Comparison of classical method and microdebrider technique for adenoidectomy in pediatric patients with obstructive sleep apnea.

Objectives: The aim of this study was to evaluate the safety and efficacy of microdebrider adenoidectomy on sleep-disordered breathing among pediatric patients with OSA. Methods: In the microdebrider group (Group I), there were 30 Japanese OSA patients consisting of 26 boys and 4 girls. For comparison, we had 15 children (13 boys and 2 girls) who underwent classical adenoidectomy (Group II). Patients in Group I were selected from a pool of 95 pediatric Japanese OSA patients and were matched by age, preoperative AHI, and Kaup index with those in Group II.Parameters such as the amount of residual adenoid tissue, bleeding, duration of the procedure, and sleep-related metrics were compared between the two groups. Results: A significant improvement in postoperative AHI was observed in Group I (p<0.05). The prevalence of AHI <1 was significantly higher in Group I compared with Group II (p<0.05). Additionally, the amount of postoperative residual adenoid was significantly less in Group I (3/30 of Grade 3 and 4 adenoid size) than in Group II (7/15, p<0.05). Furthermore, a reduction in postoperative AHI was proportionally associated with a decrease in residual adenoid. Conclusions: The newly developed microdebrider adenoidectomy technique for pediatric OSA patients with adenotonsillar hypertrophy demonstrated greater accuracy and efficacy in ameliorating sleep apnea symptoms compared with the standard adenoidectomy approach.

Deglutition dynamics of patients with obstructive sleep apnea.

Objectives: In the present study, we performed a detailed analysis of deglutitive dynamics during sleep in patients with obstructive sleep apnea (OSA) using a methodology developed by Sato et al. We hypothesized that the frequency of deglutition would decrease with increasing severity of OSA. The aim of this study is to clarify the involvement of deglutitive dynamics during sleep in OSA by investigating the correlations between deglutition and sleep parameters. Methods: This study included 30 adult patients with OSA. To analyze deglutition dynamics during sleep, surface electromyography recordings of the suprahyoid and thyrohyoid neck muscles, which are involved in deglutition, were performed simultaneous with conventional polysomnography. The "index of deglutition" was defined as the frequency of deglutition per hour of sleep. We examined correlations between this index and sleep parameters (apnea-hypopnea index [AHI], apnea index, hypopnea index, and lowest blood oxygen saturation). Results: By analyzing the obtained polysomnography and electromyography waveforms, we identified two deglutition patterns with and without respiratory arousal during sleep. We found a significant negative correlation between the index of deglutition in sleep stage 1 and the AHI, with a correlation coefficient of -0.48. (p=0.02). Conclusions: In the current study, we distinguished deglutition during sleep with and without arousal. In addition we discovered a significant negative correlation between the index of deglutition in sleep stage 1 and the AHI. This new finding will provide a platform for future research on OSA in aspiration pneumonia.

Relationship between size of pharyngeal and palatine tonsils and apnea-hypopnea index in pediatric obstructive sleep apnea.

Objective: To determine whether the combination of the pharyngeal tonsil grade and palatine tonsil grade results in differences in the apnea-hypopnea index (AHI) and to determine whether each parameter separately (pharyngeal tonsil grade and palatine tonsil grade) results in differences in severe obstructive sleep apnea (OSA). Methods: This cross-sectional study involved 107 children (mean age, 7.2 years; range, 4-12 years) suspected of having OSA because of snoring or sleep-related complaints. The patients underwent polysomnography, and their palatine and pharyngeal tonsils were graded. Results: In examining whether the palatine tonsils and pharyngeal tonsils could be risk factors for severe OSA, the adjusted odds ratios were 4.42 for palatine tonsil grade 4 versus 1-3 and 10.40 for pharyngeal tonsil grade 4 versus 1-3; both were highly statistically significant. We also found that the AHI when both the pharyngeal and palatine tonsils were grade 4 was higher than the AHI expected for the pharyngeal and palatine tonsils alone. Conclusions: The combination of grade 4 pharyngeal tonsils and grade 4 palatine tonsils resulted in an AHI much higher than the AHI of other combinations (pharyngeal tonsils grades 1-3 and 4, palatine tonsils grades 1-3 and 4). We believe that grade 4 pharyngeal tonsils and grade 4 palatine tonsils have a great influence on severe OSA and that grade 4 pharyngeal tonsils increase the AHI.

