Tracking of serum lipid levels from childhood to adulthood: Systematic review and meta-analysis.

BACKGROUND AND AIMS: The utility of lipid screening in pediatric settings for preventing adult atherosclerotic cardiovascular diseases partly depends on the lifelong tracking of lipid levels. This systematic review aimed to quantify the tracking of lipid levels from childhood and adolescence to adulthood. METHODS: We systematically searched MEDLINE, Embase, Web of Science, and Google Scholar in March 2022. The protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO; ID: CRD42020208859). We included cohort studies that measured tracking of lipids from childhood or adolescence (<18 years) to adulthood (≥18) with correlation or tracking coefficients. We estimated pooled correlation and tracking coefficients using random-effects meta-analysis. Risk of bias was assessed with a review-specific tool. RESULTS: Thirty-three studies of 19 cohorts (11,020 participants) were included. The degree of tracking from childhood and adolescence to adulthood differed among lipids. Tracking was observed for low-density lipoprotein cholesterol (pooled r = 0.55-0.65), total cholesterol (pooled r = 0.51-0.65), high-density lipoprotein cholesterol (pooled r = 0.46-0.57), and triglycerides (pooled r = 0.32-0.40). Only one study included tracking of non-high-density lipoprotein cholesterol (r = 0.42-0.59). Substantial heterogeneity was observed. Study risk of bias was moderate, mostly due to insufficient reporting and singular measurements at baseline and follow-up. CONCLUSIONS: Early-life lipid measurements are important for predicting adult levels. However, further research is needed to understand the tracking of non-high-density lipoprotein cholesterol and the stability of risk classification over time, which may further inform pediatric lipid screening and assessment strategies.

Physical Activity and Health of Middle-Aged and Older Japanese Across the COVID-19 Pandemic: Differential Outcomes Highlight a Problematic Life Stage.

INTRODUCTION: COVID-19 caused major disruptions across the super-aged nation of Japan, yet few studies explored temporal changes among middle-aged and older cohorts from baseline to the height of community transmission. Changes in physical activity and sedentary behavior during global pandemics may alter patterns of morbidity and mortality among susceptible aging populations. OBJECTIVES: This study investigated patterns of physical activity, sitting behavior, and health among representative samples of middle-aged and older adults in Tokyo before and during the pandemic. METHODS: Repeated online surveys were conducted with quota samples of 800 Tokyo residents in 2019 and 2021 using validated Japanese-language measures, including the short form-International Physical Activity Questionnaire and the Basic Ecological Health Scale-6. Statistical analyses included comparative evaluations of activity parameters by age cohort, gender, and selected covariates. Statistical tests included the Kruskal-Wallis test, Mann-Whitney U test, chi-square test for Independence and Hierarchical Regression. RESULTS: Over 34% of respondents were inactive at each data collection point, and 72% reported negative impacts of COVID-19 on their physical activities. Older adults showed no significant changes in their activity and sitting behavior and reported better health compared with those in middle age across the pandemic. Middle-aged males reported a significant decline in total activity of 33% across the pandemic period (U = 16,958, z = -2.64, p = .008, r = .13). Middle-aged females reported the lowest levels of physical activity, and health, and showed a 29% increase in sitting behavior across the pandemic (U = 16,925, z = -2.68, p = .007, r = .13). Subjective health status was consistently associated with higher overall activity and walking before and during the pandemic. CONCLUSION: Differential outcomes were identified between age and gender regarding health, physical activity, walking, and sitting across the pandemic with significantly worse impacts reported among middle-aged samples. IMPLICATIONS: These results have implications for healthy transitions to later life and the design of postpandemic interventions to address activity opportunities in Japan.

Tracking of apolipoprotein B levels measured in childhood and adolescence: systematic review and meta-analysis.

