Trends in adolescent psychosomatic complaints: a quantile regression analysis of Swedish HBSC data 1985-2017.

BACKGROUND AND AIMS: According to recent criticism, survey-based measures of adolescent psychosomatic complaints have poor content validity insofar as they conflate trivial with severe complaints. It is argued that this means that estimates of prevalence and trends in complaints may reflect trivial complaints that are not indicators of health problems. In this study, two observable implications of this criticism were investigated: (a) that self-reported psychosomatic complaints should have a bimodal distribution; and (b) that the increase in complaints over time should be of approximately equal size throughout the distribution of complaints. METHODS: Three decades (1985/1986-2017/2018) of repeated cross-sectional data from the Swedish Health Behaviour in School-aged Children survey were used. Psychosomatic complaints were measured using the screening instrument Health Behaviour in School-aged Children symptom checklist. Histograms, bar charts and quantile regression models were used for the analysis. RESULTS AND CONCLUSIONS: With regard to the first implication, the results showed that the distribution of complaints was not bimodal and that there were no clusters of respondents. This suggests that binary categorisations of students can be reductive and conceal important variations across students. With regard to the second implication, the results showed that the increase in complaints was greatest among students who report frequent and co-occurring complaints. This suggests that reports of increasing complaints in adolescents cannot be explained as being primarily due to a greater inclination to report trivial complaints. It is concluded that any conflation of trivial and more severe complaints in surveys of psychosomatic complaints is not reflected in population-based estimates.

Feasibility, reliability and validity of the health-related quality of life instrument Child Health Utility 9D (CHU9D) among school-aged children and adolescents in Sweden.

BACKGROUND: This study was conducted in a general population of schoolchildren in Sweden, with the aim to assess the psychometric properties of a generic preference-based health related quality of life (HRQoL) instrument, the Swedish Child Health Utility 9D (CHU9D), among schoolchildren aged 7-15 years, and in subgroups aged 7-9, 10-12 and 13-15 years. METHODS: In total, 486 school aged children, aged 7-15 years, completed a questionnaire including the CHU9D, the Pediatric quality of life inventory 4.0 (PedsQL), KIDSCREEN-10, questions on general health, long-term illness, and sociodemographic characteristics. Psychometric testing was undertaken of feasibility, internal consistency reliability, test-retest reliability, construct validity, factorial validity, concurrent validity, convergent validity and divergent validity. RESULTS: The CHU9D evidenced very few missing values, minimal ceiling, and no floor effects. The instrument achieved satisfactory internal consistency (Cronbach's Alfa > 0.7) and strong test-retest reliability (r > 0.6). Confirmatory factor analyses supported the proposed one-factor structure of the CHU9D. For child algorithm, RMSEA = 0.05, CFI = 0.95, TLI = 0.94, and SRMR = 0.04. For adult algorithm RMSEA = 0.04, CFI = 0.96, TLI = 0.95, and SRMR = 0.04. The CHU9D utility value correlated moderately or strongly with KIDSCREEN-10 and PedsQL total scores (r > 0.5-0.7). The CHU9D discriminated as anticipated on health and on three of five sociodemographic characteristics (sex, age, and custody arrangement, but not socioeconomic status and ethnic origin). CONCLUSIONS: This study provides evidence that the Swedish CHU9D is a feasible, reliable and valid measure of preference-based HRQoL in children. The study furthermore suggests that the CHU9D is appropriate for use among children 7-15 years of age in the general population, as well as among subgroups aged 7- 9, 10-12 and 13-15 years.

Perceived problems with academic achievement in school-aged children with recurrent pain - a longitudinal study.

Aims: The overall aim was to explore the relationship between recurrent pain and perceived problems with academic achievement among boys and girls in middle and late elementary school. Methods: This 3-year follow-up study was based on data from the Study of Health in School-aged Children from Umeå (Sweden) and included children attending grade 6 in years 2003 and 2006, and a follow-up 3 years later in grade 9 (n = 1524, participation rate 90%). Results: Recurrent pain (head, stomach or back) at least doubled the odds of concurrent- and subsequent perceived problems with academic achievement. This applied for pain on a monthly and weekly basis, from single and multiple sites, and from each of the three studied pain sites. The odds increased with increasing pain frequency and number of pain sites. Problems with sleep, concentration or school absenteeism did not explain the association. Conclusions: Recurrent pain seems to be a potential predictor of perceived problems with academic achievement for school-aged children. This emphasises the importance of early identification and prevention of recurrent pain problems.

