Accelerometry-assessed sleep clusters and cardiometabolic risk factors in adolescents.

OBJECTIVE: This study aimed to identify sleep clusters based on objective multidimensional sleep characteristics and test their associations with adolescent cardiometabolic health. METHODS: The authors included 1090 participants aged 14.3 to 16.4 years (mean = 15.2 years) who wore 7-day accelerometers during the 15-year follow-up of the German Infant Study on the influence of Nutrition Intervention PLUS environmental and genetic influences on allergy development (GINIplus) and the Influence of Lifestyle factors on the development of the Immune System and Allergies in East and West Germany (LISA) birth cohorts. K-means cluster analysis was performed across 12 sleep characteristics reflecting sleep quantity, quality, schedule, variability, and regularity. Cardiometabolic risk factors included fat mass index (FMI), blood pressure, triglycerides, high-density lipoprotein cholesterol, high-sensitivity C-reactive protein, and insulin resistance (n = 505). Linear and logistic regression models were examined. RESULTS: Five sleep clusters were identified: good sleep (n = 337); delayed sleep phase (n = 244); sleep irregularity and variability (n = 108); fragmented sleep (n = 313); and prolonged sleep latency (n = 88). The "prolonged sleep latency" cluster was associated with increased sex-scaled FMI (ß = 0.39, 95% CI: 0.15-0.62) compared with the "good sleep" cluster. The "sleep irregularity and variability" cluster was associated with increased odds of high triglycerides only in male individuals (odds ratio: 9.50, 95% CI: 3.22-28.07), but this finding was not confirmed in linear models. CONCLUSIONS: The prolonged sleep latency cluster was associated with higher FMI in adolescents, whereas the sleep irregularity and variability cluster was specifically linked to elevated triglycerides (≥1.7 mmol/L) in male individuals.

Full Breastfeeding and Allergic Diseases-Long-Term Protection or Rebound Effects?

A previous follow-up of the GINIplus study showed that breastfeeding could protect against early eczema. However, effects diminished in adolescence, possibly indicating a "rebound effect" in breastfed children after initial protection. We evaluated the role of early eczema until three years of age on allergies until young adulthood and assessed whether early eczema modifies the association between breastfeeding and allergies. Data from GINIplus until 20-years of age (N = 4058) were considered. Information on atopic eczema, asthma, and rhinitis was based on reported physician's diagnoses. Adjusted Odds Ratios (aOR) were modelled by using generalized estimating equations. Early eczema was associated with eczema (aORs = 3.2-14.4), asthma (aORs = 2.2-2.7), and rhinitis (aORs = 1.2-2.7) until young adulthood. For eczema, this association decreased with age (p-for-interaction = 0.002-0.006). Longitudinal models did not show associations between breastfeeding and the respective allergies from 5 to 20 years of age. Moreover, early eczema generally did not modify the association between milk feeding and allergies except for rhinitis in participants without family history of atopy. Early eczema strongly predicts allergies until young adulthood. While preventive effects of full breastfeeding on eczema in infants with family history of atopy does not persist until young adulthood, the hypothesis of a rebound effect after initial protection cannot be confirmed.

Gene-environment interaction in the association of residential greenness and 25(OH) vitamin D.

There is increasing awareness for beneficial health effects of green space surrounding the home, but the underlying mechanisms are not yet fully understood and challenging to study given the correlation with other exposures. Here, the association of residential greenness and vitamin D including a gene-environment interaction is investigated. 25-hydroxyvitamin D (25(OH)D) was measured by electrochemiluminescence at ages 10 and 15 years in participants of two German birth cohorts GINIplus and LISA. Greenness was measured using the Landsat-derived Normalized Difference Vegetation Index (NDVI) in a 500 m buffer surrounding the home. Linear and logistic regression models were applied at both time points adjusted for several covariates (N10Y = 2,504, N15Y = 2,613). In additional analyses vitamin D-related genes, physical activity, time spent outdoors, supplements, and measurement season were investigated as potential confounders or effect modifiers. A 1.5-SD increase in NDVI was significantly associated with increased 25(OH)D values at ages 10 and 15 years (ß10y = 2.41 nmol/l, p=<0.01; ß15y = 2.03 nmol/l, p = 0.02). In stratified analyses, the associations were not seen in participants spending more than 5 h/day outside in summer, having a high physical activity level, taking supplements, or being examined during the winter season. In a subset (n = 1,732) with genetic data, a significant gene-environment interaction of NDVI with CYP2R1, an upstream gene in 25(OH)D synthesis, was observed at age 10 years. When investigating 25(OH)D sufficiency, defined as values above 50 nmol/l, a 1.5-SD increase in NDVI was associated with significantly higher odds of having sufficient 25 (OH)D levels at age 10 years (OR = 1.48, 1.19-1.83). In conclusion, robust associations between residential greenness and 25 (OH)D levels were observed in children and adolescents independent of other confounders and additionally supported by the presence of a gene-environment interaction. Effects of NDVI were stronger in those having lower vitamin D levels at age 10 years due to their covariate profile or genetically lower 25(OH)D synthesis.

