Albert Martin Li

Insomnia is a common sleep problem in youth, with prevalence estimates up to 37% (Chan et al., 2020; Li et al., 2018). If left untreated, insomnia symptoms may persist and negatively affect individ...

Objective: To investigate the prevalence, characteristics, risk factors, and clinical outcomes of positional obstructive sleep apnea (POSA) in Chinese children. Methods: This was a retrospective analysis of children aged 4– 17 years with OSA from local referrals for sleep-disordered breathing. Children who underwent diagnostic polysomnography (PSG) with at least 30 minutes of total sleep time in both supine and non-supine sleep were included. Standardized sleep questionnaires, Sleepiness Scales, Child Behavior Checklist and 24-hour ambulatory blood pressure monitoring were completed. OSA was defined as obstructive apnea-hypopnea index (OAHI) ≥ 1/h. POSA was defined as OAHI in the supine position ≥ two times the OAHI in the non-supine position. Results: 314 children (mean age: 10.88± 3.22 years; male: 70%) with OSA were analyzed, of whom 147 (46.8%) had moderate/severe OSA (OAHI≥ 5). Prevalence of POSA was 58% within our cohort and 51% among those with moderate/severe OSA. Children with POSA were older (10.8± 3.3 years vs 9.1± 2.6 years; p< 0.001), had milder disease [OAHI 4.12 (2.14– 8.62) events/h vs 6.16 events/h); p=0.026] and had smaller tonsillar size (55% vs 72%; p=0.011). By logistic regression, POSA was associated with older age (OR 1.20; 95% confidence interval (CI) 1.09– 1.32; p< 0.001) and lower OAHI (B– 0.036; SE 0.011; OR 0.964; 95% CI 0.943– 0.986; p=0.001). Conclusion: POSA is a prevalent phenotype seen in children, demonstrating strong associations with older age, more mature pubertal development, smaller tonsillar size and milder disease severity. Future studies should also delineate the natural history and longitudinal stability of this subtype over time.

Background: We aim to establish normative reference values of brachial artery flow-mediated dilation (FMD) by age and gender in children and adolescents, and to identify predictors of FMD in this population. Methods: A representative sample of 1498 healthy children and adolescents aged 8 to 17 years was recruited. Subjects underwent sonographic brachial artery assessment and blood sampling. Smoothed gender-specific FMD percentile curves were constructed using the Lambda-Mu-Sigma (LMS) method. Predictive factors of FMD were identified using linear regression analysis. Results: Mean FMD among children and adolescents in the community setting was 8.57 ± 0.90%. Smoothed gender-specific FMD in centiles were constructed as a reference benchmark. Regression analysis after adjustment for age, gender, body mass index (BMI) z-score, and baseline artery diameter, when applicable, demonstrated that FMD is positively correlated with age (β = 0.142, p < 0.001, 95% CI [0.081–0.203]) and high density lipoprotein (HDL) (β = 0.103, p = 0.001, 95% CI [0.041–0.165]), while negatively correlated with baseline artery diameter (β = -0.117, p = 0.001, 95% CI [-0.189 – -0.046]), diastolic blood pressure (DBP) (β = -0.053, p = 0.047, 95% CI [-0.105 – -0.001]), glucose (β = -0.091, p = 0.004, 95% CI [-0.153 – -0.030]) and triglyceride (TG) (β = -0.138, p < 0.001, 95% CI [-0.198 – -0.078]). Multivariate regression analysis showed that age, baseline artery diameter, DBP, glucose and TG were independent predictors of FMD. Conclusions: Normative reference values for FMD were constructed with predictive factors identified for children and adolescents.

Aims/hypothesis: We aimed to examine offspring adiposity trajectories from birth to age 9–14 years and to assess the joint associations of maternal overweight and gestational diabetes mellitus (GDM) with these trajectories. Methods: This is a prospective cohort study with 564 mother–child dyads from the Hyperglycemia and Adverse Pregnancy Outcome study Hong Kong field centre. Assessments and anthropometric measurements were taken during pregnancy, at delivery and at median ages of 7 and 10 years postpartum. Offspring adiposity was primarily assessed using sum of skinfold thickness. We used linear mixed-effect models to evaluate the independent and joint associations of maternal overweight and GDM with the offspring adiposity trajectories, and applied group-based trajectory modelling to identify distinct patterns of adiposity development based on both statistical indices and clinical interpretability. Results: Offspring skinfold thickness trajectories varied significantly based on maternal overweight and GDM (pp=0.006) of the rapidly increasing trajectory. Linear mixed-effect model analysis showed greater increases in skinfold thickness among offspring of mothers with either condition, with the highest trajectory observed in offspring of mothers with both conditions (β 1.62; 95% CI 0.69, 2.54; p=0.001). Conclusions/interpretation: Maternal overweight and GDM are independently and jointly associated with rapidly increasing adiposity trajectories from birth to early adolescence. The findings underscore the importance of considering both maternal metabolic conditions when evaluating offspring adiposity risk. Graphical

