Dietary digestible carbohydrates are associated with higher prevalence of asthma in humans and with aggravated lung allergic inflammation in mice.

BACKGROUND: Dietary carbohydrates and fats are intrinsically correlated within the habitual diet. We aimed to disentangle the associations of starch and sucrose from those of fat, in relation to allergic sensitization, asthma and rhinoconjuctivitis prevalence in humans, and to investigate underlying mechanisms using murine models. METHODS: Epidemiological data from participants of two German birth cohorts (age 15) were used in logistic regression analyses testing cross-sectional associations of starch and sucrose (and their main dietary sources) with aeroallergen sensitization, asthma and rhinoconjunctivitis, adjusting for correlated fats (saturated, monounsaturated, omega-6 and omega-3 polyunsaturated) and other covariates. For mechanistic insights, murine models of aeroallergen-induced allergic airway inflammation (AAI) fed with a low-fat-high-sucrose or -high-starch versus a high-fat diet were used to characterize and quantify disease development. Metabolic and physiologic parameters were used to track outcomes of dietary interventions and cellular and molecular responses to monitor the development of AAI. Oxidative stress biomarkers were measured in murine sera or lung homogenates. RESULTS: We demonstrate a direct association of dietary sucrose with asthma prevalence in males, while starch was associated with higher asthma prevalence in females. In mice, high-carbohydrate feeding, despite scant metabolic effects, aggravated AAI compared to high-fat in both sexes, as displayed by humoral response, mucus hypersecretion, lung inflammatory cell infiltration and TH 2-TH 17 profiles. Compared to high-fat, high-carbohydrate intake was associated with increased pulmonary oxidative stress, signals of metabolic switch to glycolysis and decreased systemic anti-oxidative capacity. CONCLUSION: High consumption of digestible carbohydrates is associated with an increased prevalence of asthma in humans and aggravated lung allergic inflammation in mice, involving oxidative stress-related mechanisms.

Allergic disease trajectories up to adolescence: Characteristics, early-life, and genetic determinants.

BACKGROUND: Allergic diseases often develop jointly during early childhood but differ in timing of onset, remission, and progression. Their disease course over time is often difficult to predict and determinants are not well understood. OBJECTIVES: We aimed to identify trajectories of allergic diseases up to adolescence and to investigate their association with early-life and genetic determinants and clinical characteristics. METHODS: Longitudinal k-means clustering was used to derive trajectories of allergic diseases (asthma, atopic dermatitis, and rhinitis) in two German birth cohorts (GINIplus/LISA). Associations with early-life determinants, polygenic risk scores, food and aeroallergen sensitization, and lung function were estimated by multinomial models. The results were replicated in the independent Swedish BAMSE cohort. RESULTS: Seven allergic disease trajectories were identified: "Intermittently allergic," "rhinitis," "early-resolving dermatitis," "mid-persisting dermatitis," "multimorbid," "persisting dermatitis plus rhinitis," and "early-transient asthma." Family history of allergies was more prevalent in all allergic disease trajectories compared the non-allergic controls with stronger effect sizes for clusters comprising more than one allergic disease (e.g., RRR = 5.0, 95% CI = [3.1-8.0] in the multimorbid versus 1.8 [1.4-2.4] in the mild intermittently allergic cluster). Specific polygenic risk scores for single allergic diseases were significantly associated with their relevant trajectories. The derived trajectories and their association with genetic effects and clinical characteristics showed similar results in BAMSE. CONCLUSION: Seven robust allergic clusters were identified and showed associations with early life and genetic factors as well as clinical characteristics.

Activation of immune cell proteasomes in peripheral blood of smokers and COPD patients: implications for therapy.