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.

Der p 23-specific IgE response throughout childhood and its association with allergic disease: A birth cohort study.

BACKGROUND: The Dermatophagoides pteronyssinus molecule Der p 23 is a major allergen whose clinical relevance has been shown in cross-sectional studies. We longitudinally analysed the trajectory of Der p 23-specific IgE antibody (sIgE) levels throughout childhood and youth, their early-life determinants and their clinical relevance for allergic rhinitis and asthma. METHODS: We obtained sera and clinical data of 191 participants of the German Multicentre Allergy Study, a prospective birth cohort. Serum samples from birth to 20 years of age with sIgE reactivity to Der p 23 in a customised semiquantitative microarray were newly analysed with a singleplex quantitative assay. Early mite exposure was assessed by measuring the average content of Der p 1 in house dust at 6 and 18 months. RESULTS: Der p 23-sIgE levels were detected at least once in 97/191 participants (51%). Prevalence of Der p 23 sensitisation and mean sIgE levels increased until age 10 years, plateaued until age 13 years and were lowest at age 20 years. Asthma, allergic rhinitis (AR) and atopic dermatitis (AD) were more prevalent in Der p 23-sensitised children, including those with monomolecular but persistent sensitisation (11/97, 11%). A higher exposure to mites in infancy and occurrence of AD before 5 years of age preceded the onset of Der p 23 sensitisation, which in turn preceded a higher incidence of asthma. CONCLUSIONS: Der p 23 sensitisation peaks in late childhood and then decreases. It is preceded by early mite exposure and AD. Asthma and AR can occur in patients persistently sensitised to Der p 23 as the only mite allergen, suggesting the inclusion of molecular testing of Der p 23-sIgE for subjects with clinical suspicion of HDM allergy but without sIgE to other major D.pt. allergens.

Psychopathological symptoms as precursors of depressive symptoms in adolescence: a prospective analysis of the GINIplus and LISA birth cohort studies.

INTRODUCTION: Depressive symptoms are highly prevalent in adolescence, highlighting the need for early identification of precursors. Research into psychopathological symptoms predicting depressive psychopathology in adolescents is therefore of great relevance. Moreover, given that the prevalence of depressive symptomatology in adolescence shows marked differences between girls and boys, insight into potential sex-specific differences in precursors is important. METHODS: This study examined the relationships between emotional problems, conduct problems, hyperactivity/inattention, peer problems, and difficulties in prosocial behaviour at age 10 (Strengths and Difficulties Questionnaire), and the presence of depressive symptoms at age 15 (Depression Screener for Teenagers). Using data from 2824 participants of the GINIplus and LISA birth cohorts, the association of each SDQ subscale at age 10 years with the presence of depressive symptoms at age 15 years was analyzed using sex-specific logistic regression, adjusting for potential confounders. RESULTS: Emotional problems [odds ratio (OR) 1.99, p = 0.002 for boys and OR 1.77, p < 0.001 for girls] and peer problems (OR 2.62, p < 0.001 for boys, OR 1.91, p = 0.001 for girls) at age 10 showed an increased risk for the presence of depressive symptoms at age 15. Additionally, boys with conduct problems at age 10 were at greater risk of showing depressive symptoms in adolescence (OR 2.50, p < 0.001). DISCUSSION: Based on the identified prospective relationships in our study, it might be of particular importance to tailor prevention approaches during childhood to peer and emotional problems to reduce the risk of depressive psychopathology in adolescence. Moreover, particularly in boys, it seems important to also target conduct problems in childhood as a precursor of depressive symptoms in the adolescent period.