The Bidirectional Relationship Between Subjective Well-Being and Academic Achievement in Adolescence.

The well-being of young people in relation to their school performance has received increased attention in recent years. However, there is a lack of knowledge about the longitudinal and reciprocal relationship between adolescents' subjective well-being and their academic achievements. The current study examined the bidirectional relationship between subjective well-being and academic achievement across two timepoints (T1 and T2) during the course of mid to late adolescence, i.e., in school year 9 (age 15), and school years 11-12 (ages 17-18). The study also investigated variation in the association as a function of adolescent gender. Data on subjective well-being and teacher-assigned school grades of 723 adolescents (48.7% girls) residing in Sweden were analyzed by estimating a series of cross-lagged path models. The findings suggest gender differences in the relationship as no associations were found among boys. Support for a bidirectional relationship between the constructs was only found for girls. For girls, higher subjective well-being at T1 was associated with higher academic achievements at T2, while higher academic achievements at T1 was associated with lower subjective well-being at T2. These findings highlight that the subjective well-being of adolescent girls may be important for their ability to perform at school, but their academic achievements may also inflict negatively on their subjective well-being.

Health-Related Quality of Life in Children With Low Language or Congenital Hearing Loss, as Measured by the PedsQL and Health Utility Index Mark 3.

OBJECTIVES: To examine health-related quality of life (HRQoL) in young children with low language or congenital hearing loss and to explore the value of assessing HRQoL by concurrently administering 2 HRQoL instruments in populations of children. METHODS: Data were from 2 Australian community-based studies: Language for Learning (children with typical and low language at age 4 years, n = 1012) and the Statewide Comparison of Outcomes study (children with hearing loss, n = 108). HRQoL was measured using the parent-reported Health Utilities Index Mark 3 (HUI3) and the Pediatrics Quality of Life Inventory 4.0 (PedsQL) generic core scale. Agreement between the HRQoL instruments was assessed using intraclass correlation and Bland-Altman plots. RESULTS: Children with low language and with hearing loss had lower HRQoL than children with normal language; the worst HRQoL was experienced by children with both. The lower HRQoL was mainly due to impaired school functioning (PedsQL) and speech and cognition (HUI3). Children with hearing loss also had impaired physical and social functioning (PedsQL), vision, hearing, dexterity, and ambulation (HUI3). Correlations between instruments were poor to moderate, with low agreement. CONCLUSIONS: Children with low language and congenital hearing loss might benefit from interventions targeting overall health and well-being, not just their impairments. The HUI3 and PedsQL each seemed to provide unique information and thus may supplement each other in assessing HRQoL of young children, including those with low language or congenital hearing loss.

Recurrent Pain and Academic Achievement in School-Aged Children: A Systematic Review.

Recurrent pain and school failures are common problems in children visiting the school nurses office. The overall aim of the current study was to investigate the relationship between recurrent pain and academic achievement in school-aged children. Literature was searched in seven electronic databases and in relevant bibliographies. Study selection, data extraction, and study and evidence quality assessments were performed systematically with standardized tools. Twenty-one studies met the inclusion criteria and 13 verified an association between recurrent pain (headache, stomachache, and musculoskeletal pain) and negative academic achievement. Two longitudinal studies indicated a likely causal effect of pain on academic achievement. All studies had substantial methodological drawbacks and the overall quality of the evidence for the identified associations was low. Thus, children's lack of success in school may be partly attributed to recurrent pain problems. However, more high-quality studies are needed, including on the direction of the association and its moderators and mediators.

Preteen children's health related quality of life in Sweden: changes over time and disparities between different sociodemographic groups.

