Seasonal variability in body mass index, waist circumference, and skinfolds in Norwegian children.

OBJECTIVES: Studies have shown that children develop a higher body weight during summer months. This has been demonstrated repeatedly using the body mass index (BMI), but the effect of season on other weight-related anthropometric measurements is still unclear. METHODS: Measurements of height, weight, waist circumference (WC), triceps, and subscapular skinfolds (TSF and SSF), collected from September till May in a cross-sectional sample of 4-16-year-old children and adolescents (n = 4525) from the Bergen Growth Study 1 (BGS1). Differences in z-score by season were tested with linear models adjusted for age group and separately for sex. Overall differences were tested with a one-way between-group analysis of variance. RESULTS: The girls had higher BMIz (+0.12, p = .03) and WCz (+0.18, p = .002) in fall compared with spring. TSFz (-0.19, p < .001) and SSFz (-0.18, p < .001) were lower in winter in girls, and in boys both in fall (TSFz -0.10, p = .046; SSFz - 0.16, p < .001), and winter (TSFz -0.15, p = .004; SSFz -0.14, p = .003), when compared with spring. CONCLUSIONS: Seasonal variation was detected for all anthropometric measures, but differences in the direction of the effect between measures of global (BMI), central (WC) or subcutaneous (SF) adiposity suggest a more complex mechanism that needs further exploration.

Trends in overweight and obesity in Bergen, Norway, using data from routine child healthcare 2010-2022.

AIM: Trends in childhood overweight, obesity and severe obesity have been lacking in Norway. This study assessed pre-pandemic trends from 2010 to 2019 and evaluated differences in prevalence during the 2020-2022 pandemic years. METHODS: Routine height and weight measurements from child and school health centres were extracted retrospectively from children aged 2, 4, 6, 8 and 13 years. Overweight, obesity and severe obesity was classified according to the International Obesity Task Force cut-offs. Pre-pandemic trends were estimated using linear regression. The prevalence during the pandemic was compared to the 95% prediction interval of this model. RESULTS: We obtained 181 527 body mass index measurements on 78 024 children (51.0% boys). There was a decrease in the prevalence of overweight including obesity from 2010 to 2019 in boys and this was statistically significant at 4 and 13 years of age. We found no significant trends in girls during this period. During the pandemic, the prevalence of overweight including obesity exceeded the prediction intervals for boys aged 4, 6, and 8 years, and for 6-year-old girls. CONCLUSION: From 2010-2019, overweight including obesity plateaued in girls and decreased in boys but increased during the pandemic among prepubertal boys. Routine healthcare data is useful for estimating the prevalence of different weight status.

SARS-CoV-2 seroprevalence and determinants for salivary seropositivity among pupils and school staff: a prospective cohort study.

Representative school data on SARS-CoV-2 past-infection are scarce, and differences between pupils and staff remain ambiguous. We performed a nation-wide prospective seroprevalence study among pupils and staff over time and in relation to determinants of infection using Poisson regression and generalised estimating equations. A cluster random sample was selected with allocation by region and sociodemographic (SES) background. Surveys and saliva samples were collected in December 2020, March, and June 2021, and also in October and December 2021 for primary pupils. We recruited 885 primary and 569 secondary pupils and 799 staff in 84 schools. Cumulative seroprevalence (95% CI) among primary pupils increased from 11.0% (7.6; 15.9) at baseline to 60.4% (53.4; 68.3) in December 2021. Group estimates were similar at baseline; however, in June they were significantly higher among primary staff (38.9% (32.5; 46.4)) compared to pupils and secondary staff (24.2% (20.3; 28.8)). Infections were asymptomatic in 48-56% of pupils and 28% of staff. Seropositivity was associated with individual SES in pupils, and with school level, school SES and language network in staff in June. Associations with behavioural characteristics were inconsistent. Seroconversion rates increased two- to four-fold after self-reported high-risk contacts, especially with adults. Seroprevalence studies using non-invasive sampling can inform public health management.

