Pedometer-determined physical activity among youth in the Tokyo Metropolitan area: a cross-sectional study

Factors associated with low bone mineral density in Turner syndrome: a multicenter prospective observational study

Turner syndrome (TS) is associated with a high risk of fracture due to low bone mineral density (BMD). While hypogonadism is known to play a role in decreasing BMD, other factors have not been studied well. Focusing on diet, exercise, and bone metabolism markers, the present, multicentric, prospective, observational study aimed to identify factors contributing to decreased BMD in TS. In total, 48 patients with TS aged between 5 and 49 years comprising a pre-pubertal group (n = 9), a cyclical menstruation group (n = 6), and a hormone replacement therapy (HRT) group (n = 33) were enrolled. The cyclical menstruation group and the HRT group were referred to collectively as the post-pubertal group. The bone mineral apparent density (BMAD) Z-score was higher in the pre-pubertal group than in the post-pubertal group (-0.3 SD vs. -1.8 SD; p = 0.014). Within the post-pubertal group, the median BMAD Z-score was -0.2 SD in the cyclical menstruation group and -2.3 SD in the HRT group (p = 0.016). Spearman's rank correlation revealed no correlation between the BMAD Z-score and bone metabolism markers. No significant relationship was observed between the BMAD Z-score and either the vitamin D sufficiency rate or the step sufficiency rate. A negative correlation was found between BMAD Z-score and serum sclerostin in the pre-pubertal group and serum FSH in the post-pubertal group. In conclusion, the present study found no relationship between the vertebral BMAD Z-score and diet or exercise habits in TS, indicating that estrogen deficiency is the chief reason for low BMD in TS.

Validation of the Physical Activity Questions in the World Health Organization Health Behavior in School-Aged Children Survey Using Accelerometer Data in Japanese Children and Adolescents

BACKGROUND

An international physical activity (PA) questionnaire is beneficial to make cross-country comparisons among children and adolescents. This study assesses the validity of the PA questions in the World Health Organization Health Behavior in School-Aged Children (WHO HBSC) survey in Japanese children and adolescents.

METHODS

Participants were fifth- to sixth-grade Japanese primary school students (67 students aged 10.8 [0.5] y) and first- to third-grade junior high school students (108 students aged 13.0 [0.7] y). The Japanese version of the PA questions in the WHO HBSC (WHO HBSC-J) was used. To assess the validity of the PA questions, the authors used a partial correlation adjusted for sex, age, and relative weight between the answers to the survey questions and objectively measured moderate to vigorous PA (MVPA) by an accelerometer.

RESULTS

A significant positive correlation was found between accelerometer-measured MVPA and the number of reported days with at least 60 minutes/day of MVPA in primary school students (r = .39, P = .002) and junior high school students (r = .32, P < .001).

CONCLUSION

The HBSC-J has moderate validity for evaluating MVPA in Japanese primary school and junior high school students.

Sensor-based categorization of upper limb performance in daily life of persons with and without neurological upper limb deficits

Background: The use of wearable sensor technology (e. g., accelerometers) for tracking human physical activity have allowed for measurement of actual activity performance of the upper limb (UL) in daily life. Data extracted from accelerometers can be used to quantify multiple variables measuring different aspects of UL performance in one or both limbs. A limitation is that several variables are needed to understand the complexity of UL performance in daily life.

Purpose: To identify categories of UL performance in daily life in adults with and without neurological UL deficits.

Methods: This study analyzed data extracted from bimanual, wrist-worn triaxial accelerometers from adults from three previous cohorts (N = 211), two samples of persons with stroke and one sample from neurologically intact adult controls. Data used in these analyses were UL performance variables calculated from accelerometer data, associated clinical measures, and participant characteristics. A total of twelve cluster solutions (3-, 4-, or 5-clusters based with 12, 9, 7, or 5 input variables) were calculated to systematically evaluate the most parsimonious solution. Quality metrics and principal component analysis of each solution were calculated to arrive at a locally-optimal solution with respect to number of input variables and number of clusters.

Results: Across different numbers of input variables, two principal components consistently explained the most variance. Across the models with differing numbers of UL input performance variables, a 5-cluster solution explained the most overall total variance (79%) and had the best model-fit.

Conclusion: The present study identified 5 categories of UL performance formed from 5 UL performance variables in cohorts with and without neurological UL deficits. Further validation of both the number of UL performance variables and categories will be required on a larger, more heterogeneous sample. Following validation, these categories may be used as outcomes in UL stroke research and implemented into rehabilitation clinical practice.

Relationship between children physical activity, inflammatory mediators and lymphocyte activation: possible impact of social isolation (COVID-19)

Objective

Lifestyle and body composition may be simultaneously responsible for immune response modulation. This study aimed to compare plasmatic adipokines concentration and lymphocyte cytokine production in children with different daily steps (DS) range, as well as to discuss the potential negative impact of the social isolation during COVID-19 pandemic in this context. DS can be a useful and low-cost way of monitoring children's health status.