Alpha/Beta Gliadin MM1 Is a Novel Antigen for Wheat-Dependent Exercise-Induced Anaphylaxis.

INTRODUCTION: Screening for ω-5 gliadin specific IgE antibody (sIgE) has high diagnostic utility in cases of suspected wheat-dependent exercise-induced anaphylaxis (WDEIA); however, negative cases may require confirmatory tests, such as the oral challenge test. Thus, newly identified allergens that can be used for the serological diagnosis of WDEIA are needed. This study aimed to identify additional sIgE biomarkers of WDEIA. METHODS: Forty-two patients with WDEIA (5 negative/37 positive for ω-5 gliadin sIgE) were enrolled. For comparison, 8 patients with immediate-type wheat allergy without WDEIA and 20 healthy controls without wheat allergy were also enrolled. Extracted wheat proteins were separated by 2D-PAGE. Proteins that reacted with serum IgE antibody in 2D Western blotting (2D-WB) were identified using mass spectrometry. Recombinant proteins were synthesized in Escherichia coli, and the antigenicity was tested using ELISA and the basophil activation test. RESULTS: In 2D-WB, nine proteins reacted with the serum IgE antibody from at least 60% of patients with WDEIA (n ≥ 25/42). ELISA revealed that alpha/beta gliadin MM1 exhibited the highest positive immunoreactivity in 23 of 26 patients who were positive for ω-5 gliadin sIgE (88%) and in 5 of 5 patients who were negative for ω-5 gliadin sIgE (100%). Alpha/beta gliadin MM1 exhibited significantly higher basophil activation in 14 patients with WDEIA when compared to 5 individuals without a wheat allergy. CONCLUSIONS: Alpha/beta gliadin MM1 sIgE exhibited the highest seropositivity, even among patients who were negative for ω-5 gliadin sIgE. The inclusion of alpha/beta gliadin MM1 in allergen-sIgE tests may improve the sensitivity for diagnosing WDEIA.

Comparison of electromyography, sound, bioimpedance, and high-resolution manometry for differentiating swallowing and vocalization events.

OBJECTIVES: Non-invasive surface recording devices used for detecting swallowing events include electromyography (EMG), sound, and bioimpedance. However, to our knowledge there are no comparative studies in which these waveforms were recorded simultaneously. We assessed the accuracy and efficiency of high-resolution manometry (HRM) topography, EMG, sound, and bioimpedance waveforms, for identifying swallowing events. METHODS: Six participants randomly performed saliva swallow or vocalization of "ah" 62 times. Pharyngeal pressure data were obtained using an HRM catheter. EMG, sound, and bioimpedance data were recorded using surface devices on the neck. Six examiners independently judged whether the four measurement tools indicated a saliva swallow or vocalization. Statistical analyses included the Cochrane's Q test with Bonferroni correction and the Fleiss' kappa coefficient. RESULTS: Classification accuracy was significantly different between the four measurement methods (P < 0.001). The highest classification accuracy was for HRM topography (>99%), followed by sound and bioimpedance waveforms (98%), then EMG waveform (97%). The Fleiss' kappa value was highest for HRM topography, followed by bioimpedance, sound, and then EMG waveforms. Classification accuracy of the EMG waveform showed the greatest difference between certified otorhinolaryngologists (experienced examiners) and non-physicians (naive examiners). CONCLUSION: HRM, EMG, sound, and bioimpedance have fairly reliable discrimination capabilities for swallowing and non-swallowing events. User experience with EMG may increase identification and interrater reliability. Non-invasive sound, bioimpedance, and EMG are potential methods for counting swallowing events in screening for dysphagia, although further study is needed.

Sleep Apnea Syndrome (SAS) Clinical Practice Guidelines 2020.

