir, SpO₂; apnea hypopnea index, AHI; arousal index, AI; maximum end-tidal CO₂; non-REM sleep duration), and inflammation (high-sensitivity C-reactive protein, hsCRP).

RESULTS

Subjects (55% female) were mean (SD) 14.4 (2.1) years, with BMI Z-score of 2.3 (0.4). AHI was >5 in 10 (18%) subjects and 1< AHI ≤5 in 22 (39%). Visceral adipose tissue area (VAT) was positively correlated with OGTT 1 and 2 h insulin and 1 h glucose, and hsCRP (r=0.3-0.5, p≤0.007 for each). VAT was negatively correlated with sensitivity to insulin (r=-0.4, p=0.005) and SpO₂ nadir (r=-0.3, p=0.04) but not with other sleep measures. After adjustment for BMI-Z, sex, population ancestry, age, and sleep measures, VAT remained independently associated with insulin measures and 1 h glucose, but no other measures of glycemia. SAT was not associated with measures of glycemia or insulin resistance.

CONCLUSIONS

Among adolescents with obesity, visceral adiposity was associated with insulin resistance, SpO₂ nadir, and inflammation. The independent association of visceral adiposity with insulin resistance highlights the potential role of VAT in obesity-related chronic disease.

Waist-hip ratio is an independent predictor of moderate-to-severe OSA in nonobese males: a cross-sectional study

BACKGROUND

Adiposity is a well-established risk factor for obstructive sleep apnea (OSA), but whether a combination of preferable anthropometric measurements may improve the accuracy of detecting OSA is unknown. This study aimed to explore the accuracies of the waist-hip ratio (WHR) in conjunction with the body mass index (BMI) when identifying the severity of OSA.

DESIGN

A total of 2012 participants in the China-Japan Friendship Hospital from January 2018 to December 2019 underwent anthropometric measurements and an overnight home sleep test (HST). The 244 subjects who met the criteria for obstructive sleep apnea (apnea-hypopnea index (AHI) ≥ 5 events/hour) were divided into four groups: Group A (55 patients with WHR ≥ 0.9 and BMI ≥ 28 kg/m²); Group B (12 patients with WHR < 0.9 and BMI ≥ 28 kg/m²); Group C (69 patients with WHR ≥ 0.9 and BMI < 28 kg/m²); and group D (108 patients with WHR < 0.9 and BMI < 28 kg/m²).

RESULTS

The AHI, apnea index (AI), hypopnea index (HI), and oxygen desaturation index (ODI) were significantly different among the 4 groups (p < 0.05). The WHR was positively correlated with AHI (r = 0.22, p < 0.001), AI (r = 0.270, p = 0.004), and ODI (r = 0.286, p = 0.0022) and negatively correlated with lowest oxygen pulse saturation (LSpO₂) (r = 0.246, p = 0.008) only in nonobese patients. Moreover, the WHR was found to be a screening marker for moderate-to-severe OSA in Group D (p < 0.05). When used to identify severe OSA in Group D, the WHR cut-off point of 0.873 yielded a sensitivity of 65% and specificity of 56% (p < 0.05).

CONCLUSION

In nonobese male OSA patients, WHR is a moderate screening marker for moderate-to-severe OSA and an independent risk factor for OSA severity.

Twenty-year follow-up of children with obstructive sleep apnea

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) in children is associated with acute metabolic, cardiovascular, and neuro-cognitive abnormalities. The long-term outcomes of childhood OSA into adulthood has not been established. We performed a 20-year follow-up of patients with polysomnographically documented OSA in childhood compared to a healthy control group to evaluate the long-term anthropometric, sleep, cognitive, and cardiovascular outcomes.

METHODS

Children diagnosed to have severe OSA between the ages of 1 - 17 years (4.87 ± 2.77) were prospectively contacted by telephone as young adults after approximately 20 years. Data collected included reported anthropometric, educational level, health history, and the Berlin questionnaire.

RESULTS

Young adults with confirmed severe OSA in childhood had significantly higher adulthood BMI (p=0.038), lower academic degrees (p<0.001), and more snoring (p=0.045) compared to controls. The AHI during childhood trended towards predicting cardiovascular outcomes and the Berlin questionnaire in adulthood.

CONCLUSIONS

Adults with history of severe childhood OSA have a high risk of having snoring, elevated BMI, and lower academic achievement in adulthood. Thus, children with severe OSA may be at increased risk of chronic diseases later in life. The intervening COVID-19 pandemic has introduced considerable additional neurobehavioral morbidity complicating the identification of the full long-term consequences of childhood OSA.

Polysomnographic comparison of sleep in children with obesity and normal weight without suspected sleep-related breathing disorder

Short sleep and obstructive apneas/hypopneas have been shown to be associated with childhood obesity. Still, few studies have compared sleep in children with obesity, without suspected sleep disordered breathing and normal weight peers by objective sleep measures and compared results with subjective parent assessment of sleep. Children with obesity aged 7-13 years (N = 44) and a matched group of normal weight children (N = 42) completed clinical polysomnography (Embla A10 Recording System). Parents scored their children's sleep on the Children's Sleep Habits Questionnaire (CSHQ). Mann-Whitney U tests were used to compare groups. There was a higher obstructive apnea/hypopnea index (AHI) (median obesity = 1.20 vs. median normal  = 0.66; z = -1.33, U = 560.50, p = 0.002) and number of oxygen desaturation events per hour (median obesity = 0.7 vs. median normal  = 0.2; z = -3.45, U = 402.50, p = 0.001) in the children with obesity compared to children with normal weight. The children with obesity had a significantly longer sleep duration (median obesity 8:50 h = vs. median normal = 8:32 h; z = -2.05, U = 687.00, p = 0.041), longer stage N2 sleep (median obesity = 87 min vs. median normal = 52 min; z = -2.87, U = 576.50, p = 0. 004) and shorter REM sleep (median obesity = 94 min vs. median normal = 121 min; z = 5.05, U = 1477.00, p ≤ .001). No differences were observed for time in sleep stage N1 and N3, wake time after sleep onset or the total arousal index . Further, no group differences were found on the CSHQ sleep-disordered breathing sub-scale (p = 0.399). The children with obesity demonstrated significantly more mild to moderate sleep disordered breathing than children with normal weight, although this was not corroborated by parent report.

The impact of obstructive sleep apnea on endothelial function during weight loss in an obese pediatric population

BACKGROUND

Childhood obesity is an increasing problem with substantial comorbidities such as obstructive sleep apnea (OSA) and increased cardiovascular morbidity. Endothelial dysfunction is an underlying mechanism related to both obesity and OSA.

RESEARCH QUESTION

To investigate the effect of weight loss on endothelial function and OSA in obese children and to determine whether a change in endothelial function can be linked to an improvement in OSA.

METHODS

Obese children between 8 and 18 years of age were recruited while entering a 12-month inpatient weight loss program. Patients were followed at 3 study visits: baseline, after 10 months of weight loss, and 6 months after ending the program (18 months). Anthropometry and endothelial function (EndoPAT) were determined at all study visits. At baseline, sleep screening with a portable device (ApneaLink) was performed. This was repeated after 10 months if OSA was diagnosed at baseline.

RESULTS

At baseline, 130 children were included, of which 87 had OSA (67%). Seventy-two patients attended the follow-up visit at 10 months, and 28 patients attended the follow-up visit at 18 months. The BMI z-score decreased after 10 months (from 2.7 (1.4-3.4) to 1.7 (0.5-2.7); p < 0.001) and remained stable at 18 months. Endothelial function improved significantly after weight loss, evidenced by a shorter time to peak response (TPR) and higher reactive hyperemia index (p = 0.02 and p < 0.001), and remained improved after 18 months (p < 0.001 and p = 0.007). After 10 months of weight loss, 10 patients had residual OSA. These patients had a higher TPR at 10 months (225 (75-285)s) than those without OSA (135 (45-225)s) and patients with a normalized sleep study (105 (45-285)s; p = 0.02). Linear mixed models showed that more severe OSA was associated with a worse TPR at baseline and less improvement after weight loss.

