Association between physical activity and cardiovascular risk in Chinese youth independent of age and pubertal stage

Secular trends in sleep and circadian problems among adolescents in Hong Kong: From 2011-2012 to 2017-2019

OBJECTIVE

The study aimed to investigate secular trends in sleep and circadian problems in Hong Kong Chinese adolescents.

METHODS

This study analyzed cross-sectional data from two large-scale school-based sleep surveys conducted in 2011-2012 and 2017-2019. Sleep and circadian problems, including sleep-wake pattern, insomnia, chronotype, social jetlag, daytime sleepiness, and other sleep-related factors, were compared between two survey years.

RESULTS

A total of 8082 adolescents (5639 students in 2011-2012 [Mean age: 14.4 years, 50.9% boys] and 2443 students in 2017-2019 [Mean age: 14.7 years, 54.0% boys]) were included in this 7-year study. The average time in bed of Hong Kong adolescents decreased from 8.38 hours to 8.08 hours from 2011-2012 to 2017-2019. There was a 0.28-hour delay in weekday bedtime, 0.54-hour advance in weekend wake-up time, and a 0.36-hour decline in average time in bed, resulting in increased trends of sleep loss (Time in bed <8h: OR = 2.06, 95%CI: 1.44-2.93, p < 0.01; Time in bed <7h: OR = 2.73, 95%CI: 1.92-3.89, p < 0.01), daytime sleepiness (OR = 1.70, 95%CI: 1.34-2.16, p < 0.01), and evening chronotype (OR = 1.26, 95%CI: 1.08-1.48, p < 0.01). The increased trend in insomnia disorder, however, was insignificant when covariates were adjusted.

CONCLUSION

A secular trend of reduced time in bed, delay in weekday bedtime, advance in weekend wake-up time, increase in evening chronotype and daytime sleepiness from 2011-2012 to 2017-2019 were observed. There is a timely need for systematic intervention to promote sleep health in adolescents.

Physical Activity Levels and Factors Affecting Them in Hospitalized Children With Leukemia

BACKGROUND

Physical activity promotes healthy physical and mental development in children with leukemia. However, the level of physical activity in hospitalized children with leukemia and the factors that influence it are unknown.

OBJECTIVES

The aims of this study were to understand the physical activity level of hospitalized children with leukemia and to explore the factors influencing it to provide a reference for physical activity assessment and intervention in such children.

METHODS

A total of 133 hospitalized children with leukemia completed a general information questionnaire, the Chinese University of Hong Kong Physical Activity Rating for Children and Youth, and the Children's Social Anxiety Scale. A cross-sectional study was used to explore the effects of different variables on the children's activity levels.

RESULTS

Among the study participants, 44.4% had a low-intensity activity level, 35.3% had a moderate-intensity activity level, and 20.3% had a high-intensity activity level, with a total physical activity rating of 3 (1, 6). Chemotherapy phase (P = .007), screen time (P = .001), and social anxiety (P = .012) were identified as influential factors.

CONCLUSIONS

Our results showed that children with hospitalized leukemia had lower-intensity physical activity levels, especially in the chemotherapy phase of induction remission. Furthermore, screen time and social anxiety had negative effects on the children's activity levels.

IMPLICATIONS FOR PRACTICE

According to the physical activity level of the children and the influencing factors, healthcare professionals should gradually improve children's mobility and promote their physical and mental health development through guidance and encouragement, and the development of personalized activity intervention programs.

The Nexus of Sports-Based Development and Education of Mental Health and Physical Fitness

Physical inactivity has increased globally, particularly in developed nations. A high proportion of the human population is unable to meet the physical activity recommendation of the World Health Organisation due to hypertension, metabolic syndrome, obesity, and other medical conditions. Non-communicable diseases and mental health problems are becoming more prevalent, particularly in low and middle-income nations. This study aimed to determine the effectivenessof a mentorship programmeon university students' mental health and physical fitness. The intervention comprised the effects of sports-based development and education on physical fitness and mental health. A total of 196 and 234 students from two universities were randomly assigned to the intervention and control groups, respectively. The primary outcomes were engagement in physical activities (number of push-ups for 1 min, the strength of hand grip (kg), and the Jump test while standing (cm)), body fat proportion and psychological resilience, self-efficacy, and relationship with family and schoolmates. Participants in the control group had access to a web-based health education game, whereas the intervention group wassubjected to intensive interventional activities for one month based on the eight principles of the National Research Council and Institute of Medicine. Data were analysed using Analysis of Variance (ANOVA) to compare the physical and mental components between the intervention and control groups. Relative to baseline, all the physical health components (push-ups, sit-ups, and jump tests), psychological resilience, relationship with family members, and self-efficacy increased significantly in the intervention compared to the control group. Body fat composition was significantly reduced in the intervention when compared tothe control group. In conclusion, the mentorship programme effectively improved the participants' physical and psychological health and could be developed further for application in a larger population.

Associations between Lifestyle Factors and Neurocognitive Impairment among Chinese Adolescent and Young Adult (AYA) Survivors of Sarcoma

BACKGROUND

The effect of lifestyle on neurocognitive impairment among cancer survivors remain an understudied area. This study explored the association between lifestyle factors and neurocognitive outcomes (specifically, attention, memory, processing speed and cognitive flexibility) in AYA survivors (aged 15-39 years) of sarcoma.

METHODS

This study recruited 116 AYA survivors (age 28.2 (SD = 8.2) years), who were diagnosed with osteosarcoma (49%) or soft-tissue sarcoma (51%) at age 13.3 (SD = 7.2) years. The neurocognitive battery included measures of attention, memory, motor-processing speed, and cognitive flexibility. Survivors reported health-damaging practices, which included: physical inactivity, smoking, alcohol intake, inadequate sleep (<7 h of actual sleep/day), sleep-related fatigue (Multidimensional Fatigue Scale) and long working hours (>9 h/day). General linear modeling was conducted to examine the association between lifestyle factors and neurocognitive outcomes, adjusting for age at diagnosis, sex, education attainment and clinical/treatment variables.