The prevalence of sleep disordered breathing (SDB) is reportedly very high. Among SDBs, the incidence of obstructive sleep apnea (OSA) is higher than previously believed, with patients having moderate-to-severe OSA accounting for approximately 20% of adult males and 10% of postmenopausal women not only in Western countries but also in Eastern countries, including Japan. Since 1998, when health insurance coverage became available, the number of patients using continuous positive airway pressure (CPAP) therapy for sleep apnea has increased sharply, with the number of patients about to exceed 500,000 in Japan. Although the "Guidelines for Diagnosis and Treatment of Sleep Apnea Syndrome (SAS) in Adults" was published in 2005, a new guideline was prepared in order to indicate the standard medical care based on the latest trends, as supervised by and in cooperation with the Japanese Respiratory Society and the "Survey and Research on Refractory Respiratory Diseases and Pulmonary Hypertension" Group, of Ministry of Health, Labor and Welfare and other related academic societies, including the Japanese Society of Sleep Research, in addition to referring to the previous guidelines. Because sleep apnea is an interdisciplinary field covering many areas, this guideline was prepared including 36 clinical questions (CQs). In the English version, therapies and managements for SAS, which were written from CQ16 to 36, were shown. The Japanese version was published in July 2020 and permitted as well as published as one of the Medical Information Network Distribution Service (Minds) clinical practice guidelines in Japan in July 2021.

Sleep Apnea Syndrome (SAS) Clinical Practice Guidelines 2020.

The prevalence of sleep-disordered breathing (SDB) is reportedly very high. Among SDBs, the incidence of obstructive sleep apnea (OSA) is higher than previously believed, with patients having moderate-to-severe OSA accounting for approximately 20% of adult males and 10% of postmenopausal women not only in Western countries but also in Eastern countries, including Japan. Since 1998, when health insurance coverage became available, the number of patients using continuous positive airway pressure (CPAP) therapy for sleep apnea has increased sharply, with the number of patients about to exceed 500,000 in Japan. Although the "Guidelines for Diagnosis and Treatment of Sleep Apnea Syndrome (SAS) in Adults" was published in 2005, a new guideline was prepared to indicate the standard medical care based on the latest trends, as supervised by and in cooperation with the Japanese Respiratory Society and the "Survey and Research on Refractory Respiratory Diseases and Pulmonary Hypertension" Group, of Ministry of Health, Labor and Welfare and other related academic societies, including the Japanese Society of Sleep Research, in addition to referring to the previous guidelines. Since sleep apnea is an interdisciplinary field covering many areas, this guideline was prepared including 36 clinical questions (CQs). In the English version, therapies and managements for SAS, which were written from CQ16 to 36, were shown. The Japanese version was published in July 2020 and permitted as well as published as one of the Medical Information Network Distribution Service (Minds) clinical practice guidelines in Japan in July 2021.

Clinical indication of nasal surgery for the CPAP intolerance in obstructive sleep apnea with nasal obstruction.

OBJECTIVE: The role of isolated nasal surgery for obstructive sleep apnea (OSA) patients with nasal obstruction, especially for an intolerance for continuous positive airway pressure (CPAP), is unclear. The aim of this study was to assess the effects of surgery for OSA patients with symptomatic nasal obstruction and CPAP intolerance. METHOD: Retrospectve comparative study.1037 OSA patients with apnea-hypopnea index (AHI) ≥ 20 were enrolled. Case-control study was performed between the male apnea patients undergoing nasal surgery: surgery group (n = 43) and the pair-matched apnea patients for age, sex, body mass index, and race: control group (n = 43). The surgery group suffering from nasal obstruction could not use continuous positive airway pressure, and the CPAP group free from nasal obstruction could use it successfully. RESULTS: In surgery group, surgery significantly decreased the nasal resistance and Epworth sleepiness scale scores without changing the AHI. Surgery significantly increased the nadir of oxygen saturation and shortened the apnea-hypopnea duration. Although all of the surgery group failed to use positive airway pressure preoperatively, the 40 patients of the 43 CPAP intolerance patients were able to use CPAP postoperatively. The resting three patients were cured OSA or changed the treatment to oral appliance(OA). For both groups, the cutoff nasal resistance for differentiating the failure of positive airway pressure and its success was 0.31 Pa/cm3/s. CONCLUSION: Isolated nasal surgery is effective for an intolerance of positive airway pressure in sleep apnea with nasal obstruction presumably by decreasing nasal resistance.

Nasal patency as a factor for successful transnasal endoscopy.