BACKGROUND: Assessing disparities in health-related quality of Life (HRQoL) is important as a part of health-related disparities in the society. The aim of this study was to explore HRQoL among 12-year-olds in Sweden in terms of differences between years 2005 and 2009 and disparities related to sociodemographic background. METHODS: During the school years 2005 and 2009, a total of 18,325 sixth grade students in Sweden were invited to a celiac disease screening study; 13,279 agreed to participate. Jointly with the celiac screening, the children answered a questionnaire that included EuroQol 5 Dimensions-youth (EQ-5D-Y) and their parents responded to separate questionnaires about their own and their child's country of birth, family structure, their employment status, occupation, and education. In total 11,009 child-parent questionnaires were collected. Logistic regression was used to study differences in HRQoL between 2005 and 2009, and between various sociodemographic subgroups. RESULTS: Compared with 2005, children in 2009 reported more pain (OR: 1.20, 95% CI: 1.1-1.3) and more mood problems (OR: 1.35, 95% CI: 1.2-1.5). In general, girls reported more pain and mood problems and had more disparities than boys. There were no significant differences based on parents' occupation, however, children of parents with low or medium education levels reported less "mood problems" than those of parents with high education levels (OR: 0.65, 95% CI: 0.46-0.92) and (OR: 0.84, 95% CI: 0.73-0.96), respectively. A slight variation was seen in HRQoL between children with different migration background. Girls living in small municipalities reported more pain (OR: 1.51, 95% CI: 1.14-2.01), and problems performing usual activities (OR: 3.77, 95% CI: 2.08-6.84), compared to girls living in large municipalities. In addition, children living with two parents had less mood problems than children living in other family constellations. CONCLUSION: More children reported pain and mood problems in 2009 compared with 2005. To study future trends, health outcomes among children in Sweden should continue to be reported periodically. More efforts should be invested to increase the awareness of health-related disparities as highlighted in this study especially for girls living in small municipalities and children of parents with high education level.

The interplay between national and parental unemployment in relation to adolescent life satisfaction in 27 countries: analyses of repeated cross-sectional school surveys.

BACKGROUND: Previous research shows that parental unemployment is associated with low life satisfaction in adolescents. It is unclear whether this translates to an association between national unemployment and adolescent life satisfaction, and whether such a contextual association is entirely explained by parental unemployment, or if it changes as a function thereof. For adults, associations have been shown between unemployment and mental health, including that national unemployment can affect mental health and life satisfaction of both the employed and the unemployed, but to different degrees. The aim of this paper is to analyse how national unemployment levels are related to adolescent life satisfaction, across countries as well as over time within a country, and to what extent and in what ways such an association depends on whether the individual's own parents are unemployed or not. METHODS: Repeated cross-sectional data on adolescents' (aged 11, 13 and 15 years, n = 386,402) life satisfaction and parental unemployment were collected in the Health Behaviour in School-aged Children (HBSC) survey, in 27 countries and 74 country-years, across 2001/02, 2005/06 and 2009/10 survey cycles. We linked this data to national harmonised unemployment rates provided by OECD and tested their associations using multilevel linear regression, including interaction terms between national and parental unemployment. RESULTS: Higher national unemployment rates were related to lower adolescent life satisfaction, cross-sectionally between countries but not over time within countries. The verified association was significant for adolescents with and without unemployed parents, but stronger so in adolescents with unemployed fathers or both parents unemployed. Having an unemployed father, mother och both parents was in itself related to lower life satisfaction. CONCLUSION: Living in a country with higher national unemployment seems to be related to lower adolescent life satisfaction, whether parents are unemployed or not, although stronger among adolescents where the father or both parents are unemployed. However, variation in unemployment over the years did not show an association with adolescent life satisfaction.

School experiences in relation to emotional and conduct problems in adolescence: a 3-year follow up study.

BACKGROUND: Mental health in adolescents has become a major public health issue. This study examined school experiences in relation to mental health (emotional problems and conduct problems) from early to middle adolescence. METHODS: This longitudinal 3-year follow up study used data from the Swedish Study of Health in School Children in Umeå. Analyses were conducted in 1379 participants that were attending grade six in 2003 or 2006 (age 12 years). KIDSCREEN-52 was used to assess school experiences and the Strengths and Difficulties Questionnaire for emotional and conduct problems. Statistical analyses included repeated measures ANOVA and multiple linear regressions. RESULTS: Positive school experiences decreased while emotional and conduct problem scores increased from grades six to nine. Positive school experiences were negatively associated with emotional and conduct problem scores and contributed to the explanation of mental health scores in middle adolescence after controlling for background factors. When baseline mental health problem scores were taken into account the association with early school experiences disappeared (except for conduct problems in boys). However, incorporating concurrent school experiences in the analysis increased the levels of explanation for emotional and conduct problem scores further. CONCLUSIONS: The results of this study confirm that school experiences are linked to emotional and conduct problems. That link may be stronger for conduct problems. In addition, the association of school experiences in early adolescence with later mental health may be overridden by concurrent school experiences in middle adolescence.