BACKGROUND: Immune cells contain a specialised type of proteasome, i.e. the immunoproteasome, which is required for intracellular protein degradation. Immunoproteasomes are key regulators of immune cell differentiation, inflammatory activation and autoimmunity. Immunoproteasome function in peripheral immune cells might be altered by smoking and in chronic obstructive pulmonary disease (COPD), thereby affecting immune cell responses. METHODS: We analysed the expression and activity of proteasome complexes in peripheral blood mononuclear cells (PBMCs) isolated from healthy male young smokers as well as from patients with severe COPD and compared them with matching controls. RESULTS: Proteasome expression was upregulated in COPD patients as assessed by quantitative reverse transcriptase-PCR and mass spectrometry-based proteomic analysis. Proteasome activity was quantified using activity-based probes and native gel analysis. We observed distinct activation of immunoproteasomes in the peripheral blood cells of young male smokers and severely ill COPD patients. Native gel analysis and linear regression modelling confirmed robust activation and elevated assembly of 20S proteasomes, which correlated significantly with reduced lung function parameters in COPD patients. The immunoproteasome was distinctly activated in COPD patients upon inflammatory cytokine stimulation of PBMCs in vitro. Inhibition of the immunoproteasome reduced pro-inflammatory cytokine expression in COPD-derived blood immune cells. CONCLUSIONS: Given the crucial role of chronic inflammatory signalling and the emerging involvement of autoimmune responses in COPD, therapeutic targeting of the immunoproteasome might represent a novel therapeutic concept for COPD.

Early-life respiratory tract infections and the risk of school-age lower lung function and asthma: a meta-analysis of 150 000 European children.

BACKGROUND: Early-life respiratory tract infections might affect chronic obstructive respiratory diseases, but conclusive studies from general populations are lacking. Our objective was to examine if children with early-life respiratory tract infections had increased risks of lower lung function and asthma at school age. METHODS: We used individual participant data of 150 090 children primarily from the EU Child Cohort Network to examine the associations of upper and lower respiratory tract infections from age 6 months to 5 years with forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, forced expiratory flow at 75% of FVC (FEF75%) and asthma at a median (range) age of 7 (4-15) years. RESULTS: Children with early-life lower, not upper, respiratory tract infections had a lower school-age FEV1, FEV1/FVC and FEF75% (z-score range: -0.09 (95% CI -0.14- -0.04) to -0.30 (95% CI -0.36- -0.24)). Children with early-life lower respiratory tract infections had a higher increased risk of school-age asthma than those with upper respiratory tract infections (OR range: 2.10 (95% CI 1.98-2.22) to 6.30 (95% CI 5.64-7.04) and 1.25 (95% CI 1.18-1.32) to 1.55 (95% CI 1.47-1.65), respectively). Adjustment for preceding respiratory tract infections slightly decreased the strength of the effects. Observed associations were similar for those with and without early-life wheezing as a proxy for early-life asthma. CONCLUSIONS: Our findings suggest that early-life respiratory tract infections affect development of chronic obstructive respiratory diseases in later life, with the strongest effects for lower respiratory tract infections.

Differential effects of lung inflammation on insulin resistance in humans and mice.

BACKGROUND: The rates of obesity, its associated diseases, and allergies are raising at alarming rates in most countries. House dust mites (HDM) are highly allergenic and exposure often associates with an urban sedentary indoor lifestyle, also resulting in obesity. The aim of this study was to investigate the epidemiological association and physiological impact of lung inflammation on obesity and glucose homeostasis. METHODS: Epidemiological data from 2207 adults of the population-based KORA FF4 cohort were used to test associations between asthma and rhinitis with metrics of body weight and insulin sensitivity. To obtain functional insights, C57BL/6J mice were intranasally sensitized and challenged with HDM and simultaneously fed with either low-fat or high-fat diet for 12 weeks followed by a detailed metabolic and biochemical phenotyping of the lung, liver, and adipose tissues. RESULTS: We found a direct association of asthma with insulin resistance but not body weight in humans. In mice, co-development of obesity and HDM-induced lung inflammation attenuated inflammation in lung and perigonadal fat, with little impact on body weight, but small shifts in the composition of gut microbiota. Exposure to HDM improved glucose tolerance, reduced hepatosteatosis, and increased energy expenditure and basal metabolic rate. These effects associate with increased activity of thermogenic adipose tissues independent of uncoupling protein 1. CONCLUSIONS: Asthma associates with insulin resistance in humans, but HDM challenge results in opposing effects on glucose homeostasis in mice due to increased energy expenditure, reduced adipose inflammation, and hepatosteatosis.

Green space quality and adolescent mental health: do personality traits matter?