In recent years, transnasal endoscopy had been more widely accepted for its safety and convenience, and although it can lead to a weaker pharyngeal reflex, compared with the effects of transoral endoscopy, examinees often suffer intolerable pain and discomfort during passage of the endoscope through the nasal cavity. The aim of this study was to estimate the relationship between the uncomfortable factors during transnasal endoscopy and nasal patency. The subjects comprised 23 consecutive patients who underwent transnasal endoscopy from October 2007 to April 2009 at our Gastroenterology and Otorhinolaryngology Departments. Immediately prior to endoscopy, the left and right nasal resistance was measured with an active anterior rhinomanometer; a value of 100 Pa was determined as nasal resistance. The transnasal endoscope was inserted in the subjectively preferred side by the examinee. Thereafter, the subjects were asked to fill in a questionnaire on physical tolerance during the procedure, to quantify the sensations of nasal pain, nausea, and choking on a 10-point visual analogue scale. The mean scores were 3.0 ± 2.7 for nasal pain, 1.7 ± 2.0 for choking, and 1.6 ± 1.9 for nausea. The most intolerable factor among the complaints was pain (45%), which was followed by nausea (18%) and choking (9%). Unilateral nasal resistance was significantly related with nasal pain only (P = 0.0135). In conclusion, the most difficult problem during transnasal endoscopy was pain, which was related to nasal patency. We successfully demonstrated the clinical significance of nasal patency in determining the side of insertion for transnasal endoscopy.

Mechanisms Underlying Improvement in Obstructive Sleep Apnea Syndrome by Uvulopalatopharyngoplasty.

In a previous case report, we determined for the first time that uvulopalatopharyngoplasty (UPPP) does not change the volume of the upper airway but causes morphological changes in the entire upper airway. The objective of this study is to elucidate the mechanisms underlying the improvement in obstructive sleep apnea syndrome (OSAS) by UPPP. We present an additional case involving a patient with OSAS treated using UPPP. Morphological and numerical parameter changes after surgery were compared with the corresponding preoperative values. Anatomically accurate upper airway computational models were reconstructed from computed tomographic imaging data. In addition, computed fluid dynamics analysis was performed to reveal inhalation flow characteristics before and after UPPP and clearly assess the effect of UPPP on airflow patterns in the patient's upper airway. An important benefit of UPPP is the morphological changes in the entire upper airway, in addition to widening the restricted area. These morphological changes induce laminarization of the pharyngeal jet. To obtain sufficient efficacy of UPPP in OSAS, the morphological changes in the upper airway and the airflow pattern after the surgery must be controlled.

Cytokeratin 13, Cytokeratin 17, and Ki-67 Expression in Human Acquired Cholesteatoma and Their Correlation With Its Destructive Capacity.

OBJECTIVES: Cholesteatoma is a nonneoplastic destructive lesion of the temporal bone with debated pathogenesis and bone resorptive mechanism. Both molecular and cellular events chiefly master its activity. Continued research is necessary to clarify factors related to its aggressiveness. We aimed to investigate the expression of Ki-67, cytokeratin 13 (CK13) and cytokeratin 17 (CK17) in acquired nonrecurrent human cholesteatoma and correlate them with its bone destructive capacity. METHODS: A prospective quantitative immunohistochemical study was carried out using fresh acquired cholesteatoma tissues (n=19), collected during cholesteatoma surgery. Deep meatal skin tissues from the same patients were used as control (n=8). Cholesteatoma patients were divided into 2 groups and compared (invasive and noninvasive) according to a grading score for bone resorption based upon clinical, radiologic and intraoperative findings. To our knowledge, the role of CK17 in cholesteatoma aggressiveness was first investigated in this paper. RESULTS: Both Ki-67 and CK17 were significantly overexpressed in cholesteatoma than control tissues (P<0.001 for both Ki-67 and CK17). In addition, Ki-67 and CK17 were significantly higher in the invasive group than noninvasive group of cholesteatoma (P=0.029, P=0.033, respectively). Furthermore, Ki-67 and CK17 showed a moderate positive correlation with bone erosion scores (r=0.547, P=0.015 and r=0.588, P=0.008, respectively). In terms of CK13, no significant difference was found between cholesteatoma and skin (P=0.766). CONCLUSION: Both Ki-67 and CK17 were overexpressed in cholesteatoma tissue and positively correlated with bone resorption activity. The concept that Ki-67 can be a predictor for aggressiveness of cholesteatoma was supported. In addition, this is the first study demonstrating CK17 as a favoring marker in the aggressiveness of acquired cholesteatoma.

Pathogenesis and Bone Resorption in Acquired Cholesteatoma: Current Knowledge and Future Prospectives.