Evaluating national guidelines for monitoring early growth using routinely collected data in Bergen, Norway.

AIMS: The overarching aim of this study was to evaluate the Norwegian guidelines for growth monitoring using routinely collected data from healthy children up to five years of age. We analysed criteria for both status (size for age) and change (centile crossing) in growth. METHODS: Longitudinal data were obtained from the electronic health record (EHR) at the well-baby clinic for 2130 children included in the Bergen growth study 1 (BGS1). Measurements of length, weight, weight-for-length, body mass index (BMI) and head circumference were converted to z-scores and compared with the World Health Organization (WHO) growth standards and the national growth reference. RESULTS: Using the WHO growth standard, the proportion of children above +2SD was generally higher than the expected 2.3% for all traits at birth and for length at all ages. Crossing percentile channels was common during the first two years of life, particularly for length/height. By the age of five years, 37.9% of the children had been identified for follow-up regarding length/height, 33% for head circumference and 13.6% for high weight-for-length/BMI. CONCLUSIONS: The proportion of children beyond the normal limits of the charts is higher than expected, and a surprisingly large number of children were identified for rules concerning length or growth in head circumference. This suggests the need for a revision of the current guidelines for growth monitoring in Norway.

SARS-CoV-2 infection prevention and control measures in Belgian schools between December 2020 and June 2021 and their association with seroprevalence: a cross-sectional analysis of a prospective cohort study.

BACKGROUND: To protect school-aged children from the potential consequences of a new viral infection, public health authorities recommended to implement infection prevention and control (IPC) measures in school settings. Few studies evaluated the implementation of these measures and their effect on SARS-CoV-2 infection rates among pupils and staff. The aim of this study was to describe the implementation of infection prevention and control (IPC) measures in Belgian schools and assess its relation to the prevalence of anti-SARS-CoV-2 antibodies among pupils and staff. METHODS: We conducted a prospective cohort study in a representative sample of primary and secondary schools in Belgium between December 2020 and June 2021. The implementation of IPC measures in schools was assessed using a questionnaire. Schools were classified according to their compliance with the implementation of IPC measures as 'poor', 'moderate' or 'thorough'. Saliva samples were collected from pupils and staff to determine the SARS-CoV-2 seroprevalence. To assess the association between the strength of implementation of IPC measures and SARS-CoV-2 seroprevalence among pupils and staff, we conducted a cross-sectional analysis using the data collected in December 2020/January 2021. RESULTS: A variety of IPC measures (ventilation, hygiene and physical distancing) was implemented by more than 60% of schools, with most attention placed on hygiene measures. In January 2021, poor implementation of IPC measures was associated with an increase in anti-SARS-CoV-2 antibody prevalence among pupils from 8.6% (95%CI: 4.5 - 16.6) to 16.7% (95%CI: 10.2 - 27.4) and staff from 11.5% (95%CI: 8.1 - 16.4) to 17.6% (95%CI: 11.5 - 27.0). This association was only statistically significant for the assessment of all IPC measures together in the population comprised of pupils and staff. CONCLUSIONS: Belgian schools were relatively compliant with recommended IPC measures at the school level. Higher SARS-CoV-2 seroprevalence among pupils and staff was found in schools with poor implementation of IPC measures, compared to schools with thorough implementation. TRIAL REGISTRATION: This trial is registered under the NCT04613817 ClinicalTrials.gov Identifier on November 3, 2020.

Trends in the prevalence of breastfeeding up to 6 months of age using structured data from routine child healthcare visits.