To quantify the tracking of apolipoprotein B (apoB) levels from childhood and adolescence and compare the tracking of apoB with low-density lipoprotein (LDL) cholesterol, a systematic search of MEDLINE, Embase, Web of Science, and Google Scholar was performed in October 2023 (PROSPERO protocol: CRD42022298663). Cohort studies that measured tracking of apoB from childhood/adolescence (< 19 years) with a minimum follow-up of 1 year, using tracking estimates such as correlation coefficients or tracking coefficients, were eligible. Pooled correlations were estimated using random-effects meta-analysis. Risk of bias was assessed with a review-specific tool. Ten studies of eight unique cohorts involving 4677 participants met the inclusion criteria. Tracking of apoB was observed (pooled r = 0.63; 95% confidence interval [CI] = 0.53-0.71; I2 = 96%) with no significant sources of heterogeneity identified. Data from five cohorts with tracking data for both lipids showed the degree of tracking was similar for apoB (pooled r = 0.59; 95% CI = 0.55-0.63) and LDL cholesterol (pooled r = 0.58; 95% CI = 0.47-0.68). Study risk of bias was moderate, mostly due to attrition and insufficient reporting. CONCLUSION: ApoB levels track strongly from childhood, but do not surpass LDL cholesterol in this regard. While there is strong evidence that apoB is more effective at predicting ASCVD risk than LDL cholesterol in adults, there is currently insufficient evidence to support its increased utility in pediatric settings. This also applies to tracking data, where more comprehensive data are required. WHAT IS KNOWN: • Apolipoprotein B is a known cause of atherosclerotic cardiovascular disease. • Apolipoprotein B levels are not typically measured in pediatric settings, where low-density lipoprotein cholesterol remains the primary lipid screening measure. WHAT IS NEW: • This meta-analysis of 10 studies showed apolipoprotein B levels tracked strongly from childhood but did not exceed low-density lipoprotein cholesterol in this regard. • More comprehensive tracking data are needed to provide sufficient evidence for increased utility of apolipoprotein B in pediatric settings.

Geographical Disparity in Cardiorespiratory Fitness among 3,189,540 Japanese Children and Adolescents before and during the Coronavirus 2019 Pandemic: An Ecological Study.

This ecological study aimed to use nationally representative physical fitness (PF) data to investigate the geographical disparities in cardiorespiratory fitness (CRF) among Japanese children across prefectures before and during the coronavirus 2019 (COVID-19) pandemic. The publicly available descriptive PF data of children from Grade 5 (10-11 years; n = 1,946,437) and adolescents from Grade 8 (13-14 years; n = 1,243,103) at the prefecture level (47 prefectures) were obtained from the annual census PF survey in 2019 (before the pandemic) and 2021 (during the pandemic). The 20 m shuttle run performance was used as a measure of CRF. Geographical disparity was evaluated using the coefficient of variation (CV) for CRF across prefectures. There were significant negative relationships between the magnitude of infections (evaluated as the number of confirmed cases) and changes in CRF at the prefecture level (r ≤ -0.293, p < 0.05). This study also found a substantial increase in CVs of CRF across prefectures for Grade 8 students, suggesting that COVID-19-related restrictions had widened the geographical disparity in CRF among Japanese adolescents. Adolescents' CRF is an important marker for current and future health; hence, the findings of widening geographical disparities in CRF are suggestive of widening geographical disparities in health among the Japanese population.

Feasibility, Safety, Enjoyment, and System Usability of Web-Based Aerobic Dance Exercise Program in Older Adults: Single-Arm Pilot Study.

BACKGROUND: During the COVID-19 epidemic, opportunities for social interaction and physical activity among older people are decreasing, which may have a negative impact on their health. As a solution, a web-based group exercise program provided through a videoconferencing platform would be useful. As a web-based exercise program that older adults can easily, safely, and enjoyably perform at home, we developed a short-duration, light-intensity aerobic dance exercise program. Before studying the effectiveness of this exercise program, its characteristics, such as feasibility, safety, enjoyment, and system usability, should be examined among older adults. OBJECTIVE: This pilot study aimed to examine the feasibility, safety, and enjoyment of a web-based aerobic dance exercise program and the usability of a web-based exercise delivery system using a videoconferencing platform for older adults. METHODS: This study was designed as a prospective single-arm pilot study. A total of 16 older adults participated in an 8-week web-based aerobic dance program held every morning (8:30 AM to 8:50 AM) on weekdays at home. Retention and adherence rates were measured for the program's feasibility. Safety was assessed by the heart rate reserve, an index of exercise intensity calculated from heart rate, and the number of adverse events during exercise sessions. Enjoyment of this exercise program was assessed by an 11-point Likert scale ranging from 0 (not enjoyable at all) to 10 (extremely enjoyable) obtained through telephone interviews after the first-, third-, sixth-, and eighth-week intervention. For usability, the ease of the videoconferencing platform system was assessed through telephone interviews after the intervention. RESULTS: A female participant with hypertension dropped out in the second week because of the continuously reported high blood pressure (≥180 mmHg) before attending the exercise session in the first week. Therefore, the retention rate was 93.8% (15/16). Among the remaining participants, the median (IQR) overall adherence rate was 97.4% (94.7-100). Regarding safety, the mean (SD) heart rate reserve during the aerobic dance exercise was 29.8% (6.8%), showing that the exercise was relatively safe with very light to light intensity. There were no adverse events during the exercise session. The enjoyment score (0-10 points) significantly increased from the first (6.7 [1.7]) to sixth (8.2 [1.3]) and eighth week (8.5 [1.3]). Regarding usability, 11 participants reported difficulties at the beginning, such as basic touch panel operations and the use of unfamiliar applications; however, all got accustomed to it and subsequently reported no difficulty. CONCLUSIONS: This study showed high feasibility, enjoyment, and safety of the web-based aerobic dance exercise program in older adults, and the web-based exercise delivery system may have areas for improvement, albeit without serious problems. Our web-based aerobic dance exercise program may contribute to an increase in physical and social activities among older adults.