CONCLUSION

Weight loss improves endothelial function in an obese pediatric population. However, even after weight loss, endothelial function improved less in the presence of OSA.

Association of Pediatric Obstructive Sleep Apnea With Elevated Blood Pressure and Orthostatic Hypertension in Adolescence

Importance

Although pediatric guidelines have delineated updated thresholds for elevated blood pressure (eBP) in youth and adult guidelines have recognized obstructive sleep apnea (OSA) as an established risk factor for eBP, the relative association of pediatric OSA with adolescent eBP remains unexplored.

Objective

To assess the association of pediatric OSA with eBP and its orthostatic reactivity in adolescence.

Design, Setting, and Participants

At baseline of this population-based cohort study (Penn State Child Cohort) in 2000-2005, a random sample of 700 children aged 5 to 12 years from the general population was studied. A total of 421 participants (60.1%) were followed up in 2010-2013 after 7.4 years as adolescents (ages, 12-23 years). Data analyses were conducted from July 6 to October 29, 2020.

Main Outcomes and Measures

Outcomes were the apnea-hypopnea index (AHI) score, ascertained via polysomnography conducted in a laboratory; eBP measured in the seated position identified using guideline-recommended pediatric criteria; orthostatic hyperreactivity identified with BP assessed in the supine and standing positions; and visceral adipose tissue assessed via dual-energy x-ray absorptiometry.

Results

Among the 421 participants (mean [SD] age at follow-up, 16.5 [2.3] years), 227 (53.9%) were male and 92 (21.9%) were racial/ethnic minorities. A persistent AHI of 2 or more since childhood was longitudinally associated with adolescent eBP (odds ratio [OR], 2.9; 95% CI 1.1-7.5), while a remitted AHI of 2 or more was not (OR, 0.9; 95% CI 0.3-2.6). Adolescent OSA was associated with eBP in a dose-response manner; however, the association of an AHI of 2 to less than 5 among adolescents was nonsignificant (OR, 1.5; 95% CI, 0.9-2.6) and that of an AHI of 5 or more was approximately 2-fold (OR, 2.3; 95% CI, 1.1-4.9) after adjusting for visceral adipose tissue. An AHI of 5 or more (OR, 3.1; 95% CI, 1.2-8.5), but not between 2 and less than 5 (OR, 1.3; 95% CI, 0.6-3.0), was associated with orthostatic hyperreactivity among adolescents even after adjusting for visceral adipose tissue. Childhood OSA was not associated with adolescent eBP in female participants, while the risk of OSA and eBP was greater in male participants.

Conclusions and Relevance

The results of this cohort study suggest that childhood OSA is associated with adolescent hypertension only if it persists during this developmental period. Visceral adiposity explains a large extent of, but not all, the risk of hypertension associated with adolescent OSA, which is greater in male individuals.

Evaluation of Blood Levels of C-Reactive Protein Marker in Obstructive Sleep Apnea: A Systematic Review, Meta-Analysis and Meta-Regression

(1) Introduction: High sensitivity C-reactive protein (hs-CRP) and CRP are inflammatory biomarkers associated with several inflammatory diseases. In both pediatric and adult individuals with Obstructive Sleep Apnea (OSA) higher hs-CRP and CRP were observed, compared to controls. With the present systematic review, meta-analysis and meta-regression we expand upon previous meta-analyses in four ways: (1) We included 109 studies (96 in adults and 13 in children); (2) we reported subgroup and meta-regression analyses in adults with OSA compared to controls on the serum and plasma levels of hs-CRP; (3) we reported subgroup and meta-regression analyses in adults with OSA compared to controls on the serum and plasma levels of CRP; (4) we reported serum and plasma levels of both hs-CRP and CRP in children with OSA, always compared to controls. (2) Materials and Methods: The PubMed/Medline, Scopus, Cochrane Library, and Web of Science databases were searched to retrieve articles published until 31 May 2020, with no restrictions. The data included basic information involving the first author, publication year, country of study, ethnicity of participants in each study, age, BMI, and AHI of both groups, and mean and standard deviation (SD) of plasma and serum levels of CRP and hs-CRP. (3) Results: A total of 1046 records were retrieved from the databases, and 109 studies were selected for the analysis (96 studies reporting the blood levels of hs-CRP/CRP in adults and 13 studies in children). For adults, 11 studies reported plasma hs-CRP, 44 serum hs-CRP, 9 plasma CRP, and 32 serum CRP levels. For children, 6 studies reported plasma hs-CRP, 4 serum hs-CRP, 1 plasma CRP, and 2 serum CRP levels. Compared to controls, the pooled MD of plasma hs-CRP levels in adults with OSA was 0.11 mg/dL (p < 0.00001). Compared to controls, the pooled MD of serum hs-CRP levels in adults with OSA was 0.09 mg/dL (p < 0.00001). Compared to controls, the pooled MD of plasma CRP levels in adults with OSA was 0.06 mg/dL (p = 0.72). Compared to controls, the pooled MD of serum CRP levels in adults with OSA was 0.36 mg/dL (p < 0.00001). Compared to controls, the pooled MD of plasma hs-CRP, serum hs-CRP, plasma hs-CRP, and serum hs-CRP in children with OSA was 1.17 mg/dL (p = 0.005), 0.18 mg/dL (p = 0.05), 0.08 mg/dL (p = 0.10), and 0.04 mg/dL (p = 0.33), respectively. The meta-regression showed that with a greater apnea-hypapnea index (AHI), serum hs-CRP levels were significantly higher. (4) Conclusions: The results of the present systematic review, meta-analysis and meta-regression showed that compared to healthy controls plasma and serum levels of hs-CRP and serum CRP level were higher in adults with OSA; for children, and compared to controls, just plasma hs-CRP levels in children with OSA were higher.

Does neck circumference predict obstructive sleep apnea in children with obesity?

OBJECTIVES

Obstructive sleep apnea (OSA) affects 10-50% of children with obesity, but its identification is challenging and wait times for testing are long. Previous studies suggest that neck circumference (NC) and neck-to-height ratio (NHR) may predict OSA. Our objectives were to 1) evaluate associations of NC and NHR with OSA; 2) model NHR as a predictor of OSA, adjusting for age, sex, and Tanner stage; and 3) identify thresholds of NHR associated with OSA, in children with obesity.

METHODS

Participants were aged 8-17 years, with obesity (BMI >95%ile), undergoing polysomnography. Associations between NC and NHR with OSA were evaluated. NHR, age, sex and self-reported Tanner stage (early/late) were included in a negative binomial multiple regression model to predict obstructive apnea hypopnea index (OAHI).

RESULTS

71 children participated, with median age 14.8 years (IQR 12.6, 16.0), 54% male, median BMI z-score 2.5 (IQR 2.3, 2.7), and 77% late Tanner stage. OSA was severe in 18 children (25.4%), moderate in 12 (16.9%), and mild in 18 (25.4%). In the model, each 0.01 increase in NHR was associated with a 55% increase in OAHI (95% CI: 36%, 80%); boys had a 119% higher OAHI than girls (95% CI: 10%, 337%). Threshold NHR associated with moderate-severe OSA was 0.25 in females and 0.23 in males.

CONCLUSIONS

NHR and male sex independently predict OSA severity in children with obesity, adjusting for age and Tanner stage. Children with obesity and NHR above identified thresholds are more likely to have moderate-severe OSA, and may benefit from earlier polysomnography.

The Association Between Serum/Plasma Leptin Levels and Obstructive Sleep Apnea Syndrome: A Meta-Analysis and Meta-Regression

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is associated with various adipokines. Leptin, a common adipokine, has attracted considerable attention of many researchers in recent years. So far, there has been little agreement on whether blood leptin levels differ in patients with OSAS. Thus, this meta-analysis examined the relationship between serum/plasma leptin levels and the occurrence of OSAS.

METHOD

WanFang, Embase, CNKI, Medline, SinoMed, Web of Science, and PubMed were searched for articles before March 30, 2021, with no language limitations. STATA version 11.0 and R software version 3.6.1 were used to analyze the obtained data. The weighted mean difference and correlation coefficients were used as the main effect sizes with a random-effects model and a fixed-effects model, respectively. Trial sequential analysis was conducted using dedicated software.

