Association of breastfeeding with asthma in young Aboriginal children in Canada

Nonlinear effects of humidex on risk of outpatient visit for allergic conjunctivitis among children and adolescents in Shanghai, China: A time series analysis

Background

Various epidemiological studies have focused on the adverse health outcomes of meteorological factors. However, there has been little research on the impact of humidex on allergic conjunctivitis, especially in child and adolescent populations. We aimed to explore the impact of humidex, a comprehensive index of relative humidity and temperature, on child and adolescent allergic conjunctivitis admissions.

Methods

Outpatient visit data for allergic conjunctivitis, meteorological factors and air pollutants in Shanghai for the 2017-2022 period were retrieved. For the purpose of analysing the nonlinear connection and lag impact between humidex and admissions for paediatric and adolescent allergic conjunctivitis, the distributed lag nonlinear model (DLNM) was fitted.

Results

A total of 147 090 cases were included in our cohort. We found a significantly nonlinear effect on humidex and allergic conjunctivitis. In the single-day lag pattern, the relative risks (RR) of allergic conjunctivitis were significant at lag 0 (RR = 1.08, 95% confidence interval (CI) = 1.05-1.11) to lag 2 (RR = 1.01, 95% CI = 1.00-1.01), lag 5 (RR = 1.01, 95% CI = 1.00-1.01) to lag 9 (RR = 1.01, 95% CI = 1.00-1.01), and lag 14 (RR = 1.02, 95% CI: 1.01-1.03). In the cumulative-lag day pattern, the RR of allergic conjunctivitis were significant at lag 0-0 (RR = 1.08, 95% CI = 1.05-1.11) to lag 0-14 (RR = 1.21, 95% CI = 1.13-1.28). We found that boys, children aged 7-17 years, and children in the warm season were more vulnerable to humidex. In addition, the highest attributable fraction (AF) and attributable number (AN) of humidex are at lag 0-14 (AF = 0.17, AN = 25 026).

Conclusions

Humidex exposure markedly increased the risk of allergic conjunctivitis, especially in highly high humidex. Appropriate public health management is needed for disease management and early intervention.

Impacts of exposure to humidex on the risk of childhood asthma hospitalizations in Hefei, China: Effect modification by gender and age

BACKGROUND

With global climate change, there is growing concern about the effects of temperature changes on childhood asthma. However, current research only focuses on the effects of temperature, while ignoring the adverse effects of humidity on children.

OBJECTIVES

Our study aimed to quantify the impact of humidex on childhood asthma hospitalizations, which combined temperature and humidity, and further to assess how the effect is modified by individual-factors, such as age and gender.

METHODS

Poisson generalized linear models combined with distributed lag nonlinear models were used to estimate the association between daily childhood asthma hospitalizations and humidex from 2013 to 2016. Air pollutions (CO, O_3, and NO₂) and wind velocity were modelled simultaneously using DLNM, as well as day of week, seasonality and long-term trend.

RESULTS

Low humidex was associated with an increased risk of admissions for asthma in children. The adverse effect appeared on the 4th day, with the RR of 1.045 (95%CI: 1.007-1.084) and lasted until the 7th day (RR: 1.045, 95%CI: 1.006-1.085). Compared with the male, there was an immediate effect on female exposed to low humidex. And the female seems to be more sensitive to low humidex. Besides, the significant effects of humidex on children asthma were detected in the children with preschool and school-age, whereas not for the subgroup of infants. And the school-age children are most sensitive to low humidex.

CONCLUSIONS

Low humidex was associated with the increased risk of admissions for childhood asthma in Hefei. Children suffering from asthma should avoid exposure to the low humidex environment, especially in female and school-age children. In addition, the index of humidex was more significant for disease prevention and public health than the average temperature. These findings may provide epidemiology evidence for formulating precaution guidelines to reduce the risk of childhood asthma hospitalizations.