Bone turnover is altered in transgenic rats overexpressing the P2Y2 purinergic receptor.

It is now widely recognized that purinergic signaling plays an important role in the regulation of bone remodeling. One receptor subtype, which has been suggested to be involved in this regulation, is the P2Y2 receptor (P2Y2R). In the present study, we investigated the effect of P2Y2R overexpression on bone status and bone cell function using a transgenic rat. Three-month-old female transgenic Sprague Dawley rats overexpressing P2Y2R (P2Y2R-Tg) showed higher bone strength of the femoral neck. Histomorphometry showed increase in resorptive surfaces and reduction in mineralizing surfaces. Both mineral apposition rate and thickness of the endocortical osteoid layer were higher in the P2Y2R-Tg rats. µCT analysis showed reduced trabecular thickness and structural model index in P2Y2R-Tg rats. Femoral length was increased in the P2Y2R-Tg rats compared to Wt rats. In vitro, there was an increased formation of osteoclasts, but no change in total resorption in cultures from P2Y2R-Tg rats. The formation of mineralized nodules was significantly reduced in the osteoblastic cultures from P2Y2R-Tg rats. In conclusion, our study suggests that P2Y2R is involved in regulation of bone turnover, due to the effects on both osteoblasts and osteoclasts and that these effects might be relevant in the regulation of bone growth.

Mental problems and their socio-demographic determinants in young schoolchildren in Sweden, a country with high gender and income equality.

AIMS: Mental problems and their potential socio-demographic determinants were investigated in young schoolchildren in Sweden, a high-income country in the top of income- and gender-equality rankings. METHODS: Cross-sectional study of 1465 schoolchildren in grades 3 and 6. Mental health was measured by the Child Behavior Checklist and the Youth Self Report (Total problems and 14 specific problem areas). Potential socio-demographic determinants were sex, parental education and occupation, family structure, and immigrant status. RESULTS: Mental problems were present in 14% of the sixth graders and in 7% of the third graders. In grade 3, the mean total problem score was lower in girls than in boys, but the prevalence of problems at a subclinical/clinical level did not differ by sex. Furthermore, in nine to 13 of the 14 specific problem areas, problems were equally distributed by sex, parental education, parental occupation, immigrant status, and family structure. In grade 6, both the total mean score and the overall odds of subclinical/clinical problems were similar in girls and boys. Likewise, in all the specific problem areas, problems were evenly distributed by parental education and occupation, and only independently associated with immigrant status and family structure in one problem area. In five specific problem areas, boys had higher odds of problems than girls. CONCLUSIONS: This study shows that also in a relatively wealthy and equal country such as Sweden, mental problems are a significant child public health issue. The association between socio-demographic background and mental problems seems to be rather weak, but differ dependent on the type of mental problem in focus.

School experiences may be important determinants of mental health problems in middle childhood - a Swedish longitudinal population-based study.

AIM: Little is known about the association between school experiences and mental health in young schoolchildren. This study explored the cross-sectional and prospective associations between children's school experiences and mental health in middle childhood. METHODS: We gathered comprehensive population-based data on the school experiences and mental health of 592 schoolchildren attending grades three and six in Sweden (ages approximately nine and 12 years). The KIDSCREEN questionnaire was used to measure school experiences in both age groups while the Child Behavior Checklist and the Strengths and Difficulties Questionnaire measured mental health in grades three and six, respectively. RESULTS: Children with problematic school experiences in grade three had an approximately two times higher odds for concurrent total, internalised, externalised, attention-hyperactivity and social problems. They also had a 1.5-2.5 higher odds for these mental health problems three years later. Likewise, there was an association between problematic school experiences in grade three and lower levels of prosocial behaviour three years later. These associations were shown in both boys and girls, but were particularly pronounced in girls. CONCLUSION: This study indicated that school experiences in young schoolchildren may be important determinants of concurrent and later mental health problems.

Health-related quality of life in indigenous Sami schoolchildren in Sweden.

