Body Mass Index From Early to Late Childhood and Cardiometabolic Measurements at 11 to 12 Years.

OBJECTIVES: To examine how overweight and obesity at specific ages and overall BMI growth patterns throughout childhood predict cardiometabolic phenotypes at 11 to 12 years. METHODS: In a population-based sample of 5107 infants, BMI was measured every 2 years between ages 2 to 3 and 10 to 11 years. We identified 5 BMI trajectories using growth curve models. At ages 11 to 12 years, 1811 children completed assessments for metabolic syndrome risk scores, carotid-femoral pulse wave velocity, and carotid intima-media thickness. Multivariable regression models were used to estimate associations, adjusted for potential confounders (eg, age, sex, smoking exposure, and small for gestational age). RESULTS: Overweight and obesity from early childhood onward were strongly associated with higher cardiometabolic risk at 11 to 12 years of age. At age 6 to 7 years, compared with those with a healthy weight, children with overweight had higher metabolic syndrome risk scores by 0.23 SD units (95% confidence interval 0.05 to 0.41) and with obesity by 0.76 SD units (0.51-1.01), with associations almost doubling by age 10 to 11 years. Obese (but not overweight) children had higher outcome pulse wave velocity (0.64-0.73 SD units) from ages 6 to 7 years and slightly higher outcome carotid intima-media thickness (0.20-0.30 SD units) at all ages. Cumulative exposure to high BMI from 2 to 3 years of age carried the greatest cardiometabolic risk, with a gradient of risk across trajectories. CONCLUSIONS: High early-childhood BMI is already silently associated with the development of cardiometabolic risk by 11 to 12 years, highlighting the urgent need for effective action to reduce overweight and obesity in early childhood.

Association between breakfast frequency and physical activity and sedentary time: a cross-sectional study in children from 12 countries.

BACKGROUND: Existing research has documented inconsistent findings for the associations among breakfast frequency, physical activity (PA), and sedentary time in children. The primary aim of this study was to examine the associations among breakfast frequency and objectively-measured PA and sedentary time in a sample of children from 12 countries representing a wide range of human development, economic development and inequality. The secondary aim was to examine interactions of these associations between study sites. METHODS: This multinational, cross-sectional study included 6228 children aged 9-11 years from the 12 International Study of Childhood Obesity, Lifestyle and the Environment sites. Multilevel statistical models were used to examine associations between self-reported habitual breakfast frequency defined using three categories (breakfast consumed 0 to 2 days/week [rare], 3 to 5 days/week [occasional] or 6 to 7 days/week [frequent]) or two categories (breakfast consumed less than daily or daily) and accelerometry-derived PA and sedentary time during the morning (wake time to 1200 h) and afternoon (1200 h to bed time) with study site included as an interaction term. Model covariates included age, sex, highest parental education, body mass index z-score, and accelerometer waking wear time. RESULTS: Participants averaged 60 (s.d. 25) min/day in moderate-to-vigorous PA (MVPA), 315 (s.d. 53) min/day in light PA and 513 (s.d. 69) min/day sedentary. Controlling for covariates, breakfast frequency was not significantly associated with total daily or afternoon PA and sedentary time. For the morning, frequent breakfast consumption was associated with a higher proportion of time in MVPA (0.3%), higher proportion of time in light PA (1.0%) and lower min/day and proportion of time sedentary (3.4 min/day and 1.3%) than rare breakfast consumption (all p ≤ 0.05). No significant associations were found when comparing occasional with rare or frequent breakfast consumption, or daily with less than daily breakfast consumption. Very few significant interactions with study site were found. CONCLUSIONS: In this multinational sample of children, frequent breakfast consumption was associated with higher MVPA and light PA time and lower sedentary time in the morning when compared with rare breakfast consumption, although the small magnitude of the associations may lack clinical relevance. TRIAL REGISTRATION: The International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) is registered at (Identifier NCT01722500 ).

Multiple components of fitness improved among overweight and obese adolescents following a community-based lifestyle intervention.

Fitness is an important component of health, and obese adolescents regularly have poor fitness. Unfortunately, few have assessed the impact of community-based lifestyle interventions on multiple components of fitness. The purpose of this study was to assess the impact of participation in a community-based intervention involving adolescents and parents on multiple components of fitness of obese adolescents. In a within-subject, waitlist controlled clinical trial with 12 months follow-up in Western Australia, participants (n = 56) completed multiple fitness measures at baseline, immediately prior to beginning an 8-week intervention and at 3, 6 and 12 months during a maintenance period. Performance on the shuttle walk was improved immediately post-intervention (increase of 42.8 m, 95% CI: 7.5, 78.2) and at 12 months post-intervention (increase of 44.6 m, 95% CI: 1.3, 87.8) compared with pre-intervention. Muscle performance of quadriceps and deltoids were improved post-intervention (increase of 1.1 (95% CI: 0.1, 2.1) kg · F and 1.0 (0.02, 2.1) kg · F, respectively) and all muscle performance measures were improved at 12 months following the intervention. There were no changes in waist circumference. A community-based lifestyle programme such as Curtin University's Activity, Food and Attitudes Program (CAFAP) may be a viable strategy for improving fitness in overweight adolescents.

