Relationship between body fat distribution and upper airway dynamic function during sleep in adolescents

Is Reducing the Obesity Epidemic in Children and Adolescents Really a Mission Impossible?

The prevalence of pediatric excess weight has reached such levels that there are fears of a sharp increase in associated noncommunicable diseases when today's children become adults [...].

Associations of fat, bone, and muscle indices with disease severity in patients with obstructive sleep apnea hypopnea syndrome

PURPOSE

To investigate the relationship between obstructive sleep apnea hypopnea syndrome (OSAHS) severity and fat, bone, and muscle indices.

METHODS

This study included 102 patients with OSAHS and retrospectively reviewed their physical examination data. All patients underwent polysomnography, body composition analysis, dual-energy X-ray absorptiometry, computed tomography (CT) and blood test. Correlation and multiple linear regression analyses were performed using SPSS 22.0.

RESULTS

Among the fat indices, fat mass (FM) (r = 0.27-0.43), body fat percentage (BFP) (r = 0. 25-0.35), visceral fat area (VFA) (r = 0.28-0.40) and trunk fat mass (TFM) (r = 0.26-0.34) were positively correlated with hypopnea index (HI), apnea-hypopnea index (AHI), oxygen desaturation index (ODI), and percent of time spent with oxygen saturation below 90% (T90%), respectively, and negatively correlated with mean pulse oxygen saturation (SpO2) (r= -0.28--0.41). For bone indexes, T8, T9, T11, L1-CT value, mean vertebral CT value and 25-Hydroxyvitamin D3 were positively correlated with mean SpO2 (r = 0.23-0.32), respectively. For muscle indexes, pectoralis muscle density (PMD) was negatively correlated with HI, AHI, and ODI (r= -0.20--0.36) and positively correlated with mean SpO2 (r = 0.26). In separate models predicting sleep measures, AHI increased by 0.36, 0.29, 0.34 and 0.25 events/h per unit increase in FM, BFP, VFA, and triglyceride (TG), respectively. AHI decreased by 0.27 per unit increase in PMD. T90% increased with FM, BFP, VFA, WHR, TG and total cholesterol (TC), but decreased with appendicular skeletal muscle mass (ASM) and PMD respectively.

CONCLUSION

Higher fat levels and lower vertebral CT values, muscle mass and density correlated with a higher degree of OSAHS severity. Intermittent hypoxia may affect fat, bone, and muscle metabolism in patients with OSAHS.

Correlation of cephalometric variables with obstructive sleep apnea severity among children: a hierarchical regression analysis

OBJECTIVE

To evaluate the correlation between cephalometric parameters and apnea-hypopnea index (AHI) after controlling gender, body mass index (BMI), and adenoid size in children with obstructive sleep apnea (OSA).

METHODS

Sixty-four children with OSA (40 males, 24 females, 8.72 ± 0.899 years) were chosen by simple random sampling for a cross-sectional study from January 2018 to March 2022. They were diagnosed with OSA, assessed by Obstructive Sleep Apnea-18 questionnaire and home polysomnography and underwent lateral cephalograms.

RESULTS

Hierarchical regression analysis indicated that cephalometric parameters (except adenoid size) were associated with OSA severity, explaining 18.1% of the AHI variance. Among cephalometric measurements, AHI was positively associated with H-RGn and N-Go-Me angle (p< 0.05) and negatively associated with NP (p< 0.05).

CONCLUSION

The sagittal diameter of the oropharynx, lower gonial angle, and hyoid position are significant AHI predictors in children with OSA, independent of demographic characteristics and adenoid size.

Non-Pharmacological Treatment for Cardiovascular Risk Prevention in Children and Adolescents with Obesity

In younger generations, excess weight has reached very alarming levels. Excess weight in adults is associated with increased mortality and morbidity from cardiovascular disease. However, it is not easy to distinguish to what extent these effects are the result of obesity itself or how much is due to the various cardiovascular risk factors that often accompany excess weight. Several risk factors, such as hypertension, dyslipidemia, hyperuricemia, glucose intolerance, and type 2 diabetes mellitus, are already present in pediatric age. Therefore, early intervention with the goal of correcting and/or eliminating them is particularly important. In the child and adolescent with obesity, the first approach to achieve weight reduction and correct the risk factors associated with severe excess weight should always be non-pharmacologic and based on changing poor eating habits and unhealthy lifestyles. The purpose of this review is to give an update on non-pharmacological interventions to be implemented for cardiovascular prevention in children and adolescents with obesity, and their effectiveness. In particular, interventions targeting each individual cardiovascular risk factor will be discussed.