RESULTS

At 14.9 (SD = 7.6) years post-diagnosis, survivors demonstrated impairment in attentiveness (4.3-13.0%), processing speed (34.5%) and cognitive flexibility (18.1%). Nearly half (45.7%) had developed a chronic health condition (CHC). Low physical activity (estimate = -0.97, p = 0.003) and sleep-related fatigue (estimate = -0.08, p = 0.005) were associated with inattention. Survivors who worked >9 h/day (n = 15) demonstrated worse attention (estimate = 5.42, p = 0.023) and cognitive flexibility (estimate = 5.22, p = 0.005) than survivors who worked ≤9 h/day (n = 66). Interaction analysis (CHCs*physical activity) showed that survivors who developed CHCs and reported low physical activity had worse attention (p = 0.032) and cognitive-flexibility (p = 0.019) scores than other subgroups.

CONCLUSION

Treatment-related CHCs, coupled with continued physical inactivity, may exacerbate inattention and executive dysfunction among survivors. Long working hours and sleep-related fatigue are associated with worse functioning; this finding should be validated with prospective assessment of work-related stressors and objective sleep measures.

Patients with Adolescent Idiopathic Scoliosis Have Higher Metabolic Cost during High-Intensity Interval Training

BACKGROUND

Patients with adolescent idiopathic scoliosis (AIS) are found to have a lower level of physical activity, and may have reduced exercise capacity due to spinal deformity. Previous study showed the benefits of high-intensity interval training (HIIT), named E-Fit, which is specifically designed for patients with AIS to improve musculoskeletal health and psychological well-being. To optimize the beneficial effects of training, the current study aimed to investigate the appropriate exercise intensity and metabolic demand in patients with AIS when performing E-Fit.

METHODS

In all, 22 female subjects, 10 diagnosed with AIS and 12 gender-matched healthy controls, aged between 10 and 16 years, were recruited. Subjects were instructed to perform two trials of a seven min E-Fit. Breath-by-breath gas exchange parameters including oxygen consumption (VO₂), heart rate (HR) and the rate of perceived exertion (PRE) were measured during exercise. Demographic data and clinical features of AIS and body composition were obtained. Metabolic demand between AIS and control groups was compared using MANOVA with covariates adjustment.

RESULTS

Patients with AIS had an earlier onset of menarche (p = 0.01), higher visceral adipose tissue (p = 0.04) and percentage body fat (p = 0.03) as compared to controls. Patients with AIS showed a significantly higher adjusted means of VO₂ average in both the first (p = 0.014) and second trials (p = 0.011) of E-Fit. The adjusted mean of the highest measured VO₂ was higher than healthy controls and reached statistical significance in the second trial (p = 0.004). Both the AIS and control group exercised at a similar percentage of VO₂ peak (64.26% vs. 64.60%).

CONCLUSION

Patients with AIS showed higher oxygen consumption during E-Fit than heathy controls, which might indicate a higher metabolic cost. Patients with AIS could carry out exercise at a moderate exercise intensity similar to that of healthy controls, but special considerations in designing an exercise program, such as frequent rest intervals, would be useful to avoid fatigue among patients with AIS.

Exercise training in paediatric congenital heart disease: fit for purpose?

Exercise and physical activity (PA) have been shown to be effective, safe and feasible in both healthy children and children with congenital heart disease (CHD). However, implementing exercise training as an intervention is still not routine in children with CHD despite considerable evidence of health benefits and well-being. Understanding how children with CHD can safely participate in exercise can boost participation in PA and subsequently reduce inactivity-related diseases. Home-based exercise intervention, with the use of personal wearable activity trackers, and high-intensity interval training have been beneficial in adults' cardiac rehabilitation programmes. However, these remain underutilised in paediatric care. Therefore, the aims of this narrative review were to synthesise prescribed exercise interventions in children with CHD, identify possible limitation to exercise training prescription and provide an overview on how to best integrate exercise intervention effectively for this population into daily practice.

Associations Between Physical Activity and Hypertension in Chinese Children: A Cross-Sectional Study From Chongqing

Background: Childhood blood pressure is a marker for cardiovascular disease risk later in life. Few studies examined the association between physical activity (PA) and hypertension in Chinese children, and this study aimed to explore this relationship.

Methods: A cross-sectional study among pupils was conducted in Chongqing in 2014. In total, 15,203 children aged 6–12 years in Chongqing were included in this study. The duration of self-reported PA on school days and the weekend in pupils were collected with a standardized questionnaire.

Results: The results showed that, on school days, only 22.3% of boys and 17.8% of girls engaged in more than 60 min of PA per day; while on the weekend, only 38.5% of boys and 32.0% of girls engaged in at least 60 min of PA per day. There was no strong evidence for an association between PA and systolic or diastolic hypertension in boys. However, in girls, a weak negative association between PA on weekdays and hypertension was observed, and there was a significant interactive effect of PA and obesity on hypertension risk (P_{for interaction} = 0.042). In obese children, PA was positively related to the risk of hypertension.

Conclusion: The overall level of PA among pupils in Chongqing was insufficient, and a weak negative relationship between PA and hypertension was found in girls.

The trajectories and associations of eveningness and insomnia with daytime sleepiness, depression and suicidal ideation in adolescents: A 3-year longitudinal study

BACKGROUND

Eveningness and insomnia are highly comorbid and closely related to psychopathology in adolescents. We aimed to prospectively investigate the trajectories and associations of eveningness and insomnia with daytime functioning, depression and suicidal risk in adolescents.