AIM: The Norwegian Action Plan for a Healthier Diet (2017-2021) set the target that 25% of infants should be exclusively breastfed for 6 months by 2022. Our aim was to determine trends in the prevalence and duration of breastfeeding in the municipality of Bergen. METHODS: Data on breastfeeding status in 2010-2018 were extracted from a standardised electronic medical record kept by public child health centres and recorded as exclusive, partial or none, at 6 weeks and 6 months of age. RESULTS: We found that 28,503 and 26,735 infants attended the 6-week and 6-month consultations, respectively. The prevalence of any breastfeeding was 92.0% at 6 weeks and 78.0% at 6 months with no trend over time between 2010 and 2018. The prevalence of exclusive breastfeeding at 6 weeks was 73.9% and stable over time, but it declined at 6 months, from 28.1% in 2010 to 11.1% in 2014 and remained stable thereafter. CONCLUSION: During 2010-2018, the prevalence of any and exclusive breastfeeding at 6 weeks and any breastfeeding at 6 months was stable. Exclusive breastfeeding at 6 months declined halfway through the study period, to a stable, but low, prevalence of 11.1% by 2014.

Deep phenotyping of pubertal development in Norwegian children: the Bergen Growth Study 2.

BACKGROUND: The Bergen Growth Study 2 (BGS2) aims to characterise somatic and endocrine changes in healthy Norwegian children using a novel methodology. SUBJECTS AND METHODS: A cross-sectional sample of 1285 children aged 6-16 years was examined in 2016 using novel objective ultrasound assessments of breast developmental stages and testicular volume in addition to the traditional Tanner pubertal stages. Blood samples allowed for measurements of pubertal hormones, endocrine disruptive chemicals, and genetic analyses. RESULTS: Ultrasound staging of breast development in girls showed a high degree of agreement within and between observers, and ultrasound measurement of testicular volume in boys also showed small intra- and interobserver differences. The median age was 10.4 years for Tanner B2 (pubertal onset) and 12.7 years for menarche. Norwegian boys reached a pubertal testicular volume at a mean age of 11.7 years. Continuous reference curves for testicular volume and sex hormones were constructed using the LMS method. CONCLUSIONS: Ultrasound-based assessments of puberty provided novel references for breast developmental stages and enabled the measurement of testicular volume on a continuous scale. Endocrine z-scores allowed for an intuitive interpretation of changing hormonal levels during puberty on a quantitative scale, which, in turn, provides opportunities for further analysis of pubertal development using machine-learning approaches.

Objective evaluation of facial features in Congolese newborns by facial measurements. The need for population-specific measurements.

The evaluation of dysmorphism is often subjective because many continuous traits are not easily measured or lack normal values. Because many common morphologic profiles vary between populations, population-specific reference ranges of relevant traits are needed. We aim to evaluate the objective assessment of facial dysmorphism in 553 Congolese newborns based on facial measurements. Measurements taken with a ruler were on average larger compared to those with a caliper, but the bias did not depend on the size of the measurement. We therefore introduced a correction factor that allows to use both techniques for facial measurements interchangeably in future studies. The outer canthal distance, palpebral fissure length, and mouth width were significantly larger in Congolese newborns (respectively mean 6.59 [SD 0.48]; mean 2.20 [SD 0.24]; mean 2.78 [SD 0.26]) when compared to references based on European newborns (respectively mean 3.59 [SD 1.76]; mean 4.20 [SD 2.26]; mean 0.47 [SD 1.21]), while the rest of measurements were significantly smaller. The interpupillary distance (IPD) calculated from inner canthal distance and outer canthal distance was not significantly different. We observed a poor agreement between clinical evaluation and measured features (kappa of 0.432). Clinicians were more likely to recognize a face as having wide-spaced eyes when it had been recognized as such during the clinical examination, more than if the child had a high interpupillary distance. This suggests that the measured IPD is not precisely reflecting what is clinically evaluated as wide-spaced eyes.

Age-dependent seroprevalence of SARS-CoV-2 antibodies in school-aged children from areas with low and high community transmission.

