Genetic basis of sleep phenotypes and rare neurodevelopmental syndromes reveal shared molecular pathways.

Sleep-related phenotypes have been frequently reported in early on-set epileptic encephalopathies and in developmental delay syndromes, in particular in syndromes related to autism spectrum disorder. Yet the convergent pathogenetic mechanisms between these comorbidities are largely unknown. We first performed a gene enrichment study that identified shared risk genes among rare epileptic encephalopathies/neurodevelopmental disorders, rare developmental delay genetic syndromes and sleep disturbances. We then determined cellular and molecular pathways enriched among genes shared between sleep phenotypes and those two early onset mental illnesses, aiming to identify genetic disparities and commonalities among these phenotypic groups. The sleep gene set was observed as significantly overlapped with the two gene lists associated to rare genetic syndromes (i.e., epileptic encephalopathies/neurodevelopmental disorders and developmental delay gene sets), suggesting shared genetic contribution. Similarities across significantly enriched pathways between the two intersect lists comprehended mostly synapse-related pathways, such as retrograde endocannabinoid signaling, serotonergic, and GABAergic synapse. Network analysis indicates epileptic encephalopathies/neurodevelopmental disorders versus sleep-specific clusters and developmental delay versus sleep-specific clusters related to synaptic and transcriptional regulation, respectively. Longstanding functional patterns previously described in epileptic encephalopathies and neurodevelopmental disorders genetic architecture were recaptured after dissecting the overlap between the genes associated to those developmental phenotypes and sleep disturbances, suggesting that during neurodevelopment different molecular and functional mechanisms are related to alterations on circadian rhythm. The overlapping gene set and biological pathways highlighted by this study may serve as a primer for new functional investigations of shared molecular mechanisms between sleep disturbances and rare developmental syndromes.

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 (MetScoreFM) and dichotomous (metabolic syndrome, MetS) CMR were determined. Associations between MetScoreFM 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 MetScoreFM (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.

Narcolepsy, Precocious Puberty and Obesity in the Pediatric Population: a Literature Review.

Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness, cataplexy, sleep paralysis and hypnagogic and hypnopompic hallucinations. The onset of the symptoms usually occurs in childhood, and previous studies have reported an association between narcolepsy and other endocrine diseases in the pediatric population, such as obesity and precocious puberty. The incidence of overweight or obesity ranges from 25% to 74% in patients with narcolepsy type I, while precocious puberty is present in 17% of children with narcolepsy with cataplexy. However, the mechanisms involved in the association of narcolepsy with obesity and precocious puberty have not been fully elucidated yet. In this review, we aimed to discuss narcolepsy in pediatric populations, highlighting the diagnostic difficulties and the complexity of the possible mechanisms that can relate narcolepsy to precocious puberty and obesity. We also emphasized the fact that endocrine diseases must be taken into consideration in children diagnosed with narcolepsy.

Sleep quality of mother-caregivers of Duchenne muscular dystrophy patients.

BACKGROUND: Sleep disturbance is a common problem for caregivers. In general, patients with Duchenne muscular dystrophy (DMD) use noninvasive ventilation to maintain quality of life and improve survival. OBJECTIVE: The aim of this study was to evaluate the sleep quality of caregiver-mothers of sons with DMD and factors that are associated with their sleep quality. METHODS: We evaluated 32 caregiver-mothers of sons with DMD and 32 mothers of sons without any neuromuscular or chronic disease (control-CTRL group). The evaluation of quality of sleep was made using the Pittsburgh Sleep Quality Index (PSQI). RESULTS: Caregiver-mothers had poor sleep quality, specifically longer sleep latency and reduced sleep efficiency. The impaired sleep quality of the caregiver-mothers was associated with the length of time of noninvasive ventilation used by their sons. CONCLUSIONS: Our results suggest that caregiver-mothers of sons with DMD have poor quality of sleep, and the length of use of noninvasive ventilation of their sons is associated with better sleep of caregiver-mothers.

Prevalence of obstructive sleep apnea in patients with mucopolysaccharidosis types I, II, and VI in a reference center.