Study design

Fifty children were classified into clusters based in DS measured by pedometer: Sedentary Group (DS = 9338 ± 902 steps) and Active Group (DS = 13,614 ± 1003 steps). Plasma and lymphocytes were isolated and cultured to evaluate cytokine production.

Results

Sedentary group presented lower adiponectin (7573 ± 232 pg/mL), higher leptin (16,250 ± 1825 pg/mL) plasma concentration, and higher lymphocyte production of IL-17, IFN-gamma, TNF-, IL-2 in relation to active group, suggesting predominance of Th1 response. Otherwise, the active group presented higher lymphocyte supernatant concentration of IL-10 and higher regulatory T cell (Treg) percentage.

Conclusion

These results indicate that lymphocytes of children performing higher DS have an anti-inflammatory profile, especially of Treg. Besides, the prolonged social isolation in children during the COVID-19 pandemic, limiting physical mobility and exercise, reduces DS and increases adiposity, which could impair the immune system function and raise the susceptibility to inflammatory diseases.

Prevalence and Correlates of Physical Activity Among Children and Adolescents: A Cross-Sectional Population-Based Study of a Rural City in Japan

BACKGROUND

Although moderate-to-vigorous physical activity (MVPA) has multiple health benefits, current participation in recommended MVPA level and its determinants among Japanese children and adolescents remain unclear. Therefore, this cross-sectional study investigated the prevalence of meeting recommended MVPA level and its correlates among Japanese children and adolescents.

METHODS

Using the Japanese version of the World Health Organization (WHO) Health Behaviour in School-aged Children survey questionnaire, we confirmed the prevalence of meeting recommended MVPA level in all primary schools (PS) and junior high schools (JHS) in Unnan City, Japan. We evaluated its association with school grade, gender, body weight status, screen time, consumption of breakfast, physical activity (PA) preference, and population density using Poisson regression.

RESULTS

We found that 20.1% of the 1,794 students (9-15 years old) met the WHO recommendation. Meeting recommended MVPA level was significantly associated with being in the sixth grade of PS (prevalence ratio [PR] 0.57; 95% confidence interval [CI], 0.39-0.84) and first (PR 1.52; 95% CI, 1.16-1.99), second (PR 1.45; 95% CI, 1.10-1.90), and third grade of JHS (PR 0.40; 95% CI, 0.26-0.62) (vs fourth grade of PS); being a boy (PR 1.33; 95% CI, 1.12-1.59) (vs girl); liking PA (PR 3.72; 95% CI, 2.22-6.22) (vs dislike); and belonging to a medium-population-density (PR 0.73; 95% CI, 0.61-0.88) or low-population-density area (PR 0.67; 95% CI, 0.48-0.94) (vs high-population-density area).

CONCLUSIONS

About 20% of Japanese children and adolescents engaged in the recommended MVPA level. MVPA was associated with grade, gender, preference for PA, and population density.

School-based study showed a correlation between physical activity and smartphone and tablet use by students aged eight, 11 and 14

AIM

This study investigated correlations between objectively measured physical activity (PA) and smartphone and tablet usage by sex and age in subjects aged eight, 11 and 14.

METHODS

We recruited 549 children and adolescents (264 boys) from six schools in three middle-class communities in south-eastern Sweden. Steps per day were objectively measured using sealed pedometers and a brief daily questionnaire about smartphone and tablet usage. Correlations between mean steps per day and mean daily minutes of smartphone and tablet usage, and differences between low and high users, were investigated.

RESULTS

There was a moderately inverse correlation between steps per day and smartphone and tablet usage in the total sample (r = -.329, P < .001), but it was lower in boys (r = -.340, P < .001) than girls (r = -.401, P < .001). When stratified further by both sex and age, this correlation was only found among 14-year-old girls (r = -.385, P < .001) and this group only, differences between low and high users (P = .005) were seen.

CONCLUSION

There was a moderately inverse correlation between steps per day and smartphone and tablet usage. When stratified by both sex and age groups, this correlation was only observed in 14-year-old girls. The results may have implications for future PA interventions that target adolescent girls.

Comparisons of pedometer-determined weekday physical activity among Swedish school children and adolescents in 2000 and 2017 showed the highest reductions in adolescents

AIM

This study compared differences in weekday physical activity among school children and adolescents in middle-class communities in south-eastern Sweden in 2000 and 2017.

METHODS

Data were drawn from two independent cross-sectional cohorts of children and adolescents aged 8, 11 and 14. The same six schools, protocols, procedures and instruments were used in both years, with 332 subjects in 2000 and 562 in 2017. Mean steps per day (SPD) were measured with a Yamax SW-200 pedometer.

RESULTS

The mean weekday SPD was similar among eight-year-old girls in both years, but 8% (p = 0.040) higher among eight-year-old boys in 2017. However, among 11-year-old children, the mean SPD were 12% lower among both girls (p = 0.033) and boys (p = 0.001). The SPD among 14-year-old adolescents were 24% (p = 0.012) and 30% (p < 0.001) lower among girls and boys, respectively.

