Environmental contributions to social and mental health outcomes following pediatric stroke

Mental health and social outcomes following acquired brain injury (ABI) in children are often considered to be due to brain insult, but other factors, such as environment, may also play a role. We assessed mental health and social function in children with chronic illness, with and without stroke (a form of ABI), and typically developing (TD) controls to examine environmental influences on these outcomes. We recruited 36 children diagnosed with stroke, 15 with chronic asthma, and 43 TD controls. Children and parents completed questionnaires rating child mental health and social function and distal and proximal environment. TD children had significantly less internalizing and social problems than stroke and asthma groups, and engaged in more social activities than children with stroke. Poorer parent mental health predicted more internalizing and social problems and lower social participation. Family dysfunction was associated with internalizing problems. Lower parent education contributed to children's social function. Children with chronic illness are at elevated risk of poorer mental health and social function. Addition of brain insult leads to poorer social participation. Quality of home environment contributes to children's outcomes, suggesting that supporting parent and family function provides an opportunity to optimize child mental health and social outcomes.

Does disability status modify the association between psychosocial job quality and mental health? A longitudinal fixed-effects analysis

BACKGROUND: People with disabilities have difficulties in obtaining work. However, evidence suggests that those with disabilities derive substantial mental health benefits from employment. This paper assesses how the relationship between work and mental health is influenced by psychosocial job quality for people working with a disability. METHODS: The study design was a longitudinal cohort with 13 annual waves of data collection, yielding a sample of 122,883 observations from 21,848 people. Fixed-effects within-person regression was used to control for time invariant confounding. The Mental Component Summary (MCS) of the Short Form 36 (SF-36) measure was used as the primary outcome measure. The main exposure was a six-category measure of psychosocial job quality and employment status (including 'not in the labour force' [NILF] and unemployment). Disability status ('no waves of disability reported' and 'all contributed waves with reported disability') was assessed as an effect modifier. We also conducted a secondary analysis on respondents contributing both disability and non-disability waves. RESULTS: For those with no disability, the greatest difference in mental health (compared to optimal employment) occurs when people have the poorest quality jobs (-2.12, 95% CI -2.48, -1.75, p < 0.001). The relative difference in mental health was less in relation to NILF and unemployment (-0.39 and -0.66 respectively). For those with consistent disability, the difference in mental health when employed in an optimal job was similar between the poorest quality jobs (-2.25, 95% CI -3.84, -0.65, p = 0.006), NILF (-2.84, 95% CI -4.49, -1.20, p = 0.001) or unemployment (-2.56, 95% CI -4.32, -0.80, p = 0.004). These results were confirmed by the secondary analysis. CONCLUSIONS: Efforts to improve psychosocial job quality may have significant mental health benefits for people with disabilities. This will contribute to the economic viability of disability employment insurance schemes in Australia and other high-income countries.

Comparative analysis of microRNA expression in mouse and human brown adipose tissue

BACKGROUND: In small mammals brown adipose tissue (BAT) plays a predominant role in regulating energy expenditure (EE) via adaptive thermogenesis. New-born babies require BAT to control their body temperature, however its relevance in adults has been questioned. Active BAT has recently been observed in adult humans, albeit in much lower relative quantities than small mammals. Comparing and contrasting the molecular mechanisms controlling BAT growth and development in mice and humans will increase our understanding or how human BAT is developed and may identify potential therapeutic targets to increase EE. MicroRNAs are molecular mechanisms involved in mouse BAT development however, little is known about the miRNA profile in human BAT. The aims of this study were to establish a mouse BAT-enriched miRNA profile and compare this with miRNAs measured in human BAT. To achieve this we firstly established a mouse BAT enriched-miRNA profile by comparing miRNAs expressed in mouse BAT, white adipose tissue and skeletal muscle. Following this the BAT-enriched miRNAs predicted to target genes potentially involved in growth and development were identified.

METHODS: MiRNA levels were measured using PCR-based miRNA arrays. Results were analysed using ExpressionSuite software with the global mean expression value of all expressed miRNAs in a givensample used as the normalisation factor. Bio-informatic analyses was used to predict gene targets followed by Ingenuity Pathway Analysis.