RESULT

Screening of 34 publications identified 45 studies that met the inclusion criteria of this meta-analysis and meta-regression. Our results suggested that plasma/serum leptin levels were remarkably higher in individuals with OSAS than in healthy individuals. Subgroup analyses were performed based on OSAS severity, ethnicity, age, body mass index, assay type, and sample source. The serum and plasma leptin levels were increased in nearly all OSAS subgroups compared to those in the corresponding control groups. Meta-regression analysis indicated that age, BMI, severity, assay approaches, study design, PSG type and ethnicity did not have independent effect on leptin levels. Furthermore, a positive relationship between the serum/plasma leptin level and apnea-hypopnea index (AHI) was found in the meta-analysis. The results of the trial sequential analysis suggested that the enrolled studies surpassed the required information size, confirming that our study findings were reliable.

CONCLUSION

Our study results demonstrate that OSAS patients have higher leptin levels in serum/plasma compared to controls, and the serum/plasma leptin level is positively correlated with AHI, especially in adults.

A multidisciplinary weight loss intervention in obese adolescents with and without sleep-disordered breathing improves cardiometabolic health, whether SDB was normalized or not

OBJECTIVES

Pediatric obesity and sleep-disordered breathing (SDB) are strongly associated, and both promote metabolic impairments. However, the effects of a lifestyle intervention on the overall metabolic syndrome (MetS) are unknown. The objectives were i) to evaluate the effects of a lifestyle intervention on cardiometabolic risk (CMR), assessed with a dichotomous (MetS) and a continuous (MetScore_FM) instrument, in obese adolescents with and without SDB and ii) to compare the post-intervention cardiometabolic responses between adolescents with persistent (apnea-hypopnea index; AHI≥2) or normalized-SDB (AHI<2).

METHODS

Seventy-six adolescents with obesity recruited from two specialized institutions underwent a 9-12month diet and exercise intervention. Sleep and SDB (AHI≥2) were studied by polysomnography. Anthropometric parameters, fat mass (FM), glucose, insulin, lipid and leptin profiles, blood pressure (BP), MetScore_FM and MetS were assessed pre- and post-intervention. We performed comparisons between Non-SDB and SDB groups and between Normalized-SDB and Persistent-SDB subgroups.

RESULTS

Fifty participants completed the study. Pre-intervention, twenty youth had SDB (40%) with higher insulin concentrations and systolic BP than Non-SDB participants (p < 0.01), for a similar degree of obesity. Post-intervention, MetScore_FM (p < 0.001) and MetS prevalence (p < 0.05) were decreased in both groups. Eleven participants (55%) normalized SDB along with a decrease in insulin concentrations and BP (p < 0.05). Triglycerides, total cholesterol and LDL-cholesterol concentrations (p < 0.01) improved equally in the Normalized and Persistent-SDB subgroups.

CONCLUSION

SDB was associated with lower insulin sensitivity and higher BP but did not affect the lipid profile. A diet and exercise lifestyle intervention is effective in decreasing the CMR whether or not SDB was normalized in obese adolescents.

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.

Obstructive sleep apnea and insulin resistance in children with obesity

STUDY OBJECTIVES

Because existing data investigating obstructive sleep apnea (OSA) and insulin resistance (IR) are inconsistent, we examine OSA and IR in a pediatric obesity clinic.

METHODS

Children (2-18 years) in the obesity clinic (2013-2017) undergoing polysomnography (PSG), anthropometric measurements, and fasting laboratory tests were included. Linear regression assessed OSA defined by the obstructive apnea-hypopnea index (oAHI) with the homeostatic model assessment of insulin resistance (HOMA-IR). Secondary aims assessed oxygen desaturation index (ODI) and age interactions with HOMA-IR. Logistic regression models and receiver operating characteristic analysis were performed to investigate optimal oAHI and ODI cutoffs relative to HOMA-IR ≥ 3.

RESULTS

Eighty children were included (mean age, 11.4 ± 4.0 years; 56% female; 46% Caucasian; median body mass index [BMI], 34.6 kg/m² [interquartile ratio, 29.9-40.1], median BMI z-score, 2.5 [interquartile ratio, 2.3-2.8); 46% with oAHI ≥ 5 events/h. HOMA-IR was higher in the OSA group (oAHI ≥ 5 events/h): 5 vs 3.8 (P = .034). After adjustment for sex, race, and BMI z-score, oAHI ≥ 5 events/h retained significance with HOMA-IR (P = .041). HOMA-IR increased in older children (age ≥ 12 years) when adjusting for waist circumference z-score and waist-height ratio (statistical interaction, P = .020 and .034, respectively). Receiver operating characteristic showed optimal cut points of oAHI and ODI for predicting significant IR 4.9 (area under the curve, 0.70; 95% confidence interval, 0.57-0.83; sensitivity, 0.76; specificity, 0.66) and 4.6 (area under the curve, 0.68; 95% confidence interval, 0.55-0.80; sensitivity, 0.70; specificity, 0.67), respectively.

CONCLUSIONS

In a clinic-based pediatric cohort with obesity, OSA is associated with increased IR even after adjusting for confounders including obesity defined by the BMI z-score. Age ≥ 12 years was associated with AHI relative to IR after adjustment for waist circumference z-score and waist-height ratio. Significant IR could be discriminated by oAHI ≥ 4.9 with moderate sensitivity/specificity. Future studies are needed to verify these findings.

Sleep-disordered breathing in adolescents with obesity: When does it start to affect cardiometabolic health?

BACKGROUND AND AIMS

Pediatric obesity and sleep-disordered breathing (SDB) are associated with cardiometabolic risk (CMR), but the degree of severity at which SDB affects cardiometabolic health is unknown. We assessed the relationship between the CMR and the apnea-hypopnea index (AHI), to identify a threshold of AHI from which an increase in the CMR is observed, in adolescents with obesity. We also compared the clinical, cardiometabolic and sleep characteristics between adolescents presenting a high (CMR+) and low CMR (CMR-), according to the threshold of AHI.

METHODS AND RESULTS

114 adolescents with obesity were recruited from three institutions specialized in obesity management. Sleep and SDB as assessed by polysomnography, anthropometric parameters, fat mass (FM), glucose and lipid profiles, and blood pressure (BP) were measured at admission. Continuous (MetScore_FM) and dichotomous (metabolic syndrome, MetS) CMR were determined. Associations between MetScore_FM and AHI adjusted for BMI, sex and age were assessed by multivariable analyses. Data of 82 adolescents were analyzed. Multivariable analyses enabled us to identify a threshold of AHI = 2 above which we observed a strong and significant association between CMR and AHI (Cohen's d effect-size = 0.57 [0.11; 1.02] p = 0.02). Adolescents with CMR+ exhibited higher MetScore_FM (p < 0.05), insulin resistance (p < 0.05), systolic BP (p < 0.001), sleep fragmentation (p < 0.01) and intermittent hypoxia than CMR- group (p < 0.0001). MetS was found in 90.9% of adolescents with CMR+, versus 69.4% in the CMR- group (p < 0.05).

CONCLUSIONS

The identification of a threshold of AHI ≥ 2 corresponding to the cardiometabolic alterations highlights the need for the early management of SDB and obesity in adolescents, to prevent cardiometabolic diseases.

CLINICAL TRIALS

NCT03466359, NCT02588469 and NCT01358773.

Are obstructive sleep apnea and sleep improved in response to multidisciplinary weight loss interventions in youth with obesity? A systematic review and meta-analysis

BACKGROUND

Pediatric obesity is closely associated with obstructive sleep apnea (OSA) and short sleep duration. While multidisciplinary weight loss interventions are recommended for pediatric obesity management, the evidence for their effects on OSA severity and overall sleep in youth have not been systematically examined.

OBJECTIVES

To conduct a systematic review and meta-analysis investigating the effects of multidisciplinary weight loss interventions on OSA severity and prevalence, and on overall sleep health in youth with obesity.

