The association between device-measured sitting time and cardiometabolic health risk factors in children

BACKGROUND

There is limited evidence of the associations between postural-derived sitting time, waist-worn derived sedentary time and children's health and the moderation effect of physical activity (PA). This study examined associations of children's device-measured sitting time with cardiometabolic health risk factors, including moderation by physical activity.

METHODS

Cross-sectional baseline data from children (mean-age 8.2 ± 0.5 years) in Melbourne, Australia (2010) participating in the TransformUs program were used. Children simultaneously wore an activPAL to assess sitting time and an ActiGraph GT3X to assess sedentary time and physical activity intensity. Cardiometabolic health risk factors included: adiposity (body mass index [BMI], waist circumference [WC]), systolic and diastolic blood pressure (SBP, DBP), high-density lipoprotein (HDL), low-density lipoprotein (LDL), cholesterol, triglycerides, fasting plasma glucose (FPG), serum insulin, and 25-hydroxyvitaminD (25[OH]D). Linear regression models (n = 71-113) assessed associations between sitting time with each health risk factor, adjusted for different PA intensities (i.e. light [LIPA], moderate-vigorous intensities [MVPA], separately on each model), age, sex, adiposity, and clustering by school. Interaction terms examined moderation. The analyses were repeated using device-measured sedentary time (i.e. ActiGraph GT3X) for comparison.

RESULTS

Sitting time was positively associated with SBP (b = 0.015; 95%CI: 0.004, 0.026), DBP (b = 0.012; 95%CI:0.004, 0.020), and FPG (b = 0.001; 95%CI: 0.000, 0.000), after adjusting for higher PA intensities. The association between sitting time and insulin (b = 0.003; 95%CI: 0.000, 0.006) was attenuated after adjusting for higher PA intensities. When the models were adjusted for LIPA and MVPA, there was a negative association with LDL (b=-0.001; 95%CI: -0.002, -0.000 and b=-0.001; 95%CI: -0.003, -0.000, respectively). There was a negative association of sedentary time with WCz (b=-0.003; 95%CI: -0.005, 0.000) and BMIz (b=-0.003; 95%CI: -0.006, -0.000) when the models were adjusted by MVPA. Sedentary time was positively associated with triglycerides (b = 0.001; 95%CI: 0.000, 0.001) but attenuated after adjusting for MVPA. No evidence of moderation effects was found.

CONCLUSIONS

Higher volumes of sitting and sedentary time were associated with some adverse associations on some cardiometabolic health risk factors in children. These associations were more evident when sitting time was the predictor. This suggests that reducing time spent sitting may benefit some cardiometabolic health outcomes, but future experimental research is needed to confirm causal relationships and identify the biological mechanisms that might be involved.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry: ACTRN12609000715279.

Life-course trajectories of body mass index and cardiovascular disease risks and health outcomes in adulthood: Systematic review and meta-analysis

OBJECTIVE

This systematic review aimed to assess the effect of life course body mass index (BMI) trajectories (childhood to adulthood) on cardiovascular disease (CVD) risk factors and outcomes.

METHODS

Prospective or retrospective cohort studies were identified that assessed the association of BMI trajectories with CVD risks and outcomes from databases published in English. The pooled effect sizes were estimated using a random-effects model.

FINDINGS

Seventeen eligible studies were included in this systematic review. The results revealed that a persistently overweight trajectory from childhood to adulthood was associated with a higher risk of hypertension (RR: 2.49; 95% CI: 1.9, 3.28) and type 2 diabetes (RR: 4.62; 95% CI: 2.36, 9.04) compared with a trajectory characterized by a normal BMI throughout both childhood and adulthood. Similarly, the risk of hypertension (RR: 2.38; 95% CI: 1.70, 3.33) and type 2 diabetes (RR: 3.66; 95% CI: 2.57, 5.19) was higher in those with normal-to-overweight trajectory compared with participants with a stable normal weight trajectory.

CONCLUSION

The findings suggest that lifetime BMI trajectories may be influential on health outcomes, and preventive strategies should be designed accordingly. Implementing appropriate preventive strategies at all life stages may reduce CVD risks and adverse outcomes later in life.