Sleep-disordered breathing and pregnancy outcomes: The impact of maternal oxygen saturation

OBJECTIVE

To investigate pathological associations between sleep-disordered breathing (SDB) and pregnancy outcomes.

METHODS

From May 2016 to September 2019, obese women during their uncomplicated singleton pregnancies underwent screening sleep questionnaires, oxygen saturation monitoring, and, in proper cases, complete overnight polysomnography. Their medical records were also recorded.

RESULTS

In all, 112 pregnant women were included in the study cohort; 44 showed an oxygen desaturation index ≥10, and their newborns had a significantly higher rate of congenital abnormalities and respiratory distress syndrome compared with the women with normal pulse oximetry. Stepwise multivariate regression analysis showed that basal oxygen saturation was independently associated with the occurrence of fetal growth restriction.

CONCLUSION

Among obese pregnant women, the rate of congenital abnormalities is higher in the ones with altered pulse oximetry. Maternal basal oxygen saturation in the first trimester of pregnancy predicts fetal growth restriction independently of maternal age, ethnicity, body mass index, gravidity, and hypertensive disorders of pregnancy.

Relationships of orexigenic and anorexigenic hormones with body fat distribution in patients with obstructive sleep apnea syndrome

PURPOSE

We aimed to examine the relationships of disease activity and risk factors with serum levels of orexigenic and anorexigenic hormones in patients with obstructive sleep apnea syndrome (OSAS).

METHODS

Fasting blood samples were taken for hormonal analysis of all participants, abdominal/neck bioimpedance measurements were recorded, and polysomnography (PSG) analyses were performed. According to the apnea-hypopnea index (AHI), 34 patients with newly diagnosed OSAS and 34 participants without OSAS were compared.

RESULTS

The median body mass index (BMI) measured in the OSAS group was 30.39 kg/m² and AHI was 18.95 and these values were 25.40 kg/m² and 1.55 in the control group. There was a higher level of visceral adiposity and neuropeptide Y (NPY) in the moderate-to-severe OSAS group compared to the mild OSAS and control groups, and in the mild OSAS group compared to the control group (p = 0.001, p < 0.001). A positive correlation between the level of NPY and AHI and BMI (p < 0.001, p = 0.011), and a negative correlation between NPY levels and oxygen saturation (p = 0.001) was found. Oxygen saturation and desaturation rates were correlated with body fat percentage, body fat mass, abdominal adiposity, visceral adiposity, resting metabolic rate, and NPY levels.

CONCLUSIONS

The visceral adiposity ratio and increase in NPY levels are important parameters that increase the severity of OSAS. Considering the negative effects of NPY on vascular endothelium, measurement of basal NPY level before PSG in patients with OSAS is considered a parameter related to disease severity.

Childhood diabetes and sleep

Sleep modulates glucose metabolism, both in healthy states and in disease. Alterations in sleep duration (insufficient and excessive) and obstructive sleep apnea may have reciprocal ties with obesity, insulin resistance and Type 2 diabetes, as demonstrated by emerging evidence in children and adolescents. Type 1 diabetes is also associated with sleep disturbances due to the influence of wide glycemic fluctuations upon sleep architecture, the need to treat nocturnal hypoglycemia, and the need for glucose monitoring and insulin delivery technologies. In this article, we provide an extensive and critical review on published pediatric literature regarding these topics, reviewing both epidemiologic and qualitative data, and provide an overview of the pathophysiology linking sleep with disorders of glucose homeostasis.

Neck fat and obstructive sleep apnea in obese adolescents

STUDY OBJECTIVES

Increased neck circumference, a surrogate for the neck fat that can narrow the upper airway in obese individuals, is a risk factor for obstructive sleep apnea syndrome (OSAS) in adults, but the association between neck fat and OSAS in adolescent males and females is unknown. We hypothesized that obese adolescents with OSAS have more neck fat than controls, females more neck fat than males, and that neck fat correlates with obesity and OSAS severity.

METHODS

Obese adolescents with OSAS and obese and normal-weight controls underwent upper airway magnetic resonance imaging, polysomnography, and anthropometrics, including neck circumference measurement. Intra-neck and subcutaneous neck fat measurements were manually segmented and compared among the three groups using ANOVA and between males and females using t-tests. The relationship between polysomnographic parameters and neck fat measurements was assessed in adolescents with OSAS using Pearson correlations.