METHODS

A systematic search of interventional studies (participants age range: 10-19 yrs) was performed using PubMed, CENTRAL and Embase, from inception to May 2019. The quality of the evidence was assessed using the Cochrane risk of bias tool.

RESULTS

Ten studies were included by the end of the screening process. Ninety percent of the included studies reported a decrease in OSA prevalence post-intervention, and OSA was normalized for 46.2-79.7% of the youth. The meta-analysis comprising seven longitudinal studies revealed significant reductions in apnea-hypopnea index (effect size: -0.51, 95%CI -0.94 to -0.08, p = 0.019), and oxygen desaturation index (effect size: -0.28, 95%CI = -0.50 to -0.05, p = 0.016). Seventy-five percent of the studies reported improved sleep duration in youth with OSA.

CONCLUSIONS

Evidence suggests that multidisciplinary weight loss interventions result in improvements in OSA severity and sleep duration in youth with obesity. Future randomized controlled trials are warranted to better assess and understand the independent implications of weight loss, fat mass decrease and chronic exercise on OSA and sleep health in this population.

Intramyocellular Lipids, Insulin Resistance, and Functional Performance in Patients with Severe Obstructive Sleep Apnea

PURPOSE

An increasing number of studies have linked the severity of obstructive sleep apnea (OSA) with metabolic dysfunction. However, little is known about the lipid compartments (intramyocellular [IMCL] and extramyocellular [EMCL] lipids) inside the musculature in these patients. The present study was designed to investigate the IMCL and EMCL, biochemical data, and functional performance in patients with severe OSA, and to examine the correlations between intramuscular lipid contents and test variables.

PARTICIPANTS AND METHODS

Twenty patients with severe OSA (apnea-hypopnea index [AHI]: ≥30/h; body mass index [BMI]: 26.05±2.92) and 20 age- and BMI-matched controls (AHI <5/h) were enrolled. Proton magnetic resonance spectroscopy was used to measure the IMCL and EMCL of the right vastus lateralis muscle. Biochemical data, including levels of fasting plasma glucose, insulin, lipid profiles, and high-sensitivity C-reactive protein (hsCRP), were measured. Insulin resistance index (IR) was calculated using the homeostasis model assessment method. Performance tests included a cardiopulmonary exercise test and knee extension strength and endurance measurements.

RESULTS

Patients with severe OSA had significantly (P<0.05) lower values of IMCL (14.1±5.4 AU) and EMCL (10.3±5.8 AU) compared to the control group (25.2±17.6 AU and 14.3±11.1 AU, respectively). Patients with severe OSA had significantly higher hsCRP, IR, and dyslipidemia compared with controls (all P<0.05). Furthermore, IMCL was negatively correlated with AHI, cumulative time with nocturnal pulse oximetric saturation lower than 90% (TSpO₂<90%) (ρ=-0.35, P<0.05), IR (ρ=-0.40, P<0.05), glucose (ρ=-0.33, P<0.05), and insulin (ρ=-0.36, P<0.05), and positively correlated with lowest oximetric saturation (ρ=0.33, P<0.01).

CONCLUSION

Skeletal muscle dysfunction and metabolic abnormalities were observed in patients with OSA that did not have obesity. IMCL was positively correlated with aerobic capacity and muscular performance, but negatively correlated with AHI and IR. Large-scale clinical trials are required to explore the complicated mechanism among OSA, intramuscular metabolism, and insulin action.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00813852.

Effects of CPAP on visceral adipose tissue in patients with obstructive sleep apnea: a meta-analysis

PURPOSE

The efficacy of obstructive sleep apnea (OSA) treatment with continuous positive airway pressure (CPAP) on visceral adipose tissue (VAT) yielded conflicting results. This meta-analysis was performed to assess whether OSA treatment with CPAP could reduce VAT.

METHODS

The PubMed, Cochrane Library, Embase, and Web of Science were searched before April 2019. Information on characteristics of study participants, pre- and post-CPAP treatment of VAT, and study design was utilized for analysis. Standardized mean difference (SMD) and 95% confidence interval (CI) were used to fully analyze the overall effects. Eleven studies were obtained and the meta-analysis was performed using RevMan v.5.2 and STATA 12.0.

RESULTS

A total of 11 studies (16 cohorts) were pooled into meta-analysis, which included 398 patients. The value of VAT before and after CPAP treatment showed no change in OSA patients (SMD = - 0.02, 95% CI - 0.16 to 0.12, z = 0.24, p = 0.81). Subgroup analyses were further conducted, which revealed that age, gender distribution, baseline body mass index, daily duration, CPAP therapy duration, measure, sample size, and study design did not affect the results.

CONCLUSIONS

This meta-analysis revealed that CPAP therapy has no effect on VAT in OSA patients. Further large-scale, well-designed randomized controlled trials are required to address this issue.

Association between obesity and sleep disorders in primary school children: a cross-sectional study

BACKGROUND The prevalence of obesity in primary school children in Jakarta has reached 14% in 2013. Among many disorders, obesity can cause sleep disorders. However, sleep disorders in children are often overlooked by parents, even though they can cause physical, social, and psychological impacts. Therefore, it is necessary to find the association between obesity and sleep disorders in primary school children. METHODS This cross-sectional study was performed between July–September 2015 on 107 children attending Menteng 01 Primary School, Jakarta. Children's weight and height were measured and then their parents filled out the brief infant sleep questionnaire (BISQ). The collected data were analyzed using chi-square. RESULTS In this study, 20.6% of the children were obese, which was higher than the prevalence of obesity in Jakarta. Meanwhile, sleep disorders occurred in 62.6% of children. Data about children’s sleep habits and parents’ opinion about their children’s sleep were obtained. It showed that snoring and parents’ opinion about sleep disorders were factors associated with children’s sleep disorder. Statistical analysis also showed a significant association between obesity and sleep disorders in children (p = 0.037). CONCLUSIONS The incidence of obesity in primary school children is high and is associated with sleep disorders.

Visceral fat, cardiometabolic risk factors, and nocturnal blood pressure fall in young adults with primary hypertension

The aims of this study were to assess associations of body fat levels and distribution with metabolic profiles and 24-hour blood pressure in young adults with primary hypertension. Visceral fat (VF) was estimated using dual-energy X-ray absorptiometry. VF was highly significantly associated with a high frequency of overweight/obesity, impaired fasting glucose, increased levels of triglycerides and LDL-cholesterol, and lowered level of HDL-cholesterol. The value of systolic blood pressure (SBP) nocturnal fall was similar between patients receiving RAAS inhibitors, beta-blockers, and calcium channel blockers. In multiple regression, the VF/weight ratio after adjusting for age, gender, total fat, and chronotherapeutic drug delivery was associated with the percentage SBP nocturnal fall (β = -.3108; 95% CI: -0.5923; -0.0980; P = .013). In males, excess VF increased the odds by 2.3 times for non-dipping blood pressure. Our results suggest that in young adult hypertensives, the VF/weight ratio might be associated with non-dipping blood pressure.

Facilitators and Barriers to Positive Airway Pressure Adherence for Adolescents. A Qualitative Study

RATIONALE

Low adherence to positive airway pressure (PAP) treatment for adolescents with obstructive sleep apnea (OSA) can have long-term cardiometabolic and developmental impact.

OBJECTIVES

To explore the facilitators and barriers to PAP use in adolescents with OSA.

METHODS

We conducted a qualitative study using a descriptive thematic analysis approach. A total of 21 interviews were conducted in the clinical setting with adolescents prescribed PAP to treat OSA within the previous 12 months. Interview audio recordings were transcribed verbatim for analysis. Transcripts were reviewed, and data were categorized using a coding framework developed by the research team. Codes were structured into themes related to the barriers and facilitators to using PAP.

RESULTS

Participants described numerous challenges with the physical design of the PAP machine, including the restriction of the tubing, the discomfort of the mask, and concerns with its size and weight. A period of adjustment to wearing and preparing the PAP machine was described whereby participants had to develop their own strategies to improve comfort. After initiating the therapy, the challenges experienced by participants were cited more often than the perceived benefits, particularly for those who were less adherent. Finally, the unique needs of adolescents were highlighted, which impacted the amount of family support desired in using PAP.

