The present study aimed to investigate associations between leisure activities and well-being, behavioral difficulties, and parental leisure time engagement. A total of 959 adolescents aged 10 to 18 years were included in the present study. We assessed their leisure activities (e.g., family time, meeting friends, screen time, sports participation), well-being (Kidscreen-27) and behavioral difficulties (Strengths and Difficulties Questionnaire SDQ) using questionnaires. The leisure behavior of parents was assessed using a parent version of the leisure activities questionnaire. We applied linear and logistic mixed-effect models to assess associations, adjusting for age, sex, and SES. The associations between leisure activities and well-being differed depending on the type of activity. Active leisure (e.g., family time, meeting friends, café visits, visiting a museum/art exhibition/cinema, visiting a concert/opera, voluntary work, sports participation) was associated with better well-being, especially physical well-being, and fewer behavioral difficulties. Passive leisure activities (screen time, chilling) were associated with lower well-being and more behavioral difficulties. We also observed that adolescents reported more frequently participation in the described leisure activities if their parents did so. We need to promote active leisure behavior among young people and their parents to improve adolescents’ well-being.

Abstract Background Leisure activities are substantial for adolescents’ development and are influenced by various factors. The present study aimed to investigate the associations between leisure activities and well-being, behavioral difficulties, and parental leisure time engagement. Methods A total of 959 adolescents aged 10 to 18 years were included in the present study. We assessed the adolescents’ leisure activities (e.g., family time, meeting friends, different media, organized sports), well-being (Kidscreen-27) and behavioral difficulties (Strengths and Difficulties Questionnaire SDQ) using questionnaires. We applied linear and generalized mixed-effect models to assess associations, adjusting for age group, sex, and SES. Results The associations between leisure activities and well-being differed depending on the type of activity. Active leisure (e.g., family time, meeting friends, café visits, visiting a museum/art exhibition/cinema, visiting a concert/opera, voluntary work, physical activity) was associated with better well-being, especially physical well-being, and fewer behavioral difficulties. Passive leisure activities (e.g., screen time, chilling), on the contrary, were associated with lower well-being and more behavioral difficulties. We also observed that adolescents reported greater participation in the described leisure activities if their parents did so. With a few exceptions, leisure behavior did not change during the COVID-19 pandemic. Conclusion Our findings underline the importance of leisure activities, their potential impact on adolescents’ well-being and the role parents might play in shaping their children’s leisure time. Therefore, we need to promote the active leisure behavior of young people and their parents.

Purpose The physical health and development of an individual are influenced by multiple parameters and shaped by internal and external factors during pregnancy. However, it is unclear whether there is an association between maternal lipid concentrations in the third trimester of pregnancy and infant serum lipids as well as anthropometric growth, and whether these factors are influenced by the socioeconomic status (SES) of the mothers. Methods Between 2011 and 2021, 982 mother–child pairs were recruited in the LIFE-Child study. To investigate the influence of prenatal factors, pregnant women at the 24th and 36th week of gestation as well as children at the age of 3, 6 and 12 months were examined and serum lipids determined. Socioeconomic status (SES) was assessed using the validated Winkler Index. Results A higher maternal BMI was associated with a significantly lower Winkler score and a higher infant weight, height, head circumference and BMI from birth up to the 4th–5th week of life. In addition, the Winkler Index correlates with maternal HDL cholesterol and ApoA1 levels. There was no relation between the delivery mode and the maternal BMI or SES. For the maternal HDL cholesterol concentration in the third trimester, an inverse relation to children’s height, weight, head circumference and BMI up to the first year of life as well as the chest and abdominal circumference to an age of 3 months was found. Children born to mothers with dyslipidemia in pregnancy tended to have a worse lipid profile than those born to normolipidemic mothers. Conclusion Serum lipid concentrations and anthropometric parameters of children in the first year of life are affected by multiple factors like maternal BMI, lipid levels and SES.