Obesogenic eating behaviour and dietary intake in German children and adolescents: results from the GINIplus and LISA birth cohort studies.

BACKGROUND/OBJECTIVES: The transition to adolescence is characterised by considerable behavioural changes, including diet. This study describes the level of obesogenic eating behaviours in 10- and 15-year-olds, and their association with dietary intake. SUBJECTS/METHODS: Participants of the 10- and 15-year follow-ups of the German GINIplus and LISA birth cohort studies were included (N10 = 2257; N15 = 1880). Eating behaviours and dietary intake were assessed via self-report questionnaires. Sex-stratified, cross-sectional associations of "external eating", "emotional eating" and "dietary restraint" (the latter at age 15 years only) with dietary intake (17 food groups-categorised into tertiles, macronutrients, and total energy) were assessed using multinomial logistic or multiple linear regression as required, adjusting for covariates and correcting for multiple testing. RESULTS: Reported levels of eating behaviours were low in both age-groups. External eating was higher in 10-year-old males than females, while all eating behaviours were most pronounced in 15-year-old females. At 10 years, emotional eating was associated with medium vegetable intake in females (Relative Risk Ratio (RRR) = 1.84, p = 0.0017). At 15 years, external eating was associated with total energy (kJ) in females (ß = 718, p = 0.0002) and high butter intake in males (RRR = 1.96, p = 0.0019). Dietary restraint in females was inversely associated with total energy (ß = -967, p < 0.0001) and omega-3 fatty acids (Means Ratio (MR) = 0.94, p = 0.0017), and positively associated with high fruit (RRR = 2.20, p = 0.0003) and whole grains (RRR = 1.94, p = 0.0013). CONCLUSION: Obesogenic eating behaviour scores are low among children and adolescents of a predominantly high socioeconomic status population and present only few associations with specific aspects of diet, mainly among adolescent females.

Residential green space and age at menarche in German and Australian adolescent girls: A longitudinal study.

BACKGROUND: A large multicentre European study reported later onset of menopause among women residing in greener areas. This influence on the timing of a reproductive event like menopause, raises the question whether similar associations can be observed with timing of menarche. We investigated whether exposure to residential green space was related to the age at menarche in German and Australian adolescent girls. METHODS: The analytic samples comprised of 1706 German and 1474 Australian adolescent girls. Percentage of green space was calculated in 1000 m buffers around a residential address or its surrogate at the previous follow-up. Mixed effects Cox proportional hazard models were used to explore the associations. The survival object was the occurrence of menarche at the time of follow-up (15-year follow-up of the German cohorts and the study wave at 14-15 years in the Australian cohort) and number of years since baseline (10-year follow-up in the German cohort and the study wave at 10-11 years in the Australian cohort). Participants who did not reach menarche were included as censored observations. RESULTS: A greener residence was not associated with the age at menarche. Null findings were consistent in the general population and in analyses stratified by socioeconomic status or urbanicity in both countries. Urban residents were more likely to have earlier menarche, and this association was consistent across Germany and Australia. CONCLUSION: The results of our analysis do not support the hypothesis that residing in places with more green space can influence timing of menarche. However, given the limitations of our study, researchers should not be discouraged to further explore environmental risk factors of early menarche.

Outdoor air pollution and hormone-assessed pubertal development in children: Results from the GINIplus and LISA birth cohorts.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Long-term Air Pollution Exposure Under European Union Limits and Adolescents' Lung Function: Modifying Effect of Abnormal Weight in the GINIplus and LISA Birth Cohorts.