CONCLUSIONS

This study identifies factors affecting PAP adherence when prescribed in adolescence and highlights the need for ongoing dialogue between adolescents and their clinical team with respect to challenges encountered, troubleshooting, adherence strategies, and parental engagement.

The Association Between ENT Diseases and Obesity in Pediatric Population: A Systemic Review of Current Knowledge

Obesity in pediatric population is an important global problem. The prevalence of obesity in children is dramatically rising. According to World Health Organization, about 41 million children under the age of 5 years are obese or overweight worldwide. Overweight and obesity are well-known risk factors for a number of health disorders. Diseases commonly observed in this group of patients are metabolic disorders, type 2 diabetes mellitus, cardiovascular diseases, fatty liver disease, musculoskeletal problems, and many others. The main aim of this study was to present the current knowledge of the association between childhood obesity and common otorhinolaryngological disorders. It is suggested that obese children are more prone to suffer from otorhinolaryngological illnesses than the lean ones. Obesity may predispose to otorhinolaryngological diseases in various ways. It strongly interferes with the immune system (increases serum levels of interleukin 6, tumor necrosis factor, C-reactive protein, and leptin and reduces adiponectin concentration) affecting organs of the upper respiratory tract. Additionally, obesity induces mechanical disorders in the upper airways. According to our review, obesity predisposes to otitis media with effusion, acute otitis media, recurrent otitis media, obstructive sleep apnea, sensorineural hearing loss, adenotonsillar hypertrophy, and post-/perioperative complications after adenotonsillectomy. Obesity in children significantly correlates with both obstructive sleep apnea (OSA) and asthma and constitutes a significant component of "OSA, obesity, asthma" triad.

Beneficial effects of a lifestyle intervention program on C-reactive protein: impact of cardiorespiratory fitness in obese adolescents with sleep disturbances

The objectives of this study were to assess the relationship between inflammation and obstructive sleep apnea (OSA) and determine whether the lifestyle program's effects on inflammatory markers are associated with changes in anthropometric parameters, cardiorespiratory fitness, sleep duration, and OSA severity in severely obese adolescents. Participants were aged 14.6 (SD 1.2) yr, with a body mass index (BMI) of 40.2 (SD 6.5) kg/m². Sleep, anthropometric parameters, glucose metabolism, inflammatory profile, and cardiorespiratory fitness [V̇o_2peak relative to body weight (V̇o_2peakBW) and fat-free mass (V̇o_2peakFFM)] were assessed at admission and at the end of a 9-mo lifestyle intervention program (LIP). Associations between C-reactive protein (CRP) concentrations and BMI, sex, oxygen desaturation index (ODI), sleep fragmentation, total sleep time (TST), and V̇o_2peak were assessed via ANCOVA. Twenty-three subjects completed the study. OSA subjects ( n = 13) exhibited higher CRP concentrations and a trend for higher BMI than non-OSA subjects ( P = 0.09) at admission. After intervention, OSA was normalized in six subjects, and CRP significantly decreased in the OSA group and in the whole population. In both groups, leptin levels significantly decreased, whereas adiponectin concentrations increased. At admission, BMI adjusted for sex, arousal index, ODI, TST, and V̇o_2peakBW was associated with CRP levels (adjusted r² = 0.32, P < 0.05). The decrease in CRP concentrations postintervention was associated with enhanced V̇o_2peakFFM adjusted for sex, weight loss, and changed sleep parameters (adjusted r² = 0.75, P < 0.05). Despite higher amounts of CRP in OSA subjects, obesity severity outweighs the proinflammatory effects of OSA, short sleep duration, and low cardiorespiratory fitness. However, enhanced cardiorespiratory fitness is associated with the decrease of inflammation after controlling for the same parameters.

Childhood obesity, weight loss and developmental trajectories predict the persistence and remission of childhood sleep-disordered breathing

BACKGROUND

Obesity has been recognized as a risk factor for childhood sleep-disordered breathing (SDB), yet it remains unclear how obesity and weight change predict the course of childhood SDB.

OBJECTIVE

The objective of the study is to investigate the role of body weight, upper airway abnormalities and developmental trajectories on the persistence and remission of childhood SDB in the transition to adolescence.

METHODS

The Penn State Child Cohort is a representative population sample of 700 children (5-12 years), of whom 421 were followed up as adolescents (12-23 years). Participants underwent a clinical history, physical examination and polysomnography at both time points.

RESULTS

Obesity and enlarged tonsils were cross-sectionally associated with childhood SDB. Longitudinally, baseline obesity predicted the persistence of childhood SDB (OR = 3.75, 95% CI = 2.00-7.05), while weight loss predicted its remission (OR = 1.67, 95% CI = 1.11-2.50). Children with enlarged tonsils who remitted from SDB had not experienced significant weight loss and only 4.4% had undergone adeno/tonsillectomy. Body fat distribution/composition at follow-up was similar in those who had remitted from childhood SDB as compared with those who had never experienced SDB, while those who persisted with childhood SDB showed significant android distribution and visceral adiposity at follow-up.

CONCLUSIONS

Our data support a causal role for obesity and weight loss in the chronicity and remission, respectively, of childhood SDB in the transition to adolescence and suggest that remission of SDB is related to developmental trajectories of the upper airway in a significant proportion of children. Thus, targeting childhood obesity and weight gain should be a priority in the prevention and treatment of SDB during this critical developmental period.

The shifting relationship between weight and pediatric obstructive sleep apnea: A historical review

OBJECTIVES

For more than a century, pediatric obstructive sleep apnea (OSA) was associated with failure to thrive. However, that association has faded over the last few decades. A 21st century child with OSA is much more likely to be overweight than underweight. This raises the question: Has pediatric OSA changed over time, or has the rise of childhood obesity in the United States created a new, separate disease? This literature review explores the historical shift in the relationship between weight and OSA, and the associated changes in treatment.

RESULTS

We demonstrate a clear transition in the prevalence of failure to thrive and obesity in the OSA literature in the mid-2000s. What is less clear is whether these two clinical phenotypes should be considered two distinct diseases, or whether subtle differences in one set of pathophysiologic pathways-adenotonsillar hypertrophy, altered inflammation, and increased energy expenditure-can lead to divergent metabolic outcomes. More research is needed to fully elucidate the pathophysiology of OSA in children with obesity.

CONCLUSIONS

We may need new and different treatments for obesity-associated OSA as adenotonsillectomy-which is effective at reversing failure to thrive in OSA-is not as effective at treating OSA in children with obesity. One option is drug-induced sleep endoscopy, which could personalize and improve surgical treatment of OSA. There is some evidence that therapies used for OSA in adults (e.g., weight loss and positive airway pressure) are also helpful for overweight/obese children with OSA. Laryngoscope, 129:2414-2419, 2019.

Intermittent nocturnal hypoxia and metabolic risk in obese adolescents with obstructive sleep apnea

PURPOSE

There is conflicting data regarding the independent associations of obstructive sleep apnea (OSA) with metabolic risk in obese youth. Previous studies have not consistently addressed central adiposity, specifically elevated waist to height ratio (WHtR), which is associated with metabolic risk independent of body mass index.

OBJECTIVE

The objective of this study was to determine the independent effects of the obstructive apnea-hypopnea index (OAHI) and associated indices of nocturnal hypoxia on metabolic function in obese youth after adjusting for WHtR.

METHODS

Subjects had standardized anthropometric measurements. Fasting blood included insulin, glucose, glycated hemoglobin, alanine transferase, and aspartate transaminase. Insulin resistance was quantified with the homeostatic model assessment. Overnight polysomnography determined the OAHI and nocturnal oxygenation indices.