INTRODUCTION: Adolescents, especially females, tend to experience poorer mental health if they are higher in introversion and neuroticism. As a result, they also may have more to gain from having quality green space (e.g. parks) nearby to enable restoration, but this remains tested. METHOD: Cross-sectional data on 2946 adolescents aged 16-17y were extracted from the Longitudinal Study of Australian Children. Multilevel linear regressions assessed association between parent/caregiver green space quality perception with self-reported Strengths and Difficulties Questionnaire Total Difficulties Scores (TDS) and internalising (e.g. anxiety) and externalising (e.g. fidgetiness) subscales. Models were weighted for representativeness, accounted for spatial clustering within postcodes, and adjusted for geographic stratum and socioeconomic confounders. This was followed by adjustment for introversion and neuroticism, and then three-way interaction terms between each trait, green space quality and sex to assess for potential effect modification. RESULTS: Quality green spaces was associated with higher TDS (ß = 1.506; SE = 0.371), internalising (ß = 0.982; SE = 0.220) and externalising (ß = 0.518; SE = 0.234) scores (i.e. poorer mental health). Introversion was associated with higher TDS (ß = 1.416; SE = 0.089), higher internalising (ß = 1.233; SE = 0.050) and higher externalising scores (ß = 0.181; SE = 0.056). Similar associations were observed for neuroticism and TDS (ß = 2.283; SE = 0.084), internalising (ß = 1.627; SE = 0.046) and externalising scores (ß = 0.656; SE = 0.056). Mean levels of introversion were similar for girls and boys (1.73 vs 1.76, p = 0.6573), but mean levels of neuroticism were notably higher in girls than boys (2.42 and 1.67, p < 0.0001). Likelihood ratio tests indicated three-way interactions improved models analysing the internalising subscale outcome only. Green space quality made no difference to associations between introversion or neuroticism and internalising scores in males. Quality green space was associated with 3.2 and 2.1 reductions in mean internalising scores among females with the highest levels of introversion or neuroticism, respectively. CONCLUSIONS: Individual differences in psychological traits may predispose some adolescents, and females especially, to restoration from green space.

Early age exposure to moisture and mould is related to FeNO at the age of 6 years.

BACKGROUND: Exposure to indoor moisture damage and visible mold has been found to be associated with asthma and respiratory symptoms in several questionnaire-based studies by self-report. We aimed to define the prospective association between the early life exposure to residential moisture damage or mold and fractional exhaled nitric oxide (FeNO) and lung function parameters as objective markers for airway inflammation and asthma in 6-year-old children. METHODS: Home inspections were performed in children's homes when infants were on average 5 months old. At age 6 years, data on FeNO (n = 322) as well as lung function (n = 216) measurements were collected. Logistic regression and generalized additive models were used for statistical analyses. RESULTS: Early age major moisture damage and moisture damage or mold in the child's main living areas were significantly associated with increased FeNO levels (>75th percentile) at the age of 6 years (adjusted odds ratios, 95% confidence intervals, aOR (95% CI): 3.10 (1.35-7.07) and 3.16 (1.43-6.98), respectively. Effects were more pronounced in those who did not change residential address throughout the study period. For lung function, major structural damage within the whole home was associated with reduced FEV1 and FVC, but not with FEV1/FVC. No association with lung function was observed with early moisture damage or mold in the child's main living areas. CONCLUSION: These results underline the importance of prevention and remediation efforts of moisture and mold-damaged buildings in order to avoid harmful effects within the vulnerable phase of the infants and children's immunologic development.

Variations in accelerometry measured physical activity and sedentary time across Europe - harmonized analyses of 47,497 children and adolescents.

BACKGROUND: Levels of physical activity and variation in physical activity and sedentary time by place and person in European children and adolescents are largely unknown. The objective of the study was to assess the variations in objectively measured physical activity and sedentary time in children and adolescents across Europe. METHODS: Six databases were systematically searched to identify pan-European and national data sets on physical activity and sedentary time assessed by the same accelerometer in children (2 to 9.9 years) and adolescents (≥10 to 18 years). We harmonized individual-level data by reprocessing hip-worn raw accelerometer data files from 30 different studies conducted between 1997 and 2014, representing 47,497 individuals (2-18 years) from 18 different European countries. RESULTS: Overall, a maximum of 29% (95% CI: 25, 33) of children and 29% (95% CI: 25, 32) of adolescents were categorized as sufficiently physically active. We observed substantial country- and region-specific differences in physical activity and sedentary time, with lower physical activity levels and prevalence estimates in Southern European countries. Boys were more active and less sedentary in all age-categories. The onset of age-related lowering or leveling-off of physical activity and increase in sedentary time seems to become apparent at around 6 to 7 years of age. CONCLUSIONS: Two third of European children and adolescents are not sufficiently active. Our findings suggest substantial gender-, country- and region-specific differences in physical activity. These results should encourage policymakers, governments, and local and national stakeholders to take action to facilitate an increase in the physical activity levels of young people across Europe.