AIM: To investigate health-related quality of life (HRQOL) in indigenous Sami schoolchildren in Sweden and its associations with sex, age, enculturation and ethnicity-related negative treatment. METHODS: The study population was comprised of all children in grades 6-12 (ages 12-18 years) who attended specific Sami school programmes in Sweden. HRQOL was measured by the Kidscreen-52 self-report form, which was filled in at school (n = 121). RESULTS: The indigenous Sami children in Sweden experienced lower HRQOL than Swedish children in general, with regard to their school situation, financial resources, parents' relations, physical well-being and social support from peers. In Sami children, functioning and well-being generally decreased by older age group and girls reported lower physical well-being, more negative feelings and more negative self-perception than boys. Finally, more than half of the Sami children had experienced ethnicity-related negative treatment, and these children reported a robustly lower functioning and well-being compared with those without this experience. CONCLUSION: In some aspects of HRQOL, indigenous Sami schoolchildren with an explicit ethnic identity experienced less favourable functioning and well-being than Swedish children in general, which is worrisome. A high degree of ethnicity-related negative treatment may partly explain this lower HRQOL in Sami children.

Health-related quality of life is not impaired in children with undetected as well as diagnosed celiac disease: a large population based cross-sectional study.

BACKGROUND: Knowledge regarding the health-related quality of life (HRQoL) of children with celiac disease remains limited and inconclusive. We investigated the HRQoL of three groups of 12-year-olds with: i) undetected celiac disease ii) clinically diagnosed celiac disease, and iii) without celiac disease. METHODS: A school-based cross-sectional multicenter screening study invited 18 325 children, whereof 68% consented to participate. Participants provided a blood sample, which was later analyzed for anti-tissue-tranglutaminase antibodies, and alongside filled in a questionnaire. When anti-tissue-tranglutaminase antibodies were elevated, a small intestinal biopsy verified the screening-detected celiac disease diagnosis. Self-reported HRQoL was measured using Kidscreen, a generic 52 items instrument with proven reliability and validity. Scores were linearly transformed into a 0-100 scale with higher values indicating better HRQoL. Mean values with standard deviations (mean ± SD) were compared, and uni- and multivariate logistic regression models tested the odds of a low HRQoL among children with undetected or diagnosed celiac disease, respectively. RESULTS: Children with undetected celiac disease (n = 238) reported similar HRQoL as children without celiac disease (n = 12 037) (83.0 ± 11.0 vs. 82.5 ± 11.3, P = 0.51), and also similar HRQoL (82.2 ± 12.2, P = 0.28) to that of children with diagnosed celiac disease (n = 90), of whom 92% were adherent to treatment. Having undetected celiac disease did not increase the odds of low overall HRQoL, independent of sex, area of residence, study year and occurrence of gastrointestinal symptoms (adjusted odds ratio 0.77, 95% CI 0.54-1.10). Comparable results were seen for diagnosed celiac disease cases (adjusted odds ratio 1.11, 95% CI 0.67-1.85). CONCLUSION: Children with undetected celiac disease reported comparable HRQoL as their peers with diagnosed celiac disease, and those without celiac disease, when reporting prior to receiving the diagnosis through screening. Thus, children with celiac disease, both untreated and diagnosed, perceive their HRQoL as unimpaired by their disease.

Parental encouragement of healthy behaviors: adolescent weight status and health-related quality of life.

BACKGROUND: Obesity is a major health concern for adolescents, with one in four being overweight or obese in Australia. The purpose of this study was to examine the moderation effect of parental encouragement of healthy behaviors on the relationship between adolescent weight status and Health-Related Quality of Life (HRQoL). METHODS: Baseline data were collected from 3,040 adolescents participating in the It's Your Move project, conducted in the Barwon South-West region of Victoria, in 2005. The Paediatric Quality of Life Inventory was used to measure HRQoL, and parental encouragement was derived from purposely designed self-report items. Weight status was calculated according to World Health Organization growth standards from measured weight and height. Linear regression analyses modeled direct relationships and interaction terms. Analyses were adjusted for age, sex, physical activity level, nutrition and school attended. RESULTS: Higher levels of parental encouragement, as compared to low encouragement, were positively associated with higher global HRQoL scores, particularly in the physical functioning domain. To a lesser degree, high parental encouragement was also associated with higher scores on the psychosocial domain. Obese weight status showed a significant association with lower HRQoL on all scales. Parental encouragement significantly moderated the inverse relationship between overweight status and physical wellbeing. CONCLUSIONS: Findings suggest that parental encouragement of healthy behavior is associated with increased HRQoL scores for adolescents. Whilst more research is needed to validate the significant interaction effect, main effects suggest that parental encouragement of healthy behavior is an important factor in adolescent wellbeing and should be considered when developing prevention and clinical interventions for obesity.