RESULTS

Of the 75 recruited subjects, 23% were diagnosed with OSA. Adjusting for age, gender, and WHtR in multivariable linear regression models, a higher oxygen desaturation index was associated with a higher fasting insulin (coefficient [standard error] = 48.076 [11.255], p < 0.001), higher glycated hemoglobin (coefficient [standard error] = 0.097 [0.041], p = 0.02), higher insulin resistance (coefficient [standard error] = 1.516 [0.364], p < 0.001), elevated alanine transferase (coefficient [standard error] = 11.631 [2.770], p < 0.001), and aspartate transaminase (coefficient [standard error] = 4.880 [1.444], p = 0.001). However, there were no significant associations between OAHI, glucose metabolism, and liver enzymes.

CONCLUSION

Intermittent nocturnal hypoxia rather than the OAHI was associated with metabolic risk in obese youth after adjusting for WHtR. Measures of abdominal adiposity such as WHtR should be considered in future studies that evaluate the impact of OSA on metabolic health.

Current child, but not maternal, snoring is bi-directionally related to adiposity and cardiometabolic risk markers: A cross-sectional and a prospective cohort analysis

PURPOSE

Obstructive sleep apnea (OSA), typically manifested as snoring, is closely associated with obesity. However, the directionality of associations of OSA with cardiometabolic risk markers is unclear, as obesity increases risk for OSA, and OSA results in excess weight gain and its metabolic consequences. Less is known about how obesity and OSA may relate in children and adolescents and whether maternal OSA may influence the development of obesity and cardiometabolic dysfunction in offspring.

BASIC PROCEDURES

Among 1078 children from the Project Viva cohort, we examined cross-sectionally and prospectively associations of parent-reported child or maternal snoring with cardiometabolic outcomes, including adiposity, adipokines, and insulin resistance.

MAIN FINDINGS

Cross-sectionally, child snoring was related to adiposity and metabolic risk, particularly body mass index (BMI; β 0.61kg/m2, 95% CI 0.33, 0.89; p<0.001), trunk fat mass index (β 0.23kg/m2, CI 0.12, 0.34; p<0.001), high-density lipoprotein cholesterol (β -1.47mg/dL, CI -2.69, -0.25; p=0.02), and metabolic risk z-score (β 0.08, CI 0.02, 0.14; p=0.01) after correction for covariates. Prospectively, adiposity (BMI, trunk fat, fat mass, and waist circumference) and cardiometabolic (leptin, HOMA-IR, CRP, and global metabolic risk) measures at mid-childhood (~7y) were associated with child snoring at the early teen visit (~12y) after correction for covariates. Child snoring at ~9y was related to changes in adiposity between mid-childhood and early teen visits.

CONCLUSIONS

Child but not maternal snoring, was related to child adiposity and cardiometabolic outcomes. Adiposity and child snoring are associated with each other cross-sectionally and are each predictive of the other among children/adolescents prospectively. These results suggest similar mechanisms in pediatric/adolescent populations as in adults for the development of sleep-disordered breathing and sleep apnea that will need to be confirmed in randomized clinical trials. Importantly, this research points to the need to target both sleep and obesity in order to break this vicious cycle.

Role of body mass index in school-aged children with lower urinary tract dysfunction: Does weight classification predict treatment outcome?

INTRODUCTION

Lower urinary tract (LUT) dysfunction comprises a large percentage of pediatric urology referrals. Childhood obesity is a major health concern, and has been associated with voiding symptoms. We assessed the impact of body mass index (BMI) on treatment outcomes of children presenting with LUT or bladder-bowel dysfunction (BBD).

STUDY DESIGN

Children aged 5-17 years diagnosed with non-neurogenic LUT dysfunction and no prior urologic diagnoses were identified. Patient demographics including BMI, lower urinary tract symptoms, constipation, medical and psychologic comorbidities, imaging, and treatment outcomes were evaluated. BMI was normalized by age and gender according to percentiles: underweight < 5th, healthy 5th to <85th, overweight 85th to <95th, and obese > 95th percentile. Uni- and multivariate analyses were performed to identify predictors of treatment response.

RESULTS

During an 18-month period, 100 children (54 girls, 46 boys) met the inclusion criteria. The mean age at diagnosis was 7.7 ± 2.4 years, and mean length of follow-up 15.3 ± 13.1 months. Sixty-nine patients were a normal weight, 22 were overweight, and nine were obese. Fifteen percent of the children had complete treatment response, 63% partial response, and 22% non-response. On univariate analysis, children with elevated BMI (p = 0.04) or history of urinary tract infection (p = 0.01) were statistically more likely to not respond to treatment. Controlling for all other variables, children with BMI > 85th percentile had 3.1 times (95% CI 1.11-8.64; p = 0.03) increased odds of treatment failure (Table).

DISCUSSION

BBD management includes implementation of a bowel program and timed voiding regimen, with additional treatment modalities tailored on the basis of the prevailing symptoms. We observed that school-aged children with a BMI ≥ 85th percentile were over three times more likely to experience treatment failure when controlling for all other patient characteristics including constipation and a history of urinary tract infection. Limitations of the study include the relatively small sample size, lack of uroflow with electromyography to confirm the presence or the absence of detrusor sphincter dyssynergia, and inconsistent anticholinergic dosing.

CONCLUSIONS

Nearly one-third of school-aged children presenting to our institution with LUT or BBD were overweight or obese when normalized for age and gender. Children with LUT dysfunction and elevated BMI are significantly less likely to experience treatment response.

Increased inflammation from childhood to adolescence predicts sleep apnea in boys: A preliminary study

While chronic systemic inflammation in obstructive sleep apnea (OSA) has been traditionally considered a consequence of intermittent hypoxia, several treatment studies targeting inflammation suggest that this process may precede the development of the disorder. A recent cross-sectional study in the Penn State Child Cohort (PSCC) revealed that inflammation largely mediates the association between visceral adiposity and OSA in adolescence. The purpose of this study was to examine for the first time whether, longitudinally, inflammation precedes OSA during this developmental period. A subsample of the PSCC with longitudinal sleep and inflammation data (n=51) was included in this study. Participants underwent 9-h polysomnography (22:00-7:00), physical exam, and fasting morning blood draw at both time points. Plasma C-reactive protein (CRP) was measured via ELISA. At follow-up, visceral, subcutaneous, and total fat area were assessed via dual X-ray absorptiometry. Sex differences in body composition emerged in adolescence, with boys having more visceral adiposity than girls. Longitudinal increases in waist circumference from childhood to adolescence were associated with increases in CRP (ΔCRP) and follow-up CRP in boys, but not girls. Furthermore, in boys, ΔCRP was associated with higher follow-up apnea/hypopnea index (AHI). When ΔCRP was entered into a model predicting follow-up AHI, Δwaist circumference was no longer significant, indicating that inflammation largely explains the association between increasing central obesity and OSA severity. These preliminary findings, in a longitudinal, non-clinical sample of children developing OSA, suggest that inflammation derived from visceral adipose tissue precedes the development of the disorder, suggesting a potential causal mechanism.

Effect of Obstructive Sleep Apnea Treatment on Lipids in Obese Children

Obesity in children is associated with several co-morbidities including dyslipidemia. Obstructive sleep apnea (OSA) is commonly seen in obese children. In adults, diagnosis of OSA independent of obesity is associated with cardiometabolic risk factors including dyslipidemia. There is limited data on the impact of treatment of OSA on lipids in children. The objective of the study was to examine the impact of treatment of OSA on lipids in 24 obese children. Methods: Seventeen children were treated with continuous positive airway pressure (CPAP) and five underwent adenotonsillectomy. Mean apnea hypopnea index prior to treatment was 13.0 + 12.1 and mean body mass index (BMI) was 38.0 + 10.6 kg/m². Results: Treatment of OSA was associated with improvement in total cholesterol (mean change = −11 mg/dL, p < 0.001), and low-density lipoprotein cholesterol (mean change = –8.8 mg/dL, p = 0.021). Conclusion: Obese children should be routinely screened for OSA, as treatment of OSA favorably influences lipids and therefore decreases their cardiovascular risk.

Body Fat Distribution Ratios and Obstructive Sleep Apnea Severity in Youth With Obesity

STUDY OBJECTIVES

Obesity and regional fat distribution, measured by neck fat mass percentage using dual-energy X-ray absorptiometry (DXA), correlate with obstructive sleep apnea (OSA) severity in adults. In obese children, neck-to-waist-circumference ratio predicts OSA. This study examined associations between body fat percentage and distribution and sleep-disordered breathing (SDB) severity in obese youth, measured with DXA.

