Background The causal link between body mass index (BMI) or obesity and asthma in children is still being debated. Analyses of large longitudinal studies with a sufficient number of incident cases ...and in which the time-dependent processes of both excess weight and asthma development can be validly analyzed are lacking. Objective We sought to investigate whether the course of BMI predicts incident asthma in childhood. Methods Data from 12,050 subjects of 8 European birth cohorts on asthma and allergies were combined. BMI and doctor-diagnosed asthma were modeled during the first 6 years of life with latent growth mixture modeling and discrete time hazard models. Subpopulations of children were identified with similar standardized BMI trajectories according to age- and sex-specific “World Health Organization (WHO) child growth standards” and “WHO growth standards for school aged children and adolescents” for children up to age 5 years and older than 5 years, respectively (BMI-SDS). These types of growth profiles were analyzed as predictors for incident asthma. Results Children with a rapid BMI-SDS gain in the first 2 years of life had a higher risk for incident asthma up to age 6 years than children with a less pronounced weight gain slope in early childhood. The hazard ratio was 1.3 (95% CI, 1.1-1.5) after adjustment for birth weight, weight-for-length at birth, gestational age, sex, maternal smoking in pregnancy, breast-feeding, and family history of asthma or allergies. A rapid BMI gain at 2 to 6 years of age in addition to rapid gain in the first 2 years of life did not significantly enhance the risk of asthma. Conclusion Rapid growth in BMI during the first 2 years of life increases the risk of asthma up to age 6 years.
The aim of this study was to determine the effect of six traffic-related air pollution metrics (nitrogen dioxide, nitrogen oxides, particulate matter with an aerodynamic diameter <10 μm (PM10), ...PM2.5, coarse particulate matter and PM2.5 absorbance) on childhood asthma and wheeze prevalence in five European birth cohorts: MAAS (England, UK), BAMSE (Sweden), PIAMA (the Netherlands), GINI and LISA (both Germany, divided into north and south areas). Land-use regression models were developed for each study area and used to estimate outdoor air pollution exposure at the home address of each child. Information on asthma and current wheeze prevalence at the ages of 4-5 and 8-10 years was collected using validated questionnaires. Multiple logistic regression was used to analyse the association between pollutant exposure and asthma within each cohort. Random-effects meta-analyses were used to combine effect estimates from individual cohorts. The meta-analyses showed no significant association between asthma prevalence and air pollution exposure (e.g. adjusted OR (95%CI) for asthma at age 8-10 years and exposure at the birth address (n=10377): 1.10 (0.81-1.49) per 10 μg · m(-3) nitrogen dioxide; 0.88 (0.63-1.24) per 10 μg · m(-3) PM10; 1.23 (0.78-1.95) per 5 μg · m(-3) PM2.5). This result was consistently found in initial crude models, adjusted models and further sensitivity analyses. This study found no significant association between air pollution exposure and childhood asthma prevalence in five European birth cohorts.
Physical activity (PA) is a well-known and underused protective factor for numerous health outcomes, and interventions are hampered by lack of objective data. We combined accelerometers with diaries ...to estimate the contributions to total activity from different domains throughout the day and week in adolescents.
Accelerometric and diary data from 1403 adolescents (45% male, mean age 15.6 ± 0.5 years) were combined to evaluate daily levels and domains of sedentary, light, and moderate-to-vigorous activity (MVPA) during a typical week. Freedson's cutoff points were applied to determine levels of activity. Total activity was broken down into school physical education (PE), school outside PE, transportation to school, sport, and other time.
About 2/3 of adolescents' time was spent sedentary, 1/3 in light activity, and about 5% in MVPA. Boys and girls averaged 46 (SD 22) and 38 (23) minutes MVPA per day. Adolescents were most active during leisure sport, spending about 30% of it in MVPA, followed by PE (about 20%) transport to school (14%) and either school class time or other time (3%). PE provided 5% of total MVPA, while leisure sport provided 16% and transportation to school 8%. School was the most sedentary part of the day with over 75% of time outside PE spent sedentary.