PURPOSE: Mucopolysaccharidosis (MPS) encompasses a group of rare lysosomal storage disorders that are associated with the accumulation of glycosaminoglycans in organs and tissues. Respiratory disorders occur in all MPS types. In these patients, the prevalence of obstructive sleep apnea syndrome (OSAS), which may confer additional morbidity, remains overlooked, and the results of the few existing studies are controversial. The present study aimed to characterize the prevalence of OSAS in patients with MPS types I, II, and VI in a reference center. METHODS: Forty-five patients with MPS (I, n=17; II, n=16; and VI; n=12) in the Centro de Referência em Erros Inatos do Metabolismo, who underwent full-night polysomnography, were enrolled in a retrospective study. Demographic data and clinical history were collected from medical records of the first medical consultation. RESULTS: The prevalence of OSAS in patients with MPS was 69.8%. MPS type I patients seemed to be more susceptible to OSA-induced hypoxemia, as indicated by reduced mean SpO2 levels during both NREM and rapid eye movement sleep as well as during SpO2 nadir. CONCLUSIONS: Patients with MPS displayed a high prevalence of OSAS, often with moderate to high severity. Together, our results reinforce the need for OSAS screening in all patients with MPS.

Obstructive sleep apnea in asthmatic children: a cross-sectional study about prevalence and risk factors.

OBJECTIVES: Primary objectives were to analyze the prevalence of obstructive sleep apnea in (1) boys and girls, and (2) severe asthma versus moderate and mild cases. The authors hypothesized that girls and severe asthma would have a higher prevalence of obstructive sleep apnea. METHODS: Cross-sectional evaluation of asthmatic children attending a tertiary Pediatric Pulmonology clinic. The authors performed a history, physical examination, pulmonary function test, and home sleep apnea test. RESULTS: The authors studied 80 consecutive patients, 7-18 years old, mean age of 11.6 years (standard deviation 2.7), 51.3% female, and 18.5% obese. Pulmonary function tests were obtained from 80 volunteers, 45% with obstruction pattern. Home sleep apnea tests were available from 76 volunteers, with a mean obstructive respiratory index of 1.8 events/h. Obstructive sleep apnea was found in 49 volunteers (61.2%). The authors did not find associations between obstructive sleep apnea and sex or asthma severity. CONCLUSIONS: Obstructive sleep apnea was frequent among these asthmatic children. Sex and asthma severity were not risk factors. Considering the interrelationship of both diseases, it is worth keeping in mind the possibility of obstructive sleep apnea among children and teenagers with asthma.

Rapid maxillary expansion in patient with obstructive sleep apnea: case report.

The aim of this case report was to evaluate the polysomnography indices, air space in the oropharyngeal region and quality of life scores using the OSA-18 questionnaire in a patient diagnosed with obstructive sleep apnea before and after rapid maxillary expansion (RME). It is a case report with a male patient, seven years old, with maxillary hypoplasia, who underwent adenotonsillectomy surgery two years ago, had restless sleep, snore more than five times a week. Pre- and post-treatment diagnostic tests were performed, including nasofibroscopy, polysomnography, computed tomography, orthodontic records and the OSA-18 quality of life questionnaire. The treatment consisted of RME with Hyrax maxillary expander. After six months, the exams were redone. The polysomnographic record before treatment: IAH 2.8/h, after treatment 0.5/h. We concluded that rapid maxillary expansion (RME) in children with OSA appears to be an effective treatment.

Insomnia episodes, new-onset pharmacological treatments, and other sleep disturbances during the COVID-19 pandemic: a nationwide cross-sectional study in Brazilian health care professionals.

STUDY OBJECTIVES: To evaluate the impact of the coronavirus disease 2019 (COVID-19) pandemic on insomnia and other sleep disturbances in health care professionals. METHODS: A survey was distributed using social media and organizational emails to Brazilian active health care professionals during the COVID-19 outbreak. We explored potential associated factors including age, sex, occupation, workplace, work hours, income, previous infection with COVID-19, recent/current contact with COVID-19 patients, regional number of incident deaths, anxiety, and burnout. We evaluated new-onset/previous insomnia worsening episodes (primary outcome), new pharmacological treatments, sleep quality, duration, nightmares, and snoring (secondary outcomes). RESULTS: A total of 4,384 health professionals from all regions of the country were included in the analysis (44 ± 12 years, 76% females, 53.8% physicians). Overall, 55.7% were assisting patients with COVID-19, and 9.2% had a previous COVID-19 infection. The primary outcome occurred in 32.9% of respondents in parallel to 13% new pharmacological treatments for insomnia. The sleep quality worsened for 61.4%, while 43.5% and 22.8% reported ≥ 1-hour sleep duration reduction and worsening or new-onset nightmares, respectively. Multivariate analyses showed that age (odds ratio [OR]: 1.008; 95% confidence interval [CI] 1.001-1.015), females (OR: 1.590; 95% CI 1.335-1.900), weight change (decrease: OR: 1.772; 95% CI 1.453-2.161; increase: OR: 1.468; 95% CI 1.249-1.728), prevalent anxiety (OR: 3.414; 95% CI 2.954-3.948), new-onset burnout (OR: 1.761; 95% CI 1.489-2.083), family income reduction > 30% (OR: 1.288; 95% CI 1.069-1.553), and assisting patients with COVID-19 (OR: 1.275; 95% CI 1.081-1.506) were independently associated with new-onset or worsening of previous insomnia episodes. CONCLUSIONS: We observed a huge burden of insomnia episodes and other sleep disturbances in health care professionals during the COVID-19 pandemic. CITATION: Drager LF, Pachito DV, Moreno CRC, et al. Insomnia episodes, new-onset pharmacological treatments, and other sleep disturbances during the COVID-19 pandemic: a nationwide cross-sectional study in Brazilian health care professionals. J Clin Sleep Med. 2022;18(2):373-382.