Prevalence and risk factors for asthma among children aged 0-14 years in Hangzhou: a cross-sectional survey

Background

Asthma is a global problem. Prevalence varies among different countries and cities. We aimed to obtain the prevalence, describe the characteristics, and discover factors that may relate to asthma in Hangzhou.

Methods

This cross-sectional study was conducted in Hangzhou. The subjects were children aged 14 years and younger. A control group of non-asthma children that matched in age and sex with each asthmatic patient was also randomly selected and interviewed. International Study of Asthma and Allergies in Childhood and National Epidemiology study of Asthma and Allergies in China questionnaires were used in this survey.

Results

We have questionnaired 13,877 children, and 665 (4.8 %) children were diagnosed asthma. The guardians regarded the cost of asthma management affordable in 49.4 %, tolerable in 46.9 %, and intolerable in 3.7 %. Both guardians and children have been absent from work or school due to children’s asthma.

Respiratory tract infection was the most common trigger of asthma attacks (85.1 %). Other common causes included cold air, house dust, exercise, fish and shrimp, pollen, and et al. Interestingly, we also found in children 6 years and older, some triggers happened more than that in children 5 years and younger. Those factors included exercise, emotional changes, house dust, pollen, renovation works in the home, mosquito–repellent incense and pets (all the p values were <0.05).

We compared some factors may relate to asthma development. Higher percentage of family history of asthma, personal history of allergy (atopic dermatitis, drug allergy and food allergy), comorbidities (allergic rhinitis, sinusitis, adenoidal hypertrophy, and urticaria), caesarean birth and complications ever happened during pregnancy were discovered in asthma children than in non-asthma children (all the p values were <0.05). Exclusive breastfeeding within first 6 months and keeping animals had higher percentage in non-asthma children than in asthma (both the p values were <0.05).

Inhaled corticosteroid (ICS)/ICS + long-acting beta2 agonists (LABA) was applied to 46.2 % of patients. Traditional Chinese medicine (TCM) was used in 44.2 % of asthma children, while leukotriene receptor antagonist (LTRA) was used in 36.4 % of them. The adherence scored higher in TCM than in ICS/ICS + LABA (P = 0.003) and LTRA.

Conclusions

In conclusion, we conducted an epidemiology study in Hangzhou. The prevalence of childhood asthma was 4.8 %. Asthma was an economic and social burden to both children and guardians. Risk factors of asthma development may include caesarean birth, personal history of allergy and concomitant allergic diseases. Exclusive breastfeeding within first 6 months and keeping animals might be protecting factors. TCM was really popular in China besides ICS/ICS + LABA and LTRA.

Prevalence and risk factors of asthma in First Nations children living on reserves in Canada

OBJECTIVES

To explore the prevalence and determine the risk factors of asthma in First Nations children aged 0 to 11 years living on reserves in Canada.

METHODS

In this cross-sectional study, we considered the data collected as part of the First Nations Regional Health Survey involving 6,657 children living in 238 First Nations communities in the 10 Canadian provinces, the Northwest Territories and the Yukon.

RESULTS

The overall prevalence of asthma that has lasted or is expected to last at least six months (ever-asthma) among children living on reserves was 14.6%: a prevalence of 12.9% among 0 to 4 year olds and 15.6% among 5 to 11 year olds. The prevalence of ever-asthma was greater among boys (16.1%) than girls (13.2%). Children from homes with two or more children aged less than 11 years and those who were engaged in daily physical activities were less likely to have a report of ever-asthma. Children from high-income families and smoke-free homes were more likely to have a report of ever-asthma. The association between allergy and ever-asthma was stronger in children with low birth weight. The association between chronic ear infections and ever-asthma was stronger in girls than boys.

CONCLUSIONS

The overall prevalence of ever-asthma and factors associated with ever-asthma in First Nations children living on reserves were similar to those reported for off-reserve Aboriginal children and non-Aboriginal Canadian children.