Accelerometry measured ethnic differences in activity in rural adolescents

Associations Among Physical Activity, Adiposity, and Insulin Resistance in Children Exposed In Utero to Maternal Obesity With and Without Gestational Diabetes

PURPOSE

Investigate whether obesity risk and current weight status are independently associated with physical activity (PA) and whether PA is associated with adiposity and insulin resistance (homeostatic model assessment of insulin resistance) among children with high versus low obesity risk based on in utero exposure to maternal overweight/obesity with gestational diabetes mellitus (GDM; high risk) or without GDM (overweight/obesity; high risk) or maternal normal weight without GDM (low risk).

METHOD

Secondary analysis of data from children born to women with overweight/obesity and GDM, overweight/obesity without GDM, or normal weight without GDM. PA was assessed with accelerometry, percentage of body fat derived from anthropometrics, and homeostatic model assessment of insulin resistance calculated from glucose and insulin.

RESULTS

Among 4- to 10-year-old children (N = 163), analyses of covariance showed that children with a current BMI ≥85th percentile had less vigorous PA than those with BMI <85th percentile, but in utero exposure was not an independent predictor of PA. In linear regression modeling, moderate to vigorous PA was inversely associated with percentage of body fat and homeostatic model assessment of insulin resistance independent of age, Tanner stage, and accelerometer wear time, with stronger associations in high-risk groups.

CONCLUSIONS

Children's PA is related to current weight status but not underlying risk for obesity but may be especially important to reduce obesity and insulin resistance in high-risk children.

Movement Behaviour and Health Outcomes in Rural Children: A Systematic Review

BACKGROUND

Studies with rural children are limited, and results are divergent regarding the information on movement behaviours.

PURPOSE

to (i) describe the physical activity and sedentary behaviour in children; (ii) synthetize the year and place of publication, methodological quality, and instruments used to measure physical activity and sedentary behaviour; and (iii) to analyse the relationship between physical activity, sedentary behaviour, and health outcomes in these children.

METHODS

We use the databases PubMed, Web of Science, SPORTDiscus, Scopus, Virtual Health Library, and SciELO, considering papers published until October 2021. A total of 12,196 studies were identified, and after the exclusion of duplicate, title and abstract screening, and the full-text assessment, a total of 68 were included in the study.

RESULTS

A cross-sectional design was dominant among the studies, with sample sizes ranging from 23 to 44,631 children of both sexes. One-third of the studies were conducted in North America and Europe, and most of them used device-based measurements. Inequalities were observed regarding sex, age, economic level, race, and physical activity domains within and between the places of residence. Sociodemographic characteristics were also related to health outcomes for children living in rural and urban areas.

CONCLUSION

It is necessary to increase the evidence on movement behaviours among children living in the countries of South America and Oceania, as well as to increase the level of evidence on the role of school for physical activity in children in rural areas, given the inconsistent findings.

Accelerometer-Measured Physical Activity in Children and Adolescents at Altitudes over 3500 Meters: A Cross-Sectional Study in Tibet

There is a scarcity of studies on the physical activity (PA) of children and adolescents who live at high altitudes. This study aimed to objectively assess PA of children and adolescents living in the Tibet at altitudes over 3500 m and to examine its difference by ethnicity, gender, age/grade, and body weight status groups. A sample of 397 students aged 9–18 years were recruited from 7 schools in Lhasa, Tibet. PA was measured using accelerometers (ActiGraph GT3X) for seven consecutive days and moderate to vigorous PA (MVPA) was identified using the Evenson (2008) cut-points. Participant MVPA was 62.3 min/day, with 65.5 min/day during weekdays and 54.1 min/day on weekends. Indigenous Tibetans were more active than Hans, and boys had more MVPA than girls. Age had a significantly weak negative correlation with MVPA. There was no significant difference in MVPA between the non-overweight and overweight/obese groups. Overall, only 9.1% (13.8% in boys and 4.5% in girls) accumulated at least 60 min of MVPA per day. Compared to their counterparts in other regions, the daily MVPA of children and adolescents living on the Tibetan Plateau at altitudes over 3500 m was relatively high. However, the proportion of meeting the WHO’s PA recommendations was extremely low.