Cholesteatoma is a cystic non tumorous lesion of the temporal bone that has the ability to destroy nearby structures by its power to cause bone resorption and as a result, fatal complications prevail. We aimed to conduct a comprehensive review for pathogenesis of acquired cholesteatoma, bone resorption mechanisms, and offer a future vision of this serious disease. We have reviewed different theories for pathogenesis of acquired cholesteatoma including the most relevant and updated ones with special emphasis on the mechanisms of bone resorption through Medline/PubMed research using the keywords 'aetiopathogenesis, bone resorption, acquired cholesteatoma, temporal bone, and cytokines.' In order to strengthen our study, we searched the reference lists of identified reviews. Cholesteatoma is a subject of debate among otolaryngologists since it was prescribed firstly. Over many decades, several theories were postulated for aetiopathogenesis of cholesteatoma with a tendency to follow more than one theory to explain the proper nature of that disease. Until now, the mechanism of bone resorption has yet to be more clarified. In the last century, a leap has occurred in the field of biomolecular cholesteatoma research which improved our knowledge about its pathophysiology and bone destructive mechanism. However, surgery is still the only available treatment. We conclude that discovery of new therapeutic choices for cholesteatoma other than surgery by the use of anti-growth, anti-proliferative, apoptotic agents as well as medications that antagonize osteoclastogenesis should be the main concern in the future clinical and experimental research work. Also, searching for predictors of the aggressiveness of cholesteatoma can affect the timing of intervention and prevent occurrence of complications.

Volumes of Velopharyngeal and Glossopharyngeal Airway Were Not Changed after Uvulopalatopharyngoplasty: Report of Three Cases.

Objective. The aim of this study was to investigate the changes in velopharyngeal and glossopharyngeal airway morphology and volume after uvulopalatopharyngoplasty in three adult obstructive sleep apnea syndrome patients who had bilateral large tonsils using three-dimensional computed tomography. Case Report. All three patients (one male and two females) who presented with a history of heavy snoring and excessive daytime sleepiness were examined with overnight nocturnal polysomnography, which indicated moderate-to-severe obstructive sleep apnea syndrome. Because all patients had large tonsils, uvulopalatopharyngoplasty was expected to enlarge the pharyngeal airway. Polysomnography and three-dimensional computed tomography scanning were performed and compared, both before and 3 months after uvulopalatopharyngoplasty. Results. Unexpectedly, although the morphology of the glossopharyngeal airway clearly changed after UPPP, the volume changes in the velopharyngeal and glossopharyngeal airways were negligible.

Craniofacial contribution to residual obstructive sleep apnea after adenotonsillectomy in children: a preliminary study.

STUDY OBJECTIVES: Pediatric obstructive sleep apnea (OSA) is frequently associated with adenotonsillar hypertrophy, and the fact that about 30% of affected children continue to show OSA after adenotonsillectomy (AT) suggests the presence of some other predisposing factor(s). We hypothesized that abnormal maxillofacial morphology may be a predisposing factor for residual OSA in pediatric patients. METHODS: A total of 13 pediatric OSA patients (9 boys and 4 girls, age [median (interquartile range)] = 4.7 (4.0, 6.4) y, body mass index (BMI) z score = -0.3 (-0.8, 0.5)) who had undergone AT were recruited for this study. Maxillomandibular size was measured using an upright lateral cephalogram, and correlations between size and the apnea hypopnea index (AHI) values obtained before (pre AT AHI) and about 6 months after AT (post AT AHI) were analyzed. RESULTS: AHI decreased from 12.3 (8.9, 26.5)/h to 3.0 (1.5, 4.6)/h after AT (p < 0.05). Residual OSA was seen in 11 of the 13 patients (84.6%) and their AHI after AT was 3.1 (2.7, 4.7)/h. The mandible was smaller than the Japanese standard value, and a significant negative correlation was seen between maxillomandibular size and post AT AHI (p < 0.05). CONCLUSIONS: These findings suggest that the persistence of OSA after AT may be partly due to the smaller sizes of the mandible in pediatric patients. We propose that the maxillomandibular morphology should be carefully examined when a treatment plan is developed for OSA children.

Evaluation of adenotonsillectomy and tonsillectomy for pediatric obstructive sleep apnea by rhinomanometry and the OSA-18 questionnaire.