Quality of life related to residual snoring after adenotonsillectomy: a pilot study.

INTRODUCTION: Few studies have addressed long-term quality of life related to residual snoring after adenotonsillectomy. The aim of this study was to compare scores from the OSA-18 questionnaire between children with residual snoring and non-snoring children two or more years after adenotonsillectomy. MATERIAL AND METHODS: The sample comprised 25 children divided into two groups, a group of 14 snoring children, and a control group of 11 non-snoring children. The OSA-18 questionnaire was applied to the volunteers. In the control group, it was completed by the caregivers of the children, while in individuals with residual snoring it was completed by the caregivers of children in the presence of a doctor or dentist. A statistical comparison was made using a generalized linear model. RESULTS: The snorer group had a higher total OSA-18 score, and a higher score in all five domains compared to the control group. CONCLUSION: Children with residual snoring two or more years after adenotonsillectomy may have a worse quality of life compared to the control group.

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 (MetScoreFM) 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), MetScoreFM 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, MetScoreFM (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.

Sleep and restless legs syndrome in female adolescents with idiopathic musculoskeletal pain.

OBJECTIVES: To assess the presence of restless legs syndrome, periodic leg movement, and sleep disorders in female adolescents with idiopathic musculoskeletal pain through a sleep scale and polysomnography, and to compare these data in adolescents without pain history. METHOD: Twenty-six adolescents diagnosed with idiopathic musculoskeletal pain followed in a pain outpatient clinic and 25 healthy controls matched by age and education were recruited. The restless legs syndrome criteria were evaluated according to the International Restless Legs Syndrome Study Group, the Sleep Disturbance Scale for Children was completed, nocturnal polysomnography was performed, and anxiety symptoms were recorded. RESULTS: The mean age of idiopathic musculoskeletal pain adolescents was 13.9±1.6 years; in controls, it was 14.4±1.4 years. One adolescent in the control group (4 %) and nine patients with idiopathic musculoskeletal pain (34.6 %) fulfilled the restless legs syndrome criteria (p=0.011). The authors did not observe significant differences in Sleep Disturbance Scale for Children scores between the groups in all components: disorders of initiating and maintaining sleep (p=0.290), sleep breathing disorders (p=0.576), disorders of arousal (p=0.162), sleep-wake transition disorders (p=0.258), disorder of excessive daytime somnolence (p=0.594), and sleep hyperhidrosis (p=0.797). The neurophysiological, respiratory, and periodic leg movement parameters were similar in both groups. Having anxiety was not associated with restless legs syndrome (p=0.11). Three patients with idiopathic musculoskeletal pain (11.5 %) presented restless legs syndrome and periodic leg movement simultaneously, which was absent in the control group. CONCLUSION: Female adolescents with idiopathic musculoskeletal pain present criteria for RLS more frequently than healthy adolescents. However, this study did not observe relevant changes in objective and subject sleep variables.

Obstructive sleep apnea in asthmatic children: a cross-sectional study about prevalence and risk factors

Abstract Objectives: Primary objectives were to analyze the prevalence of obstructive sleep apnea in (1) boys and girls, and (2) severe asthma versus moderate and mild cases. The authors hypothesized that girls and severe asthma would have a higher prevalence of obstructive sleep apnea. Methods: Cross-sectional evaluation of asthmatic children attending a tertiary Pediatric Pulmonology clinic. The authors performed a history, physical examination, pulmonary function test, and home sleep apnea test. Results: The authors studied 80 consecutive patients, 7-18 years old, mean age of 11.6 years (standard deviation 2.7), 51.3% female, and 18.5% obese. Pulmonary function tests were obtained from 80 volunteers, 45% with obstruction pattern. Home sleep apnea tests were available from 76 volunteers, with a mean obstructive respiratory index of 1.8 events/h. Obstructive sleep apnea was found in 49 volunteers (61.2%). The authors did not find associations between obstructive sleep apnea and sex or asthma severity. Conclusions: Obstructive sleep apnea was frequent among these asthmatic children. Sex and asthma severity were not risk factors. Considering the interrelationship of both diseases, it is worth keeping in mind the possibility of obstructive sleep apnea among children and teenagers with asthma.