It is not yet clear to what extent SARS-CoV-2 infection rates in children reflect community transmission, nor whether infection rates differ between primary schoolchildren and young teenagers. A cross-sectional serosurvey compared the SARS-CoV2 attack-rate in a sample of 362 children recruited from September 21 to October 6, 2020, in primary (ages 6-12) or lower secondary school (ages 12-15) in a municipality with low community transmission (Pelt) to a municipality with high community transmission (Alken) in Belgium. Children were equally distributed over grades and regions. Blood samples were tested for the presence of antibodies to SARS-CoV-2 with an enzyme-linked immunosorbent assay. We found anti-SARS-CoV-2 antibodies in 4.4% of children in the low transmission region and in 14.4% of children in the high transmission region. None of the primary schoolchildren were seropositive in the low transmission region, whereas the seroprevalence among primary and secondary schoolchildren did not differ significantly in the high transmission region. None of the seropositive children suffered from severe disease. Children who were in contact with a confirmed case (RR 2.9; 95%CI 1.6-4.5), who participated in extracurricular activities (RR 5.6; 95%CI 1.2-25.3), or whose caregiver is a healthcare worker who had contact with COVID-19 patients (RR 2.2; 95%CI 1.0-4.6) were at higher risk of seropositivity. If SARS-CoV2 circulation in the community is high, this will be reflected in the pediatric population with similar infection rates in children aged 6-12 years and 12-15 years. What is Known: •Children are generally less affected by COVID-19 than adults but SARS-CoV2 infection rates among children are not well known. •There were large regional differences in infection rates during the first wave of the SARS-CoV2 pandemic. What is New: •None of the primary schoolchildren (6-12 years) were seropositive for SARS-CoV2 in an area with a low community transmission, but infection rates were higher in adolescents (12-15 years). •In an area with high community transmission, seroprevalence rates in younger children were more comparable to those in adolescents.

Perceived team roles of medical students: a five year cross-sectional study.

INTRODUCTION: Despite the increasing importance of teamwork in healthcare, medical education still puts great emphasis on individual achievements. The purpose of this study is to examine medical students' team role preferences, including the association with gender and specialty; and to provide implications for policy makers and medical educators. METHODS: We used an exploratory methodology, following a cross-sectional design. Data was collected from first year master students in medicine (n = 2293) during five consecutive years (2016-2020). The Belbin Team Role Self Perception Inventory (BTRSPI) was used to measure medical students' self-perceptions of their team role. RESULTS: The Team Worker was the most preferred team role among medical students (35.8%), regardless of gender or specialty. Female and male students had similar team role patterns, although female students scored higher on Team Worker (40.4% vs. 29.1%, P < .001) and Completer-Finisher (14.0% vs. 8.0%, P < .001). With regard to specialties, the Team Worker role was more often chosen by general practitioners than by person-centered and technique-oriented specialties (47.1% vs. 41.8% vs. 29.1%, P < .001). CONCLUSIONS: Our findings contribute to an increased scientific understanding of how medical students perceive their own team role, and how this is related to gender and specialty. This is valuable due to the increased importance of interdisciplinary teamwork in healthcare. Medical schools should prioritize stimulating teamwork skills through the implementation of different interventions at all stages (i.e. from the admission process to curricula to residency) and all levels (i.e. explicit and implicit curricula).

Immunogenicity and Safety of the 9-Valent Human Papillomavirus Vaccine in Solid Organ Transplant Recipients and Adults Infected With Human Immunodeficiency Virus (HIV).