RESULTS

One-hundred nineteen adolescents (38 females) were studied: 39 obese with OSAS, 34 obese controls, and 46 normal-weight controls. Neck fat was not greater in adolescents with OSAS compared to obese controls (p=0.35), and neck fat volume was not related to OSAS severity (p = 0.36). However, obese adolescents had more neck fat than normal-weight controls (p < 0.001), and neck fat volume correlated with neck circumference (r = 0.53, p < 0.001). Females had significantly greater cross-sectional neck fat than males (p < 0.001).

CONCLUSIONS

While neck fat is associated with obesity and neck circumference in adolescents and is greater in females versus males, it does not appear to correlate with presence and severity of OSAS.

Evaluation of Central Obesity, Increased Body Mass Index, and its Relation to Oropharyngeal Airway Space Using Lateral Cephalogram in Risk Prediction of Obstructive Sleep Apnea

Introduction

Maxillofacial radiologists play a significant role in detecting airway changes using radiographic tools. Clinical examination parameters and lateral cephalogram parameters play a vital role in diagnosing obstructive sleep apnea (OSA) and dreadful consequences.

Aim and Objectives

This study aims to evaluate central obesity, increased body mass index (BMI), and its relation to oropharyngeal airway space using lateral cephalogram in risk prediction of OSA. Objectives are to measure central obesity and BMI.

Methodology

BMI is measured using World Health Organization guidelines to measure oropharyngeal airway space and the tongue and soft palate area using lateral cephalogram to predict OSA's risk using Berlin's questionnaire. Age group between 18 and 60 years with 20 individuals in each group will be present in the study.

Conclusion

Cephalometric upper airway space and soft-tissue variables in different BMI groups were compared, and it was found that there was a decrease in SPAS, MAS with an increase in BMI, and in patients with BMI <24, there was narrower nasopharynx and oropharynx.

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.

COVID-19 and ethnicity: A novel pathophysiological role for inflammation

INTRODUCTION

There have been recent mounting concerns regarding multiple reports stating a significantly elevated relative-risk of COVID-19 mortality amongst the Black and Minority Ethnic (BAME) population. An urgent national enquiry investigating the possible reasons for this phenomenon has been issued in the UK. Inflammation is at the forefront of COVID-19 research as disease severity appears to correlate with pro-inflammatory cytokine dysregulation. This narrative review aims to shed light on the novel, pathophysiological role of inflammation in contributing towards the increased COVID-19 mortality risk amongst the BAME population.

METHODS

Searches in PubMed, Medline, Scopus, medRxiv and Google Scholar were performed to identify articles published in English from inception to 18th June 2020. These databases were searched using keywords including: 'COVID-19' or 'Black and Minority Ethnic' or 'Inflammation'. A narrative review was synthesized using these included articles.

RESULTS

We suggest a novel pathophysiological mechanism by which acute inflammation from COVID-19 may augment existing chronic inflammation, in order to potentiate a 'cytokine storm' and thus the more severe disease phenotype observed in the BAME population. Obesity, insulin resistance, cardiovascular disease, psychological stress, chronic infections and genetic predispositions are all relevant factors which may be contributing to elevated chronic systemic inflammation amongst the BAME population.

CONCLUSION

Overall, this review provides early insights and directions for ongoing research regarding the pathophysiological mechanisms that may explain the severe COVID-19 disease phenotype observed amongst the BAME population. We suggest 'personalization' of chronic disease management, which can be used with other interventions, in order to tackle this.

Prevalence of malocclusions and oral dysfunctions in children with persistent sleep-disordered breathing after adenotonsillectomy in the long term

STUDY OBJECTIVES

To evaluate the prevalence of craniofacial/orthodontic abnormalities and oral dysfunctions in a population of children with persistent sleep-disordered breathing despite adenotonsillectomy.

METHODS

Medical charts of 4,000 children with sleep-disordered breathing operated on in a tertiary hospital were retrospectively reviewed. Patients reporting persistent sleep-disordered breathing symptoms were invited to an orthodontic/myofunctional evaluation following the Sleep Clinical Score), followed by a 1-night ambulatory type III sleep study.