Physical fitness before and during the COVID-19 pandemic: Results of annual national physical fitness surveillance among 16,647,699 Japanese children and adolescents between 2013 and 2021.

BACKGROUND: Limited nationally representative evidence is available on temporal trends in physical fitness (PF) for children and adolescents during the coronavirus disease 2019 (COVID-19) pandemic. The primary aim was to examine the temporal trends in PF for Japanese children and adolescents before and during the COVID-19 pandemic. The secondary aim was to estimate the concurrent trends in body size (measured as body mass and height) and movement behaviors (exercise, screen, and sleep time). METHODS: Census PF data for children in Grade 5 (aged 10-11 years) and adolescents in Grade 8 (aged 13-14 years) were obtained for the years 2013-2021 from the National Survey of Physical Fitness, Athletic Performance, and Exercise Habits in Japan (n = 16,647,699). PF and body size were objectively measured, and movement behaviors were self-reported. Using sample-weighted linear regression, temporal trends in mean PF were calculated before the pandemic (2013-2019) and during the pandemic (2019-2021) with adjustments for age, sex, body size, and exercise time. RESULTS: When adjusted for age, sex, body size, and exercise time, there were significant declines in PF during the pandemic, with the largest declines observed in 20-m shuttle run (standardized (Cohen's) effect size (ES) = -0.109 per annum (p.a.)) and sit-ups performance (ES = -0.133 p.a.). The magnitude of the declines in 20-m shuttle run and sit-ups performances were 18- and 15-fold larger, respectively, than the improvements seen before the pandemic (2013-2019), after adjusting for age, sex, body size, and exercise time. During the pandemic, both body mass and screen time significantly increased, and exercise time decreased. CONCLUSION: Declines in 20-m shuttle run and sit-ups performances suggest corresponding declines in population health during the COVID-19 pandemic.

Top 10 International Priorities for Physical Fitness Research and Surveillance Among Children and Adolescents: A Twin-Panel Delphi Study.

BACKGROUND: The measurement of physical fitness has a history that dates back nearly 200 years. Recently, there has been an increase in international research and surveillance on physical fitness creating a need for setting international priorities that could help guide future efforts. OBJECTIVE: This study aimed to produce a list of the top 10 international priorities for research and surveillance on physical fitness among children and adolescents. METHODS: Using a twin-panel Delphi method, two independent panels consisting of 46 international experts were identified (panel 1 = 28, panel 2 = 18). The panel participants were asked to list up to five priorities for research or surveillance (round 1), and then rated the items from their own panel on a 5-point Likert scale of importance (round 2). In round 3, experts were asked to rate the priorities identified by the other panel. RESULTS: There was strong between-panel agreement (panel 1: rs = 0.76, p < 0.01; panel 2: rs = 0.77, p < 0.01) in the priorities identified. The list of the final top 10 priorities included (i) "conduct longitudinal studies to assess changes in fitness and associations with health". This was followed by (ii) "use fitness surveillance to inform decision making", and (iii) "implement regular and consistent international/national fitness surveys using common measures". CONCLUSIONS: The priorities identified in this study provide guidance for future international collaborations and research efforts on the physical fitness of children and adolescents over the next decade and beyond.

