Dataset Information

A systematic review of associations between environmental exposures and development of asthma in children aged up to 9 years.

ABSTRACT:

Objectives

Childhood asthma is a complex condition where many environmental factors are implicated in causation. The aim of this study was to complete a systematic review of the literature describing associations between environmental exposures and the development of asthma in young children.

Setting

A systematic review of the literature up to November 2013 was conducted using key words agreed by the research team. Abstracts were screened and potentially eligible papers reviewed. Papers describing associations between exposures and exacerbation of pre-existing asthma were not included. Papers were placed into the following predefined categories: secondhand smoke (SHS), inhaled chemicals, damp housing/mould, inhaled allergens, air pollution, domestic combustion, dietary exposures, respiratory virus infection and medications.

Participants

Children aged up to 9 years.

Primary outcomes

Diagnosed asthma and wheeze.

Results

14,691 abstracts were identified, 207 papers reviewed and 135 included in the present review of which 15 were systematic reviews, 6 were meta-analyses and 14 were intervention studies. There was consistent evidence linking exposures to SHS, inhaled chemicals, mould, ambient air pollutants, some deficiencies in maternal diet and respiratory viruses to an increased risk for asthma (OR typically increased by 1.5-2.0). There was less consistent evidence linking exposures to pets, breast feeding and infant dietary exposures to asthma risk, and although there were consistent associations between exposures to antibiotics and paracetamol in early life, these associations might reflect reverse causation. There was good evidence that exposures to house dust mites (in isolation) was not associated with asthma risk. Evidence from observational and intervention studies suggest that interactions between exposures were important to asthma causation, where the effect size was typically 1.5-3.0.

Conclusions

There are many publications reporting associations between environmental exposures and modest changes in risk for asthma in young children, and this review highlights the complex interactions between exposures that further increase risk.

SUBMITTER: Dick S

PROVIDER: S-EPMC4244417 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

A systematic review of associations between environmental exposures and development of asthma in children aged up to 9 years.

Dick S S Friend A A Dynes K K AlKandari F F Doust E E Cowie H H Ayres J G JG Turner S W SW

BMJ open 20141124 11

<h4>Objectives</h4>Childhood asthma is a complex condition where many environmental factors are implicated in causation. The aim of this study was to complete a systematic review of the literature describing associations between environmental exposures and the development of asthma in young children.<h4>Setting</h4>A systematic review of the literature up to November 2013 was conducted using key words agreed by the research team. Abstracts were screened and potentially eligible papers reviewed. ...[more]

PMID: 25421340

Similar Datasets

Project description:BackgroundEarly childhood is a critical period for growth and development, yet the association with physical activity during this important period is unknown. The aim of this review is to critically summarize the evidence on the prospective associations between physical activity and health and development in children aged < 5 years.MethodsA systematic search in three electronic databases (Pubmed, PsycINFO, and Sportdiscus) was conducted to identify prospective studies examining the associations between physical activity (all types; specified by quantity) and health indicators (body composition, cardiometabolic health, bone health and risks/harm) or development (motor, cognitive and social-emotional development) in young children (mean age < 5 years at baseline). Two independent researchers assessed the methodological quality using the 'Quality Assessment Tool for Quantitative Studies' (EPHPP). This tool covers eight quality criteria: selection bias, study design, confounders, blinding, data collection methods, withdrawals and drop-outs, intervention integrity and data-analysis.ResultsThirty-nine studies, predominantly conducted in preschoolers (ages 3-5 years), were included of which nine were rated as high methodological quality. There was moderate evidence for a positive association between physical activity and motor (n = 11 studies) and cognitive development (n = 10 studies) based on consistent findings from studies having low-to-moderate methodological quality. There was insufficient evidence for an association between physical activity and body composition (n = 15 studies), cardiometabolic health indicators (n = 7 studies), social-emotional development (n = 2 studies) and bone health (n = 2 studies) based on inconsistent findings from studies having weak-to-high methodological quality.ConclusionsThere is a need for more high-quality research in order to determine the dose-response relationship between physical activity and health and development in early childhood. Special attention should be paid to studies in children below the age of 3 years.