BACKGROUND: Abnormal weights, eg, obesity, has shown a strong modifying effect on the association between air pollution exposure and lung function impairment in adults. RESEARCH QUESTION: How might weight status modify the effects of long-term air pollution exposure on adolescents' lung function, particularly in areas with pollution levels much lower than the current European Union (EU) air quality standards? STUDY DESIGN AND METHODS: In this observational study, we investigated 2,224 adolescents from the German Infant Study on the Influence of Nutrition Intervention Plus Environmental and Genetic Influences on Allergy Development and the Influence of Life Style Factors on the Development of the Immune System and Allergies in East and West Germany birth cohorts. Lung function was measured at age 15 years. Underweight, normal weight, and overweight or obese were defined using percentiles of BMI. Average concentrations of air pollution were modelled at residential addresses at four exposure windows between 0 and 15 years. Multivariate linear regression models were fitted by weight group on lung function with exposure at each window or cumulative exposure since birth. RESULTS: The median air pollution concentrations were half to two-thirds of the EU standards. Significant associations were observed only for individuals who were underweight and overweight or obese. For example, per interquartile range increase in nitrogen dioxide at the 15-year exposure window, FEV1 declined by -2.9% (95% CI, -5.2% to -0.5%) for the underweight group and -3.4% (95% CI, -5.4% to -1.2%) for the overweight or obese group. Similarly, longer exposure to moderate-level air pollution since birth was associated significantly with lung function impairment for groups with abnormal weight. INTERPRETATION: Exposure to low to moderate levels of air pollution was associated with lung function impairment for adolescents with abnormal weight. Longer exposure aggravated the adverse effect. Whether a critical exposure window since birth exists warrants further exploration.

Association of early life and acute pollen exposure with lung function and exhaled nitric oxide (FeNO). A prospective study up to adolescence in the GINIplus and LISA cohort.

BACKGROUND: Pollen exposure has both acute and chronic detrimental effects on allergic asthma, but little is known about its wider effects on respiratory health. This is increasingly important knowledge as ambient pollen levels are changing with the changing global climate. OBJECTIVE: To assess associations of pollen exposure with lung function and fractional exhaled nitric oxide (FeNO) at age 15 in two prospective German birth cohorts, GINIplus and LISA. METHODS: Background city-specific pollen exposure was measured in infancy (during the first three months of life), and contemporary (on the day of and 7 days prior to lung function measurement). Greenness levels within circular buffers (100-3000 m) around the birth and 15-year home addresses were calculated using the satellite-derived Normalized Difference Vegetation Index. Regression models were used to assess the associations of grass and birch pollen with lung function and FeNO, and the modifying effects of residential greenness were explored. RESULTS: Cumulative early life exposure to grass pollen was associated with reduced lung function in adolescence (FEV1: -4.9 mL 95%CI: -9.2, -0.6 and FVC: -5.2 mL 95%CI: -9.8, -0.5 per doubling of pollen count). Acute grass pollen exposure was associated with increased airway inflammation in all children, with higher FeNO increases in children living in green areas. In contrast acute birch pollen exposure was associated with reduced lung function only in children sensitised to birch allergens. CONCLUSION: This study provides suggestive evidence that early pollen exposure has a negative effect on later lung function, which is in turn influenced by acute pollen exposures.

Air pollution during infancy and lung function development into adolescence: The GINIplus/LISA birth cohorts study.

BACKGROUND: Limited evidence exists on how air pollution exposure during infancy, i.e. the first year of life, may affect lung function development into adolescence. OBJECTIVES: 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. METHODS: 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. RESULTS: 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. DISCUSSION: 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.

Impact of Residential Green Space on Sleep Quality and Sufficiency in Children and Adolescents Residing in Australia and Germany.

Increasing evidence suggests adults living in greener areas tend to have more favourable sleep-related outcomes, but children and adolescents are under-researched. We hypothesised that children and adolescents living in greener areas would have better quality and more sufficient levels of sleep on average, especially within the context of high traffic noise exposure. These hypotheses were tested using multilevel logistic regressions fitted on samples from the nationally representative Longitudinal Study of Australian Children (10-11 years old, n = 3469, and 14-15 years old, n = 2814) and the GINIplus and LISA cohorts (10 years old, n = 1461, and 15 years old, n = 4172) from the Munich, Wesel, and Leipzig areas of Germany. Questionnaire-based binary indicators of sleep sufficiency and sleep quality in each cohort were assessed with respect to objectively measured green space exposures adjusting for age, sex, and maternal education. Models were augmented with proxy measures of traffic noise and two-way interaction terms to test for effect modification. Cross-tabulations illustrated little convincing evidence of association between green space and insufficient sleep or poor sleep quality in either sample, except for insufficient sleep among 10 year old participants in Germany. These null findings were replicated in adjusted models. The proxy for traffic noise was associated with poor quality sleep in 15 year old participants in Germany, but no convincing evidence of modified association with green space was observed.