A model for presenting accelerometer paradata in large studies: ISCOLE.

BACKGROUND: We present a model for reporting accelerometer paradata (process-related data produced from survey administration) collected in the International Study of Childhood Obesity Lifestyle and the Environment (ISCOLE), a multi-national investigation of >7000 children (averaging 10.5 years of age) sampled from 12 different developed and developing countries and five continents. METHODS: ISCOLE employed a 24-hr waist worn 7-day protocol using the ActiGraph GT3X+. Checklists, flow charts, and systematic data queries documented accelerometer paradata from enrollment to data collection and treatment. Paradata included counts of consented and eligible participants, accelerometers distributed for initial and additional monitoring (site specific decisions in the face of initial monitoring failure), inadequate data (e.g., lost/malfunction, insufficient wear time), and averages for waking wear time, valid days of data, participants with valid data (≥4 valid days of data, including 1 weekend day), and minutes with implausibly high values (≥20,000 activity counts/min). RESULTS: Of 7806 consented participants, 7372 were deemed eligible to participate, 7314 accelerometers were distributed for initial monitoring and another 106 for additional monitoring. 414 accelerometer data files were inadequate (primarily due to insufficient wear time). Only 29 accelerometers were lost during the implementation of ISCOLE worldwide. The final locked data file consisted of 6553 participant files (90.0% relative to number of participants who completed monitoring) with valid waking wear time, averaging 6.5 valid days and 888.4 minutes/day (14.8 hours). We documented 4762 minutes with implausibly high activity count values from 695 unique participants (9.4% of eligible participants and <0.01% of all minutes). CONCLUSIONS: Detailed accelerometer paradata is useful for standardizing communication, facilitating study management, improving the representative qualities of surveys, tracking study endpoint attainment, comparing studies, and ultimately anticipating and controlling costs. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01722500.

Improving wear time compliance with a 24-hour waist-worn accelerometer protocol in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE).

BACKGROUND: We compared 24-hour waist-worn accelerometer wear time characteristics of 9-11 year old children in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) to similarly aged U.S. children providing waking-hours waist-worn accelerometer data in the 2003-2006 National Health and Nutrition Examination Survey (NHANES). METHODS: Valid cases were defined as having ≥4 days with ≥10 hours of waking wear time in a 24-hour period, including one weekend day. Previously published algorithms for extracting total sleep episode time from 24-hour accelerometer data and for identifying wear time (in both the 24-hour and waking-hours protocols) were applied. The number of valid days obtained and a ratio (percent) of valid cases to the number of participants originally wearing an accelerometer were computed for both ISCOLE and NHANES. Given the two surveys' discrepant sampling designs, wear time (minutes/day, hours/day) from U.S. ISCOLE was compared to NHANES using a meta-analytic approach. Wear time for the 11 additional countries participating in ISCOLE were graphically compared with NHANES. RESULTS: 491 U.S. ISCOLE children (9.92±0.03 years of age [M±SE]) and 586 NHANES children (10.43 ± 0.04 years of age) were deemed valid cases. The ratio of valid cases to the number of participants originally wearing an accelerometer was 76.7% in U.S. ISCOLE and 62.6% in NHANES. Wear time averaged 1357.0 ± 4.2 minutes per 24-hour day in ISCOLE. Waking wear time was 884.4 ± 2.2 minutes/day for U.S. ISCOLE children and 822.6 ± 4.3 minutes/day in NHANES children (difference = 61.8 minutes/day, p < 0.001). Wear time characteristics were consistently higher in all ISCOLE study sites compared to the NHANES protocol. CONCLUSIONS: A 24-hour waist-worn accelerometry protocol implemented in U.S. children produced 22.6 out of 24 hours of possible wear time, and 61.8 more minutes/day of waking wear time than a similarly implemented and processed waking wear time waist-worn accelerometry protocol. Consistent results were obtained internationally. The 24-hour protocol may produce an important increase in wear time compliance that also provides an opportunity to study the total sleep episode time separate and distinct from physical activity and sedentary time detected during waking-hours. TRIAL REGISTRATION: ClinicalTrials.gov NCT01722500 .

