Kun-Tai Kang

Body weight status and obstructive sleep apnea in children

Objective:The relationship between weight status, adenotonsillar hypertrophy and obstructive sleep apnea (OSA) in children has not yet been well studied. As the sleep parameters may show a disparity in different weight statuses, this study examined the relationship between the data of over-night polysomnography and different weight statuses, as well as the impact of adenotonsillar hypertrophy on children with OSA.Methods:Children with sleep disturbances were recruited from our clinics. Standard physical examinations, history taking, lateral neck roentgenography, and full-night polysomnography were obtained. Children were divided into four groups based on the age- and gender-corrected body mass index (BMI): underweight, normal weight, overweight and obese. An adenoidal/nasopharyngeal ratio of more than 0.67 was considered adenoidal hypertrophy. Tonsillar hypertrophy was defined as having Grade III tonsils or above.Results:From July 2006 to January 2009, 197 children were included in this study. Obese children had a significantly higher apnea–hypopnea index (AHI), obstructive apnea index and lower minimum oxygen saturation (MinSaO2) than those of the other groups. Underweight children had the second highest AHI. A negative correlation was also found between BMI z scores and MinSaO2 (r=−0.194; P=0.007). Children with tonsillar hypertrophy (P=0.001) were associated with a higher risk of having OSA. The risk of having OSA was significantly higher in obese children (P=0.001) and underweight children (P=0.043) than in those with a normal weight.Conclusion:Obesity, underweight status and tonsillar hypertrophy are associated with children having OSA, and obese children have a significantly higher risk than children with underweight status.

Associations between Adenotonsillar Hypertrophy, Age, and Obesity in Children with Obstructive Sleep Apnea

Objective To investigate the contributions of adenoid and tonsil size to childhood obstructive sleep apnea (OSA) and the interactions between adenotonsillar hypertrophy, age, and obesity in children with OSA. Methods In total, 495 symptomatic patients were recruited. The patients were assigned to four groups according to age：toddler (age 1-3, n=42), preschool (age 3-6, n=164), school (age 6-12, n=200), and adolescence (age 12-18, n=89). All subjects had tonsil size graded by otolaryngologists, adenoid size determined on lateral radiographs (Fujioka method), and a full-night polysomnography. The apnea-hypopnea index (AHI), adenoid size, and tonsil size were compared in obese and non-obese children in the four age groups. Adjusted odds ratios (ORs) and 95% confidence interval (CI) of adenotonsillar hypertrophy and OSA risk were estimated by multi-logistic regression. Results The AHI was positively related to tonsil grade (r=0.33, p <0.001) and adenoid size (r=0.24, p <0.01) in all patients. Tonsil grade was positively related to AHI in all four age groups. Adenoid size was positively related to AHI in the toddler, preschool, school groups, but not in the adolescent group (r=0.11, p=0.37). Tonsil grade and adenoid size were both positively related to AHI in obese and non-obese children. In the regression model, obesity (OR=2.89; 95% CI 1.47-5.68), tonsillar hypertrophy (OR=3.15; 95% CI 2.04-4.88), and adenoidal hypertrophy (OR=1.89; 95% CI 1.19-3.00) significantly increased OSA risk. Conclusions Adenotonsillar hypertrophy and obesity are the major determinants of OSA in children. However, the influence of adenoid size decreases in adolescence.

Impacts of body weight after surgery for obstructive sleep apnea in children

Objective:To investigate the impacts of body weight status on surgical outcomes and shifts of body weight status after adenotonsillectomy(T&A) in children with obstructive sleep apnea (OSA).Methods:From 2009 to 2011, 161 children (mean age, 7.0±3.4 years; 78% boys) were included. All the children had clinical symptoms and preoperative polysomnographic evaluations diagnosis of OSA. Children were divided into four weight status groups (underweight, normal weight, overweight and obese), based on age and gender corrected body mass index (BMI).Results:Following T&A, the four different weight status groups significantly improved in apnea/hypopnea index (AHI) and minimum oxygen saturation. However, 49.1% of the children (79/161) had residual OSA (AHI ⩾1). The incidence of residual OSA (AHI ⩾1) in the obese group was 75%, which was significantly higher than the other three groups (P<0.01). Weight status changes after T&A were documented, and 54% (13/24) of the underweight children shifted to normal weight status within 6 months after surgery.Conclusion:Although sleep parameters improved in all weight statuses, obese children had a higher incidence of residual OSA postoperatively. About half of the underweight children shifted to normal weight status after T&A.

Polysomnographic findings after adenotonsillectomy for obstructive sleep apnoea in obese and non-obese children: a systematic review and meta-analysis.

Use of polysomnography (PSG) is the gold standard of diagnosis and measurement of treatment effectiveness for paediatric obstructive sleep apnoea (OSA). Although adenotonsillectomy (T&A) is effective in diminishing the apnoea–hypopnoea index (AHI), a meta‐analysis of postoperative changes for all other PSG parameters and outcome comparisons between obese and non‐obese children following T&A have never been conducted.