BACKGROUND Research participants' satisfaction is a topic of great interest, especially in the context of longitudinal studies. Evaluation also represents an important component of quality management in the health care system. Adult studies found that personal characteristics, e.g., age, sex, ethnicity, and SES, can influence satisfaction with health care or study participation. Studies on paediatric participants are sparse. OBJECTIVES To examine how children rated the study day of a cohort study and how these ratings were associated with sociodemographic and socioeconomic characteristics and retention in the context of a large cohort study. METHODS Analyses were performed on 4- to 17-year-old participants of the German longitudinal cohort study LIFE Child (n = 2033). To assess the associations between overall satisfaction (high versus low/middle) and age, sex, body-mass index, socioecomonic status, and participation in a follow-up visit, we applied logistic mixed-effects models. RESULTS Participants' overall satisfaction with the LIFE Child study day was high ("very good": 67.8%). Overall satisfaction was higher in 7-9 years olds (odds ratio [OR] 2.00, 95% confidence interval [CI 1.51, 2.66) and 10-12 years olds (OR 1.51, 95% CI 1.16, 1.98) than in 4-6 years olds and 13-17 years olds. Children with obesity were less likely to participate in a follow-up visit (OR 0.56, 95% CI 0.39, 0.78). Children reporting high overall satisfaction at the first study visit completed a follow-up visit more frequently (OR 1.32, 95% CI 1.05,1.67). CONCLUSIONS A high level of satisfaction increased participants' attendance at a follow-up visit. Our results might be helpful for adapting the study program to the participants' needs in order to maximise retention and minimise attrition rates.

Background Substance use in childhood and adolescence continues to be a current health concern. The aims of the present study were to identify trends in the use of alcohol, cigarettes, and cannabis in children and adolescents in the last 10 years and to assess associations between substance use and quality of life and behavioral strengths and difficulties. Methods Substance use was examined in 1829 9- to 18-year-old German children and adolescents participating in the LIFE Child cohort study between 2011 and 2020. Quality of life was investigated using the KIDSCREEN-27 questionnaire. The Strength and Difficulties Questionnaire was used to assess behavioral strengths and difficulties. Associations were assessed using linear regression analyses. All effects were adjusted for age, gender, and family socio-economic status. Results 38.44% of participants reported drinking alcohol at least sometimes. Smoking (6.23%) and the use of cannabis (3.94%) were less frequent. While we observed no significant changes in smoking between 2011 and 2021, the consumption of cannabis and the frequent consumption of alcohol has increased in this time period. Cigarette and cannabis use were associated with additional symptoms of hyperactivity/inattention and reduced prosocial behavior. For all three substances, usage was associated with more conduct problems. We also found significant associations between substance use and a lower quality of life in the areas of physical wellbeing, psychological wellbeing, parent relation and autonomy, and school environment. One noteworthy finding was that cigarette consumption and frequent alcohol use were associated with higher quality of life in terms of social support/peer group relations. Some significant interactions between substance use and child age indicated that associations between substance use and quality of life or behavioral difficulties were stronger in younger than in older children. Conclusions The results show that quality of life and behavioral difficulties are associated with substance use and should be considered when developing or implementing preventive measures to counter substance use. Furthermore, the findings indicate that substance use can be accompanied by improved peer relations. Therefore, the influence of peers, especially of peers who use these substances, should not be underestimated.