Test-retest reliability of the English version of the Edinburgh Postnatal Depression Scale.

Test-retest reliability of the English version of the Edinburgh Postnatal Depression Scale (EPDS) has not been established. This study aimed to address this gap in psychometrics by examining test-retest reliability in a sample of 118 Australian mothers with babies aged under 12 months, with a mean of 2.82 (SD 1.38) days between test occasions. The EPDS was found to have a high level of test-retest reliability for total scores (ICC = 0.92) and PND risk categories (90.7 % agreement).

The impact of Curtin University's activity, food and attitudes program on physical activity, sedentary time and fruit, vegetable and junk food consumption among overweight and obese adolescents: a waitlist controlled trial.

BACKGROUND: To determine the effects of participation in Curtin University's Activity, Food and Attitudes Program (CAFAP), a community-based, family-centered behavioural intervention, on the physical activity, sedentary time, and healthy eating behaviours of overweight and obese adolescents. METHODS: In this waitlist controlled clinical trial in Western Australia, adolescents (n = 69, 71% female, mean age 14.1 (SD 1.6) years) and parents completed an 8-week intervention followed by 12 months of telephone and text message support. Assessments were completed at baseline, before beginning the intervention, immediately following the intervention, and at 3-, 6-, and 12- months follow-up. The primary outcomes were physical activity and sedentary time assessed by accelerometers and servings of fruit, vegetables and junk food assessed by 3-day food records. RESULTS: During the intensive 8-week intervention sedentary time decreased by -5.1 min/day/month (95% CI: -11.0, 0.8) which was significantly greater than the rate of change during the waitlist period (p = .014). Moderate physical activity increased by 1.8 min/day/month (95% CI: -0.04, 3.6) during the intervention period, which was significantly greater than the rate of change during the waitlist period (p = .041). Fruit consumption increased during the intervention period (monthly incidence rate ratio (IRR) 1.3, 95% CI: 1.10, 1.56) and junk food consumption decreased (monthly IRR 0.8, 95% CI: 0.74, 0.94) and these changes were different to those seen during the waitlist period (p = .004 and p = .020 respectively). CONCLUSIONS: Participating in CAFAP appeared to have a positive influence on the physical activity, sedentary and healthy eating behaviours of overweight and obese adolescents and many of these changes were maintained for one year following the intensive intervention. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Registry ACTRN12611001187932.

BMI, health behaviors, and quality of life in children and adolescents: a school-based study.

OBJECTIVE: To explore the relationship between weight status (BMI) and health-related quality of life in children and adolescents through application of the Child Health Utility 9D, a new generic preference-based instrument. METHODS: Data were collected from primary and high school students in rural and metropolitan regions of South Australia. Consenting participants (2588 in grades 4-6 and 765 in grades 9-10) were weighed and measured and categorized as underweight, healthy weight, overweight, or obese according to International Obesity Taskforce BMI cutoff points (primary outcome). Participants also completed a questionnaire including the Child Health Utility 9D and standardized measures of physical activity, sedentary behavior, sleep patterns, and eating behavior (secondary outcomes). Descriptive and multivariate linear regression analyses were undertaken to calculate mean utility differences. RESULTS: In comparison with healthy-weight primary school students, adjusted mean utilities were lower for overweight (-0.016, P = .02) or obese (-0.039, P = .001) students. For high school students, the adjusted mean utilities were also lower for overweight and obese students but were nonsignificant (-0.018, P > .10). Physical activity, sedentary behavior, sleep patterns, and eating behavior were all found to be significantly associated with utilities. CONCLUSIONS: Irrespective of BMI, young people engaging in more physical activities or less sedentary behavior, and having healthier sleep patterns or eating behavior exhibited higher utilities. Associations between utilities and sleep patterns or eating behavior were stronger than the associations with BMI. Future economic evaluations for obesity interventions should more formally investigate the relationship between changes over time in weight status and health-related quality of life for children and adolescents.

Time use clusters of New Zealand adolescents are associated with weight status, diet and ethnicity.