Is There an Association between Asthma and Dental Caries and Molar Incisor Hypomineralisation?

This epidemiological study aimed to compare the caries and molar incisor hypomineralisation (MIH) experience in asthmatic and non-asthmatic adolescents assessed at 10 and 15 years of age. 730 adolescents from ongoing birth cohort studies (GINIplus/LISA) from Munich, Germany, were examined for carious lesions at the age of 10 and 15 years to determine caries experience under inclusion of non-cavitated carious lesions D1-2T and the tooth-related decay-missing-filled index. Furthermore, MIH was scored on all permanent teeth according to the criteria of the European Academy of Paediatric Dentistry. The association between caries and MIH prevalence at the 10-year and 15-year follow-up as well as caries incidence with ever having an asthma diagnosis was analysed using hurdle regression models adjusted for potential confounders. Of the 730 adolescents, 52 and 78 were identified as asthmatics at the 10- and 15-year follow-up, respectively. There were no significant differences in caries prevalence or experience between asthma-free participants and any of the asthma groups (taking metered-dose inhaler (MDI) medication vs. taking no MDI medication). However, a significant positive association was found for asthmatic adolescents who did not take MDI medication with higher MIH/T values (OR = 2.56, 95% CI = 1.03-6.37, p = 0.043) compared to non-asthmatics. In conclusion, asthma did not influence the caries status of adolescents in the present study. Interestingly, a significant association was found between adolescents with asthma who did not take MDI medication and the number of MIH-affected teeth. The association between asthma, medication, and MIH needs further confirmation.

Epigenome-wide association study of lung function level and its change.

Previous reports link differential DNA methylation (DNAme) to environmental exposures that are associated with lung function. Direct evidence on lung function DNAme is, however, limited. We undertook an agnostic epigenome-wide association study (EWAS) on pre-bronchodilation lung function and its change in adults.In a discovery-replication EWAS design, DNAme in blood and spirometry were measured twice, 6-15 years apart, in the same participants of three adult population-based discovery cohorts (n=2043). Associated DNAme markers (p<5×10-7) were tested in seven replication cohorts (adult: n=3327; childhood: n=420). Technical bias-adjusted residuals of a regression of the normalised absolute ß-values on control probe-derived principle components were regressed on level and change of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and their ratio (FEV1/FVC) in the covariate-adjusted discovery EWAS. Inverse-variance-weighted meta-analyses were performed on results from discovery and replication samples in all participants and never-smokers.EWAS signals were enriched for smoking-related DNAme. We replicated 57 lung function DNAme markers in adult, but not childhood samples, all previously associated with smoking. Markers not previously associated with smoking failed replication. cg05575921 (AHRR (aryl hydrocarbon receptor repressor)) showed the statistically most significant association with cross-sectional lung function (FEV1/FVC: pdiscovery=3.96×10-21 and pcombined=7.22×10-50). A score combining 10 DNAme markers previously reported to mediate the effect of smoking on lung function was associated with lung function (FEV1/FVC: p=2.65×10-20).Our results reveal that lung function-associated methylation signals in adults are predominantly smoking related, and possibly of clinical utility in identifying poor lung function and accelerated decline. Larger studies with more repeat time-points are needed to identify lung function DNAme in never-smokers and in children.

Second-hand smoke exposure in adulthood and lower respiratory health during 20 year follow up in the European Community Respiratory Health Survey.