METHODS

A 3-year longitudinal study was conducted among 414 Chinese adolescents. The associations of eveningness and insomnia with daytime functioning, depression and suicidal ideation were analyzed using logistic regressions.

RESULTS

The prevalence rates of eveningness were similar at baseline and follow-up (19.3% vs 22.5%; p = 0.27), while the prevalence of insomnia increased at follow-up (29.2% vs 40.8%; p < 0.001). Among those eveningness adolescents (n=80) at baseline, 46.2% remained as stable evening-type at follow-up, and among those insomnia adolescents (n=121) at baseline, 64.5% had persistent insomnia at follow-up. Logistic regressions showed that stable, incident, and resolved eveningness were associated with excessive daytime sleepiness (EDS) at follow-up, while only persistent and incident insomnia increased the risk of EDS. Persistent and incident insomnia, as well as stable eveningness were independently associated with depression at follow-up. Persistent and incident insomnia, but not eveningness, were associated with suicidal ideation.

LIMITATIONS

The outcome assessments were based on self-reported questionnaires and the sample size is modest.

CONCLUSIONS

Persistent eveningness and insomnia are significantly associated with greater risks of EDS and depression in adolescents, while both persistent and incident insomnia, but not eveningness, increased the risk of suicidal ideation. These findings underscore the importance of addressing sleep and circadian factors in the management of adolescent mood and daytime functioning.

Neurocognitive and Behavioral Outcomes of Chinese Survivors of Childhood Lymphoblastic Leukemia

Background

Increasing attention has been dedicated to investigate modifiable risk factors of late effects in survivors of childhood cancer. This study aims to evaluate neurocognitive and behavioral functioning in a relatively young cohort of survivors of childhood acute lymphoblastic leukemia (ALL) in Hong Kong, and to identify clinical and socio-environmental factors associated with these outcomes.

Methods

This analysis included 152 survivors of childhood ALL who were ≥5 years post-diagnosis (52% male, mean [SD] age 23.5[7.2] years at evaluation, 17.2[7.6] years post-diagnosis). Survivors completed performance-based neurocognitive tests, and reported their emotional and behavioral symptoms using the Child/Adult Behavior Checklist. Socio-environmental variables (living space, fatigue, physical activity, family functioning, and academic stress) were self-reported using validated questionnaires. Clinical variables and chronic health conditions were extracted from medical charts. Multivariable linear modeling was conducted to test identify factors associated with neurocognitive/behavioral outcomes, adjusting for current age, sex, age at diagnosis and cranial radiation. An exploratory mediation analysis was performed to examine the mediating effects of risk factors on neurocognitive and behavioral outcomes.

Results

As compared to population norms, a minority of survivors developed mild-moderate impairment in motor processing speed (36.2%), memory (9.2%) and attention measures (4.0%-10.5%). Survivors also reported attention problems (12.5%), sluggish cognitive tempo (23.7%) and internalizing (depressive, anxiety and somatic symptoms) problems (17.1%). A minority of survivors developed mild-moderate treatment-related chronic conditions (n=37, 24.3%). As compared to survivors without chronic conditions, survivors with chronic conditions had more executive dysfunction (B=5.09, standard error [SE]=2.05; P=0.014) and reported more attention problems (B=5.73, SE=1.43; P<0.0001). Fatigue and poor family functioning was associated with multiple measures of behavior problems (all P<0.001). A lower level of physical activity was correlated with more self-reported symptoms of inattention (B= -1.12, SE=0.38, P=0.004) and sluggish cognitive tempo (B=-1.22, SE=0.41, P=0.003). Exploratory analysis showed that chronic health conditions were associated with behavioral measures through fatigue as the mediator.

Conclusion

The majority of young Chinese survivors of ALL had normal cognitive and behavioral function. Regular monitoring of behavioral function should be performed on survivors who develop treatment-related chronic conditions. Health behavior and socio-environment factors may be potentially modifiable risk factors associated with health outcomes in survivors.

An Update on Physical Activity Research among Children in Hong Kong: A Scoping Review

Similar to their Western counterparts, children in Hong Kong generally fail to reach the recommended levels of physical activity (PA). As an ultra-dense metropolis, Hong Kong is different from most Western cities. It is therefore important to update and appraise previous PA research in order to inform future PA promotion for Hong Kong children. Using a scoping review, the current study aimed to evaluate PA research among preschool and school-aged children in Hong Kong aged 3-12 years old who are at a critical development stage. Literature was searched from four English databases: Medline via EBSCOhost, SPORTDiscus, ERIC and PsycINFO via ProQuest; and three Chinese databases: CNKI, CQVIP and WAN-FANG. PA research among Hong Kong children published from 1 January 1997 to the searching date, 31 March 2020 was included. A total of 63 studies were identified, with the majority of studies focused on school-aged children as compared to preschoolers, adopted a cross-sectional design, using self-reported PA measures, and with small to medium sample sizes. We classified eligible studies into five main categories: (a) Health benefits of PA (k = 12). Consistent evidence on the health benefits of skeletal and cardiovascular capacity, quality of life, cognitive function, and sleep quality was revealed. However, inconsistent evidence was found on the benefits of weight-related indicators and academic performance. (b) Patterns of PA (k = 12). There is a general pattern of low levels of PA among Hong Kong children, in particular girls and children with special educational needs. (c) Measures of PA and related constructs (k = 11). The Chinese versions of self-reported measures of PA, PA-related social environment, and PA-related psychological constructs showed acceptable reliabilities and validities. (d) Correlates of PA (k = 18). The correlates of PA include physical environment, social environment, physical factors, psychological factors, and multiple correlates, which is in line with the social-ecological model. (e) Interventions for promoting PA (k = 10). PA interventions among Hong Kong children were conducted for healthy children, children with special educational needs, and children with cancer. Overall, there is a growing volume of PA research among children in Hong Kong in the recent decade. Yet, there is a lack of high-quality research for measuring, understanding, and promoting PA among Hong Kong children. It is highly recommended that future PA research among children should pay more attention on the preschoolers, adopting robust research design (e.g., randomized controlled trials), recruiting large and representative sample, and collecting device-assessed data.