Association of P2Y(2) receptor SNPs with bone mineral density and osteoporosis risk in a cohort of Dutch fracture patients.

The P2Y(2) receptor is a G-protein-coupled receptor with adenosine 5'-triphosphate (and UTP) as natural ligands. It is thought to be involved in bone physiology in an anti-osteogenic manner. As several non-synonymous single nucleotide polymorphisms (SNPs) have been identified within the P2Y(2) receptor gene in humans, we examined associations between genetic variations in the P2Y(2) receptor gene and bone mineral density (BMD) (i.e., osteoporosis risk), in a cohort of fracture patients. Six hundred and ninety women and 231 men aged ≥50 years, visiting an osteoporosis outpatient clinic at Maastricht University Medical Centre for standard medical follow-up after a recent fracture, were genotyped for three non-synonymous P2Y(2) receptor gene SNPs. BMD was measured at three locations (total hip, lumbar spine, and femoral neck) using dual-energy X-ray absorptiometry. Differences in BMD between different genotypes were tested using analysis of covariance. In women, BMD values at all sites were significantly different between the genotypes for the Leu46Pro polymorphism, with women homozygous for the variant allele showing the highest BMD values (0.05 > p > 0.01). The Arg312Ser and Arg334Cys polymorphisms showed no differences in BMD values between the different genotypes. This is the first report that describes the association between the Leu46Pro polymorphism of the human P2Y(2) receptor and the risk of osteoporosis.

Recurrent pain in school-aged children: a longitudinal study focusing on the relation to academic achievement.

ABSTRACT: Recurrent pain is an increasing public health problem among school-aged children, with potential negative impact on children's daily lives, such as schoolwork. The overall aim of this study was to investigate whether recurrent pain in school year 6 was associated with poorer academic achievement at the end of elementary school in school year 9. The study was a follow-up study based on data from " The Study of Health in School-Aged Children from Umeå". Participants were 1567 children aged 12 to 13 years who attended school year 6. A follow-up was performed in school year 9, when the children were 16 years old. The children answered a questionnaire about recurrent pain (headache, stomachache, and backache). Information about academic achievement was collected from school registers. The results showed that having weekly recurrent pain in school year 6 predicted lower final overall grade points in school year 9 than in children with no recurrent pain. This applied for recurrent headache, stomachache, backache, and multiple pains and for both girls and boys. Recurrent pain did not predict secondary school eligibility, however. Perceived problems with academic achievement and problems with concentration partly mediated the association between recurrent pain and lower final overall grade points. Sleep problems were not associated with academic achievement and were therefore not a mediator. Thus, the results suggest that recurrent pain may predict later impairment of academic achievement and that problems with concentration and children's perceived achievement in school, but not sleep problems, may partly explain this relationship.

Amylin(1-8) is devoid of anabolic activity in bone.

Amylin(1-8), a cyclic peptide consisting of the eight N-terminal amino acids of the 37-amino acid peptide amylin, has been shown to induce proliferation of primary osteoblasts and to induce bone formation in healthy male mice, whereas no data on efficacy in bone disease-related models have been reported. Therefore, we evaluated any effects of amylin(1-8) in ovariectomized rats with established osteopenia, a model for postmenopausal osteoporosis. At doses up to 100 nmol/kg/day, a dose highly effective in healthy mice, amylin(1-8) was unable to increase bone mineral density in ovariectomized rats during an 8-week treatment period. Histomorphometric analysis of the tibia indicated that amylin(1-8) did not change bone histomorphometric parameters. In an attempt to verify any potential biological effects of amylin(1-8), we investigated the efficacy of this peptide in various in vitro assays. Experiments designed to confirm previously published results on the proliferative effects of amylin(1-8) on primary osteoblasts failed to show any response. Amylin(1-8) was able to partially displace (125)I-rat amylin(1-37) from amylin receptors composed of the calcitonin receptor and RAMP1, indicating specific interaction of the peptide with the amylin binding site. However, in vitro efficacy assays with amylin(1-8) in calcitonin receptor-RAMP-positive HEK293T and MCF7 cells failed to reveal any agonist activity of amylin(1-8), whereas amylin(1-37) showed the expected agonist activity. In conclusion, our results indicate that amylin(1-8) does not show agonist activity on amylin receptors, does not affect osteoblast proliferation, and is devoid of anabolic activity in bone.