These German adolescents were typical of Europeans in showing low levels of physical activity, with significant contributions from leisure sport, transportation and school PE. Leisure sport was the most active part of the day, and participation did not vary significantly by sex, study center (region of Germany) or BMI. Transportation to school was frequent and thus accounted for a significant fraction of total MVPA. This indicates that even in a population with good access to dedicated sporting activities, frequent active transportation can add significantly to total MVPA.
Background The long-term effect of nutritional intervention with hydrolysate infant formulas on allergic manifestations in high-risk children is uncertain. Objective We sought to investigate the ...effect of hydrolysate infant formulas on allergic phenotypes in children with family history of allergies at school age. Methods We analyzed data from participants of the prospective German Infant Nutritional Intervention study after 10 years of follow-up. At birth, children were randomly assigned to receive, for the first 4 months, one of 4 blinded formulas as breast milk substitute, if necessary: partially hydrolyzed whey formula (pHF-W), extensively hydrolyzed whey formula (eHF-W), extensively hydrolyzed casein formula (eHF-C), or standard cow's milk formula. Outcomes were parent-reported, physician-diagnosed allergic diseases. Log-binomial regression models were used for statistical analysis. Results The relative risk for the cumulative incidence of any allergic disease in the intention-to-treat analysis (n = 2252) was 0.87 (95% CI, 0.77-0.99) for pHF-W, 0.94 (95% CI, 0.83-1.07) for eHF-W, and 0.83 (95% CI, 0.72-0.95) for eHF-C compared with standard cow's milk formula. The corresponding figures for atopic eczema/dermatits (AD) were 0.82 (95% CI, 0.68-1.00), 0.91 (95% CI, 0.76-1.10), and 0.72 (95% CI, 0.58-0.88), respectively. In the per-protocol analysis (n = 988) effects were stronger. The period prevalence of AD at 7 to 10 years was significantly reduced with eHF-C in this analysis, but there was no preventive effect on asthma or allergic rhinitis. Conclusion The significant preventive effect on the cumulative incidence of allergic diseases, particularly AD, with pHF-W and eHF-C persisted until 10 years without rebound, whereas eHF-W showed no significant risk reduction. There is insufficient evidence of ongoing preventive activity at 7 to 10 years of age.
•Infancy air pollution exposure affects lung function growth up to adolescence.•Airway size may be more affected than lung volume restriction.•Maternal age, asthma and breastfeeding duration may ...modify the adverse effects.
Limited evidence exists on how air pollution exposure during infancy, i.e. the first year of life, may affect lung function development into adolescence.
To investigate the association between exposure to air pollution during the first-year of life and lung function development up to the age of 15 in Germany.
We investigated 915 children from the GINIplus and LISA birth cohorts from Munich (n = 181) and Wesel (n = 734), who had at least two spirometric measurements at ages 6, 10 and 15. Z-scores of forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were calculated. Annual average concentrations of nitrogen dioxide, particulate matter with diameters <2.5, <10 and 2.5–10 µm (PM2.5/10/coarse), and PM2.5 absorbance at home addresses during the first-year of life, were estimated by land-use regression models. Associations between infancy exposure and lung function changes were fitted using multivariable linear mixed models with adjustment for potential confounders.
For per interquartile range increase in air pollutants during the first-year life, FEV1 z-scores declined annually by −0.012 (95% confidence interval (CI): −0.014, −0.009) for PM2.5 to −0.023 (95%CI: −0.028, −0.018) for PMcoarse. The declines in FVC were lower than FEV1 −0.006 (95%CI: −0.008, −0.003) to −0.011 (95%CI: −0.019, −0.003). In Munich, the attenuations were only significant for FEV1. Effect estimates of infancy exposure for certain air pollutants were higher for groups with asthma, older maternal age, and breastfeeding <12 weeks than their counterparts.