Emotion regulation strategies predict weight loss during an inpatient obesity treatment for adolescents.

OBJECTIVE: Weight loss during an inpatient obesity treatment is an important predictor of subsequent weight maintenance. However, psychological factors influencing weight loss are not well established. Psychological models suggest some importance of executive functioning and emotion regulation strategies. Therefore, this study investigated whether these factors predict weight loss during an inpatient obesity treatment and whether this effect holds after controlling for general personal and treatment characteristics. METHOD: A total of 158 adolescents with diagnosed obesity underwent inpatient obesity treatment at a German rehabilitation clinic. Psychological factors (executive functioning and emotion regulation) were measured at admission and used to predict BMI reduction after treatment completion. RESULTS: More frequent use of reappraisal as an emotion regulation strategy, but not suppression or executive functioning, predicted weight loss at the end of the obesity treatment, even after controlling for age, gender, treatment duration, and BMI at admission. CONCLUSION: Functional emotion regulation strategies, like reappraisal, might offer an additional target for obesity treatment programmes, complementary to the more traditional components of psychoeducation, physical activity, and caloric restriction.

Association between objectively assessed physical activity and sleep quality in adolescence. Results from the GINIplus and LISA studies.

STUDY OBJECTIVES: Population-based studies on the association of objectively assessed physical activity (PA) with sleep among adolescents are rare. We examined this association by applying accelerometry and accounting for the day-by-day variability. METHODS: Accelerometers (Actigraph GT3X) were worn for one week by 1223 participants during the 15-year follow-up of the German birth cohorts (German infant study on the Influence of Nutrition Intervention plus air pollution and genetics on allergy development, GINIplus) and (Influence of Lifestyle factors on the development of the Immune System and Allergies in East and West Germany, LISA) to measure PA and sleep. PA was categorised into sedentary, lifestyle and moderate-to-vigorous physical activity (MVPA) referring to Sasaki and Romanzini. Sleep was analysed according to the algorithm developed by Sadeh. Sleep quality was represented by sleep efficiency (SE), sleep onset latency (SOL) and time awake per hour after sleep onset (TAPH). Sleep and activity were additionally reported by diaries. Linear and generalized mixed-effects-models with logit-link with subject specific random intercepts were used stratified by sex and adjusted for confounding variables. RESULTS: Physical activity appears to be associated only with sleep quality the following night. Among female participants, SE improved (ß = 0.12 [95% CI = (0.05; 0.18)]) per 10 minutes increase of MVPA. SOL decreased (OR = 0.83 [95% CI = (0.69; 0.99)]) among male participants with at least 60 min of MVPA per day. Engaging in leisure sport MVPA was associated with higher SE among female (ß = 0.70 [95% CI = (0.22; 1.17)]) and male participants (ß = 0.76 [95% CI = (0.18; 1.34)]). Also, TAPH among female (ß = -0.37 [95% CI = (-0.65; -0.09)]) and SOL among male subjects (OR = 0.70 [95% CI = (0.57; 0.85)]) decreased. Increasing lifestyle activity was related to longer SOL among female (OR = 1.36 [95% CI = (1.15; 1.62)]) and male subjects (OR = 1.32 [95% CI = (1.10; 1.58)]). CONCLUSIONS: In this large population-based sample of German adolescents MVPA and leisure sport improved short term sleep quality, supporting regular PA in adolescents for their health benefit.

Dietary saturated fat and low-grade inflammation modified by accelerometer-measured physical activity in adolescence: results from the GINIplus and LISA birth cohorts.