Relationship between Sedentariness and Moderate-to-Vigorous Physical Activity in Youth: A Multivariate Multilevel Study

This study aimed to jointly analyse moderate-to-vigorous physical activity (MVPA) and sedentariness, and their correlates, in children within their school contexts, using a multivariate multilevel approach. The sample comprises 499 Portuguese children (284 girls) from 23 schools. MVPA and sedentary time were estimated by accelerometer. A set of predictor variables from both child and school levels was tested. Overall, schools explained a small amount of the total variance in both MVPA (5.6%) and sedentariness (3.2%), and a correlation coefficient of -0.45 (p < 0.05) was found between MVPA and sedentariness at the child level. Number of siblings and socioeconomic status (SES) were significantly associated with both sedentariness (SES: β = 2.372 ± 1.183; siblings: β = -8.127 ± 2.759) and MPVA (SES: β = -1.535 ± 0.421; siblings: β = 2.822 ± 0.977), but with opposite signs. Body Mass Index (BMI) (β = -4.804 ± 1.898) and sex (male) (β = 21.561 ± 3.496) were only associated with MVPA. None of the school correlates were statistically significant in their joint effects to simultaneously explain sedentariness and MVPA. These results suggest that although MVPA and sedentariness may be different constructs, they are correlated and this should be taken into account when designing strategies to reduce children's sedentariness and increase their MVPA. In addition, the small effect of the school context on this relationship highlights the important roles of child and family characteristics.

Pain is Associated with Physical Activity and Health-Related Quality of Life in Overweight and Obese Children

This study examined associations between pain, physical activity, physical fitness, and health-related quality of life (HRQOL) in overweight and obese children. Participants were 270 overweight and obese children 8-12 years of age and their parents. Children were separated into No Pain Frequency, Low Pain Frequency, and High Pain Frequency groups. Children in the Low Pain Frequency group spent less time in moderately intense physical activities compared to the No Pain Frequency group. Children in the High Pain Frequency group reported significantly lower HRQOL in most domains of functioning compared to children in the No Pain and Low Pain Frequency groups. Pain in overweight and obese children may negatively impact physical activity and HRQOL and should be assessed and treated in research and clinical work.

The impact of ethnicity on objectively measured physical activity in children

Obesity and obesity-related diseases (cardiovascular disease/metabolic risk factors) are experienced differently in individuals from different ethnic backgrounds, which originate in childhood. Physical activity is a modifiable risk factor for obesity and related diseases. Both physical activity and metabolic risk factors track to adulthood, and thus understanding the physical activity patterns in children from different ethnic backgrounds is important. Given the limitations of self-report measures in children, this study provides a review of studies which have objectively measured physical activity patterns in children from different ethnic backgrounds. From a total of 16 studies, it can be concluded that physical activity does seem to vary amongst the ethnic groups especially South Asian and Black compared to White EU (European Union). The findings are less consistent for Hispanic/Mexican American children. However, there are several methodological limitations which need to be considered in future studies. Firstly, there is a need for consistency in the measurement of physical activity. Secondly, there are a range of complex factors such as socioeconomic status and body composition which affect both physical activity and ethnicity. Studies have failed to account for these differences limiting the ability to generalise that ethnicity is an independent risk factor for physical activity.

Adiposity and physical activity are not related to academic achievement in school-aged children

OBJECTIVE

To investigate the hypotheses that in elementary school students: (1) adiposity and academic achievement are negatively correlated and (2) physical activity and academic achievement are positively correlated.

METHODS

Participants were 1963 children in fourth to sixth grades. Adiposity was assessed by calculating body mass index (BMI) percentile and percent body fat and academic achievement with statewide standardized tests in 4 content areas. Socioeconomic status and age were control variables. A subset of participants (n = 261) wore an accelerometer for 3 days to provide objective measurement of physical activity. In addition, the association between weight status and academic achievement was examined by comparing children who could be classified as "extremely obese" and the rest of the sample, as well as comparing children who could be classified as normal weight, overweight, or obese. Extreme obesity was defined as ≥1.2 times the 95th percentile.

RESULTS

The results indicated that there were no significant associations between adiposity or physical activity and achievement in students. No academic achievement differences were found between children with BMI percentiles within the extreme obesity range and those who did not fall within the extreme obesity classification. In addition, no academic achievement differences were found for children with BMI percentiles within the normal weight, overweight, or obese ranges.

CONCLUSIONS

These results do not support the hypotheses that increased adiposity is associated with decreased academic achievement or that greater physical activity is related to improved achievement. However, these results are limited by methodological weaknesses, especially the use of cross-sectional data.

Progress and future directions on physical activity research among youth

There is strong evidence to support the benefits of regular physical activity for children and adolescents (heretofore referred to as "youth"). Evidence includes improved cardiorespiratory fitness, muscular fitness, bone health, body composition, and cardiovascular and metabolic health biomarkers. Importantly, physical inactivity is a modifiable risk factor for lifestyle-related chronic diseases and conditions and may track through adulthood. Because of the potential benefits and modifiable nature of the behavior, the "2008 Physical Activity Guidelines for Americans" recommends 1 hour or more of daily physical activity for youth. Most of the time should be spent in either moderate-or vigorous-intensity aerobic activities and should also include muscle and bone strengthening activities. The 2010 World Health Organization "Global Recommendations for Physical Activity and Health" supports similar guidelines for youth.