Cadherin-related family member 3 gene impacts childhood asthma in Chinese children

BACKGROUND

A missense variant (rs6967330) of the gene encoding cadherin-related family member 3 (CDHR3) was associated with recurrent severe exacerbations in pre-schoolers. However, there were limited data on its relationship with pre-school lung function and school-age asthma. This study replicated the association between polymorphic markers at the region of CDHR3 around rs6967330 and wheezing phenotypes in two independent cohorts of Chinese children.

METHODS

Ten tagging SNPs located 10 kb around rs6967330 were selected by HaploView 5.0 based on 1000 Genomes database for Southern Han Chinese. Their associations with wheezing and lung function were examined in 1341 Chinese pre-school children, while those for asthma phenotypes were examined in an independent group of 2079 school-age children. Genotypic and haplotypic associations were analyzed by multivariate regression, and generalized multifactor dimensionality reduction was used to examine epistatic interactions for wheezing traits.

RESULTS

The mean (SD) age of pre-school cohort was 4.7 (1.0) years. Rs6967330 was associated with current wheeze (odds ratio [OR] 1.63, 95% confidence interval [CI] 1.09-2.43) and its severity (OR 1.64, 95% CI 1.10-2.44) among pre-school children. This SNP was also associated with school-age asthma (OR 1.32, 95% CI 1.04-1.69). The minor allele of rs408223 was associated with lower FEV_0.5 (β = -2.411, P = .004) and FEV_0.5 /FVC (β = -1.292, P = .015). Lower spirometric indices were also associated with minor allele of rs140154310. GAC haplotype from rs4730125, rs6967330, and rs408223 was associated with pre-school current wheeze and school-age asthma. Epistatic interaction was found between unrelated CDHR3 SNPs for FEV_0.5 among pre-schoolers.

CONCLUSION

CDHR3 is a candidate gene for early-life wheezing, school-age asthma, and lung function in Chinese children.

Evaluation Tools for Physical Activity Programs for Childhood Cancer: A Scoping Review

Research on the benefits of physical activity (PA) in childhood cancer has been translated into a handful of community-based programs. However, to foster further translation, an understanding of how to evaluate participant outcomes would be beneficial to provide feedback to participants and stimulate future research. Such a review would provide a summary of acceptable tools for work in this area. The purpose of this scoping review was to identify the evaluation tools that have been used in PA/exercise studies or programs for childhood cancer. This review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies included in the review used physical and psychosocial evaluation tools within PA and exercise programs or research for childhood cancer. In addition, studies with measures of health behavior such as PA levels and activities of daily living were included. Tools that assessed physical fitness and physical performance were excluded. Information on the types of evaluation tools used, mean age of participants, and type of cancer was extracted. Psychometric properties of each evaluation tool are reported. The most commonly assessed patient outcomes were motor performance, fatigue, well-being, functional mobility, and quality of life. Less commonly reported patient outcomes were hope, self-efficacy, and self-perception. None of the evaluation tools reported in the PA/exercise and pediatric oncology literature assess physical literacy. This review was the first step in a knowledge translation process, identifying evaluation tools that have been used in PA/exercise programs in childhood cancer survivors, that will guide the development and evaluation of current and future community-based programs.

Temporal changes in obesity and sleep habits in Hong Kong Chinese school children: a prospective study

We examined the temporal changes in obesity and sleep habits and their relationship in a prospective cohort of healthy Chinese adolescents. We collected data on anthropometric and questionnaire-measured sleep parameters in 2007-2008. 516 participants returned for examinations in 2013-2015. General obesity was defined as body mass index (BMI) ≥age- and sex-specific 95th percentile or ≥25 kg/m2 for participants aged <18 or ≥18 years, respectively. Central obesity was defined as waist circumference (WC) ≥ age- and sex-specific 90th percentile or using adult cut-offs. After a mean follow-up of 6.2 ± 0.5 years, the mean BMI increased from 18.5 ± 3.1 to 20.9 ± 3.4 kg/m2. The corresponding WC were 63.7 ± 8.9 and 69.8 ± 9.7 cm. General obesity rate increased from 8.3% (95% confidence interval [CI] 6.1-11.1) to 11.3% (8.7-14.4; p = 0.034). Central obesity rate decreased from 16.9% (13.7-20.4) to 13.5% (10.6-16.8; p = 0.034). During follow-up, more participants reported short sleep (<7 hours/day during weekday: 20.5% [17.1-24.2] vs. 15.3% [12.3-18.8]; p = 0.033) and bedtime after midnight (60.5% [56.2-64.8] vs. 16.2% [13.1-19.7]; p < 0.001) than baseline. The relative risk of overweight/obesity in participants with short sleep and late bedtime was 1.30 (0.48-3.47) and 1.46 (0.70-3.05), respectively. Despite rising rates of unhealthy sleep habits and general obesity, their associations were not significant at 6-year of follow-up.

Continuous cardiometabolic risk score definitions in early childhood: a scoping review

BACKGROUND

Cardiometabolic risk (CMR) in young children has been measured using various approaches, including a continuous summary score that incorporates components such as adiposity, lipids, metabolic factors and blood pressure.

OBJECTIVES

The objective of this study was to comprehensively review definitions of continuous CMR scores in children <10 years of age.

METHODS

A scoping review was conducted using a systematic search of four scientific databases up to June 2016. Inclusion criteria were children <10 years of age and report of a continuous CMR score.