BACKGROUND: Saturated fatty acids (SFA) have been reported to promote inflammation. Nevertheless, evidence linking dietary SFA and low-grade inflammation in adolescents is scarce and inconsistent. The modulatory role of physical activity (PA) on fat metabolism and inflammation may provide a potential explanation. Thus, we assessed the association of dietary SFA with high-sensitivity C-reactive protein (hsCRP), a marker of low-grade inflammation, in 15-year-olds, and evaluated possible interactions between dietary SFA and different levels of PA. METHODS: Children participating in the 15-year follow-ups of the GINIplus and LISA German birth cohort studies were included (N = 824). SFA intake was estimated by means of a food frequency questionnaire and PA recorded by accelerometers. Average daily minutes of PA were classified into "sedentary", "light" and "moderate-to-vigorous" (MVPA), using Freedson's cut-offs. HsCRP concentrations were measured in serum and categorized into 3 sex-specific levels (below detection limit (I), above 75th percentile (III), in between (II)). Sex-stratified cross-sectional associations between SFA and hsCRP were assessed using multinomial logistic regression, adjusting for potential confounders. Interaction terms were included between SFA and the different PA levels; and if significant interactions were observed, analyses stratified by tertiles of the relevant PA levels were performed. Relative risk ratios (RRR) and 95% confidence intervals (95%CI) were presented for a 1% increase in SFA. RESULTS: An inverse association was observed between SFA intake and hsCRP (II vs. I) in males (RRR = 0.85 [95%CI = 0.76;0.96], p = 0.008), whereas no significant association was observed in females. A significant interaction was observed with "sedentary" and "light" PA but not with MVPA in both sexes (p < 0.05). Stratified analyses indicated a significant inverse association between SFA and medium hsCRP levels in males in the highest light PA tertile (hsCRP II vs. I: 0.67 [0.517;0.858], p = 0.002). CONCLUSION: Our findings do not support a detrimental role of dietary SFA in low-grade inflammation among adolescents. In males, higher dietary SFA was associated with lower hsCRP, although this should be interpreted in the context of possibly correlated nutrients. Children spending the most time in light PA drove the observed inverse association, suggesting a synergistic effect of SFA and lifestyle PA in the resultant inflammatory response.

High-Sensitivity C-Reactive Protein and Allergic Endpoints in German Adolescents.

BACKGROUND: Assessing high-sensitivity C-reactive protein (hs-CRP) in relation to allergic endpoints can shed light on both the mechanisms of allergic disease development and early non-communicable disease prevention. However, only a few epidemiological studies so far have investigated the relationship in children and adolescents, and the results were mixed. OBJECTIVES: We sought to examine the interrelation between hs-CRP levels and allergic outcomes using a larger population size and a longitudinal study design. METHODS: Complete data were available on 1,955 participants from the 15-years follow-up of the 2 large population-based German birth cohorts - GINIplus and LISA. Serum hs-CRP concentrations were measured using the immunoturbidimetric high-sensitive assay. Six allergic endpoints were used - doctor-diagnosed asthma, doctor-diagnosed eczema, doctor-diagnosed allergic rhinitis, food sensitization, aeroallergen sensitization, and any sensitization. We used generalized estimation equation models to assess the associations between hs-CRP levels and allergic endpoints. RESULTS: Our longitudinal analyses did not detect any significant association between hs-CRP levels and any of the studied allergic outcomes (e.g., asthma, eczema, allergic rhinitis, food sensitization, aeroallergen sensitization, and any sensitization). The results were consistent in a series of sensitivity analyses. CONCLUSIONS: Our study suggests that there is no association between hs-CRP levels and any of the allergic endpoints in German adolescents. However, whether allergic diseases are inflammatory conditions and which markers might be most sensitive, remain to be confirmed in future studies.

Residential and school greenspace and academic performance: Evidence from the GINIplus and LISA longitudinal studies of German adolescents.

BACKGROUND: Few studies have reported the association between greenspace and academic performance at school level. We examined associations between both residential and school greenspace and individual school grades in German adolescents. METHODS: German and maths grades from the latest school certificate, residential and school greenspace, and covariates were available for 1351 10 and 15 years old Munich children and 1078 Wesel children from two German birth cohorts - GINIplus and LISA. Residential and school greenspace was assessed by the Normalized Difference Vegetation Index (NDVI), tree cover, and (in Munich only) proportion of agricultural land, forest, and urban green space in 500-m and 1000-m circular buffers. Longitudinal associations between each exposure-outcome pair were assessed by logistic mixed effects models with person and school as random intercepts and adjusted for potential confounders. RESULTS: No associations were observed between any of the greenspace variables and grades in Wesel children. Several statistically significant associations were observed with German and maths grades in Munich children, however associations were inconsistent across sensitivity analyses. CONCLUSIONS: There is no evidence of an association of higher greenspace at residence, school or combined with improved academic performance in German adolescents from the GINIplus and LISA longitudinal studies.