METHODS

Cross-sectional retrospective study conducted at a tertiary children's hospital. Participants were aged 6 to 18 years with obesity (body mass index [BMI] > 99th percentile [BMI z-score 2.35] or > 95th percentile with comorbidity). They underwent polysomnography and DXA to quantify body fat percentage and distribution ratios (neck-to-abdominal fat percentage [NAF % ratio]). SDB was defined as apnea-hypopnea index (AHI) > 5 and OSA as obstructive AHI (OAHI) > 1 event/h. Relationships of BMI z-score and NAF % ratio to log AHI and log OAHI were evaluated.

RESULTS

Thirty individuals participated; 18 male; median age 14.1 years. Twenty-four individuals had BMI z-scores > 2.35. Ten had AHI > 5 events/h. NAF % ratio was significantly associated with log AHI in males and with log OAHI in all, whereas total fat mass percent was not. The association between log OAHI and NAF % ratio was significant in males, but not females. NAF % ratio was significantly associated with log OAHI in those with BMI z-score above 2.35.

CONCLUSIONS

NAF % ratio was associated with OSA severity in males and youth with BMI > 99th percentile; however, total fat mass percentage was not, suggesting that body fat distribution is associated with OSA risk in youth.

Asthma and Obstructive Sleep Apnea

Objective:

To get a comprehensive understanding about the relationship between obstructive sleep apnea (OSA) and asthma by reviewing the epidemiology, pathophysiology, and clinical manifestation and then summarizing the latest progress on diagnosis and treatment.

Data Sources:

Articles referred in this review were mainly collected from a comprehensive search of the PubMed published in English from 1990 to 2015 with the terms “OSA” and “asthma” as the main keywords. Highly regarded older publications were also included.

Study Selection:

Information about the features of the two diseases in common, the pathophysiologic association between them and their current treatments from the literature search were identified, retrieved, and summarized.

Results:

Both OSA and asthma are very prevalent conditions. The incidences of them have kept on rising in recent years. Asthma is often accompanied by snoring and apnea, and OSA often combines with asthma, as well. They have many predisposing and aggravating factors in common. Possible shared direct mechanistic links between them include mechanical effects, intermittent hypoxia, nerve reflex, inflammation, leptin, etc. Indirect mechanistic links include medication, nose diseases, smoking, obesity, and gastroesophageal reflux disease. Since OSA presents many similar features with nocturnal asthma, some scholars termed them as a sole syndrome – “alternative overlap syndrome,” and proved that asthma symptoms in those patients could be improved through the treatment of continuous positive airway pressure.

Conclusions:

OSA and asthma are closely associated in pathogenesis, symptoms, and therapies. With the growing awareness of the relationship between them, we should raise our vigilance on the coexistence of OSA in those difficult-to-control asthmatic patients. Further studies are still needed to guide the clinical works.

Inflammation mediates the association between visceral adiposity and obstructive sleep apnea in adolescents

Only a handful of studies, primarily in clinical samples, have reported an association between obesity, inflammation, and obstructive sleep apnea (OSA) in children and adolescents. No studies, however, have examined the pathogenetic link between visceral adiposity, systemic inflammation, and incident OSA in a large general population sample using objective measures of sleep and body fat. Adolescents (n = 392; mean age 17.0 ± 2.2 yr, 54.0% male) from the Penn State Child Cohort (PSCC) underwent 9-h overnight polysomnography; a DXA scan to assess body fat distribution; and a single fasting blood draw for the assessment of plasma interleukin-6 (IL-6), IL-6 soluble receptor (IL-6 sR), tumor necrosis factor alpha (TNFα), tumor necrosis factor receptor 1A (TNFR1), C-reactive protein (CRP), leptin, and adiponectin levels via ELISA. Visceral fat area was significantly elevated in moderate OSA (AHI ≥ 5), especially in boys. IL-6, CRP, and leptin were highest in adolescents with moderate OSA, even after adjusting for BMI percentile. Mediation analysis revealed that 42% of the association between visceral fat and OSA in adolescents was mediated by IL-6 (p = 0.03), while 82% of the association was mediated by CRP (p = 0.01). These data are consistent with the model of a feed-forward, vicious cycle, in which the release of proinflammatory cytokines by visceral adipocytes largely explains the association between central obesity and OSA; in turn, inflammation is also elevated in OSA independent of BMI. These findings, in a large, representative, non-clinical sample of young people, add to our understanding of the developmental pathogenesis of sleep apnea.

Role of sleep quality in the metabolic syndrome

Emerging evidence has assigned an important role to sleep as a modulator of metabolic homeostasis. The impact of variations in sleep duration, sleep-disordered breathing, and chronotype to cardiometabolic function encompasses a wide array of perturbations spanning from obesity, insulin resistance, type 2 diabetes, the metabolic syndrome, and cardiovascular disease risk and mortality in both adults and children. Here, we critically and extensively review the published literature on such important issues and provide a comprehensive overview of the most salient pathophysiologic pathways underlying the links between sleep, sleep disorders, and cardiometabolic functioning.

Metabolic consequences of snoring in adolescents and younger adults: a population study in Chile

STUDY OBJECTIVES

To investigate the potential association between snoring and other symptoms indicative of sleep-disordered breathing and metabolic syndrome (MetS) in Hispanic adolescents and younger adults using a large population-based survey.

METHODS

Sleep-related information, anthropometric measurements and fasting blood samples markers of MetS were obtained from subjects aged 15-40 years collected through the 2nd Chilean Health Survey. Regression models were constructed to evaluate the associations of snoring with MetS, hypertension and serum cholesterol levels. The modulating effect of sleep duration was accounted for in the models.

RESULTS

A total of 2147 subjects (42% males, mean age 27.9±7.6 years) were included. Snoring and short sleep duration were present in 43.5 and 25% of the entire population, respectively. MetS was detected in 19.5% of the subjects. In the adjusted regression model, the odds of MetS among snoring subjects were 2.13 times higher (95% confidence interval (CI): 1.52-2.99; P<0.01), and 1.53-fold higher odds of elevated cholesterol also emerged (95% CI: 1.12-2.10; P<0.01). However, the odds of hypertension were not increased by the presence of snoring after adjusting for confounders. In addition, snoring was associated with an increase of 7.26  and 6.56 mg dl^-1 for total and low-density lipoprotein cholesterol, respectively, even after adjusting for age, sex and body mass index. Short sleep duration was associated with a small albeit significant risk increase for high systolic blood pressure.

CONCLUSIONS

In this large population-based sample of young Hispanic adults and adolescents, snoring, but not sleep duration, emerged as an independent risk factor for dyslipidemia and MetS, but not for hypertension.

Obstructive sleep apnoea in children with obesity

AIMS

The aim of this study was to identify factors that predict risk of obstructive sleep apnoea (OSA) in obese children, which could aid in prioritising sleep studies.

METHODS

A retrospective chart review was undertaken of obese children seen in the KOALA weight management clinic and Sleep clinic. Data collected included demographics, clinical history, examination findings, biochemical markers, and polysomnogram results.

RESULTS

Two hundred seventy-two obese children were seen in the KOALA clinic out of which 54 (20%) were also seen in the Sleep clinic because of snoring. Thirty-two were referred by the KOALA clinic; the remaining 22 were referred by other medical practitioners prior to being seen in the KOALA clinic. Thirty-nine had polysomnograms. The time from referral to Sleep clinic ranged from 10 days to 1.5 years with 50% seen within 6 months; with similar time gap between the blood tests and time of polysomnograms. Thirty-six percent (14/39) were reported to have OSA. Six children were Aboriginal/Torres Strait Islander (ATSI) and all had OSA, which was statistically significant (P = 0.004). There was a statistically significant correlation between high-sensitivity C-reactive protein (hs-CRP) and obstructive event index (OEI) in rapid eye movement (REM) sleep. (r = 0.50, P = 0.04). Correlation between low-density lipoprotein (LDL) and OEI in REM was r = 0.36, P = 0.06, which approached significance.