CONCLUSION: Nasal resistance and the OSA-18 score were useful for evaluating surgical treatments. The sleep disturbance score may also be useful for predicting the severity of obstructive sleep apnea (OSA) in children. OBJECTIVE: We evaluated the effect of surgery on children with OSA using polysomnography (PSG) parameters, nasal resistance, and the OSA-18 questionnaire, and also investigated the cut-off OSA-18 score to screen for pediatric OSA. METHODS: This was a retrospective study in which PSG parameters and nasal resistance were measured using a rhinomanometer and the OSA-18 score was obtained from the OSA-18 questionnaire before and after surgery in 45 children with OSA. RESULTS: The mean age of the 45 patients was 5.7 ± 2.0 years. The mean value of the obstructive apnea hypopnea index (O-AHI) improved from 16.2 ± 14.3/h before surgery to 1.1 ± 1.7/h after surgery, the mean nasal resistance improved from 0.44 ± 0.19 to 0.32 ± 0.10 Pa/cm(3)/s, and the mean OSA-18 score improved from 61.1 ± 13.7 to 30.4 ± 5.8, and all these improvements were significant. The O-AHI value was lower than 1/h after surgery in 64.4% of patients (29/45). The O-AHI value was significantly correlated with the sleep disturbance score (r = 0.352, p = 0.018). When the cut-off OSA-18 score for screening was set at 40, sensitivity was 100%.

Obstructive sleep apnea in Asian primary school children.

PURPOSE: The objectives of this study were to examine the prevalence of obstructive sleep apnea (OSA) in primary school children, relationships between OSA and tonsillar hypertrophy, adenoid, and patency of the nasal cavity, and the effects of the tonsillar hypertrophy and adenoid on the nasal patency. METHODS: An examination of the palatine tonsils and anterior rhinoscopy, completion of a questionnaire survey, a measurement of nasal resistance, an examination for sleep apnea at home using portable polysomnography device, and radiography of pharyngeal tonsil were performed in 152 primary school children. RESULTS: The obstructive apnea hypopnea index (O-AHI) increased with enlargements in the palatine tonsils. The adenoidal nasopharyngeal ratio (A/N ratio) decreased with advances in grade. A significant difference was observed in the O-AHI between those with and without adenoid. The median value of the O-AHI increased with advances in grade. The nasal resistance was significantly higher in the group with adenoid compared as in the group without. It was also higher in the nasal disease group with OSA than in the group without. Full polysomnography(PSG) was recommended in 16 (10.5%) of 152 who underwent the examination using the portable polysomnography device, and of the eight who underwent PSG, six (75%) were confirmed to have OSA, while its prevalence in all subjects was estimated as 7.9%. CONCLUSIONS: Disturbances in nasal respiration as well as tonsillar hypertrophy and adenoid were found to be a risk factor of OSA in primary school children.

Comparison of oxygen desaturation patterns in children and adults with sleep-disordered breathing.

PURPOSE: Although the number of apnea-hypopnea episodes per hour apnea-hypopnea index (AHI) is typically used to evaluate sleep-disordered breathing (SDB) in adults, it does not provide an accurate characterization of SDB in children. We investigated differences in SDB patterns in children and adults to evaluate SDB severity in children. MATERIALS AND METHODS: Fifteen adults (mean age, 45.3 ± 8.4 years) and 15 children (mean age, 6.7 ± 3.9 years) with adenotonsillar hypertrophy underwent standard polysomnography. The change of oxygen saturation (ΔSpO2) was defined as the difference between baseline SpO2 during stable nighttime breathing and the lowest SpO2 accompanied by an apnea-hypopnea event. The number of apnea-hypopnea episodes was determined using two different criteria to define an episode (criterion 1: cessation of airflow for at least 10s; criterion 2: cessation of airflow for at least two consecutive breaths). RESULTS: Mean ΔSpO2 accompanied by obstructive apneas lasting ≤10 s was significantly greater in children than in adults, although there was no significant difference in the duration of apnea-hypopnea episodes. The slope of the regression line between ΔSpO2 and apnea-hypopnea duration in children was greater than in adults (P<0.005). AHI in children was higher when calculated using criterion 2 compared to criterion 1 (10.9 ± 9.4 vs. 6.5 ± 4.9/h, P=0.003). CONCLUSIONS: ΔSpO2 is a good indicator of SDB severity in children, and should therefore be considered in the diagnosis and treatment of pediatric SDB along with AHI.

