Dietary patterns and the risk of rhinitis in primary school children: a prospective cohort study

Chronic exposure to ambient PM2.5/NO2 and respiratory health in school children: A prospective cohort study in Hong Kong

Despite increasing concerns about the detrimental effects of air pollution on respiratory health, limited evidence is available on these effects in the Hong Kong population, especially in children. In this prospective cohort study between 2012 and 2017, we aimed to investigate the associations between exposure to air pollution (concentrations of fine particulate matter [PM_2.5] and nitrogen dioxide [NO₂]) and respiratory health (lung function parameters and respiratory diseases and symptoms) in schoolchildren. We recruited 5612 schoolchildren aged 6-16 years in Hong Kong. We estimated the annual average concentrations of ambient PM_2.5 and NO₂ at each participant's address using spatiotemporal models. We conducted spirometry tests on all participants to measure their lung function parameters and used a self-administered questionnaire to collect information on their respiratory diseases and symptoms and a wide range of covariates. Linear mixed models were used to investigate the associations between exposure to air pollution and lung function. Mixed-effects logistic regression models with random effects were used to investigate the associations of exposure to air pollution with respiratory diseases and symptoms. In all of the participants, every 5-μg/m³ increase in the ambient PM_2.5 concentration was associated with changes of - 13.90 ml (95 % confidence interval [CI]: -23.65 ml, -4.10 ml), - 4.20 ml (-15.60 ml, 7.15 ml), 27.20 ml/s (-3.95 ml/s, 58.35 ml/s), and - 19.80 ml/s (-38.35 ml/s, -1.25 ml/s) in forced expiratory volume in 1 s, forced vital capacity, peak expiratory flow, and maximal mid-expiratory flow, respectively. The corresponding lung function estimates for every 5-μg/m³ increase in the ambient NO₂ concentration were - 2.70 ml (-6.05 ml, 0.60 ml), - 1.40 ml (-5.40 ml, 2.60 ml), - 6.60 ml/s (-19.75 ml/s, 6.55 ml/s), and - 3.05 ml/s (-11.10 ml/s, 5.00 ml/s), respectively. We did not observe significant associations between PM_2.5/NO₂ exposure and most respiratory diseases and symptoms. Stratified analyses by sex and age showed that the associations between exposure to air pollution and lung function parameters were stronger in male participants and older participants (11-14 year old group) than in female participants and younger participants (6-10 year old group), respectively. Our results suggest that chronic exposure to air pollution is detrimental to the respiratory health of schoolchildren, especially that of older boys. Our findings reinforce the importance of air pollution mitigation to protect schoolchildren's respiratory health.

Parental Education Moderates the Relation between Physical Activity, Dietary Patterns and Atopic Diseases in Adolescents

Background: Atopic diseases, particularly asthma, eczema, and rhinitis, are among the most common chronic diseases in childhood, with several factors implicated in their pathogenesis. Our study examined the role of parental education in the association between diet, physical activity, and atopy in adolescents. Methods: 1934 adolescents (47.5% boys) aged 13−14 years old reported information about their diet and physical activity and their parents reported their highest educational level. The moderating role of parental education level (primary/secondary vs. tertiary) in the relation between lifestyle patterns and atopic diseases was examined with logistic regression analyses. Results: High consumption of dairy products was inversely associated to adolescents’ asthma and rhinitis symptoms overall, but this relation was almost 50% stronger for the adolescents with high parental education level background. The same pattern of reduction of the odds was noticed also regarding the association among the high intake of fruits, vegetables, pulses, with all three atopic diseases and the adherence to a physically active lifestyle only with current asthma and eczema (all p < 0.05). Conclusion: Adolescents who are physically active and consume a higher intake of fruits, vegetables, and pulses and a lower intake of fast-food and sweets, and their parents/guardians having higher education, are less likely to have any current symptoms of asthma, eczema, and rhinitis than the ones who have low educated parents.

Household incense burning and children's respiratory health: A cohort study in Hong Kong

BACKGROUND

Incense burning is an important source of indoor air pollution in many Asian regions. We investigated the associations between household incense burning and lung function, lung function growth and respiratory diseases and symptoms in primary school children in Hong Kong.

METHODS

A total of 4041 children (mean age: 9.1 years) were recruited from 27 primary schools in Hong Kong. Information on incense burning and medical history of respiratory diseases and symptoms was collected by questionnaire. Spirometry tests were performed to measure the children's lung function. A follow-up study was carried out after 1-year interval. Linear and logistic regression models were used to investigate the associations between incense burning, lung function, and lung function growth, and respiratory diseases and symptoms, respectively.

RESULTS

At baseline, incense burning was associated with 48.6 mL/min [95% confidence interval (CI): -96.7, -0.5] lower maximum mid-expiratory flow (MMEF) in boys. In follow-up, incense burning was associated with reduced peak expiratory flow (PEF) growth in all participants. We also found that incense burning was associated with increased prevalence of bronchitis [odds ratio (OR) = 1.39, 95%CI: 1.11, 1.72] and bronchiolitis (OR = 1.72, 95%CI: 1.14, 2.56). Incense burning was also associated with higher prevalence of pneumonia (OR = 2.79, 95%CI: 1.10, 6.87) and wheezing (OR = 1.49, 95%CI: 1.08, 2.05) in boys, but not in girls.

CONCLUSIONS

We found that incense burning may adversely affect children's respiratory health. Further studies are warranted to elucidate the underlying mechanisms.