Infancy exposure to higher air pollution may reduce lung function development up to adolescence, with airway size more affected than lung volume restriction. The potential modifying effects of maternal age, asthmatic status of children and breastfeeding warrant further exploration.
•Associations between air pollutants and pubertal development are unclear.•Link between air pollutants and hormone-assessed pubertal development was analyzed.•Neither PM10, PM2.5, NO2, nor ozone was ...associated with pubertal development.•Air pollutants were not associated with concentrations of estradiol and testosterone.
Air pollution is hypothesized to affect pubertal development. However, the few studies on this topic yielded overall mixed results. These studies did not consider important pollutants like ozone, and none of them involved pubertal development assessed by estradiol and testosterone measurements. We aimed to analyze associations between long-term exposure to four pollutants and pubertal development based on sex hormone concentrations among 10-year-old children.
These cross-sectional analyses were based on the 10-year follow-up medical examinations of 1945 children from the Munich and Wesel centers of the GINIplus and LISA German birth cohorts. Female and male pubertal development was assessed by dichotomizing the concentration of hormones in serum at 18.4 pmol/L and 0.087 nmol/L using the lower limits of quantification for estradiol and testosterone, respectively. Land-use regression models derived annual average concentrations of particulate matter with an aerodynamic diameter < 2.5 and 10 µm (PM2.5 and PM10), as well as spatial models assessed yearly average concentrations of nitrogen dioxide (NO2) and ozone, were calculated at the 10-year residential addresses. To evaluate associations, we utilized logistic regressions adjusted for potential covariates. The analyses were stratified by area and sex.
Around 73% of the 943 females and 25% of the 1002 males had a high level of hormones and had already started puberty at the age of 10. Overall, we found no statistically significant associations between exposure to particles (PM2.5 or PM10) and pubertal development. Results on NO2 and ozone were not significant as well; for instance, per 10 µg/m3 increase in ozone concentration, odds ratios and 95% confidence intervals were 0.900 (0.605, 1.339) and 0.830 (0.573, 1.203) for females and males, respectively. Stratified by area, the aforementioned results did not reveal any associations either.
Our study did not observe the associations between ambient air pollutants and pubertal development determined by estradiol and testosterone levels in children. However, due to the current limited number of studies on this topic, our results should be cautiously interpreted. Future longitudinal studies are needed to assess the association.
Sporting activities differ in their ability to promote moderate-to-vigorous physical activity (MVPA). To assess adolescents' engagement in sport under field conditions we used accelerometers to ...measure their MVPA levels during sport. We pay special attention to differences between team and individual sport and between common sports.
Diary data and 7-day accelerometry from 1054 Germans ages 15-17 were combined to measure physical activity. 1373 diaried episodes of more than 40 common sports were identified from 626 participants and grouped into team and individual sport. We modeled the effect of team and individual sport, and described levels of MVPA and episodes of no MVPA for all recorded sports.
German boys and girls averaged 43 (SD 21) and 37 (SD 24) minutes MVPA per day. Boys got 2.2 times as much MVPA per minute during team compared to individual sport (p<0.0001) but there was no significant difference for girls. Percent of time spent in MVPA during sport ranged from 6% for weight training to 74% for jogging, with individual sports averaging 10-30% and team sports 30-50%. 11% of sport episodes had no MVPA: half of episodes of cycling, 5% of jogging, and none for tennis or badminton. An episode of individual sport was 17 times more likely to have no MVPA than an episode of team sport (p<0.0001).
Under field condition, adolescents were active for only a fraction of diaried sporting time. As measured by accelerometry, individual sport often produced no MVPA. Characteristics of the sport, such as team vs. individual, were more predictive of MVPA than were characteristics of the participant, such as background activity levels.