RESULTS

Ninety-one articles were included. Most studies were published from 2007 to 2016 (96%). Nearly all continuous CMR scores (90%) were calculated using the sum or the mean of z-scores, and many articles age-standardized and sex-standardized components within their own population. The mean number of variables included in the risk scores was 5 with a range of 3-11. The most commonly included score components were waist circumference (52%), triglycerides (87%), high-density lipoprotein cholesterol (67%), glucose (43%) and systolic blood pressure (52%).

IMPORTANCE

Continuous CMR scores are emerging frequently in the child health literature and are calculated using numerous methods with diverse components. This heterogeneity limits comparability across studies. A harmonized definition of CMR in childhood is needed.

A Sports-Based Youth Development Program, Teen Mental Health, and Physical Fitness: An RCT

OBJECTIVES

To assess the effectiveness of a positive youth development (PYD)-based sports mentorship program on the physical and mental well-being of adolescents recruited in a community setting.

METHODS

This is a randomized controlled trial in which we recruited students from 12 secondary schools in Hong Kong, China. Participants were randomly assigned in a 1:1 ratio to an intervention or a control arm after stratification for school from October 2013 to June 2014. Participants were not blinded to allocation because of the nature of the intervention. Students in the intervention arm received an after-school, PYD-based sports mentorship for 18 weeks. Each weekly session lasted 90 minutes. Students in the control arm received exclusive access to a health education Web site.

RESULTS

Six hundred and sixty-four students (mean age 12.3 years [SD 0.76]; 386 girls [58.1%]) completed baseline and postintervention assessments. The intervention improved students' mental well-being (Cohen's d, 0.25; 95% confidence interval [CI], 0.10 to 0.40; P = .001), self-efficacy (Cohen's d, 0.22; 95% CI, 0.07 to 0.37; P = .01), resilience (Cohen's d, 0.19; 95% CI, 0.03 to 0.34; P = .02), physical fitness (flexibility [Cohen's d, 0.28; 95% CI, 0.13 to 0.43; P = .02], lower limb muscle strength [Cohen's d, 0.18; 95% CI, 0.03 to 0.33; P = .03], and dynamic balance [Cohen's d, 0.21; 95% CI, 0.06 to 0.37; P = .01]), and physical activity levels (Cohen's d, 0.39; 95% CI, 0.24 to 0.55; P < .0001). The intervention did not significantly improve physical well-being (Cohen's d, -0.01; 95% CI, -0.17 to 0.14; P = .86), BMI z scores (Cohen's d, -0.03; 95% CI, -0.18 to 0.12; P = .69), body fat proportion (Cohen's d, -0.15; 95% CI, -0.31 to 0.00; P = .051), and social connectedness (Cohen's d, -0.03; 95% CI, -0.18 to 0.12; P = .72).

CONCLUSIONS

A PYD-based sports mentorship intervention improved healthy adolescents' mental well-being, psychological assets, physical fitness, and physical activity levels.

Genetic effects of multiple asthma loci identified by genomewide association studies on asthma and spirometric indices

BACKGROUND

Genomewide association study (GWAS) published by GABRIEL consortium identified 10 asthma-associated loci. However, their relationship with lung functions is unclear. This study investigated the association between asthma traits and single-nucleotide polymorphisms (SNPs) of these GWAS loci.

METHODS

Rs3894194 and rs9273349 were not genotyped due to unavailable TaqMan assays. Genetic associations of remaining eight SNPs were investigated in 903 school-age asthmatics and 1205 non-allergic controls. Four significant SNPs were then replicated in 479 adult asthmatics and 746 adult controls, and 1341 Chinese preschool children. Meta-analyses were performed by combining data from school-age children and adults. Generalized multifactor dimensionality reduction (GMDR) was used to analyze their interactions for asthma traits.

RESULTS

Childhood asthma was associated with GSDMB_rs2305480 (odds ratio [OR] 0.69, 95% confidence interval [CI] 0.57-0.83). IL13_rs1295686 was associated with all asthma (OR 1.64, 95% CI 1.16-2.32) and early-onset asthma (OR 1.92, 95% CI 1.20-3.06) in adults, whereas GSDMB_rs2305480 was only associated with early-onset asthma (OR 0.69, 95% CI 0.49-0.96). According to meta-analyses, the minor allele of rs2305480 was inversely associated with FEV1 , FVC, and FEV1 /FVC (p < 0.01). GMDR analyses revealed 2-locus models of SLC22A5 with SMAD3 to modulate FEVt /FVC in both preschool children and adults, with IL13 to determine FVC in both school-age children and adults, and with IL2RB to modulate FEV1 /FVC in school-age children.

CONCLUSIONS

IL13 and GSDMB are replicated as asthma genes. Rs2305480 of GSDMB is also associated with low FEV1 , FVC, and FEV1 /FVC among asthmatics. Moreover, SLC22A5, IL13, SMAD3, and GSDMB interact to modulate spirometric indices.

Mediating effects of body composition between physical activity and body esteem in Hong Kong adolescents: a structural equation modeling approach

This study investigated the mediating role of body mass index (BMI) in the relationship between physical activity and body esteem in adolescents. Nine hundred and five Hong Kong Chinese students aged 12-18 years participated in a cross-sectional study in 2007. Students' BMI was computed as an indicator of their body composition. Their physical activity level and body esteem were examined using the Physical Activity Rating for Children and Youth (PARCY) and Body Esteem Scale (BES), respectively. Structural equation modelling was used to investigate the mediating effects of BMI and physical activity in predicting body esteem, with stratification by sex. The overall fit of the hypothesized models was satisfactory in boys (NFI = 0.94; NNFI = 0.88; CFI = 0.95; RMSEA = 0.07) and girls (NFI = 0.89; NNFI = 0.77; CFI = 0.91; RMSEA = 0.11). When BMI was considered as a mediator, higher physical activity had a significant negative total effect on body esteem in boys, but not in girls. The indirect effect of higher physical activity on body esteem via BMI was positive in boys, but negative in girls.