Television food advertising and the prevalence of childhood overweight and obesity: a multicountry comparison.

OBJECTIVE: To estimate the contribution of television (TV) food advertising to the prevalence of obesity among 6-11-year-old children in Australia, Great Britain (England and Scotland only), Italy, The Netherlands, Sweden and the United States. DESIGN: Data from contemporary representative studies on the prevalence of childhood obesity and on TV food advertising exposure in the above countries were entered into a mathematical simulation model. Two different effect estimators were used to calculate the reduction in prevalence of overweight and obesity in the absence of TV food advertising in each country; one based on literature and one based on experts' estimates. SETTING: Six- to eleven-year-old children in six Western countries. RESULTS: Estimates of the average exposure of children to TV food advertising range from 1.8 min/d in The Netherlands to 11.5 min/d in the United States. Its contribution to the prevalence of childhood obesity is estimated at 16%-40% in the United States, 10%-28% in Australia and Italy and 4%-18% in Great Britain, Sweden and The Netherlands. CONCLUSIONS: The contribution of TV advertising of foods and drinks to the prevalence of childhood obesity differs distinctly by country and is likely to be significant in some countries.

School-related physical activity interventions and mental health among children: a systematic review and meta-analysis.

BACKGROUND: Low levels of physical activity, sedentary behaviour and mental health problems are issues that have received considerable attention in the last decade. The aim of this systematic review and meta-analysis was to investigate effects of interventions targeting school-related physical activity or sedentary behaviour on mental health in children and adolescents and to identify the features of effective interventions. METHODS: Scientific articles published between January 2009 and October 2019 fulfilling the following criteria were included: general populations of children and adolescents between age 4 and 19, all types of school-related efforts to promote physical activity or reduce sedentary behaviour. Study selection, data extraction and quality assessment were done by at least two authors independently of each other. Data were analysed with a random effects meta-analysis and by narrative moderator analyses. RESULTS: The literature search resulted in 10265 unique articles. Thirty-one articles, describing 30 interventions, were finally included. Eleven relevant outcomes were identified: health-related quality of life, well-being, self-esteem and self-worth, resilience, positive effect, positive mental health, anxiety, depression, emotional problems, negative effect and internalising mental health problems. There was a significant beneficial effect of school-related physical activity interventions on resilience (Hedges' g = 0.748, 95% CI = 0.326; 1.170, p = 0.001), positive mental health (Hedges' g = 0.405, 95% CI = 0.208; 0.603, p = < 0.001), well-being (Hedges' g = 0.877, 95% CI = 0.356; 1.398, p = < 0.001) and anxiety (Hedges' g = 0.347, 95% CI = 0.072; 0.623, p = 0.013). Heterogeneity was moderate to high (I2 = 59-98%) between studies for all outcomes except positive effect, where heterogeneity was low (I2 = 2%). The narrative moderator analyses of outcomes based on 10 or more studies showed that age of the children moderated the effect of the intervention on internalising mental health problems. Interventions in younger children showed a significantly negative or no effect on internalising mental health problems while those in older children showed a significant positive or no effect. Moreover, studies with a high implementation reach showed a significant negative or no effect while those with a low level of implementation showed no or a positive effect. No signs of effect moderation were found for self-esteem, well-being or positive mental health. Risk of publication bias was evident for several outcomes, but adjustment did not change the results. CONCLUSIONS: School-related physical activity interventions may reduce anxiety, increase resilience, improve well-being and increase positive mental health in children and adolescents. Considering the positive effects of physical activity on health in general, these findings may reinforce school-based initiatives to increase physical activity. However, the studies show considerable heterogeneity. The results should therefore be interpreted with caution. Future studies should report on implementation factors and more clearly describe the activities of the control group and whether the activity is added to or replacing ordinary physical education lessons in order to aid interpretation of results. TRIAL REGISTRATION: PROSPERO, CRD42018086757.