Association between physical activity and self-regulation in early childhood: A systematic review

Physical activity and self-regulation are important predictors of pediatric overweight and obesity. Young children (0-5 years) with lower physical activity levels and poorer self-regulation skills are at greater risk for overweight. Despite growing evidence that the two constructs are interrelated, their association remains unclear in young children. This review systematically summarized associations between physical activity and self-regulation in early childhood and explored the directionality of associations. Searches were run in six electronic databases. Forty-seven papers met inclusion criteria. Only three studies investigated all three domains of self-regulation (behavioral, cognitive, and emotional). Overall, findings were inconclusive; studies reported weak to moderate positive associations (n = 17), inverse associations (n = 5), mixed associations (n = 15), null association (n = 2), and negative (n = 1) between physical activity and self-regulation. Compared with the emotional and cognitive domains, physical activity was most consistently positively associated with behavioral self-regulation. Only one study assessed bidirectional associations, reporting a positive association. The three studies that included global self-regulation showed contradicting findings. There is some evidence that physical activity dose and sex potentially confound these associations; however, further research is needed given the paucity of studies. This review highlights the need for more in-depth investigation of the complex association between physical activity and global self-regulation.

Priority populations' experiences of the accessibility and inclusion of recreation centres: a qualitative study

BACKGROUND

Although the health benefits of physical activity are well documented, certain priority populations are often disproportionately insufficiently active and at higher risk of poor health. Recreation centres have the potential to provide accessible and supportive environments for physical activity for all. However, little is known about priority populations' experiences of these venues and their views of how accessibility and inclusion can be optimised. This study aimed to gain in-depth insights of recreation centre experiences and potential strategies for improving inclusion and accessibility amongst priority populations (women, older adults, ethnic minorities, persons living with disabilities/additional needs, individuals identifying as LGBTQIA+, low socio-economic position).

METHODS

This qualitative study (2021-2022) involved 18 semi-structured individual interviews with adult priority population users of recreation centres (50% 65 + years, 61.2% female) in one Melbourne municipality. Participants were asked to discuss their positive and negative experiences at the centres and to identify strategies for enhancing accessibility and inclusion. Interviews were audio-recorded and transcribed verbatim. Content analysis was performed for data analysis.

RESULTS

While many participants had positive views of the facilities and programs at the centres, as they met their needs, they also had suggestions for improving accessibility and inclusion. Similarly, most participants were happy with the communications, felt included, and perceived the culture positively. Those who did not feel included at the centres offered many potential strategies for changing the culture, modifying communications (e.g., signage), and establishing partnerships for better access and inclusion.

CONCLUSIONS

The present study adds to essential knowledge concerning priority populations' experiences of recreation centres. For recreation facilities that were generally perceived as having positive inclusion and accessibility, the findings nonetheless highlighted suggestions for further enhancement. These strategies may be useful more broadly for improving accessibility and inclusion, thereby promoting physical activity and ultimately health for all.

Are physical activity and sleep associated with emotional self-regulation in toddlers? a cross-sectional study

BACKGROUND

Toddlerhood (2-3 years) is a crucial period for the development of physical activity, sleep, and emotional self-regulation skills. Although there is growing evidence of positive associations between physical activity, sleep, and emotional self-regulation in school-aged children, the associations in toddlers remain unclear. Thus, this study aimed to examine the association between physical activity, sleep, and emotional self-regulation in toddlers.

METHODS

Baseline data from 1350 toddlers (2.2 ± 0.33 year) from the Let's Grow randomised controlled trial were used. Toddlers' total physical activity (TPA) and moderate- to vigorous-intensity physical activity (MVPA) were assessed via 4 + days of accelerometry and a 3-item parent-report scale. Parent-reported total sleep quantity was calculated using the sum of average night-time sleep and daytime nap durations. Sleep behaviour data including bedtime routine, bedtime resistance, sleep onset-delay, sleep duration, and night waking were collected using relevant subsections from the Child Sleep Habits Questionnaire (CSHQ) and Brief Infant Sleep Questionnaire revised (BISQ-R). A 4-item parent-report scale adapted from the Fast Track Project Child Behaviour Questionnaire was used to assess toddlers' emotional self-regulation. Linear regression models were used, adjusting for child age, sex, and parental education.

