Physical activity, sedentary behaviour, and childhood asthma: a European collaborative analysis

Abstract

Objectives: To investigate the associations of physical activity (PA) and sedentary behaviour in early childhood with asthma and reduced lung function in later childhood within a large collaborative study.

Design: Pooling of longitudinal data from collaborating birth cohorts using meta-analysis of separate cohort-specific estimates and analysis of individual participant data of all cohorts combined.

Setting: Children aged 0-18 years from 26 European birth cohorts.

Participants: 136 071 individual children from 26 cohorts, with information on PA and/or sedentary behaviour in early childhood and asthma assessment in later childhood.

Main outcome measure: Questionnaire-based current asthma and lung function measured by spirometry (forced expiratory volume in 1 s (FEV₁), FEV₁/forced vital capacity) at age 6-18 years.

Results: Questionnaire-based and accelerometry-based PA and sedentary behaviour at age 3-5 years was not associated with asthma at age 6-18 years (PA in hours/day adjusted OR 1.01, 95% CI 0.98 to 1.04; sedentary behaviour in hours/day adjusted OR 1.03, 95% CI 0.99 to 1.07). PA was not associated with lung function at any age. Analyses of sedentary behaviour and lung function showed inconsistent results.

Conclusions: Reduced PA and increased sedentary behaviour before 6 years of age were not associated with the presence of asthma later in childhood.

Keywords: Asthma; Exercise; Paediatric asthma.

Figure 1. Directed Acyclic Graph (DAG) of possible covariables on the association between physical activity and asthma. Minimal dataset was identified as sex, maternal education, and maternal BMI. BMI, body mass index. ETS, environmental tobacco smoke.

Figure 2. Overview of meta-analyses of per-cohort longitudinal analyses on questionnaire derived physical activity and sedentary behaviour at ages 0–2 and 3–5 years and current asthma at age 6–18 years. (A) Exposure: physical activity in hours/day at ages 0–2 years—outcome: current asthma at age 6–18 years. (B) Exposure: sedentary behaviour in hours/day at ages 0–2 years—outcome: current asthma at age 6–18 years. (C) Exposure: physical activity in hours/day at age 3–5 years—outcome: current asthma at age 6–18 years. (D) Exposure: sedentary behaviour in hours/day at age 3–5 years—outcome: current asthma at age 6–18 years. Current asthma is defined as physician-diagnosed asthma, ISAAC-based current asthma definition or MeDALL-based current asthma definition. Per-cohort multivariable logistic regression using a random effects model with minimum data set as confounders (sex, maternal education level and maternal BMI for all cohorts except LRC which did not have information on maternal BMI, therefore, was corrected for sex and maternal education level). BMI, body mass index; ISAAC, International Study of Asthma and Allergies in Childhood.