RESULTS

One hundred nonsyndromic symptomatic patients were examined (mean age 8.8 ± 3.5 years), from 1 to 12 years after surgery (mean 4.6 ± 3.1 years); 24% were overweight/obese; 69 had a sleep study. Although prevalent, oronasal abnormalities and malocclusions were not specifically associated with pathological sleep parameters (cartilage hypotonia 18%, septal deviation 5%, short lingual frenulum 40%). Malocclusions were associated with a higher respiratory event index in children under 8 years only, whereas an impaired nasal dilator reflex and tongue immaturity were associated with an increased obstructive respiratory event index in all patients (1.72 ± 2.29 vs 0.72 ± 1.22 events/h, P = .011) and Respiratory Event Index, respectively (3.63 ± 3.63 vs 1.19 ± 1.19 events/h). Male sex, phenotype, nasal obstruction, oral breathing, and young age at surgery (< 3 years) were significantly related to higher respiratory event index. Using the Sleep Clinical Score > 6.5 cut-off, patients with persistent sleep apnea were significantly distinct from chronic snoring (2.72 ± 2.67 vs 0.58 ± 0.55, P < .01).

CONCLUSIONS

Oronasal anatomical and functional abnormalities were quite prevalent and various in persistent sleep-disordered breathing after adenotonsillectomy. Nasal disuse and tongue motor immaturity were associated with a higher obstructive respiratory event index in the long term, whereas craniofacial risk factors might have a more pronounced impact at younger age.

Prevalence of interstitial and other lung diseases on Aruba

Background: Health care management has to be based on the local prevalence of diseases and the local diagnostic and therapeutic needs. So far, no systematic registration system for various lung diseases exists on Aruba. Questions that need to be answered are: what specific lung disorders occur on Aruba, and what are the specific needs there? The aim of this study was to assess the prevalence of lung disorders and the diversity of the patient population. Methods: Retrospectively, all records (n=2352) of patients of the Department of Respiratory Diseases of the Dr. Horatio E. Oduber Hospital, Aruba, who were seen at the clinic at least once in the period between January 2010 and October 2014 were reviewed. Results: Asthma (22%) and sleeping disorders (20%) were the most prevalent diagnoses. The mean body mass index (BMI) of the overall lung patient population was 31.6 kg/m². Obstructive sleep apnea syndrome (OSAS) was the most frequently diagnosed sleeping disorder (78.4%). A diagnosis of interstitial lung diseases (ILD) was established in 4.4% of the cases. Among the ILDs, non-specific interstitial pneumonia (NSIP: 28%), sarcoidosis (18%) and idiopathic pulmonary fibrosis (IPF: 16%) were the most frequent. Conclusion: Obesity and OSAS appeared to be major problems on Aruba. Increased awareness, education, and diagnostic facilities are required to prevent and diagnose obesity and OSAS in an early stage. NSIP, sarcoidosis and IPF are the most frequently diagnosed ILDs on Aruba, and optimization of ILD management is warranted, considering new treatment options available for ILD, especially for IPF.(Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 217-225)

Is neck circumference an appropriate tool to predict cardiovascular risk in clinical practice? A cross-sectional study in Chilean population

OBJECTIVES

Neck circumference has emerged as a predictor of obesity and metabolic syndrome, but its clinical usefulness for different groups of population is not clearly defined. The aim is to evaluate the predictive capacity of neck circumference in order to detect cardiovascular risks (CVRs) on the Chilean population and to compare it with waist circumference performance.

DESIGN

Cross-sectional study.

SETTING

General Chilean population.

PARTICIPANTS

Data of 4607 adults aged 18 and over from the Chilean National Health Survey 2009-2010 were analysed.

PRIMARY AND SECONDARY OUTCOME MEASURES

Anthropometrics measures included neck and waist circumference, height and weight. CVR was identified according to the Framingham tables adapted for the Chilean population. Receiver operating characteristics curves and logistic regression models were made to evaluate the performance of neck circumference to predict a moderate/high CVR, comparing it to waist circumference.

RESULTS

Almost 10% of the sample had a moderate or high CVR. The probability of having a moderate/high cardiovascular risk increase with cervical obesity (OR 1.95, 95% CI 1.04 to 3.68) and central obesity (OR 4.5, 95% CI 2.47 to 8.22). The area under the curves were high for cervical obesity (AUC 81.4%, 95% CI 78.8% to 84.0%) and central obesity (AUC 82.2%, 95% CI 79.7% to 84.7%) and not statistically different (p=0.152).