CONCLUSIONS

Regular physical activity may help overweight adolescents, especially boys, improve their body esteem. Kinesiologists and health professionals could explore the use of physical activity prescriptions for weight management, aiming at body esteem improvement in community health programs for adolescents.

WHAT IS KNOWN

Among Western adolescents, negative body esteem is more pervasive in girls than in boys. There are consistent findings of the association between higher body mass index and lower body esteem in adolescents, but the association between physical activity and body esteem are equivocal.

WHAT IS NEW

A negative association between body mass index and body esteem was found in both Hong Kong adolescent boys and girls. The indirect effect of physical activity on body esteem via body mass index was positive in Hong Kong adolescent boys, but negative in girls.

Associations of pubertal stage and body mass index with cardiometabolic risk in Hong Kong Chinese children: A cross-sectional study

BACKGROUND

Puberty is associated with a clustering of cardiometabolic risk factors (CMRFs) during adolescence that are manifested in later life. Although anthropometric variables such as body mass index (BMI) can predict cardiometabolic risk in children and adolescents, it is not clear whether there is an interaction between pubertal stage and BMI associated with cardiometabolic risk in this age group. This paper examines the association of pubertal stage and BMI with CMRFs in Hong Kong Chinese children.

METHODS

A cross-sectional school-based study was conducted among 1985 (95.1%) students aged 6 to 18 years. Fasting lipid profile and plasma glucose, blood pressure, body weight, body height and waist circumference were measured. A self-reported pubertal stage questionnaire was used to assess pubertal stage of participants. Two cardiometabolic risk scores, alpha and beta, were constructed to quantify cardiometabolic risk. Cardiometabolic risk score alpha refers to the sum of z-scores of sex-specific, age-adjusted waist circumference, height-adjusted systolic and diastolic blood pressure, fasting plasma glucose, triglyceride and low-density lipoprotein cholesterol, and minus z-score of sex-specific age-adjusted high-density lipoprotein cholesterol. Cardiometabolic risk score beta includes all components of risk score alpha except waist circumference.

RESULTS

The interaction of BMI z-score (ZBMI) and pubertal stage demonstrated a further increase in variance explained in both the cardiometabolic risk scores alpha and beta (0.5% and 0.8% respectively) in boys and (0.7% and 0.5% respectively) in girls.

CONCLUSIONS

Pubertal stage has an interaction effect on the association of cardiometabolic risk by BMI in boys and may have a similar but lesser effect in girls.

The impact of cancer and its treatment on physical activity levels and behavior in Hong Kong Chinese childhood cancer survivors

BACKGROUND

Research indicates that regular physical activity is associated with numerous physiological and psychological health benefits for childhood cancer survivors. A review of the literature reveals that no study has so far examined the physical activity levels and behavior of Hong Kong Chinese childhood cancer survivors, and how the cancer and its treatment affect the physical activity and other behavior of these children remains unclear.

OBJECTIVE

The aims of this study were to assess the physical activity levels of Hong Kong Chinese childhood cancer survivors and to explore the factors that affect their adherence to and maintenance of regular physical activity.

METHODS

A cross-sectional study was used. A total of 128 childhood cancer survivors (9-16-year-olds) who underwent medical follow-up in the outpatient clinic were invited to participate in the study.

RESULTS

There was a significant decline in physical activity levels among childhood cancer survivors. Most of them did not take physical exercise regularly. Concern about academic performance, fatigue, and a decrease in physical strength and endurance after remission prevented them from engaging in regular physical activity.

CONCLUSIONS

This study indicates that many childhood cancer survivors did not engage in regular physical activity and that they overlooked or underestimated its importance.

IMPLICATIONS FOR PRACTICE

It is essential for nurses to correct misconceptions about physical activity among childhood cancer survivors and their parents and, most importantly, to advocate the principle of regular physical activity for these children, with the aim of enhancing their physical and psychological well-being.

Physical activity improves mental health through resilience in Hong Kong Chinese adolescents

Background

Adolescent mental health problems are global public health concern. Primary prevention through physical activity (PA) has been suggested as a potential approach to tackling this problem. Studies in Western countries have provided some evidence of a relationship between PA and adolescent mental health, but the evidence in China is not sufficient. Furthermore, the mechanism behind this relationship has not been empirically tested. The present study aimed at testing the association between PA and mental well-being of Chinese adolescents and to investigate whether a psychological (self-efficacy and resilience) and social (school and family connectedness) mediation model is valid to explain such a relationship.

Methods

A total of 775 Chinese students in Grades 7 and 8 were recruited in this cross-sectional study. The participants were given questionnaires to assess their PA level, mental well-being, and the potential mediators. Path models were used to analyse the association between PA and mental well-being, and the roles of potential mediators.

Results

The PA level was significantly correlated with the adolescent’s mental well-being (r = 0.66, p < 0.001), self-efficacy (r = 0.21, p < 0.001), and resilience (r = 0.25, p < 0.001), but not with school connectedness (r = 0.05, p = 0.15) or family connectedness (r = 0.06, p = 0.13). After adjusting for potential confounders in the path model, the PA level was significantly associated with mental well-being (b = 0.52, p < 0.001), and resilience was the only significant mediator (b = 0.31, p < 0.001), which contributed to 60% of this relationship.

Conclusions

There was a significant positive association between the PA level and mental well-being of Chinese adolescents. Resilience mediated the majority of this relationship. Promoting physical activities that build up resilience could be a promising way to improve adolescent mental health.