Clinicals And Upper Airway Characteristics in Obese Children with Obstructive Sleep Apnea.

INTRODUCTION: Obesity is a factor that is strongly related to the occurrence of obstructive sleep apnea (OSA) in adults, although this association remains controversial for children. OBJECTIVE: The aim of this study was to compare the clinical and upper airway charactheristics, obtained by questionnaires, physical examination and laboratory tests, among obese children with and without OSA. METHOD: This was aprospective cohort study. 44 obese children (body mass index above the 95th percentile) were included in the study. Questionnaires, physical examination of the upper airway, nasofibrolaryngoscopy, polysomnography, and laboratory allergic tests were performed. RESULTS: There were 22 male patients (50%), and the mean age was 7.6±2.5 years. OSA was present in 19 (43%) patients. There were no statistically significant differences between the groups with and without OSA, in relation to clinical or laboratory allergic parameters. For the upper airway assessments, hypertrophy of the pharyngeal (p=0.001) and palatine (p=0.049) tonsils were the only parameters associated with OSA, and a modified Mallampati index of class III/IV also demonstrated a tendency towards being statistically associated with OSA (p=0.081). Moreover, these findings were confirmed to be factors associated with OSA in this group of children according to a logistic regression analysis. CONCLUSIONS: The occurrence rate of OSA in this obese pediatric population was high. Adenotonsillar hypertrophy and a modified Mallampati index of class III/IV were the factors associated with OSA.

Polisomnographic findings on children with laryngopathies.

UNLABELLED: Polysomnography is the goldstandard exam for child OSAS. When possible, polysomnography clearly distinguishes between those with isolated primary snoring and patients with sleep apnea (obstructive, central and mixed). The most common cause of OSAS in childhood is adenotonsillar hypertrophy. Laryngomalacia is the most common cause of stridor in childhood, though its physiopathology remains unknown. Among the most prominent theories are immaturity of the cartilaginous framework of the larynx and/or neuromuscular immaturity. OBJECTIVE: Our proposal was to describe polysomnographic findings in children with laryngomalacia or other isolated laryngeal alterations, that is, without other alterations in the upper airways. METHODS: The sample included 29 children with exclusively laryngeal alterations. All of them underwent an otorhinolaryngological exam, nasofibrolaryngoscopy and polysomnography. Information was recorded concerning age, nasofibrolaryngoscopy and polysomnography. For analysis, the children were divided into two groups: those with laryngomalacia and those with other laryngeal diseases. RESULTS: Among the 18 children with a diagnosis of laryngomalacia, 18 had central breathing events, knowing that the majority had showed desaturation of oxihemoglobin and bradycardia. In this same group, 3 children had obstructive events. On the other hand, 11 children with other laryngeal alterations showed no predominance of one type or another of apnea. Of these, 4 had central type breathing events and 2 obstructive type. CONCLUSION: The majority of patients with laryngomalacia showed a central type apnea. Patients with various laryngeal diseases did not present a predominant type of apnea.

Auditory processing assessment in children with obstructive sleep apnea syndrome.

INTRODUCTION: The obstructive sleep apnea syndrome (OSAS) is a respiratory disorder that occurs during sleep and it is relatively common in children. AIM: The goal of this paper is to verify if there is a relationship between the obstructive sleep apnea syndrome (OSAS) and auditory processing. METHODS: In order to do that, three groups of children ranging in age from 5 to 11 were studied, including a normal group. Twenty subjects who made up the study group were submitted to ear, nose and throat (ENT) exams and to polysomnography (PSG), and were divided in two groups: GROUP I (RO) comprised of 10 children who presented oral breathing and displayed normal PSG, and GROUP II (SAS) comprised of 10 children who presented oral breathing and displayed abnormal PSG. Their performance was compared to the performance of the third group--GROUP III (REN) comprised of 10 children who did not refer ENT difficulties. All the subjects completed a basic audiometric assessment as well as an auditory processing diagnosis. RESULTS: The analyses of the results revealed a statistically significant difference in ENT exams related to the turbinate and the palatine tonsils. Group II presented a higher incidence of turbinate hypertrophy levels II and III (p<0.001) and palatine tonsils hypertrophy grades III and IV (p 0.007). Regarding the auditory processing assessment, a statistically significant difference (p<0.001) was obtained in the dichotic digits test. Group II performed worse than group III. Also, for the non-verbal sequence memory test, Group II obtained a worse result (p<0.022) than Group I. CONCLUSION: Subjects with OSAS obtained worse results in auditory processing tests.