BACKGROUND: The burden of human papillomavirus (HPV) in human immunodeficiency virus (HIV)-infected persons and solid organ transplant (SOT) recipients is high. Clinical trials on HPV vaccines in persons living with HIV and particularly in SOT recipients have been sparse to date, included low numbers of participants, and none of them assessed the 9-valent HPV (9vHPV) vaccine. We investigated the immunogenicity with respect to HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58 and the safety of the 9vHPV vaccine in persons living with HIV and recipients of a kidney, lung, or heart transplant. METHODS: This is a phase III investigator-initiated study in 100 persons living with HIV (age 18-45 years) and 171 SOT recipients (age 18-55 years). The 9vHPV vaccine was administered at day 1, month 2, and month 6. Primary outcome was seroconversion rates to the 9vHPV types at month 7. Secondary outcomes were geometric mean titers (GMTs) and frequency of adverse events (AEs). RESULTS: All HIV-infected participants seroconverted for all HPV types, but seroconversion ranged from 46% for HPV45 to 72% for HPV58 in SOT recipients. GMTs ranged from 180 to 2985 mMU/mL in HIV-positive participants and from 17 to 170 mMU/mL in SOT recipients, depending on the HPV type. Injection-site AEs occurred in 62% of participants but were mostly mild or moderate in intensity. None of the reported serious adverse events were deemed vaccine related. No patients died during the study. CONCLUSIONS: Immunogenicity of the 9vHPV vaccine is high in persons living with HIV but suboptimal in SOT recipients. The vaccine is safe and well tolerated in both groups.

Dysmorphism and major anomalies are a main predictor of survival in newborns admitted to the neonatal intensive care unit in the Democratic Republic of Congo.

In Central-Africa, neonatal infections, asphyxia and prematurity are main reasons for admission to the neonatal intensive care unit and major determinants of newborn survival. Also, the outcome of newborns with congenital anomalies is expected to be poor, due to a lack of state-of-the art care. We conducted a study of 102 newborns recruited in the Neonatal Intensive Care Unit (NICU) at the University Hospitals of Kinshasa, DR Congo, to assess the impact of congenital anomalies. The presence of a major anomaly was associated with a hazard ratio of death of 13.2 (95%CI: 3.7-46.7, p < .001). In addition, the presence of three or more minor anomalies was associated with a 4.5-fold increased risk of death (95%CI: 1.1-18.6, p = .04). We conclude that like major anomalies, the presence of three or more minor anomalies should also be given particular attention and that the evaluation of dysmorphism should be promoted in NICU.

Norwegian children and adolescents in blended families are at risk of larger one-year BMI increments.

AIM: To study how sociodemographic factors and family structure associate with baseline BMI z-scores (BMIz) and BMIz change in 767 Norwegian children aged 6-15 years. METHODS: Baseline BMIz and 1-year BMIz increments in children from the Bergen Growth Study were analysed with linear and logistic regression, according to sociodemographic factors and family structure. A blended family was defined as including a step-parent and/or half-sibling. RESULTS: In a fully adjusted regression model, baseline BMIz were only significantly associated with maternal BMI (b = 0.087, 95%CI 0.067, 0.107). Body Mass Index z-scores increments were larger in children living in a blended family (b = 0.060, 95%CI 0.006, 0.115), with a lower parental education (b = 0.127, 95%CI 0.029, 0.226) and with a higher maternal BMI (b = 0.008, 95%CI 0.001, 0.014). The odds for a large BMIz increment (>1 SD) were higher in children living in blended families (OR 1.82, 95%CI 1.16, 2.88) and with higher maternal BMI (OR 1.07, 95%CI 1.01, 1.13) and lower in 9-11-year-old children (OR 0.44, 95%CI 0.26, 0.77) compared with 12-15-year-olds. CONCLUSION: Body Mass Index z-scores increments were more strongly associated with sociodemographic factors and living in a blended family than baseline BMIz values. BMI z-scores increments could be useful for identifying children at risk of becoming overweight or obese.

Larger head circumference in Icelandic children 0-4 years of age compared to the World Health Organization and Swedish growth charts.

