Poor sleep quality has an adverse effect on childhood asthma control and lung function measures.

BACKGROUND: It is unclear as to whether sleep respiratory breathing disorder (SRBD) is a risk factor for uncontrolled asthma in children. The aim of this study was therefore to investigate whether SRBD may have an adverse effect on childhood asthma control and lung function measures. METHODS: This was a cross-sectional study of 220 children with well-controlled (n = 108), partly controlled (n = 92), and uncontrolled asthma (n = 20) according to the Global Initiative for Asthma guideline. SRBD was assessed using the Pediatric Sleep Questionnaire (PSQ). The association of SRBD with partly controlled/uncontrolled asthma was investigated on multivariate logistic regression analysis. RESULTS: Of 220 children with asthma, 43 (19.6%) had SRBD: well-controlled, 16.7% (18/108); partly controlled, 21.7% (20/92); and uncontrolled, 25.0% (5/20; P = 0.54). There was a significant difference in forced expiratory volume in 1 s/forced vital capacity (FEV1 /FVC; P = 0.007) and childhood asthma control test (C-ACT) score (P < 0.001) according to asthma control status, but not in PSQ score (P = 0.18). Children with obstructive sleep apnea (PSQ >0.33) had a lower C-ACT score compared with controls (PSQ ≤0.33; 19.6 ± 5.1 vs 22.0 ± 4.2, P = 0.002). PSQ score was negatively correlated with FEV1 /FVC (r = -0.16, P = 0.02). On multivariate logistic regression analysis, high PSQ score increased the odds of having partly controlled/uncontrolled asthma by 9.12 (95% CI: 1.04-79.72, P = 0.046) after adjusting for confounding factors. CONCLUSION: SRBD is an independent risk factor for partly controlled/uncontrolled asthma and has an adverse effect on lung function measures in children. Further research is warranted to determine whether the improvement of sleep quality may also enhance level of asthma control and lung function in children.

Patterns of sensitisation to common food and inhalant allergens and allergic symptoms in pre-school children.

AIM: Sensitisation to allergens and allergy symptoms depends on age, but this relationship is poorly understood. We therefore investigated the effect of age on allergen sensitisation and allergy symptoms in pre-school children. METHODS: A cross-sectional study was conducted on 629 Korean children (age 3 to 6 years). Current allergic symptoms were assessed by the Korean version of the International Study of Asthma and Allergies in Childhood questionnaire that was adapted for pre-school children. Sensitisation to five airborne and three food allergens was evaluated by a skin prick test. χ(2) test was used to analyse differences in age trend. Multiple logistic regression analysis was performed to obtain the adjusted odds ratios (aOR) for allergic disease. RESULTS: As age increased, the prevalence of current rhinitis (P < 0.001), the sensitisation to pollen allergens (P < 0.001) and polysensitised children (P = 0.002) increased, but the prevalence of current asthma (P = 0.010) and the sensitisation to food allergens (P = 0.009) decreased. There was no effect of age on the prevalence of current eczema (P = 0.685), monosensitised children (P = 0.282) and atopy (P = 0.160). The agreement between sensitisation to dust mites and atopy increased with age, and was 93% at age 6 years (P = 0.05). The polysensitisation (aOR = 3.0 (95% CI, 1.4-5.0), P < 0.005) and the presence of eczema in the first 2 years of life (aOR = 4.1 (95% CI, 2.2-7.6), P < 0.001) were significant independent risk factors for current rhinoconjunctivitis. CONCLUSION: The type and number of allergen sensitisations and allergic symptoms changed from age 3 to 6 years. Careful follow-up of changes in sensitisation patterns may provide a better understanding of the pathogenesis of the allergic march.

Oscillometric and spirometric bronchodilator response in preschool children with and without asthma.

BACKGROUND: Bronchodilator responses (BDR) are routinely used in the diagnosis and management of asthma; however, their acceptability and repeatability have not been evaluated using quality control criteria for preschool children. OBJECTIVES: To compare conventional spirometry with an impulse oscillometry system (IOS) in healthy and asthmatic preschool children. METHODS: Data from 30 asthmatic children and 29 controls (two to six years of age) who underwent IOS and spirometry before and after salbutamol administration were analyzed. RESULTS: Stable asthmatic subjects significantly differed versus controls in their spirometry-assessed BDR (forced expiratory volume in 1 s [FEV1], forced vital capacity and forced expiratory flow at 25% to 75% of forced vital capacity) as well as their IOS-assessed BDR (respiratory resistance at 5 Hz [Rrs5], respiratory reactance at 5 Hz and area under the reactance curve). However, comparisons based on the area under the ROC curve for ΔFEV1 %initial versus ΔRrs5 % initial were 0.82 (95% CI 0.71 to 0.93) and 0.75 (95% CI 0.62 to 0.87), respectively. Moreover, the sensitivity and specificity for ΔFEV1 >=9% were 0.53 and 0.93, respectively. Importantly, sensitivity increased to 0.63 when either ΔFEV1 >=9% or ΔRrs5 >=29% was considered as an additional criterion for the diagnosis of asthma. CONCLUSION: The accuracy of asthma diagnosis in preschool children may be increased by combining spirometry with IOS when measuring BDR.

Analysis of reports on orphan lung diseases in Korean children.

PURPOSE: Orphan lung diseases are defined as lung diseases with a prevalence of 1 or less in 2,000 individuals. Despite an increase in the numbers of patients with such diseases, few studies on Korean children have appeared. To obtain epidemiologic and demographic data on these diseases, we systematically reviewed reports on pediatric orphan lung diseases in Korea over the last 50 years. METHODS: We reviewed 223 articles that have appeared since 1958 on orphan lung diseases in Korean children. These articles described a total of 519 patients aged between 0 and 18 years. We classified patients by year of publication, diagnosis, geographic region, and journal. RESULTS: Of 519 patients, 401 had congenital cystic lung diseases and 66 had bronchiolitis obliterans. About 80% of patients were described in reports published in three journals, Pediatric Allergy and Respiratory Disease (Korea), the Korean Journal of Pediatrics, and the Korean Journal of Thoracic and Cardiovascular Surgery, in which papers on 157 (30.2%), 138 (26.6%), and 111 (21.4%) patients appeared, respectively. The frequency of publication of case reports has increased since 1990. Of the 519 patients, 401 (77.3%) were from Seoul/Gyeonggi-do and 72 (13.9%) from Busan/Gyeongsangnam-do. CONCLUSION: The prevalence of pediatric orphan lung disease has increased since 1990, and some provinces of Korea have a higher incidence of these diseases than do others. Studies exploring the incidence of pediatric orphan lung diseases in Korea are needed for effective disease management.