A randomized controlled trial to investigate the impact of a low glycemic index (GI) diet on body mass index in obese adolescents

BACKGROUND

The role of a low glycemic index (GI) diet in the management of adolescent obesity remains controversial. In this study, we aim to evaluate the impact of low GI diet versus a conventional Chinese diet on the body mass index (BMI) and other obesity indices of obese adolescents.

METHODS

Obese adolescents aged 15-18 years were identified from population-recruited, territory-wide surveys. Obesity was defined as BMI ≥95th percentile of Hong Kong local age- and sex-specific references. Eligible subjects were randomized to either an intervention with low GI diet (consisting of 45-50% carbohydrate, 30-35% fat and 15-20% protein) or conventional Chinese diet as control (consisting of 55-60% carbohydrate, 25-30% fat and 10-15% protein). We used random intercept mixed effects model to compare the differential changes across the time points from baseline to month 6 between the 2 groups.

RESULTS

104 obese adolescents were recruited (52 in low GI group and 52 in control group; 43.3% boys). Mean age was 16.7 ± 1.0 years and 16.8 ±1.0 years in low GI and control group respectively. 58.7% subjects completed the study at 6 months (65.4% in low GI group and 51.9% in control group). After adjustment for age and sex, subjects in the low GI group had a significantly greater reduction in obesity indices including BMI, body weight and waist circumference (WC) compared to subjects in the control group (all p <0.05). After further adjustment for physical activity levels, WC was found to be significantly lower in the low GI group compared to the conventional group (p = 0.018).

CONCLUSION

Low GI diet in the context of a comprehensive lifestyle modification program may be an alternative to conventional diet in the management of obese adolescents.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Ref. No: NCT01278563.

Effect of physical activity on vascular characteristics in young children

BACKGROUND

Physical activity has long been proposed as an important modifiable cardiovascular risk factor in adults. We assessed whether physical activity already has an effect on childhood vasculature.

METHODS

In the Wheezing-Illnesses-Study-in-Leidsche-Rijn birth cohort, we performed vascular ultrasound to measure carotid intima-media thickness (cIMT) and functional properties (distensibility, elastic modulus) at 5 and 8 years of age. Child typical physical activities were inquired using a questionnaire completed by parents. Linear regression was used with physical activity level, expressed as a standardized value of time-weighted metabolic equivalent (MET) as the independent variable and vascular properties as dependent variables with further confounder adjustment and evaluation for possible body mass index and sex effect modifications.

RESULTS

In 595 5-year-old children and in 237 of those who had reached the age of 8 years, we did not find statistically significant associations between total time-weighted MET and each vascular parameter, neither in pooled nor stratified analysis. However, sport activities were associated with thinner cIMT (-3.20 µm/SD, 95% CI -6.34, -0.22, p = 0.04) at 5 years of age; a similar pattern was seen for organized sport. This effect was strongest in children in the highest body mass index tertile (-5.38 µm/SD, 95% CI -10.54, -0.19, p = 0.04). At the age of 8 years, higher sport level tended to be associated with higher vascular distensibility (2.64 × 10(3) kPa/SD, 95% CI -0.18, 5.45, p = 0.07) although this was not statistically significant.

CONCLUSIONS

Sport activity may have beneficial effects on arteries of young children, particularly those with higher relative body weight.

Divergent pathways to influence: Cognition and behavior differentially mediate the effects of optimism on physical and mental quality of life in Chinese university students

Previous research has indicated that both cognitive and behavioral variables mediate the positive effect of optimism on quality of life; yet few attempts have been made to accommodate these constructs into a single explanatory framework. Adopting Fredrickson's broaden-and-build perspective, we examined the relationships between optimism, self-rated health, resilience, exercise, and quality of life in 365 Chinese university students using path analysis. For physical quality of life, a two-stage model, in which the effects of optimism were sequentially mediated by cognitive and behavioral variables, provided the best fit. A one-stage model, with full mediation by cognitive variables, provided the best fit for mental quality of life. This suggests that optimism influences physical and mental quality of life via different pathways.

Physical Activity Research in Hong Kong From 1987 to 2012

A comprehensive understanding of research on the physical activity (PA) of Hong Kong youth is necessary to develop specific and effective intervention strategies. This review summarizes existing evidence in studies on PA among the Hong Kong youth. An electronic literature search was conducted using MEDLINE, SPORTDiscus, ERIC, and HighWire database. Forty-five studies published from 1987 to 2012 were included in this review. The findings are presented in five categories, namely, health benefits of PA, participation in PA, assessment of PA, correlates of PA, and interventions to promote PA. The results indicate that PA among the youth in Hong Kong has attracted concern in the past decade. Specifically, extensive studies focused on the areas of health benefits of PA, participation in PA, and correlates of PA. Research into context-specific correlates of PA and tailored PA promotion programs for the Hong Kong youth is warranted in the future.

Diabetes and its comorbidities--where East meets West

Fetal programming associated with in utero exposure to maternal stress is thought to alter gene expression, resulting in phenotypes that promote survival in a pathogen-rich and nutrient-poor environment but substantially increase the risk of cardiovascular, metabolic and renal disorders (such as diabetes mellitus) in adults with obesity. These (epi)genetic phenomena are modified by environmental and socioeconomic factors, resulting in multiple subphenotypes and clinical consequences. In individuals from areas undergoing rapid economic development, which is associated with a transition from communicable to noncommunicable diseases, an efficient innate immune response can exaggerate obesity-associated inflammation. By contrast, in individuals with a genetic predisposition to autoimmune or monogenic diabetes mellitus, obesity can lead to atypical presentation of diabetes mellitus, termed 'double diabetes mellitus'. The increasingly young age at diagnosis of diabetes mellitus in developing countries results in prolonged exposure to glucolipotoxicity, low-grade inflammation and increased oxidative stress, which put enormous strain on pancreatic β cells and renal function. These conditions create a metabolic milieu conducive to cancer growth. This Review discusses how rapid changes in technology and human behaviour have brought on the global epidemic of metabolic diseases, and suggests that solutions will be based on using system change, technology and behavioural strategies to combat this societal-turned-medical problem.