Quality of life after adenotonsillectomy for children with sleep-disordered breathing: A linear mixed model analysis

OBJECTIVE To study changes in quality of life (QoL) after adenotonsillectomy (T&A) in children with sleep-disordered breathing (SDB), and to elucidate discrepancies in QoL improvements after T&A in children of different gender, age, adiposity status, and disease severity. MATERIALS AND METHODS Children aged 2-18 years were recruited. All children had SDB-related symptoms and underwent preoperative full-night polysomnography (PSG). Caregivers completed the first obstructive sleep apnea 18-items questionnaire (OSA-18) prior to T&A and the second OSA-18 survey within 3 months after surgery. Disease severity was defined as primary snoring (apnea/hypopnea index, AHI < 1), mild obstructive sleep apnea (OSA) (5 > AHI ≥ 1), and moderate-to-severe OSA (AHI ≥ 5). Discrepancies in OSA-18 score changes after T&A for different groups were assessed using the linear mixed model. RESULTS In total, 144 children were enrolled (mean age, 7.0 ± 3.6 years; 76% boy). The OSA-18 total score changes after surgery were not significantly different by gender (boys vs. girls), age group (≥ 6 years vs. < 6 years), or adiposity (obese vs. non-obese). The OSA-18 total score changes after surgery differed by disease severity (primary snoring vs. moderate-to-severe OSA, P = 0.004; mild OSA vs. moderate-to-severe OSA, P = 0.003). Children with moderate-to-severe OSA had greater improvement in OSA-18 total score after surgery than those with mild OSA or primary snoring. CONCLUSIONS Children with SDB had QoL improvement after T&A, as documented by OSA-18 score changes. The QoL improvement after T&A for SDB children increased as disease severity increased, and the improvement was not affected by gender, age, or adiposity.

Quality of life after adenotonsillectomy in children with obstructive sleep apnea: Short-term and long-term results

OBJECTIVE To assess short-term and long-term changes in quality of life after adenotonsillectomy (T&A) in children with obstructive sleep apnea (OSA). MATERIALS AND METHODS Children aged 2-18 years old were enrolled. All subjects had clinical symptoms, overnight polysomnography diagnosis of OSA, and received T&A as treatment. Caregivers were asked to complete the OSA-18 survey before surgery, within 6 months after surgery (short-term), and more than 6 months after surgery (long-term). RESULTS A total of 114 children were included (mean age, 7.0±3.5 years; 75% boys). The mean OSA-18 total score was 71.5±16.0 before surgery. After surgery, the mean OSA-18 total score was significantly decreased in both the short-term (40.3±12.2, p<0.001) and the long-term (42.0±13.7, p<0.001). All five OSA-18 domains were also significantly decreased during short-term and long-term postoperative follow up (p<0.001). Short-term and long-term outcomes were compared. Mean OSA-18 total scores, sleep disturbance score, emotional distress score, daytime function score, and caregiver concerns score did not differ significantly between the short-term and long-term periods, while the physical symptom score was slightly higher in the long-term than the short-term period (9.7±3.3 vs. 8.7±3.0, p=0.02). Additionally, the physical symptoms score was higher in the long-term period in the female (p=0.01), older age (>6 years) (p=0.03), and non-obese (p=0.04) subgroups. CONCLUSION T&A improves short-term and long-term quality of life in children with OSA. Nevertheless, caregivers observed children with aggravation of physical symptoms of quality of life during long-term follow up, especially in the female, older, and non-obese subgroups.

Discrepancy between Objective and Subjective Outcomes after Adenotonsillectomy in Children with Obstructive Sleep Apnea Syndrome

Objective Adenotonsillectomy (T&A) is the first line therapy for pediatric obstructive sleep apnea (OSA); however, inconsistency between objective and subjective outcomes perplexes physicians. This study investigates changes of objective and subjective outcomes in children with OSA after T&A, in particular, to elucidate correlations and discrepancies between these 2 measures. Study Design Case series with record review. Setting Tertiary referral medical center. Subjects and Methods Symptomatic children with polysomnographic diagnosis of OSA (apnea-hypopnea index [AHI] > 1) were included. All children underwent T&A to treat OSA, along with completely objective (polysomnography) and subjective (Obstructive Sleep Apnea 18-Item Quality-of-Life Questionnaire [OSA-18]) measures before and 3 months after surgery. Results One hundred nineteen children were included (mean age, 6.9 ± 3.3 years; 76% boys). Adenotonsillectomy significantly reduced AHI from 15.4 ± 21.2 per hour to 1.6 ± 2.5 per hour (P < .001). The OSA-18 scores were significantly improved after surgery (P < .001). A weak but statistically significant positive correlation was found between AHI and OSA-18 scores preoperatively (ρ = 0.22, P = .016) but not postoperatively (ρ = 0.04, P = .677). Among those cases with residual OSA after surgery, only 6% (3/54) had a residual effect on quality of life (OSA-18 score > 60). Conclusion Adenotonsillectomy improves both objective and subjective outcomes. After surgery, quality of life significantly improved subjectively, despite an incomplete resolution of OSA objectively, leading to a better correlation between objective and subjective measures before as opposed to after surgery. Discrepancy between the 2 measures warrants an evaluation of a child both objectively and subjectively when treating OSA.