CONCLUSIONS

Neck obesity has a high capacity to predict moderate/high CVR in the Chilean population. Its good performance appears as an opportunity to use it in clinical practice when waist circumference measurement is difficult to measure and eventually replace the waist circumference measurement as the technique is easier.

[Adolescent obstructive sleep apnoea syndrome: Characteristics and treatment]

Although the prevalence of the obstructive sleep apnoea syndrome (OSAS) is high in adolescents, studies pertaining to adolescent OSAS are less numerous than childhood studies. Cases of adolescent OSAS may consist of residual OSAS after adenotonsillectomy, but most often are de novo cases. Major pathophysiological factors are weight excess or even high-grade obesity, and the association of upper airway narrowing and tonsillar hypertrophy (pharyngeal, palatal or even lingual). ENT and systematic orthodontic assessments are the main points. In case of predisposing factors such as dental, occlusal or dento-facial abnormalities, a specific orthodontic treatment can be discussed. First line treatment is surgical adenotonsillectomy; surgical reduction of the lingual tonsils is seldom required. CPAP treatment may be indicated in the case of severe comorbidities (craniofacial malformations, neuromuscular diseases…) or in obese adolescents with severe residual OSAS. Treatment of adolescent OSAS has to be comprehensive and multidisciplinary, taking into account the specific treatments of obesity and abnormal sleep/wake rhythms.

Sleep Is Compromised in -12° Head Down Tilt Position

Recent studies are elucidating the interrelation between sleep, cranial perfusion, and cerebrospinal fluid (CSF) circulation. Head down tilt (HDT) as a simulation of microgravity reduces cranial perfusion. Therefore, our aim was to assess whether HDT is affecting sleep (clinicaltrials.gov; identifier NCT 02976168). 11 male subjects were recruited for a cross-over designed study. Each subject participated in two campaigns each comprising 3 days and 2 nights. Intervention started on the second campaign day and consisted of maintenance of horizontal position or −12° HDT for 21 h. Ultrasound measurements were performed before, at the beginning and the end of intervention. Polysomnographic measurements were assessed in the second night which was either spent in horizontal posture or at −12° HDT. Endpoints were sleep efficiency, sleep onset latency, number of sleep state changes and arousals, percentages of N3, REM, light sleep stages and subjective sleep parameters. N3 and REM sleep reduced by 25.6 and 19.1 min, respectively (P = 0.002, g = -0.898; P = 0.035, g = -0.634) during −12° HDT. Light sleep (N1/2) increased by 33.0 min at −12° HDT (P = 0.002, g = 1.078). On a scale from 1 to 9 subjective sleep quality deteriorated by 1.3 points during −12° HDT (P = 0.047, g = -0.968). Ultrasonic measurement of the venous system showed a significant increase of the minimum (P = 0.009, P < 0.001) and maximum (P = 0.004, P = 0.002) cross-sectional area of the internal jugular vein at −12° HDT. The minimum cross-sectional area of the external jugular vein differed significantly between conditions over time (P = 0.001) whereas frontal skin tissue thickness was not significantly different between conditions (P = 0.077, P = 0.811). Data suggests venous congestion at −12° HDT. Since subjects felt comfortable with lying in −12° HDT under our experimental conditions, this posture only moderately deteriorates sleep. Obviously, the human body can almost compensate the several fold effects of gravity in HDT posture like an affected CSF circulation, airway obstruction, unusual patterns of propioception and effects on the cardiovascular system.

Obstructive Sleep Apnea Syndrome and Metabolic Diseases

With the rapid changes in lifestyle in modern society, including the high nutritional intake and reduced physical activity, the incidence of metabolic diseases has been increasing year by year. Obstructive sleep apnea syndrome (OSAS) is a sleep disorder, usually characterized by sudden pauses of breathing during sleep and an interrupted sleep rhythm. Although the pathological mechanism remains poorly understood, it has been strongly associated with metabolic diseases, including obesity, insulin resistance, type 2 diabetes mellitus (T2DM), and nonalcoholic fatty liver disease (NAFLD). In the present mini-review, we briefly summarize the connections between OSAS, obesity, T2DM, and NAFLD, which might help us to better understand the pathogenesis of human diseases.

Association of wider neck circumference and asthma in obese children

BACKGROUND

Obesity is a well-established risk factor for asthma. Previous studies have reported that central obesity is associated with asthma.

OBJECTIVE

To investigate the association between fat distribution, which is determined by anthropometric measures, including neck circumference (NC), and asthma in school-aged children.