RESULTS

Accelerometer-derived TPA, MVPA and parent-reported TPA were not associated with emotional self-regulation. Higher parent-reported MVPA (B = -0.01 CI95 -0.03, -0.003) was associated with poorer emotional self-regulation. Higher sleep duration was associated with better emotional self-regulation (B = 0.06 CI95 0.04, 0.08). The five sleep behaviours assessed were also positively associated with emotional self-regulation (all p < 0.01), with fewer problem sleep behaviours being associated with better emotional self-regulation.

CONCLUSIONS

This cross-sectional study suggests that sleep may be important for emotional self-regulation in toddlers, but the role of physical activity remains unclear. These findings suggest that interventions targeting sleep duration and sleep behaviours during the early toddler years may benefit the positive development of emotional self-regulation skills in this population.

Unravelling Surface Modification Strategies for Preventing Medical Device-Induced Thrombosis

The use of biomaterials in implanted medical devices remains hampered by platelet adhesion and blood coagulation. Thrombus formation is a prevalent cause of failure of these blood-contacting devices. Although systemic anticoagulant can be used to support materials and devices with poor blood compatibility, its negative effects such as an increased chance of bleeding, make materials with superior hemocompatibility extremely attractive, especially for long-term applications. This review examines blood-surface interactions, the pathogenesis of clotting on blood-contacting medical devices, popular surface modification techniques, mechanisms of action of anticoagulant coatings, and discusses future directions in biomaterial research for preventing thrombosis. In addition, this paper comprehensively reviews several novel methods that either entirely prevent interaction between material surfaces and blood components or regulate the reaction of the coagulation cascade, thrombocytes, and leukocytes.

Enhancing healthcare at home for older people in rural and regional Australia: A protocol for co-creation to design and implement system change

BACKGROUND

World-wide, health service providers are moving towards innovative models of clinical home-based care services as a key strategy to improve equity of access and quality of care. To optimise existing and new clinical home-based care programs, evidence informed approaches are needed that consider the complexity of the health care system across different contexts.

METHODS

We present a protocol for working with health services and their partners to perform rapid identification, prioritisation, and co-design of content-appropriate strategies to optimise the delivery of healthcare at home for older people in rural and regional areas. The protocol combines Systems Thinking and Implementation Science using a Consensus Mapping and Co-design (CMC) process delivered over five workshops.

DISCUSSION

The protocol will be implemented with rural and regional healthcare providers to identify digital and non-digital solutions that have the potential to inform models of service delivery, improve patient experience, and optimise health outcomes. The combination of system and implementation science is a unique approach for optimising healthcare at home for older populations, especially in the rural context where need is high. This is the first protocol to integrate the use of systems and implementation science into one process and articulating these methods will help with replicating this in future practice. Results of the design phase will translate into practice through standard health service planning methods to enhance implementation and sustainability. The delivery of the protocol will include building capacity of health service workers to embed the design, implementation, and evaluation approach into normal practice. This protocol forms part of the DELIVER (Delivering Enhanced heaLthcare at home through optImising Virtual tools for oldEr people in Rural and regional Australia) Project. Funded by Australia's Medical Research Future Fund, DELIVER involves a collaboration with public health services of Western Victoria, Australia.

Optimizing electrophysiology studies to prevent sudden cardiac death after myocardial infarction

AIMS

This study assessed associations of minimum final extrastimulus coupling interval utilized within electrophysiology study (EPS) after myocardial infarction (MI) and possible site of origin of induced ventricular tachycardia (VT) with long-term occurrence of spontaneous ventricular tachyarrhythmia and long-term survival.

