Maartje Willeboordse

Exercise training in children with asthma: a systematic review

Exercise can provoke asthma symptoms, such as dyspnoea, in children with asthma. Exercise-induced bronchoconstriction (EIB) is prevalent in 40–90% of children with asthma. Conversely, exercise can improve physical fitness. The purpose of this paper is to provide a systematic review of the literature regarding the effects of exercise training in children with asthma, particularly in relation to: EIB, asthma control, pulmonary function, cardiorespiratory parameters and parameters of underlying pathophysiology. A systematic search in several databases was performed. Controlled trials that undertook a physical training programme in children with asthma (aged 6–18 years) were selected. Twenty-nine studies were included. Training had positive effects on several cardiorespiratory fitness parameters. A few studies demonstrated that training could improve EIB, especially in cases where there was sufficient room for improvement. Peak expiratory flow was the only lung function parameter that could be improved substantially by training. The effects of training on asthma control, airway inflammation and bronchial hyper-responsiveness were barely studied. Owing to the overall beneficial effects of training and the lack of negative effects, it can be concluded that physical exercise is safe and can be recommended in children with asthma. A training programme should have a minimum duration of 3 months, with at least two 60 min training sessions per week, and a training intensity set at the (personalised) ventilatory threshold. Further research is recommended regarding the effects of exercise on underlying pathophysiological mechanisms and asthma control in children with asthma.

Sex Differences in the Relationship between Asthma and Overweight in Dutch Children: a Survey Study

Objective Obesity has been identified as a risk factor for asthma in children. However, in the Netherlands, the obesity prevalence is rising while the asthma prevalence in children is stabilising. The aim of this study is to clarify the association between asthma and Body Mass Index (BMI) in children and whether this association is influenced by sex. Study Design Parents of 39,316 children (6-16 years) in the south of the Netherlands were invited to complete an online questionnaire on respiratory symptoms, anthropometric variables and several potential confounding factors for asthma and obesity (including sex, birth weight and breastfeeding). Data was analysed by multivariable logistic regression models and an ordinal regression model. Results The response rate was 24% (n boys= 4,743, n girls= 4,529). The prevalence of asthma, overweight and obesity was 8%, 15% and 2% respectively. Body mass index - standard deviation Score (BMI-SDS) was related to current asthma (adjusted OR: 1.29; 95%CI: 1.14-1.45, p≤0.001). When stratified for sex, asthma and BMI-SDS were only related in girls (Girls: adjusted OR: 1.31; 95%CI: 1.13-1.51, p≤0.001. Boys: adjusted OR: 1.01; 95%CI: 0.91-1.14, p=0.72). Conclusions The positive association between BMI-SDS and asthma is only present in girls, not boys. Future studies into obesity and asthma should correct for sex in their analyses.

Multifactorial intervention for children with asthma and overweight (Mikado): study design of a randomised controlled trial

BackgroundIn children, the prevalence’s of both obesity and asthma are disconcertingly high. Asthmatic children with obesity are characterised by less asthma control and a high need for asthma medication. As the obese asthmatic child is becoming more common in the clinical setting and the disease burden of the asthma-obesity phenotype is high, there is an increasing need for effective treatment in these children. In adults, weight reduction resulted in improved lung function, better asthma control and less need for asthma medication. In children this is hardly studied. The Mikado study aims to evaluate the effectiveness of a long term multifactorial weight reduction intervention, on asthma characteristics in children with asthma and a high body weight.Methods/designThe Mikado study is a two-armed, randomised controlled trial. In total, 104 participants will be recruited via online questionnaires, pulmonary paediatricians, the youth department of the Municipal Health Services and cohorts of existing studies. All participants will be aged 6–16 years, will have current asthma, a Body Mass Index in the overweight or obesity range, and no serious comorbidities (such as diabetes, heart diseases). Participants in the intervention arm will receive a multifactorial intervention of 18 months consisting of sessions concerning sports, parental involvement, individual counselling and lifestyle advices including dietary advices and cognitive behavioural therapy. The control group will receive usual care. The primary outcome variables will include Forced Expiratory Volume in one second and Body Mass Index - Standard Deviation Score. Secondary outcomes will include other lung function parameters (including dynamic and static lung function parameters), asthma control, asthma-specific quality of life, use of asthma medication and markers of systemic inflammation and airway inflammation.DiscussionIn this randomised controlled trial we will study the potential of a multifactorial weight reduction intervention to improve asthma-related outcome measures in asthmatic children with overweight. Moreover, it will provide information about the underlying mechanisms in the relationship between asthma and a high body weight in children. These findings can contribute to optimal management programs and better clinical guidelines for children with asthma and overweight.Trial registrationClinicaltrial.gov NCT00998413

The Healthy Primary School of the Future: study protocol of a quasi-experimental study