BACKGROUND: Early life exposure to tobacco smoke has been extensively studied but the role of second-hand smoke (SHS) for new-onset respiratory symptoms and lung function decline in adulthood has not been widely investigated in longitudinal studies. Our aim is to investigate the associations of exposure to SHS in adults with respiratory symptoms, respiratory conditions and lung function over 20 years. METHODS: We used information from 3011 adults from 26 centres in 12 countries who participated in the European Community Respiratory Health Surveys I-III and were never or former smokers at all three surveys. Associations of SHS exposure with respiratory health (asthma symptom score, asthma, chronic bronchitis, COPD) were analysed using generalised linear mixed-effects models adjusted for confounding factors (including sex, age, smoking status, socioeconomic status and allergic sensitisation). Linear mixed-effects models with additional adjustment for height were used to assess the relationships between SHS exposure and lung function levels and decline. RESULTS: Reported exposure to SHS decreased in all 26 study centres over time. The prevalence of SHS exposure was 38.7% at baseline (1990-1994) and 7.1% after the 20-year follow-up (2008-2011). On average 2.4% of the study participants were not exposed at the first, but were exposed at the third examination. An increase in SHS exposure over time was associated with doctor-diagnosed asthma (odds ratio (OR): 2.7; 95% confidence interval (95%-CI): 1.2-5.9), chronic bronchitis (OR: 4.8; 95%-CI: 1.6-15.0), asthma symptom score (count ratio (CR): 1.9; 95%-CI: 1.2-2.9) and dyspnoea (OR: 2.7; 95%-CI: 1.1-6.7) compared to never exposed to SHS. Associations between increase in SHS exposure and incidence of COPD (OR: 2.0; 95%-CI: 0.6-6.0) or lung function (ß: - 49 ml; 95%-CI: -132, 35 for FEV1 and ß: - 62 ml; 95%-CI: -165, 40 for FVC) were not apparent. CONCLUSION: Exposure to second-hand smoke may lead to respiratory symptoms, but this is not accompanied by lung function changes.

Genome-wide association analysis identifies three new susceptibility loci for childhood body mass index.

A large number of genetic loci are associated with adult body mass index. However, the genetics of childhood body mass index are largely unknown. We performed a meta-analysis of genome-wide association studies of childhood body mass index, using sex- and age-adjusted standard deviation scores. We included 35 668 children from 20 studies in the discovery phase and 11 873 children from 13 studies in the replication phase. In total, 15 loci reached genome-wide significance (P-value < 5 × 10(-8)) in the joint discovery and replication analysis, of which 12 are previously identified loci in or close to ADCY3, GNPDA2, TMEM18, SEC16B, FAIM2, FTO, TFAP2B, TNNI3K, MC4R, GPR61, LMX1B and OLFM4 associated with adult body mass index or childhood obesity. We identified three novel loci: rs13253111 near ELP3, rs8092503 near RAB27B and rs13387838 near ADAM23. Per additional risk allele, body mass index increased 0.04 Standard Deviation Score (SDS) [Standard Error (SE) 0.007], 0.05 SDS (SE 0.008) and 0.14 SDS (SE 0.025), for rs13253111, rs8092503 and rs13387838, respectively. A genetic risk score combining all 15 SNPs showed that each additional average risk allele was associated with a 0.073 SDS (SE 0.011, P-value = 3.12 × 10(-10)) increase in childhood body mass index in a population of 1955 children. This risk score explained 2% of the variance in childhood body mass index. This study highlights the shared genetic background between childhood and adult body mass index and adds three novel loci. These loci likely represent age-related differences in strength of the associations with body mass index.

Higher serum 25(OH)D concentrations are associated with improved FEV1 and FVC in adolescence.

Vitamin D plays a role in the development of the immune system and the lung, as well as in airway remodelling. Therefore, this study investigated the association between serum 25-hydroxyvitamin D (25(OH)D) concentrations and spirometric lung function parameters at age 15 years.In the German birth cohorts GINIplus and LISAplus, lung function testing by spirometry and 25(OH)D measurements were performed during the 15-year follow-up examinations. Valid lung function measurements pre- and/or post-bronchodilation and serum 25(OH)D concentrations, which were adjusted for the date of blood sampling to account for seasonal variability, were available for 2607 adolescents. Associations between 25(OH)D concentrations and spirometric parameters were analysed using generalised additive models adjusted for confounding factors.Serum 25(OH)D concentrations were significantly associated with forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and FEV1/FVC measured before bronchodilation after adjustment for potential confounders: FEV1 increased by 10 mL (95% CI 2-17), FVC by 20 mL (95% CI 12-28) and FEV1/FVC decreased by 0.177% (95% CI -0.286 to -0.067) per 10 nmol·L-1 increase in 25(OH)D concentrations. Flow rates (forced expiratory flow rates at 25, 50 and 75% of exhaled FVC (FEF25, FEF50, FEF75) and mean flow rate between 25 and 75% of FVC (FEF25-75)) were not associated with vitamin D. Similar associations were observed for lung function parameters measured after bronchodilation.Vitamin D concentrations are positively associated with volume-related lung function parameters pre- and post-bronchodilation, suggesting structural changes in peripheral airways.