Abstract Purpose The aim of this study is to investigate the influence of maternal lipid concentrations during second and third trimester on infant lipid levels within the first year of life, infant anthropometry and the examination of socioeconomic influence. Methods Between 2011 and 2021, 982 mother-child pairs were recruited in the LIFE-Child study. To investigate the influence of prenatal factors, pregnant women at the 24th and 36th week of gestation as well as children at the age of 3, 6 and 12 months were examined and serum lipids determined. Socioeconomic status (SES) was assessed using the validated Winkler Index. Results A higher maternal BMI was associated with a significantly lower Winkler score and a higher infant weight, height, head circumference and BMI from birth up to the 4th-5th week of life. In addition, the Winkler Index correlates with maternal HDL cholesterol and ApoA1 levels. There was no relation between the delivery mode and the maternal BMI or SES. For the maternal HDL cholesterol concentration in the third trimester, an inverse relation to children’s height, weight, head circumference and BMI up to the first year of life as well as the chest and abdominal circumference to an age of 3 months was found. Children born to mothers with dyslipidemia in pregnancy tended to have a worse lipid profile than those born to normolipidemic mothers. Conclusion Serum lipid concentrations and anthropometric parameters of children in the first year of life are affected by multiple factors like the maternal BMI, lipid levels and SES.

Mid-March 2020, due to the worldwide spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and first reports of severe and fatal cases of the increasingly fast-spreading COVID-19 disease, Germany closed all of its schools as part of its first national lockdown, aimed to curb the pandemic spread of COVID-19. This first, 9 weeks enduring lockdown caused various social, economic and health problems1 and aggravated societal inequalities,2 which led to increasing pressure for the recommencement of regular in-school teaching. In order to assure the safety of school re-openings in Saxony, it was decided to scientifically accompany this throughout 2020 to monitor the potentially non-symptomatic spread of SARS-CoV-2 in schools. We longitudinally screened schools in four different districts in Saxony (Germany) for non-symptomatic active SARS-CoV-2 infections as well as seroprevalence in students and staff in three consecutive rounds (I-III) of examinations throughout 2020, cf. Figure 1. The study was approved by the Ethics Committee of the Medical Faculty of the University of Leipzig (Reg. No. 260/20-ek). All procedures conform to the declaration of Helsinki. The present study is registered in the German Clinical Trials Register (ID: DRKS00022032) as well as with the Robert Koch Institute as seroepidemiological study. In total, we tested 3,053 non-symptomatic participants in 18 schools onsite. About 60% of the participants were females, and this imbalance was mainly caused by predominantly female staff in primary (ca. 80%) and secondary (ca. 70%) schools. In sum, we analysed 7,472 oropharyngeal swabs to screen for acute infections using real-time PCR and 6,715 blood serum samples to test for SARS-CoV-2 IgG antibodies. Online questionnaires taken by about 70% of the participants provided additional information, for example regarding previous symptoms or contact to identified COVID-19 cases. During examination round (I), we found none, and in (II), we found one active infection with SARS-CoV-2. In contrast, round (III) revealed 26 SARS-CoV-2 positives out of 2,449 swab samples. As such, our observed incidence increased overall from 0·0% in spring to 0·04% in summer and up to 1·1% in autumn 2020, expectedly the relative detected infections increased with the varying regional 7-day incidence/100,000 inhabitants (7-di). The fact that in regions with the highest local incidence (300–400 7-di) disproportionately high numbers (22/717) of symptomless cases in schools were found compared to lower incidence regions (4/1748 in 100–150 7-di and 1/2438 in 1–10 7-di) could indicate that schools follow the overall pandemic development rather than driving it. Analysing the differences in infection rates between the tested groups in round (III), we found higher incidences in secondary schools (students 1·9%, staff 1·0%) than in primary schools (students 0·5%, staff 0·3%). In both school forms, students showed a higher rate of non-symptomatic infections than the respective staff, as might be expected since adolescents, and particularly, children are less symptomatic than adults3 and therefore more likely to carry undetected infections. Particularly striking is the difference in rate between 7th grade students (2·6% = 13/498) and 11th grade (1·0% = 4/401). This could not be shown to be significant (p = 0·08), but we note that the relative risk for infection with SARS-CoV-2 was 2·6-fold higher for grade 7 compared with grade 11, where only the latter were required to wear masks inside the classroom. Other studies found similar results for mandatory measures.4 Answers to the questionnaire revealed that 48% (10/21) of the currently infected participants reported symptoms within the previous 10 days compared to only 11·9% (202/1700) of the non-infected (p = 7·3*10−7). Symptoms of the respective household members also showed significant differences (p = 0·01). The seroprevalence was initially 0·6% in spring (I), remained constant over the summer (0·6% in (II)) and increased in the second pandemic wave to 1·4% in (III), so it was expectedly following the trend of the overall incidence. Our detected seroprevalence thereby exceeds officially reported COVID-19 cases by a factor of about five in rounds (I) and (II), similar to other studies.5 With this factor the seroprevalence increase we found in (III) trails the increase in officially reported cases by three to four weeks, which is longer than the expected one to two weeks for antibody development. Again, this is consistent with schools rather following the surrounding 7-day incidence. In conclusion, we found that school openings at low incidence are safe, but insufficient safety measures, especially at high incidence, are associated with more infections in schools. Nonetheless, results indicate that schools follow the surrounding pandemic incidence rather than driving it, even at elevated regional incidence. Rigorous testing of students and staff as well as mandatory mask-wearing in all age groups appear to be indispensable for safe, continuously open schools during elevated regional incidence. We thank the schools and all participants, their families, the LIFE Child-staff and supporting paediatricians, as well as M. Vogel for obtaining project funding from the Free State of Saxony. All authors declare no competing interests. This study was supported by the Free State of Saxony, Germany.