Health-Related Expectations Regarding Aging among Middle-Aged and Older Japanese: Psychometric Performance and Novel Findings from the ERA-12-J.

BACKGROUND AND OBJECTIVES: Health-related expectations regarding aging is a gerontological construct that is potentially predictive of morbidity and mortality in later life. The Expectations Regarding Ageing scale (ERA-12) is a widely used measure of health-related expectations, although it has not previously been administered in Japanese. The present research aimed to elucidate the psychometric properties of the first Japanese translation of the ERA-12 and evaluate health-related expectations among middle-aged and older Japanese. RESEARCH DESIGN AND METHODS: Repeated online surveys were conducted with representative quota samples of middle-aged and older adults in Tokyo during 2021 (N = 1600). Primary outcome measures included total and subscale scores on a Japanese translation of the ERA-12 (ERA-12-J) addressing perceptions of physical, mental, and cognitive health. Standard measures were also used to gather information regarding respondent demographic details, general health, and health-related behavior. RESULTS: The ERA-12-J and associated subscales showed acceptable test-retest reliability (t(1598) = 0.60, p = 0.63), internal consistency (α > 0.80), inter-item correlation (r = 0.21-0.78) and item-total correlation (r = 0.53-0.73). Confirmatory Factor Analysis verified the hypothesized three-factor structure and construct validity on four common indices of fit (GFI = 0.968; CFI = 0.978; AGFI = 0.950; RMSEA = 0.059). ERA-12-J scores among Japanese respondents revealed prevailing negative sentiments concerning physical and cognitive health, with less negative sentiment regarding mental health. Significant and independent differences emerged concerning gender and age cohort, with middle-aged adults and females holding more negative expectations about their future health. DISCUSSION AND IMPLICATIONS: The ERA-12-J provides a sound basis for the elucidation of health-related expectations about aging in Japan and a useful tool for international comparative studies. Education and workplace intervention may be required in Japan to address age and gender disparities in health-related expectations.

Risky Play and Social Behaviors among Japanese Preschoolers: Direct Observation Method.

While limited evidence is available, preliminary studies highlight the potential health benefits of risky play. However, most of the studies have used subjective methods (i.e., questionnaires) to evaluate children's risky play, which limits their validity and reliability. The purpose of the present study was to examine the relationship between the frequency of risky play and social behavior among Japanese preschoolers by using a valid and reliable method such as direct observation. A total of 32 Japanese preschoolers (71.4 ± 3.5 months old) participated in the study, and their social behaviors were measured by the Strength and Difficulties Questionnaire (SDQ). Data regarding the frequency of risky play was collected through direct observation. Results stated that, in a non-adjusted model, there was no significant association between children's risky play and prosocial behavior. However, the association became significant after adjusting for covariates such as gender, parental employment status, and physical activity. In contrast, there was no significant association between children's risky play and problem behavior (hyperactivity and aggression) after adjusting for covariates. In conclusion, covariates such as parental employment should be considered when examining the benefits of risky play.

The Immediate and Lasting Effects of Resident Summer Camp on Movement Behaviors Among Children.

This study aims to examine the immediate and lasting effects of resident summer camp on movement behaviors among children with repeated pre-, during-, and post-intervention measurements. In total, 21 children (aged 10.3 ± 1.2 years, 17 boys and 4 girls) participated in a 31-day nature-based resident summer camp in Japan. Daily children's movement behaviors (moderate-to-vigorous physical activity (MVPA), sedentary behavior (SB), and sleep) were continuously monitored before, during, and after the summer camp (i.e., 75 continuous days). It was found that the children engaged more time in MVPA (9.6%), less time in SB (58.0%), had more steps (22,405 steps/day), and an earlier midpoint of sleep (0:24 a.m.) in the summer camp as compared to the other periods (before and after the camp). However, the children engaged in unfavorable behaviors [reduction in MVPA (3.6%), increased SB (67.3%), and a later midpoint of sleep (1:32 a.m.)] during the summer vacation after the camp. This study indicates that the resident summer camp was effective in improving children's movement behaviors during the camp. However, the lasting effects were negligible or at least limited after its completion.