CONCLUSION

This school-based study from south-eastern Sweden showed that weekday physical activity differed between age groups in 2000 and 2017. The highest reductions were seen among older children and adolescents, particularly 14-year-old girls and boys. The only group that increased was eight-year-old boys, with no significant change in eight-year-old girls. A possible explanation might be the dramatically increased use of the Internet on phones and tablets.

Results from the Japan's 2018 report card on physical activity for children and youth

Background

The momentum to promote physical activity (PA) by various government agencies such as the Japan Sports Agency established in 2015, academic organizations, and companies is increasing towards the Tokyo Olympic and Paralympic Games. The goal of the 2018 Japan Report Card on Physical Activity for Children and Youth is to assess and track levels of health behaviors related to PA in Japanese children and youth, facilitators and barriers for PA, and related health outcomes.

Methods

Nationally representative data were used to score the indicators.

Results

The 2018 Japan Report Card on Physical Activity for Children and Youth consists of health behaviors and outcomes (7 indicators), and influences on health behaviors (4 indicators). The key four health behaviors and outcomes (Organized Sport Participation: B—; Active Transportation: A-; Physical fitness: A, Weight status: A) were favorable. Sedentary Behavior received C— grade, while 2 indicators (Overall Physical Activity, and Active Play) could not be graded. In the Influences domain, Family Influence and Community were graded as C—, while School (B+), Community and Environment (B—), and Government Strategies and Investments (B) were favorable.

Conclusions

The 2018 Japan Report Card on Physical Activity for Children and Youth shows that Japanese children and youth have favorable levels of organized sport participation, active transportation to and from school, and physical fitness and weight status. Future nationally representative surveys on overall PA and active play are needed.

Lower youth steps/day values observed at both high and low population density areas: a cross-sectional study in metropolitan Tokyo

Background

Physical activity among children and adolescents (collectively, youth) is important to ensure adult health. Population density is a factor that affects physical activity via various environmental factors. However, the relationship between population density and physical activity among youth is not fully understood, especially in extremely high density area. The aim of this study was to examine the relationship between population density and physical activity of youth using pedometer-determined step data.

Methods

A total of 13,688 youth between 6 to 15 years of age were identified from the 2011 Tokyo Metropolitan Survey of Physical Fitness, Physical Activity and Lifestyle. Participants were divided into five subgroups according to the population density of their municipality of residence. The population density’s fixed effects on in-school, out-of-school, and daily total step count adjusted for gender and school grade were estimated.

Results

The lowest (< 2500 people/km²) and highest (> 10,000 people/km²) population density subgroups had significantly lower daily total step count and out-of-school step count than those of the reference population (5000–7500 people/km²). In contrast, in-school step count did not significantly differ according to population density.

Conclusions

Both low population density and also high population density were related to lower step count. Low physical activity in high density areas has not been well documented in previous research. Considering population growth in urbanized area globally, these results suggest the importance of continued research of physical activity determinants in high population density areas.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-6028-y) contains supplementary material, which is available to authorized users.

Objectively evaluated physical activity and sedentary time in primary school children by gender, grade and types of physical education lessons

Background

During the typical school day, physical education (PE) gives children an opportunity for physical activity (PA) and reduces their sedentary time, but little is known about objectively evaluated PA and sedentary time during PE lessons and the differences across genders and grades. There is also a lack of research comparing PA and sedentary time among the different types of PE lessons. The primary aim of this study was to examine primary school students’ moderate-to-vigorous PA (MVPA) levels and sedentary time during PE and whether there are gender or grade differences in a cross-sectional study. The secondary aim was to determine which types of PE lessons are best for increasing PA and reducing sedentary time.

Methods

Objectively evaluated MVPA and sedentary time during PE lessons in Japan with a triaxial accelerometer (Active style Pro HJA-350IT, Omron Healthcare) in girls (n = 221) and boys (n = 181). Minutes of sedentary time were categorized into metabolic equivalents (METs): categories ranged from sedentary time (METs ≤1.5) to MVPA (METs ≥3.0). Time tables and PE lesson types were evaluated using logs maintained by the class teachers.

Results

Time spent in MVPA and sedentary time were 27.3 and 24.3%, respectively. After adjustments for grade, relative body weight and school, boys spent significantly more time in MVPA compared with girls, but with an estimated mean difference of approximately 1 min. After adjustment for gender, relative body weight and school, the younger grades (1st and 2nd) spent significantly more time in MVPA and significantly less time in sedentary time compared with other grades. Moreover, after adjustments for gender, grade, relative body weight and school, the time spent in MVPA during gymnastic and track and field lessons was significantly lower than that during ball game lessons. Sedentary time during gymnastic lessons was significantly longer than in track and field and ball game lessons.

Conclusions

Children did not engage in much MVPA and also spent time in sedentary time during PE, but there are no gender differences. The children were most active during ball game lessons. Therefore, it is important to increase MVPA and reduce sedentary time during PE in both genders.