METHODS AND RESULTS

This prospective study recruited consecutive patients with left ventricular ejection fraction (LVEF) ≤ 40% who underwent EPS days 3-5 after MI between 2004 and 2017. Positive EPS was defined as sustained monomorphic VT cycle length ≥200 ms for ≥10 s or shorter duration if haemodynamic compromise occurred. Each of the four extrastimuli was shortened by 10 ms at a time, until it failed to capture the ventricle (ventricular refractoriness) or induced ventricular tachyarrhythmia. Outcomes included spontaneous ventricular tachyarrhythmia occurrence and all-cause mortality. Shorter coupling interval length of final extrastimulus that induced VT was associated with higher risk of spontaneous ventricular tachyarrhythmia (P < 0.001). Significantly higher rates of spontaneous ventricular tachyarrhythmia (65.2% vs. 23.2%; P < 0.001) were observed for final coupling interval at EPS <200 ms vs. >200 ms. Right bundle branch block (RBBB) morphology of induced VT, with possible site of origin from the left ventricle, was associated with all-cause mortality [hazard ratio (HR) 3.2, P = 0.044] and a composite of spontaneous ventricular tachyarrhythmia recurrence or mortality (HR 1.8, P = 0.043).

CONCLUSION

Ventricular tachycardia induced with shorter coupling intervals was associated with higher risk of spontaneous ventricular tachyarrhythymia on follow-up, indicating that the final extrastimulus coupling interval at EPS early after MI should be determined by ventricular refractoriness. Induced VT with possible origin from left ventricle was associated with increased risk of spontaneous ventricular tachyarrhythmia recurrence or death.

Exploring differences in perceptions of child feeding practices between parents and health care professionals: a qualitative study

BACKGROUND

Evidence on child feeding practice is often based on the perspectives and experiences of parents and less that of health practitioners. In this study, we explored child feeding practice in Aboriginal communities in northern Australia from both the parents and health practitioners' perspectives with the aim of informing nutrition improvement programs.

METHODS

Qualitative research methods were employed. Using semi-structured interviews, parents (n = 30) of children aged 2-5 years, and 29 service providers who were involved in the delivery of child health and nutrition programs in the same communities, were asked about child feeding attitudes and practices. Responses were analyzed through inductive and deductive analysis, recognizing that worldviews influence child feeding practices.

RESULTS

Sharing food was a central practice within families. Parents highly valued development of child independence in food behavior but were conflicted with the easy access to unhealthy food in their communities. This easy access to unhealthy food and inadequate food storage and kitchen facilities for some families were major challenges to achieving optimal diets for children identified by Aboriginal families and service providers. The responsive style of parenting described by parents was often misunderstood by service providers as sub-optimal parenting when viewed through a dominant western lens.

CONCLUSIONS

Approaches to support healthy feeding practices and optimal child nutrition require health-enabling food environments. Along with a community-based Aboriginal health workforce, it is paramount that the non-Aboriginal workforce be supported to be reflective of the impact of worldview on their practice, to ensure a culturally safe environment for families where parenting styles are understood and appropriately supported.

Child-level evaluation of a web-based intervention to improve dietary guideline implementation in childcare centers: a cluster-randomized controlled trial

BACKGROUND

Although it is recommended that childcare centers provide foods consistent with dietary guidelines, the impact of implementing sector-specific guidelines on child outcomes is largely unknown.

OBJECTIVES

This study aims to examine the impact of a web-based program and support to implement dietary guidelines in childcare centers on children's 1) diet; 2) BMI z scores; and 3) child health-related quality of life (HRQoL).

METHODS

This study was a cluster-randomized controlled trial utilizing a Type-3 Hybrid implementation-effectiveness design conducted between October 2016 and March 2018. This study reports on child outcomes. Fifty-four childcare centers in New South Wales, Australia were randomly assigned to the intervention (a web-based menu-planning tool and support) or control group (usual care). The intervention was designed to address barriers and enablers to dietary guideline implementation according to the Theoretical Domains Framework. A quota of 35 consenting childcare centers undertook child-level evaluation of dietary intake where 522 parents consented to completing ≥1 component of data collection for their child. Child consumption of core and discretionary (unhealthy) foods while in care was assessed via dietary observations by blinded research assistants, childcare diet quality was assessed via educator-completed questionnaires, BMI z scores were assessed via measured weight and height, and child HRQoL was assessed via parent report at baseline and 12-mo follow-up.

RESULTS

There was a significant increase in mean child consumption of fruit (0.39 servings; 95% CI: 0.12, 0.65 servings) and dairy foods (0.38 servings; 95% CI: 0.19, 0.57 servings) and a significant reduction in consumption of discretionary foods (-0.40 servings; 95% CI: -0.64, -0.16 servings) in care in the intervention group, relative to control at 12-mo follow-up. No significant differences were observed in diet quality, BMI z scores, or HRQoL.