Sports activities at a young age decrease hypertension risk-The J-Fit+ study.

This study aimed to assess (1) blood pressure between young, current athletes, and non-athletes early in life; (2) hypertension prevalence between former athletes and the general population later in life; and (3) understand the mechanisms between exercise training and hypertension risks in the form of DNA methylation. Study 1: A total of 354 young male participants, including current athletes, underwent blood pressure assessment. Study 2: The prevalence of hypertension in 1269 male former athletes was compared with that in the Japanese general population. Current and former athletes were divided into three groups: endurance-, mixed-, and sprint/power-group. Study 3: We analyzed the effect of aerobic- or resistance-training on DNA methylation patterns using publicly available datasets to explore the possible underlying mechanisms. In young, current athletes, the mixed- and sprint/power-group exhibited higher systolic blood pressure, and all groups exhibited higher pulse pressure than non-athletes. In contrast, the prevalence of hypertension in former athletes was significantly lower in all groups than in the general population. Compared to endurance-group (reference), adjusted-hazard ratios for the incidence of hypertension among mixed- and sprint/power-group were 1.24 (0.87-1.84) and 1.50 (1.04-2.23), respectively. Moreover, aerobic- and resistance-training commonly modified over 3000 DNA methylation sites in skeletal muscle, and these were suggested to be associated with cardiovascular function-related pathways. These findings suggest that the high blood pressure induced by exercise training at a young age does not influence the development of future hypertension. Furthermore, previous exercise training experiences at a young age could decrease the risk of future hypertension.

The Changes in Visual Acuity Values of Japanese School Children during the COVID-19 Pandemic.

The coronavirus disease 2019 (COVID-19) pandemic may result in a greater decrease in visual acuity (VA) among Japanese children. Our study aimed to examine Japanese children's VA during the pandemic. VA data were collected using standard eye tests during school health check-ups conducted in 2019 and 2020 on 5893 children, in seven public elementary schools and four public junior high schools in Tokyo, Saitama, Kanagawa, and Shizuoka. VA changes were statistically analyzed. The relationship between the survey year and poor VA yielded a significant regression coefficient for the surveyed years in elementary and junior high school students. The 2019 VA value and VA change from 2019 to 2020 demonstrated a significant regression coefficient in elementary school students with VAs of "B (0.7−0.9)" and "C (0.3−0.6)", and junior high school students with VAs of "B", "C", and "D (<0.3)". An analysis of the relationship between the survey year and eye laterality of VA yielded a significant regression coefficient in the surveyed years for elementary (OR, 1.516; 95% CI, 1.265−1.818) and junior high school students (OR, 1.423; 95% CI, 1.136−1.782). Lifestyle changes during the COVID-19 pandemic might have affected VA and eye laterality in Japanese children.

Mental Toughness Characteristics of Male University Athletes in Relation To Contextual Factors.

Mental toughness is a psychological construct related to successful performance in academics, management, and sports among other sectors. However, studies on the determinants of mental toughness with respect to different human endeavours have remained inconclusive. This study explored mental toughness characteristics of male university athletes in selected sports in relation to contextual factors of athletes' age, playing experience, year of study, and the type of sport. The Mental Toughness Questionnaire (MTQ48) was used to collect data from male university athletes (n = 140). Results of this study showed significant difference in the following components of MT: lower scores in challenge (p = .015), emotional control (p = .005), and life control (p = .002) among athletes with shorter playing experience, and higher scores in life control (p < .001), emotional control (p = .021), and confidence in abilities (p = .009) in handball as compared to soccer players. Soccer players had significantly higher scores in the challenge component (p = .038) of mental toughness as compared to handball players. It was concluded that playing experience and the type of sport influenced characteristics of mental toughness among university athletes. Coaches, trainers, and sports psychologists need to consider these contextual factors to optimize mental toughness of athletes. Future studies should explore how specific contextual factors influence training environments and outcomes, as well as how stakeholders can leverage on the relationships between playing experience, the type of sport and mental toughness to augment athletes' mental toughness and sports performance.

Segmented physical activity and sedentary behavior patterns among children in Maasai village and Nairobi city.