Validation of the Chinese version OSA-18 quality of life questionnaire in Taiwanese children with obstructive sleep apnea

BACKGROUND/PURPOSE The OSA-18 questionnaire is one of the most widely-used sleep quality measurements in children. We tested the applicability and cross-cultural validation of the traditional Chinese version OSA-18 questionnaire. METHODS This cross-sectional study was conducted in a tertiary medical referral center. The translation and cultural adaptation of the OSA-18 questionnaire were performed based on Brislins revised model. A total of 109 children aged 2-18 years old with sleep problems were recruited. Overnight polysomnography and the OSA-18 questionnaire were administered. The reliability and validity of the traditional Chinese version of OSA-18 questionnaire were verified. RESULTS Excellent test-retest reliability and good internal consistency were achieved, and the validity of OSA-18 with overnight polysomnography was confirmed. The domain of sleep disturbance, daytime function, caregiver concerns, and the OSA-18 total scores were significantly higher in sleep apnea patients. The domain of caregiver concern had the highest score, while those of emotional distress had the lowest scores. The optimal cut-off point of the OSA-18 total scores for detecting obstructive sleep apnea was 67. CONCLUSION The traditional Chinese version of OSA-18 demonstrated high reliability and good validity in our study. The domain of caregiver concern is the major element in Taiwanese children with sleep-disordered breathing.

Detection of pediatric obstructive sleep apnea syndrome: history or anatomical findings?

OBJECTIVE To assess how history and/or anatomical findings differ in diagnosing pediatric obstructive sleep apnea (OSA). METHODS Children aged 2-18 years were recruited and assessed for anatomical (ie, tonsil size, adenoid size, and obesity) and historical findings (ie, symptoms) using a standard sheet. History and anatomical findings, as well as those measures significantly correlated with OSA, were identified to establish the historical, anatomical, and the combined model. OSA was diagnosed by polysomnography. The effectiveness of those models in detecting OSA was analyzed by model fit, discrimination (C-index), calibration (Hosmer-Lemeshow test), and reclassification properties. RESULTS A total of 222 children were enrolled. The anatomical model included tonsil hypertrophy, adenoid hypertrophy, and obesity, whereas the historical model included snoring frequency, snoring duration, awakening, and breathing pause. The C-index was 0.84 for the combined model, which significantly differed from that in the anatomical (0.78, p = 0.003) and historical models (0.72, p < 0.001). The Hosmer-Lemeshow test revealed an adequate fit for all of the models. Additionally, the combined model more accurately reclassified 10.3% (p = 0.044) and 21.9% (p = 0.003) of all of the subjects than either the anatomical or historical model. Internal validation of the combined model by the bootstrapping method showed a fair model performance. CONCLUSION Overall performance of combined anatomical and historical findings offers incremental utility in detecting OSA. Results of this study suggest integrating both history and anatomical findings for a screening scheme of pediatric OSA.

Central sleep apnea in obese children with sleep-disordered breathing

Objectives:In contrast to obstructive sleep apnea (OSA), central sleep apnea (CSA) in obese children has received lesser attention. As pediatric CSA is more prevalent than expected and adversely impacts health, this study aims to elucidate the major factors associated with central apnea index (CAI) and compare CSA between obese and non-obese children.Methods:Retrospective analysis was performed in a tertiary referral medical center. Children with sleep-disordered breathing (SDB) ranging from 2–18 years old were enrolled. All participants completed history taking, otolaryngological examination and overnight polysomnography. CSA was defined as having CAI exceeding 1 h−1. CAI and the prevalence of CSA were analyzed in children of different age groups, weight statuses and adenotonsillar sizes.Results:A total of 487 cases were included. The prevalence of CSA was 13.3% (65/487). CAI was negatively correlated with age (r=−0.32, P<0.001). Obese children had a significantly lower CAI than that of non-obese ones (0.20±0.36 vs 0.48±0.82 h−1, P<0.001). Multiple linear regression analysis demonstrated a relationship between CAI, age and obesity as ‘CAI=0.883–0.055 × Age –0.22 × (Obesity)’.Conclusions:In children with SDB, younger ones have a significantly higher CAI than older ones. Additionally, obese children had a lower CAI than non-obese ones.