CONCLUSIONS

A web-based intervention to support planning of childcare menus consistent with dietary guidelines can improve child consumption of healthier foods in daycare. This trial was registered at www.anzctr.org.au as ACTRN12616000974404.

Optimisation: defining and exploring a concept to enhance the impact of public health initiatives

BACKGROUND

Repeated, data-driven optimisation processes have been applied in many fields to rapidly transform the performance of products, processes and interventions. While such processes may similarly be employed to enhance the impact of public health initiatives, optimisation has not been defined in the context of public health and there has been little exploration of its key concepts.

METHODS

We used a modified, three-round Delphi study with an international group of researchers, public health policy-makers and practitioners to (1) generate a consensus-based definition of optimisation in the context of public health and (2i) describe key considerations for optimisation in that context. A pre-workshop literature review and elicitation of participant views regarding optimisation in public health (round 1) were followed by a daylong workshop and facilitated face-to-face group discussions to refine the definition and generate key considerations (round 2); finally, post-workshop discussions were undertaken to refine and finalise the findings (round 3). A thematic analysis was performed at each round. Study findings reflect an iterative consultation process with study participants.

RESULTS

Thirty of 33 invited individuals (91%) participated in the study. Participants reached consensus on the following definition of optimisation in public health: "A deliberate, iterative and data-driven process to improve a health intervention and/or its implementation to meet stakeholder-defined public health impacts within resource constraints". A range of optimisation considerations were explored. Optimisation was considered most suitable when existing public health initiatives are not sufficiently effective, meaningful improvements from an optimisation process are anticipated, quality data to assess impacts are routinely available, and there are stable and ongoing resources to support it. Participants believed optimisation could be applied to improve the impacts of an intervention, an implementation strategy or both, on outcomes valued by stakeholders or end users. While optimisation processes were thought to be facilitated by an understanding of the mechanisms of an intervention or implementation strategy, no agreement was reached regarding the best approach to inform decisions about modifications to improve impact.

CONCLUSIONS

The study findings provide a strong basis for future research to explore the potential impact of optimisation in the field of public health.

Geographical analysis of evaluated chronic disease programs for Aboriginal and Torres Strait Islander people in the Australian primary health care setting: a systematic scoping review

BACKGROUND

Targeted chronic disease programs are vital to improving health outcomes for Indigenous people globally. In Australia it is not known where evaluated chronic disease programs for Aboriginal and Torres Strait Islander people have been implemented. This scoping review geographically examines where evaluated chronic disease programs for Aboriginal people have been implemented in the Australian primary health care setting. Secondary objectives include scoping programs for evidence of partnerships with Aboriginal organisations, and use of ethical protocols. By doing so, geographical gaps in the literature and variations in ethical approaches to conducting program evaluations are highlighted.

METHODS

The objectives, inclusion criteria and methods for this scoping review were specified in advance and documented in a published protocol. This scoping review was undertaken in accordance with the Joanna Briggs Institute (JBI) scoping review methodology. The search included 11 academic databases, clinical trial registries, and the grey literature.

RESULTS

The search resulted in 6894 citations, with 241 retrieved from the grey literature and targeted organisation websites. Title, abstract, and full-text screening was conducted by two independent reviewers, with 314 citations undergoing full review. Of these, 74 citations evaluating 50 programs met the inclusion criteria. Of the programs included in the geographical analysis (n = 40), 32.1% were implemented in Major Cities and 29.6% in Very Remote areas of Australia. A smaller proportion of programs were delivered in Inner Regional (12.3%), Outer Regional (18.5%) and Remote areas (7.4%) of Australia. Overall, 90% (n = 45) of the included programs collaborated with an Aboriginal organisation in the implementation and/or evaluation of the program. Variation in the use of ethical guidelines and protocols in the evaluation process was evident.

CONCLUSIONS

A greater focus on the evaluation of chronic disease programs for Aboriginal people residing in Inner and Outer Regional areas, and Remote areas of Australia is required. Across all geographical areas further efforts should be made to conduct evaluations in partnership with Aboriginal communities residing in the geographical region of program implementation. The need for more scientifically and ethically rigorous approaches to Aboriginal health program evaluations is evident.