AIM: The World Health Organization (WHO) published universal growth standards for children below five year of age in 2006. Traditionally, Swedish growth references have been used to monitor growth of children in Iceland, but it is not yet known how they compare with these reference charts. METHODS: A total of 2128 longitudinal measurements of length or height, 2132 of weight and 2126 of head circumference between birth and four years of age were collected in 1996-2000 from 199 healthy children (53% boys) recruited at Landspitali University Hospital. Measurements were converted to z-scores using the WHO growth standards and Swedish growth references for further analysis with mixed-effects models. RESULTS: Length or height, weight and in particular head circumference largely exceeded the WHO standards, with average z-scores that fluctuated between 0.5 and 1.5. Likewise, the proportion of children with a z-score larger than 2 SD increased about 10-fold. Icelandic children were longer and heavier than their Swedish peers during the first six months of life, but differences were less pronounced thereafter. CONCLUSION: The growth of Icelandic children deviated significantly from the WHO growth standards. Although more comparable to the Swedish references, significant differences were found, suggesting that a national growth reference would be more appropriate.

Reference data for testicular volume measured with ultrasound and pubic hair in Norwegian boys are comparable with Northern European populations.

AIM: To estimate references for testicular volume measured with ultrasound and Tanner stages of pubic hair in Norwegian boys, and to compare the timing of puberty with data from similar populations. METHODS: Testicular volume was derived from ultrasound measurements of testicular volume in a cross-sectional study of 514 healthy boys. A continuous testicular volume for age reference curve was estimated with the LMS method. Tanner stages for pubic hair were clinically assessed in 452 boys. Age references for pubertal milestones were estimated with probit regression. RESULTS: Puberty onset, defined by an ultrasound testicular volume of 2.7 mL, equivalent to an orchidometer volume of 4 mL, occurred at a mean (SD) age of 11.7 (1.1) years. The reference range was 9.7 (3rd) to 13.7 years (97th percentile). Pubic hair (Tanner stage 2) appeared on average at 11.8 (1.2) years with a corresponding reference range of 9.5-14.1 years. CONCLUSION: The references for testicular volume measured with ultrasound are continuous in age and allow for the quantification of pubertal development. The age distribution of reaching pubertal milestones was comparable with data from other Northern European countries.

Lifestyle intervention for children and adolescents with severe obesity - results after one year. / Livsstilsbehandling av barn og ungdom med alvorlig fedme ­ resultater etter ett år.

BACKGROUND: Lifestyle interventions for children and adolescents with severe obesity show moderate short-term effects on weight reduction internationally. We evaluated treatment results at two Norwegian specialist outpatient clinics. MATERIAL AND METHOD: We performed a retrospective analysis of data from children and adolescents between 3 and 18 years of age collected in 2012-2016. Children and adolescents with severe obesity who attended their one-year follow-up were included. We included in the analyses the following body weight measures: percentage overweight as defined by the International Obesity Task Force cut-off (% IOTF-25); BMI standard deviation score; waist circumference standard deviation score; and body fat percentage at the start of treatment and at one-year follow-up. RESULTS: Of 568 children and adolescents who started treatment, 416 (73 %) attended the one-year check-up. A total of 271 (65 %) patients achieved a reduction in %IOTF-25, while 228 patients (55 %) reduced their BMI standard deviation score. There was a statistically significant mean reduction of all four registered body weight measurements. Altogether 54 of 325 children (17 %) changed category from severe obesity to obesity, 8 (2 %) went from severe obesity to overweight, and 8 of 91 children (9 %) changed category from obesity to overweight or normal weight. The proportion of participants with a reduction of more than 5 % in %IOTF-25 was 43 % (177/416), and a reduction in BMI standard deviation score of more than 0.25 was observed in 23 % (95/416) of participants. Girls responded on average more poorly to the intervention than boys. There was no clinically significant difference in results between the treatment centres. INTERPRETATION: After one year of treatment of children and adolescents with severe obesity in two specialist healthcare centres, we found a moderate mean reduction in weight, waist circumference and body fat percentage, but with large interindividual variation.

Monitoring children and adolescents with severe obesity: body mass index (BMI), BMI z-score or percentage above the International Obesity Task Force overweight cut-off?

