A Multifactorial Weight Reduction Programme for Children with Overweight and Asthma: A Randomized Controlled Trial

Abstract

Background: There is increasing evidence that obesity is related to asthma development and severity. However, it is largely unknown whether weight reduction can influence asthma management, especially in children.

Objective: To determine the effects of a multifactorial weight reduction intervention on asthma management in overweight/obese children with (a high risk of developing) asthma.

Methods: An 18-month weight-reduction randomized controlled trial was conducted in 87 children with overweight/obesity and asthma. Every six months, measurements of anthropometry, lung function, lifestyle parameters and inflammatory markers were assessed. Analyses were performed with linear mixed models for longitudinal analyses.

Results: After 18 months, the body mass index-standard deviation score decreased by -0.14±0.29 points (p<0.01) in the intervention group and -0.12±0.34 points (p<0.01) in the control group. This change over time did not differ between groups (p>0.05). Asthma features (including asthma control and asthma-related quality of life) and lung function indices (static and dynamic) improved significantly over time in both groups. The FVC% predicted improved over time by 10.1 ± 8.7% in the intervention group (p<0.001), which was significantly greater than the 6.1 ± 8.4% in the control group (p<0.05).

Conclusions & clinical relevance: Clinically relevant improvements in body weight, lung function and asthma features were found in both the intervention and control group, although some effects were more pronounced in the intervention group (FVC, asthma control, and quality of life). This implies that a weight reduction intervention could be clinically beneficial for children with asthma.

Trial registration: ClinicalTrials.gov NCT00998413.

Fig 1. Consort flow diagram.

* Two participants discontinued the sport sessions during the follow-up phase of the intervention due to membership of an organised sports association, but did continue to attend the lifestyle, individual and parental sessions. Those participants were included in the per protocol analysis.

Fig 2

Changes over time in: a) BMI-SDS, b) FEV₁%predicted, c) FVC%predicted, d), FEV1/FVC (in %) §. Data are presented as mean (SEM). *: Significant difference over time in the intervention group (p<0.05). †: Significant difference over time in the control group (p<0.05). ‡: Significant difference between intervention and control group over time (p<0.05). §: Intention to treat analyses are presented. Abbreviations: BMI-SDS: body mass index standard deviation score, FEV₁%predicted: forced expiratory volume in 1 second in %predicted, FVC: forced vital capacity in %predicted.

Fig 3

Changes over time in: a) ERV%predicted, b) TLC%predicted, c) (c)- ACT ll, d) PAQLQ ll §. Data are presented as mean (SEM). *: Significant difference over time in the intervention group (p<0.05). †: Significant difference over time in the control group (p<0.05). ‡: Significant difference between intervention and control group over time (p<0.05). §: Intention to treat analyses are presented. ll: Only subjects with an asthma diagnosis are shown. Abbreviations: (c)-ACT: (childhood) asthma control test (score can range between 0 = not well controlled to 27 = well controlled asthma), ERV%predicted: expiratory reserve volume in % predicted, PAQLQ, paediatric asthma quality of life questionnaire (with 23 questions in three domains (symptoms, activity limitation and emotional function), all questions can be scored on a 7-point scale (7 = not bothered at all—1 = extremely bothered). The overall PAQLQ score is the mean of all 23 responses.), TLC%predicted: total lung capacity in % predicted.

Fig 4

Changes over time in: a) Degree of EIB (in percent fall of FEV1 after exercise), b) Leptin concentration (in ng/ml), c) % of participants using SABA ll, d) % of participants using ICS ll §. Data are presented as mean (SEM). *: Significant difference over time in the intervention group (p<0.05). †: Significant difference over time in the control group (p<0.05). ‡: Significant difference between intervention and control group over time (p<0.05). §: Intention to treat analyses are presented. ll: Only subjects with an asthma diagnosis are shown. Abbreviations: EIB: exercise induced bronchoconstriction (in percent fall of FEV1 after exercise test), ICS: inhaled corticosteroids, SABA: short acting beta2agonists.