Self-reported waist circumference: a screening tool for classifying children with overweight/obesity and cardiometabolic risk factor clustering

OBJECTIVES

The objectives of this study were twofold - (i) to assess the agreement between self-reported waist circumference (SRWC) and assessor measured waist circumference (MWC) and (ii) to evaluate the diagnostic ability of SRWC for classifying (i) a clustering of cardiometabolic risk factors (CMRFs) and (ii) overweight/obese status in Hong Kong Chinese children aged 6-18 years.

METHODS

A cross-sectional study with cluster random sampling was conducted. A self-administrated questionnaire, which included demographic data, body weight, body height and waist circumference, was given to children to bring home for completion. Children were asked to return the questionnaire and fast themselves for at least 8 h on the day of the survey. Anthropometric measurements and blood pressure were taken by trained research staff and fasting blood samples were collected for measurements of fasting plasma glucose, total cholesterol, triglyceride, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol.

RESULTS

A total of 515 boys and 711 girls were included in the data analysis. Agreement between SRWC and MWC was assessed by intra-class correlation coefficient and it ranged from 0.77 to 0.87. The ability of sex-specific SRWC values to classify children with a clustering of CMRFs and overweight/obesity exhibited moderately high to high sensitivity and specificity, and the area under the receiver operating characteristics ranged from acceptable to excellent (from 0.76 to 0.84).

CONCLUSIONS

SRWC has good agreement with MWC and could be used as a screening tool to classify children with a clustering of CMRFs and overweight/obesity status in Hong Kong Chinese children.

Hong Kong Chinese school children with elevated urine melamine levels: a prospective follow up study

Background

In 2008, the outbreak of kidney stones in children fed by melamine-tainted milk products in Mainland China has caused major public concern of food safety. We identified Hong Kong school children with elevated urine melamine level from a community-based school survey in 2007-08 and reviewed their clinical status in 2009.

Methods

In 2007-08, 2119 school children participated in a primary and secondary school survey in Hong Kong using a cluster sampling method. Urine aliquots from 502 subjects were assayed for melamine level. High urine melamine level was defined as urine melamine/creatinine ratio >7.1 μg/mmol. Subjects with high urine melamine level were invited for clinical evaluation in 2009 including urinalysis and ultrasound imaging of the urinary system.

Results

The age range of this subcohort was 6 - 20 years with 67% girls (335 female and 167 male subjects). The spot urine melamine/creatinine ratio of the 502 urine aliquots ranged from undetectable to 1467 μg/mmol (median 0.8 μg/mmol). Of these, 213 subjects had undetectable level (42%). We invited 47 (9%) subjects with high urine melamine level for re-evaluation and one subject declined. The median duration of follow-up was 23.5 months (interquartile range: 19.8 - 30.6 months). None of the 46 subjects (28% boys, mean age 13.9 ± 2.9 years) had any abnormality detected on ultrasound study of the urinary system. All subjects had stable renal function with a median urine albumin-creatinine ratio of 0.70 mg/mmol (interquartile range: 0.00 - 2.55 mg/mmol).

Conclusions

Hong Kong Chinese school children with high urine melamine levels appeared to have benign clinical course in the short term although a long term follow-up study is advisable in those with persistently high urine melamine level.

Reliability and validity of psychosocial and environmental correlates measures of physical activity and screen-based behaviors among Chinese children in Hong Kong

Background

Insufficient participation in physical activity and excessive screen time have been observed among Chinese children. The role of social and environmental factors in shaping physical activity and sedentary behaviors among Chinese children is under-investigated. The purpose of the present study was to assess the reliability and validity of a questionnaire to measure child- and parent-reported psychosocial and environmental correlates of physical activity and screen-based behaviors among Chinese children in Hong Kong.

Methods

A total of 303 schoolchildren aged 9-14 years and their parents volunteered to participate in this study and 160 of them completed the questionnaire twice within an interval of 10 days. Intraclass correlation coefficients (ICCs), kappa statistics, and percent agreement were performed to evaluate test-retest reliability of the continuous and categorical variables, respectively. Exploratory factor analyses (EFAs) were conducted to assess convergent validity of the emergent scales. Cronbach's alpha and ICCs were performed to assess internal and test-retest reliability of the emergent scales. Criterion validity was assessed by correlating psychosocial and environmental measures with self-reported physical activity and screen-based behaviors, measured by a validated questionnaire.

Results

Reliability statistics for both child- and parent-reported continuous variables showed acceptable consistency for all of the ICC values greater than 0.70. Kappa statistics showed fair to perfect test-retest reliability for the categorical items. Adequate internal consistency and test-retest reliability were observed in most of the emergent scales. Criterion validity assessed by correlating psychosocial and environmental measures with child-reported physical activity found associations with physical activity in the self-efficacy scale (r = 0.25, P < 0.05), the peer support for physical activity scale (r = 0.25, P < 0.05) and home physical activity environmental (r = 0.14, P < 0.05). Children's screen-based behaviors were associated with the family support for physical activity scale (r = -0.22, P < 0.05) and parental role modeling of TV (r = 0.12, P = 0.053).

Conclusions

The findings provide psychometric support for using this questionnaire for examining psychosocial and environmental correlates of physical activity and screen-based behaviors among Chinese children in Hong Kong. Further research is needed to develop more robust measures based on the current questionnaire, especially for peer influence on physical activity and parental rules on screen-based behaviors.