Stijn Verhulst

Adenotonsillectomy outcomes in treatment of obstructive sleep apnea in children: a multicenter retrospective study.

RATIONALE The overall efficacy of adenotonsillectomy (AT) in treatment of obstructive sleep apnea syndrome (OSAS) in children is unknown. Although success rates are likely lower than previously estimated, factors that promote incomplete resolution of OSAS after AT remain undefined. OBJECTIVES To quantify the effect of demographic and clinical confounders known to impact the success of AT in treating OSAS. METHODS A multicenter collaborative retrospective review of all nocturnal polysomnograms performed both preoperatively and postoperatively on otherwise healthy children undergoing AT for the diagnosis of OSAS was conducted at six pediatric sleep centers in the United States and two in Europe. Multivariate generalized linear modeling was used to assess contributions of specific demographic factors on the post-AT obstructive apnea-hypopnea index (AHI). MEASUREMENTS AND MAIN RESULTS Data from 578 children (mean age, 6.9 +/- 3.8 yr) were analyzed, of which approximately 50% of included children were obese. AT resulted in a significant AHI reduction from 18.2 +/- 21.4 to 4.1 +/- 6.4/hour total sleep time (P < 0.001). Of the 578 children, only 157 (27.2%) had complete resolution of OSAS (i.e., post-AT AHI <1/h total sleep time). Age and body mass index z-score emerged as the two principal factors contributing to post-AT AHI (P < 0.001), with modest contributions by the presence of asthma and magnitude of pre-AT AHI (P < 0.05) among nonobese children. CONCLUSIONS AT leads to significant improvements in indices of sleep-disordered breathing in children. However, residual disease is present in a large proportion of children after AT, particularly among older (>7 yr) or obese children. In addition, the presence of severe OSAS in nonobese children or of chronic asthma warrants post-AT nocturnal polysomnography, in view of the higher risk for residual OSAS.

Sleep-disordered breathing in overweight and obese children and adolescents: prevalence, characteristics and the role of fat distribution

Aims: To determine the prevalence of sleep-disordered breathing (SDB) in a clinical sample of overweight and obese children and adolescents, and to examine the contribution of fat distribution. Methods: Consecutive subjects without chronic lung disease, neuromuscular disease, laryngomalacia, or any genetic or craniofacial syndrome were recruited. All underwent measurements of neck and waist circumference, waist-to-hip ratio, % fat mass and polysomnography. Obstructive apnoea index ⩾1 or obstructive apnoea–hypopnoea index (OAHI) ⩾2, further classified as mild (2⩽OAHI<5) or moderate-to-severe (OAHI⩾5), were used as diagnostic criteria for obstructive sleep apnoea (OSA). Central sleep apnoea was diagnosed when central apnoeas/hypopnoeas ⩾10 s were present accompanied by >1 age-specific bradytachycardia and/or >1 desaturation <89%. Subjects with desaturation ⩽85% after central events of any duration were also diagnosed with central sleep apnoea. Primary snoring was diagnosed when: snoring was detected by microphone and normal obstructive indices and saturation. Results: 27 overweight and 64 obese subjects were included (40 boys; mean (standard deviation (SD)) age 11.2 (2.6) years). Among the obese children, 53% were normal, 11% had primary snoring, 11% had mild OSA, 8% had moderate-to-severe OSA and 17% had central sleep apnoea. Half of the patients with central sleep apnoea had desaturation <85%. Only enlarged tonsils were predictive of moderate-to-severe OSA. On the other hand, higher levels of abdominal obesity and fat mass were associated with central sleep apnoea. Conclusion: SDB is very common in this clinical sample of overweight children. OSA is not associated with abdominal obesity. On the contrary, higher levels of abdominal obesity and fat mass are associated with central sleep apnoea.

Intrauterine Exposure to Environmental Pollutants and Body Mass Index during the First 3 Years of Life

Objective We investigated the association between body mass index (BMI) standard deviation score (SDS) and prenatal exposure to hexachlorobenzene, dichlorodiphenyldichloroethylene (DDE), dioxin-like compounds, and polychlorinated biphenyls (PCBs). Methods In this prospective birth cohort study, we assessed a random sample of mother–infant pairs (n = 138) living in Flanders, Belgium, with follow-up until the children were 3 years of age. We measured body mass index as standard deviation scores (BMI SDS) of children 1–3 years of age as well as pollutants measured in cord blood. Results DDE correlated with BMI SDS, with effect modification by maternal smoking and the child’s age. At 1 year, children of smoking mothers had higher BMI SDS than did children of nonsmoking mothers. At 3 years, this difference was reduced because of the faster rate of decline in BMI SDS in the former group. This relationship held except for children with high levels of DDE. DDE had a small effect on BMI SDS at 3 years of age in children of nonsmoking mothers (difference in BMI SDS for DDE concentrations between the 90th and 10th percentiles = 0.13). On the other hand, smoking enhanced the relation between DDE and BMI SDS at 3 years (difference in BMI SDS for DDE concentrations between the 90th and 10th percentiles = 0.76). Increasing concentrations of PCBs were associated with higher BMI SDS values at all ages (parameter estimate = 0.003 ± 0.001; p = 0.03). Conclusion In this study we demonstrated that intrauterine exposure to DDE and PCBs is associated with BMI during early childhood. Future studies are warranted to confirm our findings and to assess possible mechanisms by which these pollutants could alter energy metabolism.