OBJECTIVES: Urban-rural comparisons between those who maintain traditional lifestyles such as pastoralist Maasai children, and those who live in cities such as Nairobi, provide implications on how urbanization is associated with children's physical activity (PA) and sedentary behavior (SB) patterns. This study compares PA and SB volumes and patterns across different segments of the week among children in Maasai village and Nairobi city in Kenya. METHOD: A total of 261 children (11.4 ± 1.3 years) from Maasai (n = 118) and Nairobi (n = 143) participated in this cross-sectional study. Moderate- to vigorous-intensity PA (MVPA) and SB on weekdays (before, during, and after school) and weekends (morning, afternoon, and evening) were calculated using accelerometers (ActiGraph). Screen time and sleep duration were assessed using questionnaires. RESULTS: Maasai children were more physically active than Nairobi children with MVPA (min/day) of 166.6 and 81.4 for Maasai and Nairobi boys and 116.4 and 77.4 for Maasai and Nairobi girls, respectively. Our week segments analyses suggested that Maasai children were more active both in and out of school than Nairobi children. Additionally, Nairobi children spent more time watching television and playing computer games than Maasai children. There was no significant difference in sleep duration between Maasai and Nairobi children. CONCLUSION: Our findings suggest that urbanization is negatively associated with activity patterns both in and out of school in Kenyan children. This is concerning given that Kenya is currently undergoing rapid urbanization, which may lead to further reductions in PA among Kenyan children.

Sociocultural Dimensions of Children's Physical Activity in Contemporary Pastoralist Maasai Society.

Children's physical activity (CPA) in low- and middle-income regions has received increasing attention, but research is still very limited. This study explores the CPA in contemporary pastoralist Maasai society in rural Kenya by considering its sociocultural dimensions. The physical activity of 25 children (15 girls and 10 boys) was documented with mixed methods, including an epidemiological assessment of the CPA and semi-structured interviews with the targeted children regarding their daily activities. These methods were integrated with the ethnographic data on children's socialization in the same area. Results showed a very high level of moderate-to-vigorous physical activity (MVPA) of these children with significant gender differences especially outside school. Children reported their continued social participation in local gender-age labor divisions outside of school. As their activities outside school strongly contributed to their empirical learning of local knowledge and skills, a high MVPA plays an active role in enhancing the children's ability to access and manage livestock and different natural resources. Findings from this study first show that the CPA is not merely physical, but also has significant sociocultural meanings in the process of in situ learning of local wisdom. We call more attention to children's social roles in future investigations of CPA among less examined populations.

The Pathways Linking to Sleep Habits among Children and Adolescents: A Complete Survey at Setagaya-ku, Tokyo.

It has been noted that Japanese children sleep the least in the world, and this has become a major social issue. This study examined the pathways linked to sleep habits (SH) among children and adolescents. A questionnaire-based survey was conducted in March 2019 on children and their parents at all 63 public elementary and 29 public junior high schools in Setagaya-ku, Tokyo. For the analysis, 22,385 pairs of children-parent responses (valid response rate: 68.8%) with no missing data were used. This survey collected data on SH, physical activity (PA), screen time (ST) for the child, and lifestyle and neighborhood social capital (NSC) for the parents. Moreover, the pathways linking 'NSC' → 'parental lifestyle' → 'child's PA/ST' →'child's SH' were examined through structural equation modeling. The results indicated that children's SH were affected by their PA and ST and influenced by the lifestyle of their parents and the NSC that surrounds them. Thus, we concluded that it is necessary to provide direct interventions and take additional measures with regard to parent lifestyle and their NSC to solve persistent sleep problems in children.

Walking speed and balance both improved in older Japanese adults between 1998 and 2018.

BACKGROUND/OBJECTIVE: Physical function, the ability of an individual to carry out physical tasks, is meaningfully related to health among older adults. Few studies have analyzed temporal trends in objective performance measures of physical function for older adults. The aim of this study was to estimate temporal trends in balance and walking speed for older Japanese adults (aged 65-79 years) between 1998 and 2018. METHODS: Annual, cross-sectional, national fitness surveillance data for balance (n = 114,785) and walking speed (n = 112,289) were reported descriptively by the Japanese Ministry of Education, Culture, Sports, Science and Technology across the 1998-2018 period. Trends in means were estimated by sample-weighted regression, with trends in variability estimated as the ratio of coefficients of variation. RESULTS: There was a moderate improvement in both mean balance (standardized effect size (ES) change (95% confidence interval (CI)): 0.50 (0.48-0.52)) and mean walking speed (ES change (95%CI): 0.53 (0.51-0.55)). Improvements were seen in all gender and age groups, with small gender-related and negligible age-related temporal differences. Variability declined substantially for both balance (ratio of CVs (95%CI): 0.77 (0.75-0.79)) and walking speed (ratio of CVs (95%CI): 0.87 (0.85-0.89)). CONCLUSION: Improved physical performance is suggestive of a corresponding improvement in health. Declines in variability indicate that temporal improvements were not uniform across the distribution.