RESULTS: We identified 35 mouse BAT-enriched miRNAs that were predicted to target genes potentially involved in growth and development. We also identified 145 miRNAs expressed in both mouse and human BAT, of which 25 were enriched in mouse BAT. Of these 25 miRNAs, miR-20a was predicted to target MYF5 and PPARγ, two important genes involved in brown adipogenesis, as well as BMP2 and BMPR2, genes involved in white adipogenesis. For the first time, 69 miRNAs were identified in human BAT but absent in mouse BAT, and 181 miRNAs were expressed in mouse but not in human BAT.

CONCLUSION: The present study has identified a small sub-set of miRNAs common to both mouse and human BAT. From this sub-set bioinformatics analysis suggested a potential role of miR-20a in the control of cell fate and this warrants further investigation. The large number of miRNAs found only in mouse BAT or only in human BAT highlights the differing molecular profile between species that is likely to influence the functional role of BAT across species. Nevertheless the BAT-enriched miRNA profiles established in the present study suggest targets to investigate in the control BAT development and EE.

Low-volume high-intensity interval training in a gym setting improves cardio-metabolic and psychological health

Background Within a controlled laboratory environment, high-intensity interval training (HIT) elicits similar cardiovascular and metabolic benefits as traditional moderate-intensity continuous training (MICT). It is currently unclear how HIT can be applied effectively in a real-world environment. Purpose To investigate the hypothesis that 10 weeks of HIT, performed in an instructor-led, groupbased gym setting, elicits improvements in aerobic capacity (VO2max), cardio-metabolic risk and psychological health which are comparable to MICT. Methods Ninety physically inactive volunteers (42±11 y, 27.7±4.8 kg.m-2) were randomly assigned to HIT or MICT group exercise classes. HIT consisted of repeated sprints (15-60 seconds, >90% HRmax) interspersed with periods of recovery cycling (≥25 min.session-1, 3 sessions. week-1). MICT participants performed continuous cycling (70%HRmax, 30-45 min.session-1, 5 sessions.week-1). VO2max, markers of cardio-metabolic risk, and psychological health were assessed pre and post-intervention. Results Mean weekly training time was 55±10 (HIT) and 128±44 min (MICT) (p<0.05), with greater adherence to HIT (83±14% vs. 61±15% prescribed sessions attended, respectively; p<0.05). HIT improved VO2max, insulin sensitivity, reduced abdominal fat mass, and induced favourable changes in blood lipids (p<0.05). HIT also induced beneficial effects on health perceptions, positive and negative affect, and subjective vitality (p<0.05). No difference between HIT and MICT was seen for any of these variables. Conclusions HIT performed in a real-world gym setting improves cardio-metabolic risk factors and psychological health in physically inactive adults. With a reduced time commitment and greater adherence than MICT, HIT offers a viable and effective exercise strategy to target the growing incidence of metabolic disease and psychological ill-being associated with physical inactivity.

Assessing mediators between discrimination, health behaviours and physical health outcomes: a representative cross-sectional study

PURPOSE: Discrimination is a social determinant of health; however, the pathways linking discrimination to ill-health are under-researched. This study investigated the mediators through which discrimination affects health behaviours and physical health outcomes, as well as assessed whether sex moderated these mechanisms. METHODS: Data from a representative survey (n = 1023) of undergraduate students enrolled in a Brazilian university in 2012 were used. Structural equation models were applied to assess the following mediation mechanisms--(1) discrimination influences self-rated health and body mass index via anxiety/depression; (2) discrimination affects behaviours (alcohol consumption, problem drinking, smoking, fruit/vegetable consumption, and physical activity) through discomfort associated with discriminatory experiences. The potential of sex to act as an effect-modifying variable was also explored in each of the postulated pathways. RESULTS: The effect of discrimination on self-rated poor health was totally (100.0%) mediated by anxiety/depression, while body mass index was not correlated with discrimination. Self-reported discrimination was associated with some behaviours via discomfort. Particularly, discomfort partially mediated the positive association between discrimination, leisure time physical activity (43.3%), and fruit/vegetable consumption (52.2%). Sex modified the association between discrimination, discomfort and physical activity in that such mechanism (more discrimination → more discomfort → more physical activity) was statistically significant in the entire sample and among females, but not among males. CONCLUSIONS: This is one of the first studies to demonstrate that discrimination is associated with physical health outcomes and behaviours via distinct pathways. Future investigations should further explicate the mediational pathways between discrimination and key health outcomes.