Background and aims Transient Elastography is a non-invasive, cost-efficient, non-ionizing, observer-independent and reliable method to detect liver fibrosis using Liver Stiffness Measurement (LSM) and the degree of fat accumulation in the liver using Controlled Attenuation Parameter (CAP). This study aims to derive reference values for both measures from healthy children and adolescents. Further, we aim to assess the potential influence of age, sex, puberty, and BMI-SDS on CAP and LSM. Methods Within the LIFE Child study, amongst others, anthropometric data and pubertal status were assessed. Transient Elastography (TE) was performed using the FibroScan® device in a population-based cohort at 982 study visits of 482 healthy children aged between 10 and 18 years. Percentiles for LSM and CAP were estimated, and the effects of age, sex, puberty and weight status were assessed through hierarchical regression models. Results There was a strong age dependency for LSM with higher values for older children, most pronounced in the upper percentiles in boys. Contrarily, CAP was relatively stable across the age span without considerable difference between boys and girls. We found a significant positive correlation between BMI-SDS and both CAP and LSM for BMI-SDS >1.28. For BMI-SDS < 1.28, the association was also positive but reached statistical significance only for CAP. Further, the association between BMI-SDS and CAP was significantly stronger in younger than in older children. There was no association between pubertal status and CAP. For LSM, we found that children with a high BMI-SDS but not children with normal weight had significantly higher LSM values in Tanner stage 4. Conclusions Age, sex, pubertal status and weight status should be considered when interpreting LSM and CAP in pediatric patients to facilitate and improve early detection of abnormal liver function, which is associated with common pathologies, such as NAFLD.

Background Excessive media usage affects children’s health. This study investigated associations between children’s and mother’s media use, parent–child interactions, and early-childhood development outcomes. Methods Two hundred and ninety-six healthy 2–5-year-old preschoolers (52.4% male, mean age = 3.5 years) and 224 mothers from the LIFE Child cohort study were analyzed. Screen times and parent–child interactions were assessed using standardized parental questionnaires. Developmental skills were investigated using the standardized development test ET 6-6-R. Results High screen times in children (>1 h/day) were significantly associated with lower percentile ranks in cognition ( b = −10.96, p < 0.01), language ( b = −12.88, p < 0.01), and social–emotional skills ( b = −7.80, p = 0.05). High screen times in mothers (>5 h/day) were significantly associated with high media use by children (OR = 3.86, p < 0.01). Higher parent–child interaction scores were significantly associated with better body motor ( b = 0.41, p = 0.05), cognition ( b = 0.57, p < 0.01), language ( b = 0.48, p = 0.02), and social–emotional outcomes ( b = 0.80, p < 0.01) in children. Conclusions Public health strategies should seek to educate caregivers as competent mediators for their children’s media habits, with focus on the need for children to have frequent parent–child interactions. Impact High media usage in children is related to poorer cognition, language, and social–emotional skills. More frequent parent–child interactions are associated with better body motor, cognition, language, and social–emotional skills in children. High level of media use in mothers is not directly related to children’s development outcomes but is directly related to high media usage of children. Public health strategies should seek to raise media awareness and management in both parents and children.

BackgroundThe present study describes motor skills in a large sample of German children and adolescents and investigates associations with age, gender, body-mass index, physical activity, television time, and socioeconomic status.Methods2,106 children (1076 boys, 1030 girls) aged 4 to 17 years performed five different motor tests for strength (pushups, standing long jump), coordination (backward balancing, jumping side-to-side) and flexibility (forward bend) within the framework of the LIFE Child study (Leipzig, Germany). Anthropometric parameters were assessed through standardized measurement. Data on physical activity, television time, and socioeconomic status were collected via questionnaires. Linear regression analyses were applied to assess relations.ResultsStrength and coordination performance were higher in older than in younger children. While boys showed a higher performance in strengths tests than girls, girls performed better in flexibility and coordination during precision tasks (backward balancing). In terms of coordination under time constraint (jumping side-to-side), both genders produced similar results. Lower body-mass index, higher physical activity, and higher socioeconomic status were significantly related to better motor skills. Longer television times were significantly associated with lower performance in long jump.ConclusionsThe present findings are similar to data collected at the beginning of the century, indicating that motor skills have hardly changed in recent years. The findings furthermore suggest that children from lower social strata, children with higher body weight, and children who move little have a higher risk of developing insufficient motor skills and should therefore be given special support.

Background: This study investigates the times adolescents engage in different media activities (including entertaining and educational activities) and explores associations with behavioral strengths and difficulties and school grades. Methods: This cross-sectional study included 664 10- to 18-year-old adolescents (350 boys, 314 girls) participating in the LIFE Child study in Germany. Participants completed questionnaires on their media use, on strengths and difficulties (using the Strengths and Difficulties Questionnaire), and on their school grades in mathematics and first language. Associations of the times engaged in different media activities via mobile phone or computer (traditional communication, social media use, gaming, playing learning games, watching videos, and searching for information) with behavioral strengths/difficulties and school grades were assessed using linear regression analyses (adjusting for age, gender, and socioeconomic status). Results: With the exception of playing learning games, each media activity was followed for almost one hour per day, with high inter-relations between the single activities. Gaming, watching videos, social networking, traditional communication, and playing learning games were significantly associated with more behavioral difficulties in at least one domain (emotional problems, conduct problems, hyperactivity/inattention, peer-relationship problems, prosocial behavior) and with lower school grades. Searching for information showed the weakest associations with behavioral difficulties and no association with school grades. In a multivariate analysis, searching for information was associated with fewer behavioral difficulties. Conclusions: Using media to search for information might weaken the adverse effects of other media activities on school performance and behavioral adjustment.

Aim The relationship between mouth breathing and dental caries, gingival inflammation, and halitosis in children is contentious with studies reporting positive and negative associations; this study aimed at investigating the effect of mouth breathing on dental, gingival health status, and halitosis. Materials and methods An observational cross-sectional study was carried out involving 785 randomly selected children and adolescents between the ages of 10 and 15 in the city of Leipzig, Germany (LIFE Child cohort). Caries levels and gingival health status for the upper-right and the lower-left central incisors were assessed by evaluating ICDAS scores and CPI scores, respectively. A standardised questionnaire was used to assess self-reported mouth-breathing habit and halitosis. Results This study showed a statistically significant association between halitosis and mouth breathing (OR=3.0; 95% CI: 1.5-6.2), and a significant increase in mouth breathing habit in males compared to females (59.7% vs. 40.3%; p<0.05). There were no statistically significant differences in ICDAS scores, orthodontic treatment, CPI scores, or socioeconomic status between the mouth and nasal-breathing groups. Conclusion Mouth breathing habit has no effect on the prevalence of caries or gingivitis based on examining the upper-right central incisor (11) and the lower-left central incisor. However, mouth breathers showed a significant increase in halitosis compared to nasal-breathing individuals.

The objective of the present study was to give a detailed overview on the leisure behavior of adolescents (frequency, differences between gender, age groups and social class, time trends, and inter-relations). In total, 1449 10- to 18-year-old German adolescents were included in the study. Participants answered questionnaires about their media use, physical activity, outdoor time, engagement in choir/orchestra and theater/dancing, social life and socio-economic status (SES). The results revealed that girls, children with lower SES as well as older children reported to use screen-based media more often and that girls, older children and children with lower SES were less physically active. In addition, boys and children with lower SES engaged less frequently in choir/orchestra and theater/dancing, while children with higher SES met their friends more often. The time trend analysis showed that mobile phone use increased drastically from 2011 to 2017, while engagement in choir/orchestra and theater/dancing decreased. Regarding the inter-relation between leisure activities, high screen times were significantly associated with less physical activity and less outdoor time. Physical activity, in contrast, was significantly related to better social life and more outdoor time. These findings highlight the growing importance of electronic media in adolescents' lives and their tendency to displace other leisure activities.

Background: Skinfold thickness (ST), waist circumference (WC) and hip circumference (HC) measurements are simple methods for assessing fat tissue at defined body parts. We examined these parameters in a cohort of healthy children and adolescents in Leipzig. Our study provides current percentile curves for biceps, triceps, subscapular and iliac crest ST, plus WC, HC, waist-to-hip ratio and waist-to-height ratio. Methods: 6,344 visits were recorded involving 2,363 individuals from 3 to 16 years in age. Continuous age- and gender-related percentiles (3rd, 10th, median, 90th, 97th percentiles) were estimated using Cole’s LMS method. Results: For biceps and triceps ST, boys show a peak at the beginning of adolescence with a subsequent decrease, while percentile values among girls rise across the age range. Subscapular and iliac crest percentiles also show increasing curves with disproportionately high values for P90 and P97. Boys show higher values of WC, girls have higher levels of HC. WC and HC median percentiles constantly increase in both sexes with a plateau at the age of 16 for girls. Conclusion: Trends for all parameters of body fat are in line with other national and international studies. Unlike the KiGGS study, our study provides circumference data across the whole of our age range, i.e. from 3 to 16 years.

OBJECTIVE:This study investigated reciprocal longitudinal associations between media use/physical activity and adolescents' psychological health.METHODS:Data were collected between 2011 and 2017 in the LIFE Child study in Germany. The sample included 814 10- to 17-year-old adolescents. The participants provided information on their media use per day (hours of television/video, computer/Internet, and mobile phone use), physical activity (frequency of organized and non-organized physical activity per week), behavioral difficulties (emotional problems, conduct problems, hyperactivity/inattention, peer relationship problems), and quality of life (physical and psychological well-being; satisfaction with parents, peers, and school) at 2 time points 12 months apart. Multiple regressions were applied to analyze reciprocal longitudinal associations between media use/physical activity and behavioral difficulties/quality of life.RESULTS:Frequent use of computers/Internet at baseline was associated with an increase in internalizing behavioral difficulties (emotional problems and peer relationship problems) at follow-up. Additionally, a high frequency of computer/Internet and mobile phone use was related to a decrease in psychological well-being, whereas a high frequency of organized physical activity was linked to improved physical well-being. The analyses also revealed a link between more behavioral difficulties at baseline and increased television consumption at follow-up.CONCLUSION:This study suggests mutual dependencies between electronic media use and psychological health over time.