METHODS

Children diagnosed as having asthma were enrolled along with controls who were admitted to our outpatient department with allergic symptoms, such as rhinitis, urticaria and atopic dermatitis. Anthropometric measures, including height, weight, NC, waist circumference, and hip circumference, were obtained. Skin prick tests, blood eosinophil counts, and serum total IgE level measurements were performed.

RESULTS

A total of 196 children (92 male [46.9%]) were included. Asthma was present in 102 patients (52.1%). Ninety-one of the patients (46.4%) were overweight, and 45 patients (22.9%) were obese. The NC of children with asthma was significantly higher than that of children in the control group. Grades defined according to NC percentiles were also significantly different between groups. In children with asthma, the prevalence of children with an NC higher than the 90th percentile (grade 6) was more frequent when compared with controls. The median NC of obese-overweight children with asthma was significantly higher compared with obese-overweight controls without asthma. Results of multivariable logistic regression analysis revealed that the presence of an NC in the greater than 90th percentile was associated with asthma in obese-overweight children.

CONCLUSION

This study found that NC, which is a simple anthropometric measure, is associated with asthma in obese children.

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.

Associations of Overweight, Obesity and Related Factors with Sleep-Related Breathing Disorders and Snoring in Adolescents: A Cross-Sectional Survey

Background: Sleep-related breathing disorders (SRBD) have been identified as a major public health problem closely related to adolescent obesity. We aimed to estimate the prevalences of SRBD and snoring in adolescents in Changchun City, Northeastern China, and to evaluate the associated factors in this population. Methods: In total, 1955 adolescents aged 11–18 years were recruited in Changchun City using stratified cluster sampling. Parents and caretakers of children completed the questionnaires, which included demographic characteristics, anthropometric parameters and a pediatric sleep questionnaire (SRBD scale). Logistic regression was used to analyze the relationship between SRBD, snoring and other factors. Results: The prevalences of SRBD and snoring in our population were 3.7% and 3.3%, respectively, and the prevalences of overweight and obesity were 12.6% and 4.9%. Multivariate logistic regression showed that urban residence (OR = 2.356, 95%CI: 1.251–4.435) and post-term birth (OR = 3.275, 95%CI: 1.396–7.683) were significantly associated with SRBD. Preterm birth (OR = 2.255, 95%CI: 1.021–4.980) and parental education level of university and above (OR = 0.265, 95%CI: 0.083–0.850) were significantly associated with snoring. Overweight (OR = 2.063, 95%CI: 1.062–4.006) was also related to snoring. Conclusions: The prevalences of SRBD and snoring were similar to those reported in previous studies. Urban residence and post-term birth were important influencing factors for SRBD; overweight, highest parental education level (university and above) and preterm birth were key factors affecting snoring in adolescents.

Obstructive Sleep Apnoea: Children are not little Adults

During a child's development, several important developmental physiological sleep processes occur, and, occasionally, pathological disorders occur, which results in differences between obstructive sleep apnoea (OSA) in adults and children. There are major differences in sleep and respiratory physiology as well as OSA symptoms and treatment options between children and adults. Many practitioners do not realize these differences, which results in delays in the diagnosis and treatment of OSA in children. The treatment options for OSA in children are markedly different compared with adults, effective in most children. The use of positive airway pressure (PAP) therapy delivered through continuous or bi-level positive airway pressure modes is successful in children and even in infants; however, there are several challenges facing parents and practitioners to achieve good compliance. The early recognition and treatment of paediatric OSA are essential to prevent deleterious consequences. This article discusses the major differences between paediatric and adult OSA and demonstrates why children are not little adults.

Pharyngeal constrictor muscle fatty change may contribute to obstructive sleep apnea-hypopnea syndrome: a prospective observational study

CONCLUSIONS

Pharyngeal constrictor muscle injury and fatty changes may play important roles in the pathogenesis and progression of OSAHS.

OBJECTIVE

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a respiratory disorder caused by upper airway obstruction during sleep. The primary objectives of this study were to determine the ultrastructural characteristics of the pharyngeal constrictor muscle in patients with OSAHS.

METHODS

A pharyngeal constrictor muscle specimen was collected from all subjects. The muscle cell ultrastructure was observed under electron microscopy.