Project description:Background/aimFluoride is a natural mineral present in food, water, and dental products, constituting ubiquitous long-term exposure in early childhood and across the lifespan. Experimental evidence shows fluoride-induced lipid disturbances with potential implications for cardiometabolic health. However, epidemiological studies are scarce. For the first time, we evaluated associations between repeated fluoride measures and cardiometabolic outcomes in children.MethodsWe studied ∼ 500 Mexican children from the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) cohort with measurements on urinary fluoride at age 4, and dietary fluoride at ages 4, 6, and 8 years approximately. We used covariate-adjusted linear mixed-effects and linear regression models to assess fluoride associations with multiple cardiometabolic outcomes (ages 4-8): lipids (total cholesterol, HDL, LDL, and triglycerides), glucose, HbA1c, adipokines (leptin and adiponectin), body fat, and age- and sex-specific z-scores of body mass index (zBMI), waist circumference, and blood pressure.ResultsDietary fluoride intake at age 4 was associated with annual increases in triglycerides [β per-fluoride-doubling = 2.02 (95 % CI: 0.37, 3.69)], cholesterol [β = 1.46 (95 % CI: 0.52, 2.39)], HDL [β = 0.39 (95 % CI: 0.02, 0.76)], LDL [β = 0.87 (95 % CI: 0.02, 1.71)], and HbA1c [β = 0.76 (95 % CI: 0.28, 1.24)], and decreased leptin [β = -3.58 (95 % CI: -6.34, -0.75)] between the ages 4 and 8. In cross-sectional analyses at age 8, higher tertiles of fluoride exposure were associated with increases in zBMI, triglycerides, glucose, and leptin (p-tertile trend < 0.05). Stronger associations were observed in boys at year 8 and in girls prior to year 8 (p-sex interaction < 0.05). Fewer but consistent associations were observed for urinary fluoride at age 4, indicating increased annual changes in HDL and HbA1c with higher fluoride levels.ConclusionDietary fluoride exposures in early- and mid-childhood were associated with adverse cardiometabolic outcomes in school-aged children. Further research is needed to elucidate whether these associations persist at later ages.

Project description:ObjectiveTo investigate the associations of sleep duration, wake-up time, bedtime, and childhood abdominal obesity, and to test whether there is a weekday/weekend difference and the potential modifying role of sex.MethodsThis cross-sectional study was based on the Students' Constitution and Health Survey and included 9559 students (4840 boys and 4719 girls) aged 7-18 years (7227 aged 7-12 years, 2332 aged 13-18 years). They were divided into two groups (control group and group with abdominal obesity). The physical measurements included children and youth body height, body weight, and waist circumference (WC). A parent-report questionnaire was used to collect the information about parent characteristics as well as lifestyle and sleep patterns (sleep duration, bedtime, and wake-up time of weekdays and weekends) of children and youth.ResultsThe prevalence of abdominal obesity was 30.57% and the percentages of sleep duration <9 hours/day, wake-up time before 07:00 am on weekdays and weekends, bedtime after 10:00 pm on weekends were significantly higher in the group with abdominal obesity. After adjusting for confounders, sleep duration <9 hours/day on weekends was inversely related to abdominal obesity in the overall subjects, regardless of their sex and age, while bedtime after 10:00 pm on weekends was inversely related to abdominal obesity only in the overall subjects, boys, and children aged 7-12 years. Logistic regression models in all subjects showed that shorter hours of weekends sleep duration were associated with greater risks of abdominal obesity, even after adjusting for all confounders, including wake-up time and bedtime. The adjusted odds ratios and 95% confidence intervals of abdominal obesity (with ≥10 hours/day as the reference group) for children with 9-10 hours/day, 8-9 hours/day, and <8 hours/day of weekend sleep duration were 1.23 (1.04-1.46), 1.59 (1.32-1.91) and 1.83 (1.42-2.36), respectively. Specifically, after stratification by sex and age, this phenomenon was only observed in boys and children aged 7-12 years.ConclusionsSleep duration and bedtime on weekends were independently associated with the risk of childhood abdominal obesity, particularly in boys and children aged 7-12 years.

Dataset Information

A systematic review of associations between environmental exposures and development of asthma in children aged up to 9 years.

Objectives

Setting

Participants

Primary outcomes

Results

Conclusions

Publications

A systematic review of associations between environmental exposures and development of asthma in children aged up to 9 years.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets