Changes in the prevalence of obesity in Czech adolescents between 2018 and 2022 and its current non-genetic correlates - HBSC study.

BACKGROUND: The main aim of the study is to examine changes in the prevalence of obesity in Czech adolescents between 2018 and 2022 and its current non-genetic correlates with respect to the adolescents' families'socioeconomic status (SES) in 2022. METHODS: The sample of 24,535 adolescents (n = 11,629/12,9062018/2022; boys: 50.4/50.6%2018/2022) aged 10.5-16.5 years that was analysed was drawn from two nationally representative cohorts of Czech youngsters from the last two cycles of the Health Behaviour in School-aged Children (HBSC) online questionnaire survey from 2018 to 2022. Obesity is represented by the > 97th percentile interval on the World Health Organization Body Mass Index percentile chart, with distinctions by sex and the age of adolescents. The differences in the prevalence of obesity between boys and girls from all SES family categories in 2018 and 2022 were tested using a chi-square test (χ2). Multiple logistic regression analysis with repeated measures was used to analyse correlates of obesity in 2022. RESULTS: Between 2018 and 2022, there was no significant difference in the prevalence of obesity in girls or boys in any of the SES categories of families. Adolescents from low-SES families have the highest prevalence of obesity, 11% for boys and 5.8% for girls, significantly higher (p < .001) than its prevalence among adolescents from high-SES families, by + 4.8% points for boys and + 3.9% points for girls. Among adolescents from low-SES families, individuals who engaged in moderate-to-vigorous physical activity (PA) daily (p < .005) or vigorous PA three times per week (p < .05) were significantly less likely to be obese than their less active peers. Skipping breakfast significantly (p < .05) increased the odds of obesity, but only among adolescents from low-SES families. Shorter screen time (ST) significantly (p < .05) reduced the odds of obesity for all categories of adolescent SES. CONCLUSIONS: Obesity is most pronounced in adolescents from low-SES families as a result of a long-term positive energy balance mediated by unbalanced behaviour. Significantly lower odds of obesity in adolescents from low-SES families were confirmed to be associated with regular practice of the recommended PA, shorter ST, and not skipping breakfast.

Long-term trends in the consumption of sugary and diet soft drinks among adolescents: a cross-national survey in 21 European countries.

PURPOSE: To assess country-level trends in the prevalence of daily consumption of sugary (2002-2018) and diet (2006-2018) soft drinks among European adolescents, overall and by family material affluence. METHODS: We used 2002, 2006, 2010, 2014 and 2018 data from the 'Health Behaviour in School-aged Children' survey. Nationally representative samples of adolescents completed a standardised questionnaire at school, including a short food frequency questionnaire (n = 530,976 and 21 countries for sugary soft drinks; n = 61,487 and 4 countries for diet soft drinks). We classified adolescents into three socioeconomic categories for each country and survey year, using the Family Affluence Scale. Multilevel logistic models estimated time trends, by country. RESULTS: Sugary soft drinks: the prevalence of daily consumption (≥ 1×/day) declined in 21/21 countries (Plinear trends ≤ 0.002). Absolute [range - 31.7 to - 3.4% points] and relative [range - 84.8 to - 22.3%] reductions varied considerably across countries, with the largest declines in Ireland, England and Norway. In 3/21 countries, the prevalence of daily consumption decreased more strongly in the most affluent adolescents than in the least affluent ones (P ≤ 0.002). Daily consumption was more prevalent among the least affluent adolescents in 11/21 countries in 2018 (P ≤ 0.002). Diet soft drinks: overall, daily consumption decreased over time in 4/4 countries (Plinear trends ≤ 0.002), more largely among the most affluent adolescents in 1/4 country (P ≤ 0.002). CONCLUSIONS: Daily consumption of sugary and diet soft drinks in European adolescents decreased between 2002 (2006 for diet drinks) and 2018. Public health interventions should continue discouraging daily soft drink consumption, particularly among adolescents from lower socioeconomic groups.

Establishment of PANDA - a new human pancreatic ductal adenocarcinoma cell line with 3D cell culture technology.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive type of malignancy with one of the worst prognoses amongst any type of cancer. Surgery is applicable only to the limited number of patients with locally resectable tumors and currently represents the only curative treatment option. Treatment with chemotherapy and radiotherapy can only extend patient survival. Despite advances in conventional therapies, the five-year survival of PDAC remained largely unchanged. New in vitro and in vivo models are therefore urgently needed to investigate this type of cancer. Here, we present the establishment and characterization of a novel pancreatic cancer cell line, isolated from a patient with PDAC. Cell line abbreviated as PANDA (PANncreatic Ductal Adenocarcinoma) was established with an optimized 3D culture protocol published previously by our group. The new cancer cell line "PANDA" represents a novel in vitro approach for PDAC cancer research and new therapy testing.

Detection of therapeutically relevant and concomitant rare somatic variants in colorectal cancer.

In colorectal cancer (CRC), clinically relevant biomarkers are known for genome-guided therapy that can be detected by both first and next generation methods. The aim of our work was to introduce a robust NGS assay that will be able to detect, in addition to standard predictive single nucleotide-based biomarkers, even rare and concomitant clinically relevant variants. Another aim was to identify truncating mutations in APC and pathogenic variants in TP53 to divide patients into potentially prognostic groups. A multigene panel with hotspots in 50 cancer-critical genes was used. Finally, 86 patients diagnosed with primary or metastatic colorectal cancer were enrolled. In total, there were identified 163 pathogenic variants, among them in the genes most recurrent mutated in CRC such as TP53 (49%), the RAS family genes KRAS and NRAS (47%), APC (43%), and PIK3CA (15%). In 30 samples, two driver mutations were present in one sample, 11 patients were without any mutations covered by this panel. In one patient, a novel variant in BRAF p.D594E was found, not previously seen in CRC, and was concomitant with KRAS p.G12A. In KRAS, a potentially sensitive mutation to anti-EGFR therapy p.A59T was found along with the PIK3CA missense variant p.E545K. It was possible to divide patients into groups based on the occurrence of truncating APC variant alone or concomitant with TP53 or KRAS. Our results demonstrate the potential of small multigene panels that can be used in diagnostics for the detection of rare therapeutically relevant variants. Moreover, the division of patients into groups based on the presence of APC and TP53 mutations enables this panel to be used in retrospective studies on the effectiveness of treatment with anti-EGFR inhibitors.

Cross-national time trends in adolescent alcohol use from 2002 to 2014.

BACKGROUND: Adolescent alcohol consumption is a major public health concern that should be continuously monitored. This study aims (i) to analyze country-level trends in weekly alcohol consumption, drunkenness and early initiation in alcohol consumption and drunkenness among 15-year-old adolescents from 39 countries and regions across Europe and North America between 2002 and 2014 and (ii) to examine the geographical patterns in adolescent alcohol-related behaviours. METHODS: The sample was composed of 250 161 adolescents aged 15 from 39 countries and regions from Europe and North America. Survey years were 2002, 2006, 2010 and 2014. The alcohol consumption and drunkenness items of the HBSC questionnaire were employed. Prevalence ratios and 95% confidence intervals were estimated using Poisson regression models with robust variance. RESULTS: Data show a general decrease in all four alcohol variables between 2002 and 2014 except for some countries. However, there is variability both within a country (depending on the alcohol-related behaviour under study) and across countries (in the beginning and shape of trends). Some countries have not reduced or even increased their levels in some variables. Although some particularities have persisted over time, there are no robust patterns by regions. CONCLUSIONS: Despite an overall decrease in adolescent alcohol consumption, special attention should be paid to those countries where declines are not present, or despite decreasing, rates are still high. Further research is needed to clarify factors associated with adolescent drinking, to better understand country specificities and to implement effective policies.

Time trends in adolescent mental wellbeing in the Czech Republic between 2002 and 2018: gender, age and socioeconomic differences.

OBJECTIVES: Recent literature indicates a decline over time in adolescent mental wellbeing but results are inconsistent and rely mainly on data from Western societies. This study investigates time trends in adolescent mental wellbeing (psychological and somatic complaints, life satisfaction) among Czech adolescents and explores the moderating role of gender, age and socioeconomic status. METHODS: Nationally representative data from 29,376 Czech adolescents (50.8% girls, mean age = 13.43; SD = 1.65) across five Health Behaviour in School-aged Children (HBSC) surveys (2002, 2006, 2010, 2014, 2018) were used. Hierarchical regression models estimated national trends in adolescent mental wellbeing and established the moderating role of gender, age and socioeconomic status. RESULTS: From 2002 to 2018, an increase in the psychological complaints was observed. Life satisfaction decreased over time up to 2014 only, whereas somatic symptoms increased until 2010, followed by a decline in 2014 and 2018. Girls, older adolescents and those from low family affluence reported poorer mental wellbeing. Gender gap increased over time for psychological complaints and life satisfaction. Socioeconomic inequalities gap remained stable over the investigated timeframe. CONCLUSIONS: Our findings do not provide evidence for substantial temporal changes in mental wellbeing among adolescents in the Czech Republic. Yet, the increase in psychological complaints has been consistent which is an indicator of a small decline over time in adolescent mental wellbeing. Furthermore, the gender gap in mental wellbeing increased over time, whereas the age and socioeconomic differences remained relatively stable. This calls for the attention of public health professionals and policy makers from the Czech Republic.

Time-trends and correlates of obesity in Czech adolescents in relation to family socioeconomic status over a 16-year study period (2002-2018).

BACKGROUND: The main objective of the study is to analyse the changes in the prevalence of obesity among Czech adolescents between 2002 and 2018 with regard to the socioeconomic status (SES) of adolescents' families and to find SES-separated correlates of adolescents' obesity in 2018. METHODS: A nationally representative sample of 29,879 adolescents (49.6% of them boys) aged 10.5-16.5 years was drawn from the Health Behaviour in School-aged Children cross-sectional, self-reported questionnaire surveys conducted in 2002, 2006, 2010, 2014, and 2018 in Czechia. Chi-square (χ2) tests were performed to assess the changes in the prevalence of obesity in both genders and all SES categories of adolescents between 2002 and 2018, and SES category-related differences in the prevalence of obesity in 2018 separately for boys and girls. A series of multiple stepwise logistic regression (backward elimination) analyses were used to reveal obesity correlates separately for SES categories of adolescents. RESULTS: Across the quadrennial surveys from 2002 to 2018, we observed a clear increase in the prevalence of obesity in all SES categories of adolescents, which was most striking (p < 0.05) in adolescents with low SES (boys: + 7.5% points (p.p.); girls + 2.4 p.p.). When all the survey cycles were compared, the highest prevalence of obesity was evident in the low-SES adolescents in 2018, both in girls (5.1%) and boys (12.0%). Regardless of the adolescent SES category, the lower odds of obesity were significantly (p < 0.05) associated with regular vigorous physical activity (PA), participation in organized sport, and daily consumption of sweets. In addition, at least 60 min of moderate-to-vigorous PA significantly reduced the odds of obesity in adolescents of low and high SES categories. CONCLUSIONS: An unreasonable increase in the prevalence of obesity in adolescents with low SES highlights the need to prevent obesity in adolescents with a low-SES background. Additionally, significantly higher odds of obesity in 11- and 13-year-old adolescents from low-SES families, compared with their peers aged 15, indicated an expectable rise in obesity in older low-SES adolescents in the near future.

Pathway Analysis of Selected Circulating miRNAs in Plasma of Breast Cancer Patients: A Preliminary Study.

MicroRNAs in the circulation of breast cancer (BC) patients have great potential for the early diagnosis, treatment and monitoring of breast cancer. The aim of this preliminary study was to obtain the expression profile of selected miRNAs in the plasma of BC patients that could discriminate BC patients from healthy volunteers and may be useful in early detection of BC. Significantly deregulated miRNAs were evaluated by pathway analysis with the prediction of potential miRNA targets. The study enrolled plasma samples from 65 BC patients and 34 healthy volunteers. Selected miRNAs were screened in pilot testing by the real-time PCR (qPCR) method, and the most appropriate reference genes were selected for normalisation by the geNorm algorithm. In the final testing, we detected miR-99a, miR-130a, miR-484 and miR-1260a (p < 0.05) as significantly up-regulated in the plasma of BC patients. Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis revealed that all significantly deregulated miRNAs are involved in the Hippo and Transforming Growth Factor-beta (TGF-beta) signalling pathways. Our study confirmed a different profile of selected circulating miRNAs in the plasma of BC patients with an emphasis on some critical points in the analysis process.

Trends and correlates of overweight/obesity in Czech adolescents in relation to family socioeconomic status over a 12-year study period (2002-2014).

BACKGROUND: This study examined a) trends in overweight/obesity, moderate-to-vigorous physical activity (MVPA), and screen time (ST) among Czech adolescents over a 12-year study period (2002-2014) in relation to family affluence (FA) and b) correlates of adolescent overweight/obesity from different FA categories. METHODS: A nationally representative sample of 18,250 adolescents (51.4% girls) aged 10.5-16.5 years was drawn from the Czech Health Behaviour in School-aged Children questionnaire-based surveys in 2002, 2006, 2010, and 2014. Using the FA scale, the socioeconomic status (SES) of the respondents' families was assessed. SES-stratified trends in the prevalence of overweight/obesity meeting the MVPA (≥60 min/day), and ST (≤2 h/day) recommendations were assessed using logistic regression. RESULTS: A trend-related significant increase (p < 0.05) in the prevalence of overweight/obesity was observed in low-/medium-FA boys and medium-/high-FA girls. Unlike in high-FA adolescents, a significant decrease was revealed in the rates of meeting the MVPA recommendation in low-FA boys (28.9%2002 → 23.3%2014, OR = 0.75, 95% CI = 0.59-0.95, p < 0.05) and girls (22.3%2002 → 17.3%2014, OR = 0.73, 95% CI = 0.57-0.92, p < 0.01). A significant (p < 0.001) trend-related increase in excessive ST was evident in adolescents regardless of gender and FA category. Generally, girls and older adolescents had lower odds of overweight/obesity than boys and 11-year-old adolescents. While in the high-FA category of adolescents, achieving 60 min of MVPA daily and the absence of excessive ST on weekdays significantly (p < 0.01) reduced their odds of being overweight/obese, in low-FA adolescents this was not the case. CONCLUSIONS: High rates of overweight/obesity and a poor level of daily MVPA among low-FA children provide disturbing evidence highlighting the necessity of public health efforts to implement obesity reduction interventions for this disadvantaged population.

Next Generation Sequencing in Molecular Diagnosis of Lynch Syndrome - a Pilot Study Using New Stratification Criteria.

The development of the new technologies such as the next-generation sequencing (NGS) makes more accessible the diagnosis of genetically heterogeneous diseases such as Lynch syndrome (LS). LS is one of the most common hereditary form of colorectal cancer. This autosomal dominant inherited disorder is caused by deleterious germline mutations in one of the mismatch repair (MMR) genes - MLH1, MSH2, MSH6 or PMS2, or the deletion in the EPCAM gene. These mutations eventually result in microsatellite instability (MSI), which can be easily tested in tumor tissue. According to the actual recommendations, all patients with CRC that are suspect to have LS, should be offered the MSI testing. When the MSI is positive, these patients should be recommended to genetic counseling. Here we report a pilot study about the application of NGS in the LS diagnosis in patients considered to have sporadic colorectal cancer. The inclusion criteria for the NGS testing were MSI positivity, BRAF V600E and MHL1 methylation negativity. We have used 5 gene amplicon based massive parallel sequencing on MiSeq platform. In one patient, we have identified a new pathogenic mutation in the exon 4 of the MSH6 gene that was previously not described in ClinVar, Human Gene Mutation Database, Ensembl and InSight databases. This mutation was confirmed by the Sanger method. We have shown that the implementation of new criteria for colorectal patients screening are important in clinical praxis and the NGS gene panel testing is suitable for routine laboratory settings.

Association of single nucleotide polymorphisms in FGF-RAS/MAP signalling cascade with breast cancer susceptibility.

The fibroblast growth factor receptors (FGFRs) and Ras/mitogen activated protein (RAS/MAP) signalling cascades are the main molecular pathways involved in breast carcinogenesis. This study aims to determine the association between FGF10 (rs4415084 C>T), FGFR2 (rs2981582 C>T) and MAP3K1 (rs889312 A>C) gene polymorphisms and breast cancer, to analyse the discriminative ability of each SNP and to test the accuracy of the predictive breast cancer risk model which includes all SNPs. We conducted a case-control study of 170 women (57.06 ± 11.60 years) with histologically confirmed breast cancer and 146 controls (50.24 ± 10.69 years). High resolution melting (HRM) method with Sanger sequencing validation was used in analyses. We have revealed significant association of FGFR2 and MAP3K1 polymorphisms with breast cancer. The odds ratio of FGFR2 T allele was 1.897 (95% CI 1.231-2.936, p = 0.004) and MAP3K1 C allele 1.804 (95% CI 1.151-2.845, p = 0.012). FGFR2 polymorphism achieved the best discriminative ability (41.95%). The Random Forest algorithm selected FGFR2, MAP3K1 and age as important breast cancer predictors. The accuracy of this prediction model approached moderate accuracy (70%), with 35.9% sensitivity and 88.6% specificity.

Trends in Health Behaviour in Czech School-aged Children: HBSC Study. Preface.

The Health Behaviour in School-aged Children (HBSC) study is now in its 34th year. It continues to grow not only as a source of reliable and valid data on the health behaviours of 11-, 13- and 15-year-olds, but also regarding its membership - 46 countries and regions across Europe and North America are now included. The HBSC study is a cohort cross-sectional questionnaire-based study focusing on health and health-related behaviours in adolescents in the context of their social environment. This age was selected because of the significant cognitive, psychological, and biological processes taking place in this period of the lifespan, as well as because of the fact that health-related behaviours adopted at this age are known to persist into adulthood. The findings from the HBSC study are used to monitor health, well-being, and health-related behaviours in school-aged children; deepen the understanding of the social determinants of health; and provide evidence-based data for policy makers and practitioners aiming to improve the lives of young people.

National Time Trends in Bullying among Adolescents in the Czech Republic from 1994 to 2014.

OBJECTIVE: Bullying in school is a public health concern which continues to be a serious threat to physical and emotional health of children and adolescents. The purpose of this study is to examine trends in bullying behaviour among school-aged children in the Czech Republic. METHODS: Data were obtained from cross-sectional self-report surveys in the years 1994-2014 as a part of the Health Behaviour in School-aged Children study (HBSC) from a representative sample of 11-, 13-, and 15-year olds. RESULTS: The highest proportion of children who bullied others (20-47%) occurred during the years 1994 and 1998. The logistic regression models showed significant decreasing trends in bullying others and also in being bullied, regardless of age and gender. CONCLUSION: The decreasing trend in bullying may be the consequence of a preventive policy in the Czech Republic, but also a change in the understanding of the concept of bullying in society.

Methodological Aspects of Trend Studies and Development of the HBSC Study in the Czech Republic.

The aim of the study is to present the theoretical background of trend studies in general, to characterize the international Health Behaviour in School-aged Children (HBSC) study and to describe its methodology and changes of the Czech HBSC study between 1994 and 2014. The first part describes various types of trend research studies including their advantages and disadvantages. The second part summarizes the history of the HBSC study in an international context and particularly in the Czech Republic. The final part presents the basic methodological data from six surveys conducted in the Czech Republic between 1994 and 2014.

Trends in Overweight and Obesity in Czech Schoolchildren from 1998 to 2014.

OBJECTIVE: Overweight and obesity in adolescents is associated with many health risks and considerable direct and indirect healthcare costs. The purpose of this study is to examine trends in the prevalence of overweight and obesity in 11-, 13- and 15-year-old adolescents in the Czech Republic from 1998 to 2014. METHODS: Data from five self-reported survey rounds (1998, 2002, 2006, 2010, and 2014) of the Health Behaviour in School-aged Children Study (HBSC) were used to assess trends in overweight and obesity among Czech adolescents. The total sample consisted of 19,103 adolescents (51.2% girls). A logistic regression analysis was used to assess trends in different age and gender categories. RESULTS: From 1998 to 2014 a significant increase in the prevalence of overweight and obesity was observed among boys in all age categories (11 years old 22.2%1998- 28.3%2014; 13 years old 17.9%1998- 26.7%2014; 15 years old 9.8%1998- 20.8%2014) and among 15-year-old girls (6.0%1998- 10.9%2014). None of the age and gender categories showed an overall decrease over the 16-year period. In boys, the prevalence of overweight was significantly higher with steeper negative trends compared with girls. However, stabilization in overweight rates was observed between 2010 and 2014 in all age and gender groups. CONCLUSION: Nationally representative self-reported data show a significant increase in overweight (including obesity) prevalence among children from 1998 to 2014 in the Czech Republic. The results also suggest stabilization in overweight prevalence between 2010 and 2014. Continuing research is needed to determine future trends while interventions aimed at reducing overweight and obesity in children should be implemented on different levels of public policy.

Trends in Life Satisfaction and Self-rated Health in Czech School-aged Children: HBSC Study.

OBJECTIVE: The aim of the study is to examine cross-sectional time trends of life satisfaction and self-rated health in a representative sample of Czech children aged 11, 13 and 15 years using the Health Behaviour in School-aged Children (HBSC) study data from the Czech Republic. METHODS: Data from survey years 2002, 2006, 2010 and 2014 was used. The sample consisted of 16,357 participants (48.5% of boys). Life satisfaction (LS) was measured by Cantril's ladder; self-rated health was measured through the simple item "Would you say your health is: excellent, good, fair, poor". RESULTS: Most of the children were satisfied with their lives in all surveyed years (mean LS scores range from 7.21 to 7.51; maximum 10). LS was consistently significantly associated (p<0.001) with age and gender. Overall, children and adolescents in the Czech Republic also reported good health. In total, 87.6% of respondents from all samples reported their health as excellent or good. Gender was found to be significantly associated with self-rated health (p<0.05) in all surveyed years. CONCLUSIONS: No permanent trends in both followed indicators have been seen in the examined period.

Experience of Czech Children with Alcohol Consumption in Relation to Selected Family Indicators.

OBJECTIVE: The aim of this study is to monitor and analyze the influence of chosen family indicators related to alcohol consumption and experience of drunkenness in a representative sample of Czech children. METHODS: Data for our work were obtained from the Health Behaviour in School Aged Children (HBSC) study - a World Health Organization (WHO) cross national study. The sample consisted of 4,293 children aged 11, 13 and 15 years. Data collection was conducted in June 2010 in 88 randomly selected schools in the Czech Republic using standardized questionnaires. Statistical analysis was performed in the program NCSS 9, methods of descriptive statistics, χ2 test of independence in the contingency tables and logistic regression analysis were used. RESULTS: Regular alcohol consumption (at least weekly) was reported by 7.4% of children aged eleven, 19.3% of children aged thirteen and 38.4% of children aged fifteen years. Drunkenness at least twice in their life was admitted by 3% of children aged eleven, 15% of children aged thirteen and 43% of children aged fifteen years. Both alcohol consumption and drunkenness were significantly associated (p<0.001) with age and gender. Formal structure of family was found to have significant effect on the experience of drunkenness, but no effect on alcohol consumption was recorded. Based on our results, neither the amount of time spent together, nor the children communication with parents had a statistically significant influence on alcohol consumption or drunkenness experience within each family type. However, statistically significant differences were observed between different family types (p<0.001). CONCLUSIONS: These findings indicate a high degree of liberalism of Czech society towards alcohol. It appears that alcohol consumption will remain a serious problem in Czech society, therefore, more attention should be paid to this phenomenon in the future.

Trends in Screen Time Behaviours in Czech Schoolchildren between 2002 and 2014: HBSC Study.

OBJECTIVE: Screen-based behaviours such as watching television or computer use are among the most prevalent sedentary behaviours adolescents spend time on. There is a lack of recent estimates on prevalence and changes in the amount of time spent on screen-based behaviour across Central and Eastern Europe. The main aim is to assess the trends in the prevalence of current recommendations for the screen time (≤2 hours per day) of school-aged children in the Czech Republic between 2002 and 2014. METHODS: We used an internationally established methodology based on the Health Behaviour in School-aged Children (HSBC) study. Data was derived from Czech national representative samples of 11-, 13- and 15-year-olds collected in the years 2002 (N=4,065), 2006 (N=4,170), 2010 (N=3,962) and 2014 (N=4,338). RESULTS: The results indicated that the boys and girl surveyed in 2014 are up to two times more likely to meet the current recommendations for watching television in comparison with groups of schoolchildren of the same age surveyed in 2002. In contrast, computer use by adolescents increased markedly between 2006 and 2014. Taking total screen time into account, spending two hours per day or less on it decreased significantly among boys (OR=0.74, 95% CI=0.62-0.89) and girls (OR=0.80, 95% CI=0.70-0.92) between 2006 and 2014. CONCLUSIONS: As screen time is an important indicator of time spent in a sedentary way, our findings call for more interventions to reduce the time that school-aged children spend in front of screens.

Trends in Active Commuting to School among Czech Schoolchildren from 2006 to 2014.

OBJECTIVE: Active commuting (AC) is an important factor in increasing the total daily physical activity (PA) in children, which is significant for their health and positive physical behaviour in adulthood. The objective of the study was to describe trends in active commuting to school among Czech girls and boys aged 11-15 years from 2006 to 2014, using data from the Health Behaviour in School-aged Children (HBSC) study. METHODS: To investigate trends in AC among Czech children of school age data obtained from the HBSC surveys carried out in 2006, 2010, and 2014 was used. The study sample comprised 12,273 respondents, out of whom 5,992 (48.8%) were boys and 6,281 (51.2%) girls. The overall trends in AC were evaluated using logistic regression analysis. RESULTS: Compared with 2006, there was an overall decrease in AC among the 13-year-old boys and 13-year-old girls (boys - 1.8% in 2006 to 50.1% in 2014, girls - 69.3% in 2006 to 46.3% in 2014). The proportion of children AC (walking and cycling) to school significantly decreased from 74.3% in 2006 to 53.4% in 2014. CONCLUSION: This study demonstrated that AC to school decreased sharply among Czech children of school age from 2006 to 2014. However, walking was the most frequently used mode of travel. The boys were significantly more likely to cycle to school compared to the girls. PA interventions for youth should encourage participation in AC to school in the Czech Republic.

Trends in Lifetime Cannabis Use among Czech School-aged Children from 2002 to 2014.

OBJECTIVE: The aim of the study was to examine trends in the prevalence of lifetime cannabis use among the Czech 15-year old students. METHODS: Data from the nationally representative Health Behaviour in School-aged Children Survey, conducted in the Czech Republic in 2002, 2006, 2010 and 2014, were used. Trends in cannabis use among both boys and girls were modelled through binary logistic regression with period as a predictor of the lifetime cannabis use. RESULTS: The prevalence of lifetime cannabis use has significantly decreased among young Czechs, particularly among boys. Gender differences in cannabis use have been also gradually decreasing since 2002, with no significant differences between genders in recent period. CONCLUSIONS: Although there are positive changes in the prevalence of adolescent cannabis use, from the European perspective, Czech students still belong to those with significantly higher rates in this respect. Thus, alongside with the use of other substances, adolescent cannabis consumption remains an important challenge for the national public health policy.