RESULTS

Eighteen male patients with OSAHS (OSAHS group) and 10 male body mass index-matched patients with chronic tonsillitis (control group) were enrolled in this study. All patients were obese adults. The apnea-hypopnea index (41.22 ± 17.29 vs 2.30 ± 1.10 events/h) was significantly higher and the lowest arterial oxygen saturation (76.00 ± 8.57% vs 97.00 ± 2.00%) was significantly lower in the OSAHS group than in the control group (both p < 0.001). Myofibril disorder, mitochondrial edema, and intramyocellular lipid droplets were observed in patients with OSAHS. There was a significant correlation between the number of lipid droplets and the apnea-hypopnea index.

Impact of gender and sleep position on relationships between anthropometric parameters and obstructive sleep apnea syndrome

OBJECTIVE

Considering the mechanisms by which obesity affects obstructive sleep apnea syndrome (OSAS) and the differences of fat distribution depending on gender, associations between anthropometric parameters, and OSAS may differ depending on gender or sleep position. We analyzed the impact of gender and sleep position on the relationship between fat distribution and development of OSAS.

METHODS

One thousand thirty-two consecutive subjects were analyzed. Recorded anthropometric measurements and overnight polysomnographic data of the subjects were reviewed retrospectively. The presence of OSAS was defined by the respiratory disturbance index (RDI) ≥5 with documented symptoms of excessive daytime sleepiness.

RESULTS

Eight hundred fifty-eight males and 174 females were included. Male subjects had significantly higher body mass index (BMI), larger waist circumference (WC), and lower percent of overall body fat (P < 0.0001, P < 0.0001, and P < 0.0001, respectively). The severity of OSAS was significantly higher in male subjects (RDI 26.9 ± 22.4 in males vs. 10.2 ± 13.8 in females, P < 0.0001). In male subjects, BMI, WC, and overall body fat were significantly associated with severity of OSAS and had larger impacts on supine RDI than lateral RDI. Overall body fat was not associated with severity of OSAS in female subjects, and there were no significant differences of the associations between all anthropometric parameters and RDIs depending on sleep position.

CONCLUSIONS

Evaluation of the correlation of anthropometric data with severity of OSAS should consider sleep position as well as gender.

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.

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.

Negative Expiratory Pressure Technique: An Awake Test to Measure Upper Airway Collapsibility in Adolescents

STUDY OBJECTIVES

Upper airway (UA) collapsibility is a major pathophysiologic feature of the obstructive sleep apnea syndrome (OSAS). In adolescents, it is measured by obtaining the slope of pressure-flow relationship (SPF) while applying negative nasal pressure during sleep. An easier technique to assess UA collapsibility, consisting of application of negative expiratory pressure (NEP) during wakefulness, has demonstrated differences between control and OSAS subjects. We hypothesized that the NEP technique would correlate with SPF as a measurement of UA collapsibility in adolescents.

DESIGN

During wakefulness, NEP of -5 cm H2O in the seated and supine position was applied during the first second of expiration. The area under the expiratory flow-volume curve during NEP was compared to tidal breathing (RatioNEP). In addition, adolescents underwent SPF measurements during sleep. Two SPF techniques were performed to measure the activated and relatively hypotonic UA.

SETTING

Pediatric sleep laboratory.

PARTICIPANTS

Seven adolescents with OSAS and 20 controls.

RESULTS

In the seated position, there was a correlation between RatioNEP and both hypotonic SPF (r = -0.39, P = 0.04) and activated SPF (r = -0.62, P = 0.001). In the supine position, there was a correlation between RatioNEP and activated SPF (r = -0.43, P = 0.03) and a trend for hypotonic SPF (r = -0.38, P = 0.06).

CONCLUSIONS

The negative expiratory pressure (NEP) technique correlates with the hypotonic and activated slope of pressure-flow relationship measurements. The seated position showed the strongest correlation. The NEP technique can be used as an alternative method to evaluate upper airway collapsibility in adolescents.

Understanding the anatomic basis for obstructive sleep apnea syndrome in adolescents

RATIONALE

Structural risk factors for obstructive sleep apnea syndrome (OSAS) in adolescents have not been well characterized. Because many adolescents with OSAS are obese, we hypothesized that the anatomic OSAS risk factors would be more similar to those in adults than those in children.

OBJECTIVES

To investigate the anatomic risk factors in adolescents with OSAS compared with obese and lean control subjects using magnetic resonance imaging (MRI).

METHODS

Three groups of adolescents (age range: 12-16 yr) underwent MRI: obese individuals with OSAS (n = 49), obese control subjects (n = 38), and lean control subjects (n = 50).