Which early life events or current environmental and lifestyle factors influence lung function in adolescents? - results from the GINIplus & LISAplus studies.

BACKGROUND: Various factors may affect lung function at different stages in life. Since investigations that simultaneously consider several factors are rare, we examined the relative importance of early life, current environmental/lifestyle factors and allergic diseases on lung function in 15-year-olds. METHODS: Best subset selection was performed for linear regression models to investigate associations between 21 diverse early life events and current factors with spirometric parameters (forced vital capacity, forced expiratory volume in 1 s and maximal mid-expiratory flow (FEF25-75)) in 1326 participants of the German GINIplus and LISAplus birth cohorts. To reduce model complexity, one model for each spirometric parameter was replicated 1000 times in random subpopulations (N = 884). Only those factors that were included in >70% of the replication models were retained in the final analysis. RESULTS: A higher peak weight velocity and early lung infections were the early life events prevalently associated with airflow limitation and FEF25-75. Current environmental/lifestyle factors at age 15 years and allergic diseases that were associated with lung function were: indoor second-hand smoke exposure, vitamin D concentration, body mass index (BMI) and asthma status. Sex and height captured the majority of the explained variance (>75%), followed by BMI (≤23.7%). The variance explained by early life events was comparatively low (median: 4.8%; range: 0.2-22.4%), but these events were consistently negatively associated with airway function. CONCLUSIONS: Although the explained variance was mainly captured by well-known factors included in lung function prediction equations, our findings indicate early life and current factors that should be considered in studies on lung health among adolescents.

Early growth characteristics and the risk of reduced lung function and asthma: A meta-analysis of 25,000 children.

BACKGROUND: Children born preterm or with a small size for gestational age are at increased risk for childhood asthma. OBJECTIVE: We sought to assess the hypothesis that these associations are explained by reduced airway patency. METHODS: We used individual participant data of 24,938 children from 24 birth cohorts to examine and meta-analyze the associations of gestational age, size for gestational age, and infant weight gain with childhood lung function and asthma (age range, 3.9-19.1 years). Second, we explored whether these lung function outcomes mediated the associations of early growth characteristics with childhood asthma. RESULTS: Children born with a younger gestational age had a lower FEV1, FEV1/forced vital capacity (FVC) ratio, and forced expiratory volume after exhaling 75% of vital capacity (FEF75), whereas those born with a smaller size for gestational age at birth had a lower FEV1 but higher FEV1/FVC ratio (P < .05). Greater infant weight gain was associated with higher FEV1 but lower FEV1/FVC ratio and FEF75 in childhood (P < .05). All associations were present across the full range and independent of other early-life growth characteristics. Preterm birth, low birth weight, and greater infant weight gain were associated with an increased risk of childhood asthma (pooled odds ratio, 1.34 [95% CI, 1.15-1.57], 1.32 [95% CI, 1.07-1.62], and 1.27 [95% CI, 1.21-1.34], respectively). Mediation analyses suggested that FEV1, FEV1/FVC ratio, and FEF75 might explain 7% (95% CI, 2% to 10%) to 45% (95% CI, 15% to 81%) of the associations between early growth characteristics and asthma. CONCLUSIONS: Younger gestational age, smaller size for gestational age, and greater infant weight gain were across the full ranges associated with childhood lung function. These associations explain the risk of childhood asthma to a substantial extent.

Genome-wide association and longitudinal analyses reveal genetic loci linking pubertal height growth, pubertal timing and childhood adiposity.

The pubertal height growth spurt is a distinctive feature of childhood growth reflecting both the central onset of puberty and local growth factors. Although little is known about the underlying genetics, growth variability during puberty correlates with adult risks for hormone-dependent cancer and adverse cardiometabolic health. The only gene so far associated with pubertal height growth, LIN28B, pleiotropically influences childhood growth, puberty and cancer progression, pointing to shared underlying mechanisms. To discover genetic loci influencing pubertal height and growth and to place them in context of overall growth and maturation, we performed genome-wide association meta-analyses in 18 737 European samples utilizing longitudinally collected height measurements. We found significant associations (P < 1.67 × 10(-8)) at 10 loci, including LIN28B. Five loci associated with pubertal timing, all impacting multiple aspects of growth. In particular, a novel variant correlated with expression of MAPK3, and associated both with increased prepubertal growth and earlier menarche. Another variant near ADCY3-POMC associated with increased body mass index, reduced pubertal growth and earlier puberty. Whereas epidemiological correlations suggest that early puberty marks a pathway from rapid prepubertal growth to reduced final height and adult obesity, our study shows that individual loci associating with pubertal growth have variable longitudinal growth patterns that may differ from epidemiological observations. Overall, this study uncovers part of the complex genetic architecture linking pubertal height growth, the timing of puberty and childhood obesity and provides new information to pinpoint processes linking these traits.