Breastfeeding and maternal cardiovascular risk factors and outcomes: A systematic review

Background

There is growing evidence that breastfeeding has short- and long-term cardiovascular health benefits for mothers. The objectives of this systematic review were to examine the association between breastfeeding and maternal cardiovascular risk factors and outcomes that have not previously been synthesized systematically, including metabolic syndrome, hypertension and cardiovascular disease.

Methods and findings

This systematic review meets PRISMA guidelines. The MEDLINE, EMBASE and CINAHL databases were systematically searched for relevant publications of any study design from the earliest publication date to March 2016. The reference lists from selected articles were reviewed, and forward and backward referencing were conducted. The methodological quality of reviewed articles was appraised using validated checklists.

Twenty-one studies meeting the inclusion criteria examined the association between self-reported breastfeeding and one or more of the following outcomes: metabolic syndrome/metabolic risk factors (n = 10), inflammatory markers/adipokines (n = 2), hypertension (n = 7), subclinical cardiovascular disease (n = 2), prevalence/incidence of cardiovascular disease (n = 3) and cardiovascular disease mortality (n = 2). Overall, 19 studies (10 cross-sectional/retrospective, 9 prospective) reported significant protective effects of breastfeeding, nine studies (3 cross-sectional/retrospective, 5 prospective, 1 cluster randomized controlled trial) reported non-significant findings and none reported detrimental effects of breastfeeding. In most studies reporting significant associations, breastfeeding remained associated with both short- and long-term maternal cardiovascular health risk factors/outcomes, even after covariate adjustment. Findings from several studies suggested that the effects of breastfeeding may diminish with age and a dose-response association between breastfeeding and several metabolic risk factors. However, further longitudinal studies, including studies that measure exclusive breastfeeding, are needed to confirm these findings.

Conclusions

The evidence from this review suggests that breastfeeding is associated with cardiovascular health benefits. However, results should be interpreted with caution as the evidence gathered for each individual outcome was limited by the small number of observational studies. Additional prospective studies are needed.

PROSPERO registration number

CRD42016047766.

Acute exercise alters skeletal muscle mitochondrial respiration and H2O2 emission in response to hyperinsulinemic-euglycemic clamp in middle-aged obese men

Obesity, sedentary lifestyle and aging are associated with mitochondrial dysfunction and impaired insulin sensitivity. Acute exercise increases insulin sensitivity in skeletal muscle; however, whether mitochondria are involved in these processes remains unclear. The aim of this study was to investigate the effects of insulin stimulation at rest and after acute exercise on skeletal muscle mitochondrial respiratory function (JO₂) and hydrogen peroxide emission (JH₂O₂), and the associations with insulin sensitivity in obese, sedentary men. Nine men (means ± SD: 57 ± 6 years; BMI 33 ± 5 kg.m²) underwent hyperinsulinemic-euglycemic clamps in two separate trials 1–3 weeks apart: one under resting conditions, and another 1 hour after high-intensity exercise (4x4 min cycling at 95% HR_peak). Muscle biopsies were obtained at baseline, and pre/post clamp to measure JO₂ with high-resolution respirometry and JH₂O₂ via Amplex UltraRed from permeabilized fibers. Post-exercise, both JO₂ and JH₂O₂ during ADP stimulated state-3/OXPHOS respiration were lower compared to baseline (P<0.05), but not after subsequent insulin stimulation. JH₂O₂ was lower post-exercise and after subsequent insulin stimulation compared to insulin stimulation in the rest trial during succinate supported state-4/leak respiration (P<0.05). In contrast, JH₂O₂ increased during complex-I supported leak respiration with insulin after exercise compared with resting conditions (P<0.05). Resting insulin sensitivity and JH₂O₂ during complex-I leak respiration were positively correlated (r = 0.77, P<0.05). We conclude that in obese, older and sedentary men, acute exercise modifies skeletal muscle mitochondrial respiration and H₂O₂ emission responses to hyperinsulinemia in a respiratory state-specific manner, which may have implications for metabolic diseases involving insulin resistance.