Environmental risk factors for asthma in 13‐14 year old African children

Abstract

Background Asthma prevalence in African children is high. Factors driving the prevalence or disease severity are poorly understood. This study aims to investigate environmental factors associated with asthma and severity in African children. Methods Population based cross‐sectional study of children aged 13–14 years from 10 African centers who participated in ISAAC III. Self‐reported environmental exposures included engaging in physical exercise, television watching, various biomass and ETS exposure, consumption of paracetamol, large family sizes and having pets in the home. Univariable and multivariable analyses were done adjusting for center variations. Prevalences, odds ratio and 95% confidence intervals (CI) were calculated. Results There were 258 267 children recruited among the 13‐14‐year‐old participants. Of these, 28,391 respondents from 232 schools completed both the written questionnaire (WQ) and environmental questionnaire (EQ). The prevalence of asthma and severe asthma were 12.8% (CI 12.4‐13.2), and 8.7% (CI 8.4‐8.0) respectively. Factors strongly associated with asthma were maternal smoking (OR = 1.41; 95%CI: 1.23‐1.64), open fire heating (OR = 1.28; 95%CI: 1.08‐1.51) electric heating (OR = 1.13; 95%CI: 1.01‐1.28), physical exercise (OR = 1.29; 95%CI: 1.11‐1.50), monthly paracetamol use (OR 1.23; 95%CI 1.13‐1.33), having an elder sibling (OR = 0.87; 95%CI 0.77‐0.98). Factors associated with severe asthma were maternal smoking (OR = 1.61; 95%CI: 1.38‐1.89), cat pet (OR = 1.14; 95%CI: 1.04‐1.25), frequent physical exercise (OR = 1.42; 95%CI: 1.23‐1.64) and monthly paracetamol use (OR = 1.20; 95%CI 1.07, 1.34). Conclusion Several environmental exposures were associated with asthma and severe disease.

A worldwide charter for all children with asthma

“…Risk factors including tobacco and indoor biomass smoke, outdoor air pollution, and viral infection are particularly common in LMICs 24‐28 and in deprived communities in high‐income countries. Environmental disasters, such as wildfires, hailstorms or floods, also worsen asthma control.…”

Risk factors for asthma among schoolchildren who participated in a case-control study in urban Uganda

“…The few studies reported have suggested that current residence in urban areas is associated with a higher risk of asthma than rural residence (10,11). Other risk factors, similar to those in HICs, include maternal smoking (12,13), maternal history of asthma (14), childhood atopic sensitisation (11,15) and history of allergy (14,16). Previous reports suggest no association between biomass fuels and asthma risk (17,18), but increased asthma symptoms (18,19).…”

Pediatric Pulmonology year in review 2018: Asthma, physiology/pulmonary function testing, and respiratory infections

“…This study demonstrated that early‐life exposure to traffic‐related PM 2.5, nitric oxides, and carbon monoxide was associated with increased risk of asthma; the concentration‐response relationship being steeper at lower exposure concentrations . Ayuk et al reported a study in 10 African centers enrolled over 28,000 children aged 13 to 14 years that found an asthma prevalence of 12.8%. Exposure to maternal smoking, open fire heating, electric heating, frequent physical exercise, and monthly paracetamol use were associated with asthma while having two or more older siblings seemed to be protective.…”