Improvements in Physical Fitness are Associated with Favorable Changes in Blood Lipid Concentrations in Children.

Although accumulating evidence suggests the benefits of cardiorespiratory fitness and muscular fitness, little knowledge exists on how other physical fitness (PF) components are associated with cardiovascular disease (CVD) risk markers in children. Additionally, much of the relevant evidence is from longitudinal studies with CVD risk markers at a single time point (i.e., baseline) rather than changes in PF. The purpose of the present study was to examine whether initial 1-year changes in different performance measures of PF (i.e., endurance performance, muscular strength/endurance, flexibility, agility, and speed) can predict the subsequent changes (2-year change) in blood lipid concentrations in children. This 2-year longitudinal study included a total of 251 Japanese children (mean age 9.2 ± 0.4). PF tests were performed to comprehensively evaluate the participant's fitness levels (handgrip strength [upper body muscular strength], bent-leg sit-ups [muscular endurance], sit-and-reach [flexibility], side-step [agility], 20-meter shuttle run [endurance performance], 50-meter sprint [speed], standing long jump [lower body muscular strength], and softball throw [explosive arm strength and throwing ability]). Fasting lipid profile was assayed for triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and non-HDL-C concentration. Multilevel linear regressions were used to examine the associations between the preceding changes (over 1-year) in PF and subsequent changes (over 2-years) in blood lipid concentrations. We also examined the simultaneous associations between 2-year changes in PF and 2-year changes in blood lipid concentrations. For boys, preceding improvement in handgrip strength was negatively associated with TG concentration (ß = -0.260, p = 0.030); improvements in bent-leg sit-ups were negatively associated with clustered lipid scores (ß = -0.301, p = 0.038) and non-HDL-C (ß = -0.310, p = 0.044); and improvements in 50m sprinting were associated with subsequent changes in non-HDL-C (ß = 0.348, p = 0.006) and LDL-C (ß = 0.408, p = 0.001). For girls, improvements in handgrip strength was negatively associated with TG concentration (ß = -0.306, p = 0.017); and improvements in standing long jump were negatively associated with non-HDL-C (ß = -0.269, p = 0.021) and LDL-C (ß = -0.275, p = 0.019). For boys and girls, there were no significant simultaneous associations between 2-year changes in PF and 2-year changes in blood lipid concentrations. In conclusion, preceding change in physical fitness in relation to change in blood lipid concentration likely reflect a physiological adaptation to growth and maturation since these associations diminished in the subsequent year.

Different Types of Screen Behavior and Depression in Children and Adolescents.

The purpose of this study was to examine the associations between different types of screen behavior and depression, taking into account exercise and sleep among children and adolescents. A total of 23,573 Japanese children and adolescents (aged 8-15 years) participated in this cross-sectional study. Different types of screen behavior, weekly exercise time, sleep duration, and prevalence of depression were assessed using a questionnaire. Independent associations between various types of screen behavior and prevalence of depression were examined using logistic regression analyses after adjusting for age, school, sleep duration, exercise time, and other screen behavior types. A two-way analysis of covariance was conducted to examine whether exercise and sleep can attenuate the negative effects of screen behavior. The associations between screen behavior and depression varied by screen behavior types and participant characteristics. More time spent engaging in newer types of screen behavior, including social media, online games, and online videos, was associated with a higher prevalence of depression. In contrast, more time spent on TV was associated with a lower prevalence of depression. Sufficient exercise can lower the prevalence of depression, regardless of the length of time and content of the screen, and its associations were particularly significant for junior high school girls. Sleep was not associated with the prevalence of depression among any participant group except elementary school boys. Our findings suggest that age- and sex-specific intervention strategies that also consider screen-based behavior can effectively lower the risk of depression in children and adolescents.