Increasing epidemiological studies reported that overweight/obese asthma patients had more frequent and severe symptoms and exacerbations, indicating their asthma management may not be sufficient. Airway hyperresponsiveness (AHR), a significant feature of asthma, was found to link with the body mass index (BMI) with mixed findings using the "direct" methacholine challenge test. The objective was to examine the association between BMI and asthma control, as reflected by the "indirect" AHR with the mannitol challenge test in a paediatric asthmatic population. A total of 80 subjects with physician-diagnosed asthma, aged 6-18 years were enrolled in this cross-sectional study. Patients were first asked to complete the Asthma Control Test (ACT) questionnaire to self-evaluate their disease status. A mannitol challenge test was then performed to assess their AHR severity. Seventy-six patients (96%) rated their asthma as well-controlled with an ACT score ≥ 20, but 42 patients (53%) were tested positive in the mannitol challenge test with mild and moderate AHR. While patients with mild AHR had comparable lung functions to those without AHR, patients with moderate AHR showed slightly but significantly lower FEV₁ and FEV₁/FVC values. Although no significant difference in the BMI values was noted for patients with different levels of AHR, the trend of increasing BMI with age was steeper for patients with moderate AHR. A high prevalence of AHR (>50%) was found in asthmatic children who self-evaluated with good asthma control. No significant influence of the BMI on the AHR severity could be demonstrated in this population with the "indirect" mannitol challenge test. Since only a small number of overweight/obese subjects were recruited in the present study, further verification of the results with a larger sample size of obese subjects is required.

The study highlights the significant changes in respiratory virus epidemiology following the lifting of COVID-19 restrictions. Method: In this single-centre retrospective study, the virological readouts of adenovirus (AdV), influenza virus A (IAV), influenza virus B (IBV), parainfluenza viruses (PIV) 1, 2, 3, 4, respiratory syncytial virus (RSV), and coupled enterovirus and rhinovirus (EV/RV) were extracted from the respiratory specimens of paediatric patients in Hong Kong from January 2015 to February 2024. The subjects were stratified into five age groups. Results: The study included 18,737 and 6001 respiratory specimens in the pre-COVID-19 and post-COVID-19 mask mandate period, respectively. The mean age of hospitalised patients increased from 3.49 y ± 0.03 y to 4.37 y ± 0.05 y after the COVID-19 lockdown. The rates of single-virus infection and co-infection were significantly higher in the post-COVID-19 mask mandate period. The odds ratio for AdV for all age groups (OR: 4.53, 4.03, 2.32, 2.46, 1.31) and RSV in older children from 3 years old and above (OR: 1.95, 3.38, p < 0.01) were significantly elevated after the COVID-19 outbreak. Conclusions: Our findings suggest that public health measures to contain COVID-19 may have unintended consequences on children’s natural exposure and immunity to other respiratory viruses, potentially increasing their morbidity in the post-pandemic era.

Background: Sleep insufficiency and disturbances affect the physical, cognitive, and emotional well-being of children. Objective: To perform a narrative review on common sleep problems and disorders encountered in primary care for children and adolescents. Methods: A search of English literature in the Pubmed and Google Scholar databases published from 1 January 2000 till 31 October 2021 was conducted with the keywords “sleep problem” or “sleep disorder” and “child” or “adolescent”. Findings in the relevant articles and cross-references were compiled. Results: Sleep duration and habits of children vary widely across countries with different cultural backgrounds. There is robust evidence to support the promotion of positive bedtime routines and sleep hygiene as prevention and management of sleep problems. 15-70% of parents reported their children having sleep problems or disturbances. Common sleep complaints include difficulty in ini-tiation or maintenance of sleep, abnormal behaviors or movements, snoring or abnormal breathing, and excessive daytime sleepiness. Comprehensive sleep history and a sleep diary are the first steps for evaluation. Home video and actigraphy may be used as preliminary tools to confirm the history. Referrals to a sleep specialist for polysomnography and other tests are needed, if suspecting specific sleep disorders, such as obstructive sleep apnea and narcolepsy, needs timely intervention. Common sleep disorders in different age groups encountered in primary care are reviewed with clinical fea-tures, indications for evaluation, and treatment options summarized. Conclusion: Screening for sleep problems shall be an integral part of each child's health care visit. It is important to evaluate the impact of common sleep problems and identify specific sleep disor-ders for early intervention to prevent long-term adverse outcomes.

Background: Medical artificial intelligence (AI) has significantly contributed to decision support for disease screening, diagnosis, and management. With the growing number of medical AI developments and applications, incorporating ethics is considered essential to avoiding harm and ensuring broad benefits in the lifecycle of medical AI. One of the premises for effectively implementing ethics in Medical AI research necessitates researchers' comprehensive knowledge, enthusiastic attitude, and practical experience. However, there is currently a lack of an available instrument to measure these aspects. Objective: The aim of this study was to develop a comprehensive scale for measuring the knowledge, attitude, and practice of ethics implementation among medical AI researchers, and to evaluate its measurement properties. Methods: The construct of the Knowledge-Attitude-Practice in Ethics Implementation (KAP-EI) scale was based on the Knowledge-Attitude-Practice (KAP) model, and the evaluation of its measurement properties was in compliance with the COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN) reporting guidelines for studies on measurement instruments. The study was conducted in 2 phases. The first phase involved scale development through a systematic literature review, qualitative interviews, and item analysis based on a cross-sectional survey. The second phase involved evaluation of structural validity and reliability through another cross-sectional study. Results: The KAP-EI scale had 3 dimensions including knowledge (10 items), attitude (6 items), and practice (7 items). The Cronbach α for the whole scale reached .934. Confirmatory factor analysis showed that the goodness-of-fit indices of the scale were satisfactory (χ2/df ratio:=2.338, comparative fit index=0.949, Tucker Lewis index=0.941, root-mean-square error of approximation=0.064, and standardized root-mean-square residual=0.052). Conclusions: The results show that the scale has good reliability and structural validity; hence, it could be considered an effective instrument. This is the first instrument developed for this purpose.