Impact of corticotherapy, nutrition, and sleep disorder on quality of life of patients with Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is the second most common hereditary genetic disease in humans and has elevated mortality. DMD is an X-linked, life-limiting progressive muscle-wasting disease found predominantly in boys and young men. One of the main treatments for patients with DMD is corticosteroids. However, long-term use may cause major side effects such as obesity, a reduction in vitamin D, and osteoporosis. Sleep-disordered breathing is a common condition among patients with DMD, especially obstructive sleep apnea (OSA). In children, OSA is associated with obesity and a reduction of vitamin D concentration. In this article we aim to explore the interrelationship that exists between corticosteroids, obesity, OSA, and the risk of osteoporosis. Our main hypothesis is that factors such as nutrition and sleep are related to obesity and OSA, respectively. In addition, the chronic use of corticosteroids, obesity, and OSA are factors that can reduce serum levels of vitamin D, triggering osteoporosis. Thus, these factors play a key role in affecting the quality of life for patients with DMD and intervention based on these aspects may improve survival.

Phenotypic contrasts of Duchenne Muscular Dystrophy in women: Two case reports.

We discussed two cases of symptomatic female carriers to Duchenne Muscular Dystrophy. The first case is a 20 year-old girl with classical phenotypic manifestation of the disease, similar to the condition in boys. The case 2 is a 62 year-old woman with progressive muscular weakness. The disease is much less common in woman than men so both cases described here are considered rare forms of the disease, with several clinical implications. In both cases, a progressive muscle weakness, impairment in walking and sleeping was observed, in addition to obstructive sleep apnea syndrome and alveolar hypoventilation, that required noninvasive ventilatory support.

Acoustic arousal responses in children with obstructive sleep apnea.

Our objectives were to study the arousal responses to nonrespiratory (acoustic) stimuli in children with obstructive sleep apnea syndrome (OSAS). The acoustic arousal response was studied in children with OSAS due to adenotonsillar hypertrophy compared to normal, age-matched children. Acoustic stimuli were delivered incrementally from 30-100 dB during stage 2, slow wave sleep, and rapid eye movement (REM) sleep. The percentage of children who aroused in response to acoustic stimuli, and the arousal threshold (i.e., sound level at which arousal occurred), were compared between groups and sleep stages. The percentage of children who aroused was similar between children with OSAS and controls. The percentage of children who aroused was lower during slow wave sleep than REM sleep and stage 2 in both OSAS and controls. There were no statistically significant differences in acoustic arousal threshold between OSAS and control children. There was no difference in arousal response to moderate acoustic stimulation between children with OSAS and controls. These results contrast with previous data showing blunted arousal responses to hypercapnia and upper airway loading during sleep in children with OSAS, suggesting that children with OSAS have an arousal deficit specific to respiratory stimuli. However, further studies evaluating arousal to both respiratory and nonrespiratory stimuli in the same subjects are needed.

OSAS in children: correlation between endoscopic and polysomnographic findings.

OBJECTIVES: To correlate polysomnographic findings with clinical history of apnea, the degree of obstruction caused by tonsillar hypertrophy, and to age group. STUDY DESIGN AND SETTING: 267 children with a clinical diagnosis of obstructive sleep apnea (OSAS) were evaluated. Patients were divided into preschool- and school-age categories, and subdivided in 3 additional groups, according to tonsillar hypertrophy. Polysomnographic findings were compared within groups. RESULTS: 34% of children had history of OSAS and normal polysomnographic findings. Tonsillar hypertrophy was correlated to more severe apnea among preschool-age children, but not among school-age children. Among children with tonsillar hypertrophy, more severe apnea was observed in preschool-age children than in school-age children. CONCLUSIONS: There is little correlation between polysomnographic and clinical findings in children with OSAS. SIGNIFICANCE: Adenotonsillar hypertrophy leads to more severe polysomnographic patterns in preschool-age children. More severe apnea is observed in younger children with adenotonsillar hypertrophy than in older ones.