MEASUREMENTS AND MAIN RESULTS

We studied 137 subjects and found that (1) obese adolescents with OSAS had increased adenotonsillar tissue compared with obese and lean control subjects; (2) obese OSAS adolescents had a smaller nasopharyngeal airway than control subjects; (3) the size of other upper airway soft tissue structures (volume of the tongue, parapharyngeal fat pads, lateral walls, and soft palate) was similar between subjects with OSAS and obese control subjects; (4) although there were no major craniofacial abnormalities in most of the adolescents with OSAS, the ratio of soft tissue to craniofacial space surrounding the airway was increased; and (5) there were sex differences in the pattern of lymphoid proliferation.

CONCLUSIONS

Increased size of the pharyngeal lymphoid tissue, rather than enlargement of the upper airway soft tissue structures, is the primary anatomic risk factor for OSAS in obese adolescents. These results are important for clinical decision making and suggest that adenotonsillectomy should be considered as the initial treatment for OSAS in obese adolescents, a group that has poor continuous positive airway pressure adherence and difficulty in achieving weight loss.

Wider neck circumference is related to severe asthma in children

BACKGROUND

Obesity is an established risk factor for asthma in children. Measures of central obesity are reported to be more associated with the severity of asthma in adults. The aim of the study was to investigate the association between fat distribution, which is determined by anthropometric measures including neck circumference (NC) and asthma severity in children.

METHODS

Children with asthma who were followed in our pediatric allergy unit were consecutively recruited. Asthma severity was graded according to GINA guidelines. Children whose asthma was controlled with Step 1 or 2 treatment options formed Group 1 (mild asthma), whereas children who needed Step 3, 4, or 5 treatment options formed Group 2 (moderate-to-severe asthma). Anthropometric measures including height, weight, NC, waist circumference, and hip circumference were obtained.

RESULTS

A total of 127 children (82 male, 64.6%) with a median age of 8.3 (6.4-11.3) years were included. Atopy was present in 77 (60.6%) patients. 91 patients (71.6) were in the mild asthma group. NC of children with severe asthma was significantly wider than children with mild asthma (29.0 cm (27.0-32.0) vs. 28.0 (26.0-30.0), p = 0.019). The prevalence of children with NC higher than 90th percentile was also more frequent in children with severe asthma (15 [41.7%] vs. 21 [23.1%]). Result of multivariable logistic regression analysis revealed that presence of NC >90th percentile was associated with severe asthma in children (odds ratio; [95% confidence interval] (2.52 [1.05-6.01]; p = 0.038).

CONCLUSIONS

Neck circumference, which is a simple anthropometric tool, is associated with asthma severity in children.

Does neck-to-waist ratio predict obstructive sleep apnea in children?

OBJECTIVES

Central adiposity and large neck circumference are associated with obstructive sleep apnea (OSA) in adults but have not been evaluated in children as predictors of OSA. Study objectives were to determine whether (1) anthropometric measures including neck-to-waist ratio are associated with OSA in older children; (2) body fat distribution, measured by neck-to-waist ratio, is predictive of OSA in overweight/obese children.

METHODS

Cross-sectional study involving children 7-18 years scheduled to undergo polysomnography at a tertiary care children's hospital. OSA was defined as total apnea-hypopnea index > 5 events/h and/or obstructive apnea index > 1 event/h. Recursive partitioning was used to select candidate predictors of OSA from: age, sex, height and weight percentile, body mass index (BMI) z-score, neck-to-waist ratio, tonsil size, and Mallampati score. These were then evaluated using log binomial models and receiver operator characteristic analysis.

RESULTS

Two hundred twenty-two participants were included; 133 (60%) were overweight/obese, 121 (55%) male,47 (21%) had OSA. Neck-to-waist ratio (relative risk [RR] 1.97 per 0.1 units, 95% CI 1.48 to 2.84) and BMI z-score (RR 1.63 per unit, 95% CI 1.30 to 2.05) were identified as independent predictors of OSA. Considering only overweight/obese children, neck-to-waist ratio (RR 2.16 per 0.1 units, 95% CI 1.79 to 2.59) and BMI z-score (RR 2.02 per unit, 95% CI 1.25 to 3.26) also independently predicted OSA. However, in children not overweight/obese, these variables were not predictive of OSA.

CONCLUSIONS

Neck-to-waist ratio, an index of body fat distribution, predicts OSA in older children and youth, especially in those who were overweight/obese.