Relationship between adenoid size and severity of obstructive sleep apnea in preschool children.

OBJECTIVE: To investigate the contributions of adenoid and tonsil sizes to obstructive sleep apnea syndrome (OSAS) in normal-weight children in two age categories: preschool and schoolchildren. METHODS: Fifty-eight normal-weight (body mass index z-score<2) symptomatic children with OSAS (apnea-hypopnea index ≥ 2) were evaluated. The patients were divided into two age categories: preschool (age<6; n=33) and schoolchildren (age ≥ 6; n=25). Polysomnographic findings and adenoid and tonsil sizes were compared. The relative contributions of body mass index and adenoid and tonsil sizes were also investigated with a regression analysis. RESULTS: Adenoid grade and apnea index correlated significantly in preschool children (r=0.45, p<0.01). On regression analysis, adenoid grade was a significant predictor of the apnea index in preschool children. The influence of adenoid hypertrophy decreased from preschool to schoolchildren. Tonsil size had little influence on the apnea index in either group. CONCLUSION: Adenoid hypertrophy was a major contributor to OSAS in normal-weight preschool children. The upper airway morphology of younger children with OSAS differed from that of older children with OSAS.

Children with severe or moderate obstructive sleep apnoea syndrome show a high incidence of persistence after adenotonsillectomy.

CONCLUSION: Persistent obstructive sleep apnoea syndrome (OSAS) occurs in approximately 20% of normal-weight children after adenotonsillectomy (T&A) and, in nearly 70% of them, it is caused by adenoid regrowth. Patients with severe or moderate OSAS showed a high incidence of persistent disease even after T&A. Allergic disease, severity and large adenoid size are associated with adenoid regrowth and persistent disease. OBJECTIVES: To investigate factors contributing to persistent OSAS and adenoid regrowth after T&A in normal-weight children. METHODS: This was a prospective, observational study at a single institute and involved 49 normal-weight children with severe or moderate OSAS (apnoea-hypopnoea index, AHI, ≥ 5) who underwent T&A. Background information, nasal endoscopic data and pre- and postoperative polysomnographic data were collected. A third polysomnography (PSG) was performed 1.5 year postoperatively in children who subsequently developed symptoms of sleep disturbance. RESULTS: Thirteen children (27%, 13/49) were symptomatic 1.5 years after T&A. Allergic rhinitis (38.5% vs 11.1%, p = 0.03) and allergic disease (69.2% vs 30.6%, p = 0.02) were seen more frequently in these children. A third PSG confirmed persistent disease (AHI ≥ 5) in nine children (18.4%, 9/49). Six children (12.2%, 6/49) were diagnosed as having adenoid regrowth and three (6.1%, 3/49) underwent revision adenoidectomy.

A functional variation in the hypocretin neuropeptide precursor gene may be associated with obstructive sleep apnea syndrome in Japan.

OBJECTIVES/HYPOTHESIS: To evaluate the association of hypocretin neuropeptide precursor gene (HCRT) variations with obstructive sleep apnea syndrome (OSAS) in a cohort of Japanese patients and to further evaluate whether the significant HCRT variations have potential functional consequences on HCRT expression. STUDY DESIGN: Case-control genetic association study. METHODS: We studied the genetic variations within the HCRT gene. The study population consisted of 100 OSAS patients and 100 control subjects. The HCRT gene was amplified by polymerase chain reaction in all study subjects followed by direct sequencing and analysis of sequencing data. RESULTS: Two genetic variations within the HCRT intron, IVS1+16T>C (rs9902709) and IVS1-69G>C, were identified with significant differences between patients and controls (P < .05). A reporter gene assay using HeLa cells showed that the construct containing the C allele of the rs9902709 variation had significantly higher luciferase activity compared with the construct containing the T allele (P = .002). Furthermore, enzyme immunoassay revealed that subjects with T/C and C/C genotypes for rs9902709 had 1.4-fold and 1.5-fold increases in sera levels of orexin-A, respectively. CONCLUSIONS: Our genetic association study, followed by functional and quantitative phenotyping assays, demonstrated a functional locus within the HCRT gene, which may act to increase HCRT expression and lead to a protective effect against the development of OSAS.