Relation of lung function and current inhalant allergen-specific immunoglobulin E concentrations in adolescents (GINIplus cohort).

BACKGROUND: The prevalence of allergen sensitization reaches up to 46.6% in 14- to 17-year-old German adolescents. Polysensitization is strongly associated with a higher risk of allergic rhinitis or asthma. Whether or how sensitization also is related to lung function remains uncertain. OBJECTIVE: To assess whether sensitization to common inhalant allergens is associated with lung function in adolescents after stratification by allergic respiratory disease. METHODS: In total, 1,719 15-year-old participants of the German Infant Study on the Influence of Nutrition Intervention plus Air Pollution and Genetics on Allergy Development (GINIplus) birth cohort provided valid spirometric indices, including forced expiratory volume in 1 second, forced vital capacity (FVC), forced expiratory flow rate at 25% to 75% of the FVC, and specific immunoglobulin E (IgE) screening test to 8 inhalant allergens (ImmunoCAP). Complete information on allergic rhinitis and asthma status was available for 1,128 subjects. Associations between lung function parameters and sensitization, classified into 4 groups (no sensitization to polysensitization) were analyzed using adjusted linear regression models. RESULTS: Among participants, 21.1% (n = 347) had allergic rhinitis, 10.1% (n = 119) had asthma, and 46.4% (n = 798) had a positive screening test to inhalant allergens. Prevalences were consistently higher in boys. The percentage of subjects with rhinitis or asthma increased from 5.8% in non-sensitized subjects (n = 620) to 69.4% in polysensitized subjects (n = 144). Sensitization was not associated with any spirometric parameter considered in subjects with allergic rhinitis, asthma, or neither disease. CONCLUSION: Although allergen-specific IgE concentrations can contribute to the identification of subjects at higher risk for allergic rhinitis and asthma, sensitization to inhalant allergens is not related to impaired spirometric lung parameters within the different allergic respiratory disease subgroups.

Changes in dietary intake during puberty and their determinants: results from the GINIplus birth cohort study.

BACKGROUND: Understanding changes in dietary intake during puberty could aid the mapping of dietary interventions for primary prevention. The present study describes dietary changes from childhood to adolescence, and their associations with parental education, family income, child education, body mass index (BMI), pubertal onset and screen-time sedentary behaviour. METHODS: Dietary data (n = 1232) were obtained from food frequency questionnaires at the 10- and 15-year follow-ups of the GINIplus birth cohort study. Intakes of 17 food groups, macronutrients and antioxidant vitamins, were described by a) paired Wilcoxon rank sum tests, comparing average intakes at each time-point, and b) Cohen's kappa "tracking" coefficients, measuring stability of intakes (maintenance of relative tertile positions across time). Further, associations of changes (tertile position increase or decrease vs. tracking) with parental education, family income, child education, pubertal onset, BMI, and screen-time, were assessed by logistic regression and multinomial logistic regression models stratified by baseline intake tertile. RESULTS: Both sexes increased average intakes of water and decreased starchy vegetables, margarine and dairy. Females decreased meat and retinol intakes and increased vegetables, grains, oils and tea. Males decreased fruit and carbohydrates and increased average intakes of meat, caloric drinks, water, protein, fat, polyunsaturated fatty acids (PUFAs), vitamin C and alpha-tocopherol. Both sexes presented mainly "fair" tracking levels [κw = 0.21-0.40]. Females with high (vs. low) parental education were more likely to increase their nut intake [OR = 3.8; 95 % CI = (1.7;8.8)], and less likely to decrease vitamin C intakes [0.2 (0.1;0.5)], while males were less likely to increase egg consumption [0.2 (0.1;0.5)] and n3 PUFAs [0.2 (0.1;0.5)]. Females with a higher (vs. low) family income were more likely to maintain medium wholegrain intakes [0.2 (0.1;0.7) for decrease vs. tracking, and 0.1 (0.0;0.5) for increase vs. tracking], and were less likely to decrease vitamin C intakes [0.2 (0.1;0.6)]. Males with high education were less likely to increase sugar-sweetened foods [0.1 (0.1;0.4)]. Finally, BMI in females was negatively associated with decreasing protein intakes [0.7 (0.6;0.9)]. In males BMI was positively associated with increasing margarine [1.4 (1.1;1.6)] and vitamin C intakes [1.4 (1.1;1.6)], and negatively associated with increasing n3 PUFA. CONCLUSIONS: Average dietary intakes changed significantly, despite fair tracking levels, suggesting the presence of trends in dietary behaviour during puberty. Family income and parental education predominantly influenced intake changes. Our results support the rationale for dietary interventions targeting children, and suggest that sex-specific subpopulations, e.g. low socio-economic status, should be considered for added impact.