AIM: Body mass index (BMI) metrics are widely used as a proxy for adiposity in children with severe obesity. The BMI expressed as the percentage of a cut-off percentile for overweight or obesity has been proposed as a better alternative than BMI z-scores when monitoring children and adolescents with severe obesity. METHODS: Annual changes in BMI, BMI z-score and the percentage above the International Obesity Task Force overweight cut-off (%IOTF-25) were compared with dual-energy X-ray absorptiometry (DXA) derived body fat (%BF-DXA) in 59 children and adolescents with severe obesity. RESULTS: The change in %BF-DXA was correlated with the change in %IOTF-25 (r = 0.68) and BMI (r = 0.70), and somewhat less with the BMI z-score (r = 0.57). Cohen's Kappa statistic to detect an increase or decrease in %BF-DXA was fair for %IOTF-25 (κ = 0.25; p = 0.04) and BMI (κ = 0.33; p = 0.01), but not for the BMI z-score (κ = 0.08; p = 0.5). The change in BMI was positively biased due to a natural increase with age. CONCLUSION: Changes in the BMI metrics included in the study are associated differently with changes in %BF-DXA. The BMI z-score is widely used to monitor changes in adiposity in children and adolescents with severe obesity, but the %IOTF-25 might be a better alternative.

Meeting Report: The Role of Beliefs and Perception on Body Size. Proceedings of the 26th Aschauer Soiree, Held at Aschauhof, Altenhof, Germany, May 26th, 2018.

Thirty-one scientists met at Aschauhof, Germany to discuss the role of beliefs and self-perception on body size. In view of apparent growth stimulatory effects of dominance within the social group that is observed in social mammals, they discussed various aspects of competitive growth strategies and growth adjustments. Presentations included new data from Indonesia, a cohort-based prospective study from Merida, Yucatan, and evidence from recent meta-analyses and patterns of growth in the socially deprived. The effects of stress experienced during pregnancy and adverse childhood events were discussed, as well as obesity in school children, with emphasis on problems when using z-scores in extremely obese children. Aspects were presented on body image in African-American women, and body perception and the disappointments of menopause in view of feelings of attractiveness in different populations. Secular trends in height were presented, including short views on so called 'racial types' vs bio-plasticity, and historic data on early-life nutritional status and later-life socioeconomic outcomes during the Dutch potato famine. New tools for describing body proportions in patients with variable degrees of phocomelia were presented along with electronic growth charts. Bio-statisticians discussed the influence of randomness, community and network structures, and presented novel tools and methods for analyzing social network data.

Associations between different weight-related anthropometric traits and lifestyle factors in Norwegian children and adolescents: A case for measuring skinfolds.

OBJECTIVES: The purpose of this study was to investigate the association between weight-related anthropometric measures and children's eating habits, physical activity and sedentary lifestyle at a population level. METHODS: Data from the Bergen Growth Study were used to study the association of z-scores of waist circumference (WC), weight-to-height ratio (WHtR), subscapularis (SSF) and triceps (TSF) skinfolds and BMI, with lifestyle factors in 3063 Norwegian children (1543 boys) aged 4-15 years, using linear regression analysis. Each sex was analyzed separately. RESULTS: In a fully adjusted model with additional correction for BMI z-scores, the consumption of vegetables was associated with higher WC (b = 0.03) and TSF (b = 0.05) z-scores in girls. Sedentary behavior was not associated with any of the anthropometric measures. Physical activity was negatively associated with SSF (b = -0.07) and TSF (b = -0.07) z-scores in boys, while a significant negative association was observed with WC (b = -0.02), WHtR (b = -0.03), SSF (b = -0.04) and TSF (b = -0.06) in girls. CONCLUSION: Physical activity was negatively associated with skinfolds in both sexes. The BMI was not related to the level of physical activity, and should be complemented with direct measures of fat tissue, like skinfolds, when studying the effect of physical activity on body composition in children.