Objective To assess the association between the introduction of solid foods in the first 12 months and the occurrence of eczema during the first 4 years of life in a prospective study of newborns. ...Study design Data were taken from annually administered questionnaires from a large birth cohort (recruited 1995–1998) comprised of an intervention and a nonintervention group. Outcomes were doctor-diagnosed and symptomatic eczema. Multiple generalized estimation equation models were performed for the 2 study groups. Results From the 5991 recruited infants, 4753 (79%) were followed up. The 2 study groups were different in their family risk of allergies and feeding practices. No association was found between the time of introduction of solids or the diversity of solids and eczema. In the nonintervention group, a decreased risk was observed for avoidance of soybean/nuts, but an increased risk was seen in doctor-diagnosed eczema for the avoidance of egg in the first year. Conclusion The evidence from this study supports neither a delayed introduction of solids beyond the fourth month nor a delayed introduction of the most potentially allergenic solids beyond the sixth month of life for the prevention of eczema. However, effects under more extreme conditions cannot be ruled out.
Pulmonary rehabilitation, including aerobic exercise and strength training, improves function, such as spirometric indices, in lung disease. However, we found spirometry did not correlate with ...physical activity (PA) in healthy adolescents (Smith ERJ: 42(4), 2016). To address whether muscle strength did, we measured these adolescents' handgrip strength and correlated it with spirometry.
In 1846 non-smoking, non-asthmatic Germans (age 15.2 years, 47% male), we modeled spirometric indices as functions of handgrip strength by linear regression in each sex, corrected for factors including age, height, and lean body mass.
Handgrip averaged 35.4 (SD 7.3) kg in boys, 26.6 (4.2) in girls. Spirometric volumes and flows increased linearly with handgrip. In boys each kg handgrip was associated with about 28 mL greater FEV1 and FVC; 60 mL/sec faster PEF; and 38 mL/sec faster FEF2575. Effects were 10-30% smaller in girls (all p<0.0001) and stable when Z-scores for spirometry and grip were modeled, after further correction for environment and/or other exposures, and consistent across stages of puberty.
Grip strength was associated with spirometry in a cohort of healthy adolescents whose PA was not. Thus, research into PA's relationship with lung function should consider strength as well as total PA. Strength training may benefit healthy lungs; interventions are needed to prove causality.
Background The long-term effect of nutritional intervention with hydrolyzed infant formulas on allergy development has not been sufficiently evaluated. Objective We performed a follow–up of the ...German Infant Nutritional Intervention study until 6 years of life to investigate the long-term allergy-preventive effect of 3 hydrolyzed infant formulas compared with cow's milk formula (CMF) in a randomized, double-blind trial. Methods Between 1995 and 1998, 2252 newborns with atopic heredity were randomly assigned at birth to receive one of 4 blinded formulas: partially or extensively hydrolyzed whey formula, extensively hydrolyzed casein formula, or CMF as milk substitute for the first 4 months when breast-feeding was insufficient. The cohort was followed from birth until 6 years of age with yearly questionnaires. Outcomes were physician-diagnosed allergic diseases (atopic dermatitis, food allergy, allergic urticaria, asthma, and hay fever/allergic rhinitis). Log-binomial regression modeled with generalized estimation equations was used for the statistical analysis. Results In the intent-to-treat analysis the relative risk of a physician's diagnosis of allergic manifestation (AM) compared with CMF was 0.82 (95% CI, 0.70-0.96) for partially hydrolyzed whey formula, 0.90 (95% CI, 0.78-1.04) for extensively hydrolyzed whey formula, and 0.80 (95% CI, 0.69-0.93) for extensively hydrolyzed casein formula. The corresponding figures for atopic eczema were 0.79 (95% CI, 0.64-0.97), 0.92 (95% CI, 0.76-1.11), and 0.71 (95% CI, 0.58-0.88), respectively. In the per-protocol analysis all effects were stronger and significant. No significant effect on other AMs was found. Conclusion The data confirm a long-term allergy-preventive effect of hydrolyzed infant formulas on AM and atopic eczema until 6 years of age.
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