Fraction of exhaled nitric oxide values in childhood are associated with 17q11.2-q12 and 17q12-q21 variants.

BACKGROUND: The fraction of exhaled nitric oxide (Feno) value is a biomarker of eosinophilic airway inflammation and is associated with childhood asthma. Identification of common genetic variants associated with childhood Feno values might help to define biological mechanisms related to specific asthma phenotypes. OBJECTIVE: We sought to identify the genetic variants associated with childhood Feno values and their relation with asthma. METHODS: Feno values were measured in children age 5 to 15 years. In 14 genome-wide association studies (N = 8,858), we examined the associations of approximately 2.5 million single nucleotide polymorphisms (SNPs) with Feno values. Subsequently, we assessed whether significant SNPs were expression quantitative trait loci in genome-wide expression data sets of lymphoblastoid cell lines (n = 1,830) and were related to asthma in a previously published genome-wide association data set (cases, n = 10,365; control subjects: n = 16,110). RESULTS: We identified 3 SNPs associated with Feno values: rs3751972 in LYR motif containing 9 (LYRM9; P = 1.97 × 10(-10)) and rs944722 in inducible nitric oxide synthase 2 (NOS2; P = 1.28 × 10(-9)), both of which are located at 17q11.2-q12, and rs8069176 near gasdermin B (GSDMB; P = 1.88 × 10(-8)) at 17q12-q21. We found a cis expression quantitative trait locus for the transcript soluble galactoside-binding lectin 9 (LGALS9) that is in linkage disequilibrium with rs944722. rs8069176 was associated with GSDMB and ORM1-like 3 (ORMDL3) expression. rs8069176 at 17q12-q21, but not rs3751972 and rs944722 at 17q11.2-q12, were associated with physician-diagnosed asthma. CONCLUSION: This study identified 3 variants associated with Feno values, explaining 0.95% of the variance. Identification of functional SNPs and haplotypes in these regions might provide novel insight into the regulation of Feno values. This study highlights that both shared and distinct genetic factors affect Feno values and childhood asthma.

Cesarean delivery and risk of childhood obesity.

OBJECTIVE: To investigate whether birth by cesarean delivery rather than vaginal delivery is a risk factor for later childhood obesity. STUDY DESIGN: Healthy, full-term infants were recruited. Overweight and obesity were defined using measured weight and height according to World Health Organization reference data. Associations between cesarean delivery and being overweight or obese were investigated at age 2, 6, and 10 years (n = 1734, 1244, and 1170, respectively) by multivariate logistic regression models adjusted for socioeconomic status, child characteristics, and maternal prepregnancy characteristics. RESULTS: Mothers who gave birth by cesarean delivery (∼17%) had a higher mean prepregnancy body mass index (23.7 kg/m(2) vs 22.5 kg/m(2)), greater mean gestational weight gain (15.3 kg vs 14.5 kg), and shorter mean duration of exclusive breastfeeding (3.4 months vs 3.8 months) compared with those who delivered vaginally. The proportion of obese children was greater in the cesarean delivery group compared with the vaginal delivery group at age 2 years (13.6% vs 8.3%), but not at older ages. Regression analyses revealed a greater likelihood of obesity at age 2 years in the cesarean delivery group compared with the vaginal delivery group at age 2 years (aOR, 1.68; 95% CI, 1.10-2.58), but not at age 6 years (aOR, 1.49; 95% CI, 0.55-4.05) or age 10 years (aOR, 1.16; 95% CI, 0.59-2.29). CONCLUSION: Cesarean delivery may increase the risk of obesity in early childhood. Our results do not support the hypothesis that an increasing rate of cesarean delivery contributes to obesity in childhood.