BackgroundUnhealthy lifestyles in early childhood are a major global health challenge. These lifestyles often persist from generation to generation and contribute to a vicious cycle of health-related and social problems. This design article presents a study evaluating the effects of two novel healthy school interventions. The main outcome measure will be changes in children’s body mass index (BMI). In addition, lifestyle behaviours, academic achievement, child well-being, socio-economic differences, and societal costs will be examined.MethodsIn close collaboration with various stakeholders, a quasi-experimental study was developed, for which children of four intervention schools (n = 1200) in the southern part of the Netherlands are compared with children of four control schools (n = 1200) in the same region. The interventions started in November 2015. In two of the four intervention schools, a whole-school approach named ‘The Healthy Primary School of the Future’, is implemented with the aim of improving physical activity and dietary behaviour. For this intervention, pupils are offered an extended curriculum, including a healthy lunch, more physical exercises, and social and educational activities, next to the regular school curriculum. In the two other intervention schools, a physical-activity school approach called ‘The Physical Activity School’, is implemented, which is essentially similar to the other intervention, except that no lunch is provided. The interventions proceed during a period of 4 years. Apart from the effectiveness of both interventions, the process, the cost-effectiveness, and the expected legal implications are studied. Data collection is conducted within the school system. The baseline measurements started in September 2015 and yearly follow-up measurements are taking place until 2019.DiscussionA whole-school approach is a new concept in the Netherlands. Due to its innovative, multifaceted nature and sound scientific foundation, these integrated programmes have the potential to form a template for primary schools worldwide. The effects of this approach may extend further than the outcomes associated with well-being and academic achievement, potentially impacting legal and cultural aspects in our society.Trial registrationThe study protocol was registered in the database ClinicalTrials.gov on 14-06-2016 with the reference number NCT02800616.

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

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

The Healthy Primary School of the Future: A Contextual Action-Oriented Research Approach

Background: Schools can play an important role in promoting children’s health behaviours. A Dutch initiative, ‘The Healthy Primary School of the Future’, aims to integrate health and well-being into the school system. We use a contextual action-oriented research approach (CARA) to study the implementation process. Properties of CARA are its focus on contextual differences and the use of monitoring and feedback to support and evaluate the process of change. The aim of this article is to describe the use of the approach. Methods: Four schools (each with 200–300 children, aged 4–12 years) were included; all located in low socio-economic status areas in the south of the Netherlands. Data collection methods include interviews, observations, questionnaires, and health and behavioural measurements. Research contributions include giving feedback and providing schools with a range of possibilities for additional changes. The contextual data we examine include schools’ health promoting elements, practices of teachers and parents, dominating organisational issues, and characteristics of the student population; process data include the presence of potential barriers to changes. Discussion: CARA is an adaptive research approach that generates knowledge and experiences on how to deal with health promotion in complex systems. We think this approach can set an example for research efforts in comparable initiatives.

Socioeconomic multi-domain health inequalities in Dutch primary school children

Background This study assesses socio-economic health inequalities (SEHI) over primary school-age (4- to 12-years old) across 13 outcomes (i.e. body-mass index [BMI], handgrip strength, cardiovascular fitness, current physical conditions, moderate to vigorous physical activity, sleep duration, daily fruit and vegetable consumption, daily breakfast, exposure to smoking, mental strengths and difficulties, self-efficacy, school absenteeism and learning disabilities), covering four health domains (i.e. physical health, health behaviour, mental health and academic health). Methods Multilevel mixed effect (linear and logistic) regression analyses were applied to cross-sectional data of a Dutch quasi-experimental study that included 1403 pupils from nine primary schools. Socioeconomic background (high-middle-low) was indicated by maternal education (n = 976) and parental material deprivation (n = 784). Results Pupils with higher educated mothers had lower BMIs, higher handgrip strength and higher cardiovascular fitness; their parents reported more daily fruit and vegetable consumption, daily breakfast and less exposure to smoking. Furthermore these pupils showed less mental difficulties and less school absenteeism compared with pupils whose mothers had a lower education level. When using parental material deprivation as socio-economic indicator, similar results were found for BMI, cardiovascular fitness, sleep duration, exposure to smoking and mental strengths and difficulties. Socio-economic differences in handgrip strength, cardiovascular fitness and sleep duration were larger in older than in younger pupils. Conclusions Childhood SEHI are clearly found across multiple domains, and some are larger in older than in younger pupils. Interventions aiming to tackle SEHI may therefore need a comprehensive and perhaps more fundamental approach.

Correction: A Multifactorial Weight Reduction Programme for Children with Overweight and Asthma: A Randomized Controlled Trial (vol 11, e0157158, 2016): (vol 11, e0157158, 2016)

[This corrects the article DOI: 10.1371/journal.pone.0157158.].

Erratum to: The Healthy Primary School of the Future: study protocol of a quasi- experimental study

Following publication of this article [1], it has come to our attention that some of the terminology used in the article could be difficult to interpret.