CONCLUSIONS

Ethnicity was a significant factor with more obese ATSI children having OSA. The significant correlation between hs-CRP with OEI is consistent with findings of previous studies. Several factors (glycosylated haemoglobin, LDL) approached significance.

Natural history of sleep disordered breathing in prepubertal children transitioning to adolescence

Because there is a lack of agreed upon diagnostic criteria, it is critical to understand the natural history of obstructive sleep apnoea (OSA) in children in order to establish treatment strategies based on objective data.The Penn State Child Cohort is a representative, general-population sample of 700 elementary school children at baseline, of whom 421 were reassessed 8 years later, during adolescence.The remission of childhood apnoea-hypopnoea index (AHI) ≥2 events per h in adolescence was 52.9%. Using the higher threshold of AHI ≥5 events per h, remission was 100.0%, with 50.0% partially remitting to AHI 2- <5 events per h and the other half remitting to AHI <2 events per h. The incidence of adolescent AHI ≥2 events per h in those with childhood AHI <2 events per h was 36.5%, while the incidence of AHI ≥5 events per h in those with childhood AHI <5 events per h was 10.6%. This longitudinal study confirms that prepubertal OSA tends to resolve naturally during the transition to adolescence, and that primary snoring and mild sleep disordered breathing (SDB) do not appear to be strongly associated with progression to more severe SDB.The key risk factors for SDB in adolescence are similar to those found in middle-aged adults (i.e. male sex, older age and obesity). Moreover, consistent with recent studies in adults, this study includes the novel cross-sectional finding that visceral fat is associated with SDB as early as adolescence.

Impact of obstructive sleep apnoea on insulin resistance in nonobese and obese children

Obstructive sleep apnoea (OSA) has been inconsistently associated with insulin resistance and adverse metabolic states. We aimed to assess independent contributions of OSA to insulin resistance and dyslipidaemia in a large paediatric cohort.

Habitually snoring children underwent overnight polysomnography, anthropometric measurements and fasting laboratory evaluations. Primary outcome measures included insulin, glucose, homeostasis model of insulin resistance, lipoproteins and sleep disturbance measures.

Among 459 children aged 5–12 years, obesity was the primary driver of most associations between OSA and metabolic measures, but sleep duration was inversely associated with glucose levels, with N3 and rapid eye movement (REM) sleep being negatively associated and sleep fragmentation positively associated with insulin resistance measures. In children with mild OSA, the presence of obesity increased the odds for insulin resistance, while higher apnoea/hypopnoea index values emerged among obese children who were more insulin-resistant.

The exclusive presence of interactions between OSA and obesity in the degree of insulin resistance is coupled with synergistic contributions by sleep fragmentation to insulin resistance in the context of obesity. Insufficient N3 or REM sleep may also contribute to higher glycaemia independently of obesity. Studies are needed to better delineate the roles of puberty and sleep fragmentation in insulin resistance and the metabolic syndrome.

Sleep-disordered breathing, systemic adipokine secretion, and metabolic dysregulation in overweight and obese children and adolescents

OBJECTIVE

Obstructive sleep apnea (OSA) is common among overweight and obese children, and it is an independent risk factor for developing metabolic syndrome. However, the mechanisms linking OSA and metabolic syndrome are still unclear, but a role for adipose tissue dysfunction caused by intermittent hypoxia has been suggested. Therefore, the goal of this study was to investigate the relationship between OSA and systemic adipokine concentrations in overweight and obese children.

METHODS

We included 164 overweight and obese children in a tertiary center and distributed them in groups based on their obstructive apnea-hypopnea index (111 controls, 28 mild OSA, 25 moderate-to-severe OSA). All subjects underwent polysomnography and a blood sample was taken to determine leptin, adiponectin, tumor necrosis factor alpha, and interleukin-6 levels.

RESULTS

No significant differences were found in adipokine levels between subjects with or without OSA. Leptin correlated with oxygen desaturation index (r = -0.17, p = 0.03), adiponectin correlated with mean oxygen saturation (r = 0.24, p = 0.002) and with the percentage of sleep time with an oxygen saturation >95% (r = 0.25, p = 0.001). However, these associations did not persist after correction for adiposity. No correlations between interleukin-6 and tumor necrosis factor alpha, and OSA severity were found.

CONCLUSION

These results suggest that serum adipokine levels are mostly dependent on central obesity, while they are not influenced by OSA in an obese pediatric population.

Metabolic alterations in adolescents with obstructive sleep apnea

IMPORTANCE

Obesity is one of the leading health concerns in developed and in developing countries. The risk of obstructive sleep apnea (OSA) is greatly increased by obesity. Obesity is known to be associated with the Metabolic Syndrome and cardiovascular disease in adults. This same association in children is not well defined. Understanding the relationship of obesity, OSA, and metabolic alterations in children would improve understanding of the risks of cardiovascular disease into adulthood.

OBJECTIVE

To evaluate the association of OSA and metabolic outcomes, including lipid variables and insulin resistance, in obese adolescents.

METHODS

Retrospective, case-control series at a tertiary care children's hospital. Obese adolescents aged 12-18 years who underwent overnight polysomnography (PSG) and routine laboratory testing for lipid levels, fasting glucose, and insulin from January 1, 2006 to December 31, 2012.

RESULTS

A total of 42 patients with a mean age of 14.1±1.9 years were analyzed. Nineteen (45.2%) were male. The mean body mass index (BMI) z score was 2.23±0.86, and all patients were obese (BMI z score >95th percentile). Triglyceride, fasting blood glucose, insulin, and homeostasis model assessment-insulin resistance (HOMA-IR) levels were significantly higher in patients with OSA when compared to those with No-OSA (p<0.01). There was incremental worsening of insulin and HOMA-IR with greater severity of OSA. The apnea-hypopnea index (AHI) was positively and significantly correlated with blood glucose and HOMA-IR (p=0.01and p<0.001, respectively). Multiple linear regression analysis showed that the AHI was a predictor of blood glucose (p=0.04) and HOMA-IR (p=0.01) independent of age, gender, total sleep time and BMI z score. Logistic regression analysis showed that elevated levels of blood glucose predicted severe OSA (p=0.02) independent of gender and BMI z score. Elevation in HOMA-IR predicted severe OSA (p=0.004).

CONCLUSION

OSA severity is associated with increased fasting insulin, blood glucose and HOMA-IR even after controlling for the age, and BMI z score in adolescents.

Metabolic changes in normal- and underweight children with obstructive sleep-disordered breathing

OBJECTIVE

This study evaluates the metabolic profile of normal- and underweight children with sleep-disordered breathing (SDB) due to adenotonsillar hypertrophy.

METHODS

A total of 39 children aged 3-15 years with SDB and 28 age- and gender-matched controls were included in the study. Body mass index z score, blood pressure, and fasting serum levels of triglycerides (TGs), high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol, very-low-density lipoprotein (VLDL), blood glucose, plasma insulin, and homeostatic model assessment (HOMA) were determined in both case patients and controls.

RESULTS

We observed significantly lower levels of fasting blood glucose (p = 0.015) and higher levels of HDL (p = 0.002), LDL (p = 0.002), and cholesterol (p = 0.001) in case patients than in controls. The mean values of fasting insulin and HOMA were higher in case patients (6.42 ± 6.47 and 1.40 ± 1.48) than in controls (5.31 ± 3.40 and 1.20 ± 0.84) respectively. No direct correlation between indices of severity of SDB and various metabolic and blood pressure parameters was found. When the effect of body weight was studied by subgrouping case patients according to normal weight and underweight, significant increases in the levels of fasting insulin (p = 0.039), HOMA (p = 0.017), and fasting blood glucose (p = 0.021) were observed. Also, a significant correlation was observed between the duration of illness and fasting insulin (p = 0.023), HOMA (p = 0.020), fasting glucose (p = 0.004), and diastolic blood pressure (p = 0.030).

CONCLUSION

This study shows an independent effect of body weight and duration of illness on various metabolic and blood pressure parameters in normal- and underweight children with SDB.