OBJECTIVE: To describe New Zealand adolescent time use clusters and correlate cluster profiles. METHODS: Data were from the cross-sectional 2008/2009 National Survey of Children and Young People's Physical Activity and Dietary Behaviours, which surveyed a random sample of 10-16 year-old New Zealanders (study subset n=679). Time use data were collected using the Multimedia Activity Recall for Children and Adults, and collapsed into 17 age-adjusted variables for sex-specific cluster analysis. Cluster associations with socio-demographic, anthropometric, physical activity and dietary variables were analysed. RESULTS: Three time use clusters were discovered for both boys and girls. For boys, the Techno-active cluster was characterised by high levels of team sports and TV; the Quiet movers cluster by transport (active and passive) and quiet time; and the Social studious cluster by reading, study activities and social interaction. The boys' clusters were associated with ethnicity. The girls'Social sporty cluster was characterised by sports and social interaction; the Screenie tasker cluster by TV, computer, chores and work; and the Super studious cluster by reading, study and school-based activities. The girls' time use cluster membership was associated with weight status and serves of extra foods. CONCLUSIONS: Distinct sex-specific time use clusters and correlate profiles exist among NZ adolescents. IMPLICATIONS: These findings may assist the development of targeted time use interventions to improve adolescent health and well-being.

More than just physical activity: time use clusters and profiles of Australian youth.

OBJECTIVE: To describe time use clusters and correlate-cluster profiles of Australian youth. DESIGN: Secondary analysis of cross-sectional national survey. METHODS: Data were from the National Children's Nutrition and Physical Activity Survey, a random sample (n=1853) of 9-16 years old Australians (February-August 2007). Time use data were collected using the Multimedia Activity Recall for Children and Adults, and collapsed into 17 age-adjusted variables for sex-specific cluster analysis. Cluster associations with socio-demographic, anthropometric, health and dietary variables were analysed. RESULTS: For boys (n=930), the Social tasker cluster was characterised by social interaction and chores & work, the Techno-active cluster by team sport and TV and the Techno-studious cluster by video games and study. Average daily pedometer steps, age and remoteness were significant cluster correlates. For the girls (n=923), the Social screenie cluster was characterised by TV and social interaction, the Quiet actives cluster by quiet time and non-team sport and the Techno-studious cluster by video games and study. Pedometer steps, age, parental income and education, parent-child age difference, "extra foods", fat and fruit intakes were significant correlates. CONCLUSIONS: Distinct sex-specific time use clusters and profiles exist among Australian youth. These findings may assist the development of targeted time use interventions to improve health and well-being.

Physical activity and screen time behaviour in metropolitan, regional and rural adolescents: a -sectional study of Australians aged 9-16 years.

OBJECTIVES: While there is consistent evidence that rural adults in Australia are less active than their urban counterparts, studies relating geographical remoteness to activity patterns in Australian adolescents have yielded inconsistent results. The aim of this study was to describe objectively and subjectively measured patterns of physical activity and sedentary behaviours across remoteness categories in a representative sample of 9-16 year old Australians. DESIGN: Cross-sectional observational study. METHODS: 2071 Australian adolescents provided self-report use of time data on four days and wore a pedometer for at least 6 days within the 2007 Australian National Children's Nutrition and Physical Activity Survey. Comparisons of activity patterns were made across four objectively-determined remoteness categories (Major City, Inner Regional, Outer Regional and Remote), adjusting for household income, parental education and age. RESULTS: Adolescents living in major cities self-reported 11-29 min less moderate to vigorous physical activity each day than their counterparts living in geographically more remote areas, and took 150-850 fewer steps each day. While there were no differences in time spent in sport or active transport, differences in free play participation were significant. Males in major cities also reported higher levels of screen time. Differences were somewhat more marked among males than among females. CONCLUSIONS: Activity levels among Australian adolescents show contrasting patterns of geographical differences to those found in Australian adults. Higher levels of free play among rural Australian adolescents may be due to more available space and less fear of traffic and stranger risks.

Thin adolescents: Who are they? What do they do? Socio-demographic and use-of-time characteristics.

OBJECTIVES: Examine: (1) the anthropometric, socio-demographic and use-of-time characteristics of thin adolescents, and (2) compare these characteristics to other weight status categories. METHODS: Data were from the 2007 National Children's Nutrition and Physical Activity Survey which collected data on a random sample of 2200 9 to 16 year old Australians from February to August 2007. Seven socio-demographic variables, anthropometric data (height and weight were measured) and nine use-of-time variables were used, and compared across the weight status categories. Physical activity was measured using pedometers and the Multimedia Activity Recall for Children and Adults. RESULTS: 5.3% of adolescents were classified as thin, a percentage which did not significantly vary by age, sex, indigenous status, household income, education level or family structure. Relative to other adolescents, thin adolescents were shorter and lighter. Thin adolescents were less active than their normal weight peers, but walked further and accumulated significantly less screen and TV time than obese adolescents. CONCLUSION: Thin adolescents were found in similar proportions across all socio-demographic bands. Thin adolescents recorded similar physical activity levels to their normal weight peers, but were more active than obese adolescents. The findings from the study support in part the theory of thinness related developmental delay.