The prevalence, anatomical correlates and treatment of sleep-disordered breathing in obese children and adolescents

The prevalence of childhood obesity is increasing worldwide. One of the obesity-related complications that has received increasing attention in recent years is sleep-disordered breathing. Obese children are at a higher risk of developing sleep-disordered breathing, including habitual snoring, obstructive sleep apnea syndrome and desaturations preceded by central apneas. Both adiposity and upper airway factors, such as adenotonsillar hypertrophy, modulate the severity of sleep-disordered breathing in these children. Adenotonsillectomy seems to be effective against obstructive sleep apnea syndrome in obese children. On the other hand, there are limited data on the effects of weight loss and of treatment with continuous positive airway pressure on the severity of sleep apnea in obese children and adolescents.

Obstructive sleep disordered breathing in 2- to 18-year-old children: Diagnosis and management

This document summarises the conclusions of a European Respiratory Society Task Force on the diagnosis and management of obstructive sleep disordered breathing (SDB) in childhood and refers to children aged 2–18 years. Prospective cohort studies describing the natural history of SDB or randomised, double-blind, placebo-controlled trials regarding its management are scarce. Selected evidence (362 articles) can be consolidated into seven management steps. SDB is suspected when symptoms or abnormalities related to upper airway obstruction are present (step 1). Central nervous or cardiovascular system morbidity, growth failure or enuresis and predictors of SDB persistence in the long-term are recognised (steps 2 and 3), and SDB severity is determined objectively preferably using polysomnography (step 4). Children with an apnoea–hypopnoea index (AHI) >5 episodes·h−1, those with an AHI of 1–5 episodes·h−1 and the presence of morbidity or factors predicting SDB persistence, and children with complex conditions (e.g. Down syndrome and Prader–Willi syndrome) all appear to benefit from treatment (step 5). Treatment interventions are usually implemented in a stepwise fashion addressing all abnormalities that predispose to SDB (step 6) with re-evaluation after each intervention to detect residual disease and to determine the need for additional treatment (step 7). Management of obstructive sleep disordered breathing in childhood should follow a stepwise approach http://ow.ly/SdKwD

The Effect of Weight Loss on Sleep‐disordered Breathing in Obese Teenagers

The objective of this study was to assess the effect of weight loss on sleep‐disordered breathing (SDB) in obese teenagers attending a residential treatment center. We also assessed whether the presence of SDB at the start of the weight management therapy was correlated with the amount of weight loss achieved. Obese teenagers were recruited and underwent anthropometry and sleep screening. Subjects with SDB (apnea hypopnea index (AHI) ≥ 2) received a follow‐up screening after weight loss therapy. Sixty‐one obese subjects were included (age = 14.8 ± 2.3; BMI z score = 2.7 ± 0.4). Thirty‐one subjects were diagnosed with SDB with 38% continuing to have residual SDB after a median weight loss of 24.0 kg. Subjects with SDB had a higher median relative decrease in BMI z score compared to subjects without SDB which was 30.5, 33.6, and 50.4% in the group with AHI of the baseline screening study < 2, 2 ≤ AHI < 5, and AHI ≥ 5, respectively (P = 0.02). AHI of the baseline screening study correlated significantly with the relative decrease in BMI z score (partial r = 0.37; P = 0.003), controlling for gender, age, initial BMI z score, and time between both studies. In conclusion, weight loss was successful in treating SDB in obese teenagers. In addition, there was a positive association between the severity of SDB at the start of the treatment and the amount of weight loss achieved. These findings are in favor of considering weight loss as a first‐line treatment for SDB in obese children and adolescents.

Early cardiac abnormalities in obese children: importance of obesity per se versus associated cardiovascular risk factors.

We investigated whether obese children and adolescents have early echocardiographic signs of subclinical cardiac dysfunction and evaluated the respective influence of obesity per se versus parameters of carbohydrate and lipid metabolism that are frequently abnormal in obese subjects. The role of tissue Doppler imaging as a screening tool for these abnormalities was explored. Blood pressure and echocardiographic parameters, including tissue Doppler measurements of the septal mitral annulus were evaluated in 49 obese children and adolescents and 45 age and sex matched controls. The respective influence of obesity versus parameters of carbohydrate and lipid metabolism was examined with linear regression analysis. Obese subjects showed significantly larger left ventricular wall dimensions (posterior wall, septum, and left ventricular mass index) and signs of early diastolic filling abnormalities on conventional and tissue Doppler echocardiography compared with nonobese subjects. Multiple regression analysis showed that mainly BMI-SD scores and/or body surface area explained significant proportions of the variance of the early cardiac abnormalities. In conclusion, young, obese children and adolescents have significant changes in left ventricular wall dimensions and early diastolic filling compared with nonobese subjects. Obesity per se and not the parameters of carbohydrate and lipid metabolism predicted the early cardiac abnormalities.

Intestinal microflora and body mass index during the first three years of life: an observational study

BackgroundRecent research on obesity has demonstrated that the intestinal microflora can have an important influence on host energy balance. The aim of the study was to investigate the relationship between the intestinal microflora and the body mass index in the first 3 years of life.ResultsIn a prospective study, a faecal sample from 138 infants was taken at the age of 3, 26 and 52 weeks and cultured on selective media for 6 bacterial genera. Between the age of 1 and 3 years the Body Mass Index Standard Deviation Score (BMI SDS) of these children was determined. The association between the intestinal flora and BMI SDS was assessed for each bacterial genus. A positive correlation was found between the Bacteroides fragilis concentration and the BMI SDS at the age of 3 and 26 weeks. The Staphylococcus concentration showed a negative correlation with the BMI SDS at the age of 3 and 52 weeks. A low intestinal ratio of Staphylococcus/Bacteroides fragilis at the age of 3 weeks, corresponding to a low Staphylococcus and a high Bacteroides fragilis concentration, was associated with a higher BMI SDS during the first three years of life.ConclusionHigh intestinal Bacteroides fragilis and low Staphylococcus concentrations in infants between the age of 3 weeks and 1 year were associated with a higher risk of obesity later in life. This study could provide new targets for a better and more effective modulation of the intestinal microflora in infants.

First night effect for polysomnographic data in children and adolescents with suspected sleep disordered breathing

Aims: To assess the presence of a first night effect (FNE) in children and adolescents and to examine if a single night polysomnography (PSG) is sufficient for diagnosing obstructive sleep apnoea syndrome (OSAS). Methods: Prospective case study of 70 patients (group 1: 2–6 years, n = 22; group 2: 7–12 years, n = 32; group 3: 13–17 years, n = 16) referred for OSAS. Diagnostic criteria for OSAS: one or more of the following: (1) obstructive apnoea index (OAI) ⩾1; (2) obstructive apnoea hypopnoea index (oAHI) ⩾2; (3) SaO2 ⩽89% in association with obstruction. Results: In all age groups, but mainly in the oldest children, REMS increased during the second night, mainly at the expense of stage 2 sleep. The first night PSG correctly identified OSAS in 86%, 91%, and 100% of the children for groups 1, 2, and 3 respectively. This represents 9% false negatives for OSAS when only the first night PSG was used. All cases missed had mild OSAS, except for one with oAHI >5 on night 2. There were also seven patients with OSAS on night 1 but with a normal PSG on night 2: all had oAHI <5. Conclusion: There is a FNE in children and adolescents. A single night PSG is sufficient for diagnosing OSAS, but in cases with a suggestive history and examination and with a negative first night, a second night study might be advisable.

Sleep-disordered breathing, obesity, and airway inflammation in children and adolescents.

BACKGROUND To investigate the relationship between obstructive sleep apnea syndrome (OSAS) and exhaled nitric oxide (eNO) in overweight children and adolescents without asthma or atopy and to assess whether obesity per se is associated with increased airway inflammation. METHODS Consecutive overweight subjects without symptoms of asthma or allergy were recruited at a pediatric obesity clinic. A normal-weight control group without OSAS and asthma or allergy was also recruited. All subjects underwent polysomnography and two measurements of eNO (afternoon and morning after polysomnography). RESULTS Controlling for age, the mean (+/- SD) afternoon eNO concentration was significantly higher in the snoring group (14.1 +/- 1.1 parts per billion [ppb]) compared with the normal-weight group (10.1 +/- 0.8 ppb; p = 0.03) and with the overweight group with normal polysomnography findings (8.9 +/- 0.8 ppb; p = 0.007). The afternoon eNO concentration was also different between the OSAS group (11.9 +/- 1.0 ppb) and the overweight group with normal polysomnography findings (p = 0.03). Morning eNO values were higher in the OSAS group (12.3 +/- 1.1 ppb) than in the normal weight group (9.9 +/- 0.8 ppb; p = 0.047) and in the overweight control group (9.7 +/- 0.7 ppb; p = 0.02). BMI z score was not significantly correlated with afternoon eNO concentration or with morning eNO concentration. CONCLUSION This study illustrates that both habitual snoring and OSAS are associated with increased airway inflammation in overweight children as assessed by higher eNO levels. Furthermore, it was demonstrated that childhood obesity in the absence of sleep-disordered breathing is not associated with increased airway inflammation.