Kristy Bolton

Government food service policies and guidelines do not create healthy school canteens

Objective

Decorin is a secreted protein associated with obesity and type 2 diabetes

Objective:To characterize the expression of the small leucine-rich glycoprotein decorin in adipose tissue.Design:Real-time PCR was used to measure decorin gene expression in adipose tissue from normal glucose tolerant (NGT), impaired glucose tolerant and type 2 diabetic (T2D) Psammomys obesus. Adipose tissue was fractionated to determine which cells were responsible for decorin expression. The location of decorin protein expression in adipose tissue was determined using immunohistochemistry. Real-time PCR was used to measure decorin mRNA levels in human adipose tissue from 16 insulin-sensitive, 16 insulin-resistant and 6 T2D human subjects. Circulating plasma decorin concentrations were measured by enzyme-linked immunosorbent assay in 145 NGT and 141 T2D human individuals from a large-scale epidemiological study in Mauritius.Results:Decorin mRNA was found to be highly expressed in adipose tissue, and decorin gene expression was significantly higher in visceral than that in subcutaneous adipose tissue depots in both P. obesus and human subjects (P=0.002 and P=0.001, respectively). Decorin mRNA was predominantly expressed by stromal/vascular cells of adipose tissue, and decorin protein in adipose tissue was primarily detected adjacent to blood vessels. Circulating plasma decorin levels in humans were elevated by 12% in T2D (P=0.049) compared to NGT subjects. There was a significant independent correlation between plasma decorin levels and waist-to-hip ratio (WHR, P=0.024). In male subjects, plasma decorin levels were significantly correlated with WHR (P=0.006), and fasting and 2-h glucose levels in an oral glucose tolerance test (P=0.027 and P=0.001, respectively).Conclusions:Decorin expression in adipose tissue was markedly upregulated in the obese state and may therefore play a role in adipose tissue homeostasis or in pathophysiology associated with obesity.

Identification of secreted proteins associated with obesity and type 2 diabetes in Psammomys obesus.

Objective:Skeletal muscle produces a variety of secreted proteins that have important roles in intercellular communication and affects processes such as glucose homoeostasis. The objective of this study was to develop a novel Signal Sequence Trap (SST) in conjunction with cDNA microarray technology to identify proteins secreted from skeletal muscle of Psammomys obesus that were associated with obesity and type 2 diabetes (T2D).Design:Secreted proteins that were differentially expressed between lean, normal glucose tolerant (NGT), overweight and impaired glucose tolerant (IGT) and obese, T2D P. obesus were isolated using SST in conjunction with cDNA microarray technology. Subsequent gene expression was measured in tissues from P. obesus by real-time PCR (RT-PCR).Results:The SST yielded 1600 positive clones, which were screened for differential expression. A total of 91 (∼6%) clones were identified by microarray to be differentially expressed between NGT, IGT and T2D P. obesus. These clones were sequenced to identify 51 genes, of which only 27 were previously known to encode secreted proteins. Three candidate genes not previously associated with obesity or type 2 diabetes, sushi domain containing 2, collagen and calcium-binding EGF domains 1 and periostin (Postn), as well as one gene known to be associated, complement component 1, were shown by RT-PCR to be differentially expressed in skeletal muscle of P. obesus. Further characterization of the secreted protein Postn revealed it to be predominantly expressed in adipose tissue, with higher expression in visceral compared with subcutaneous adipose depots.Conclusion:SST in conjunction with cDNA microarray technology is a powerful tool to identify differentially expressed secreted proteins involved in complex diseases such as obesity and type 2 diabetes. Furthermore, a number of candidate genes were identified, in particular, Postn, which may have a role in the development of obesity and type 2 diabetes.

The small leucine-rich proteoglycan, biglycan, is highly expressed in adipose tissue of Psammomys obesus and is associated with obesity and type 2 diabetes

We have previously demonstrated that the small leucine-rich proteoglycan decorin may play a role in adipose tissue homeostasis and the pathophysiology of obesity. Biglycan is highly similar in structure to decorin, therefore we hypothesized it would have a similar expression profile and role to decorin in adipose tissue. Real time polymerase chain reaction was used to measure biglycan mRNA levels in adipose tissue from normal glucose tolerant and impaired glucose tolerant and type 2 diabetic (T2D) Psammomys obesus. Biglycan mRNA was found to be highly expressed in adipose tissue, and gene expression was significantly higher in visceral compared to subcutaneous adipose tissue, with elevated levels in obese, T2D compared to lean normal glucose tolerant P. obesus (P < 0.04). Biglycan mRNA was predominantly expressed by stromal/vascular cells of fractionated adipose tissue (P = 0.023). Biglycan expression in adipose tissue, particularly in the obese state, was markedly upregulated. Collectively, our data suggest that the small leucine-rich proteoglycan family proteins biglycan and decorin may play a role in the development of obesity and T2D, possibly by facilitating expansion of adipose tissue mass.

Rapid weight gain during infancy and subsequent adiposity: a systematic review and meta‐analysis of evidence

The contribution of rapid weight gain (RWG) during infancy to later adiposity has received considerable investigation. The present systematic review and meta‐analysis aimed to update the literature on association between RWG and subsequent adiposity outcomes. Electronic searches were undertaken in EMBASE, MEDLINE, psycINFO, PubMed and ScienceDirect. Studies that examined the associations between RWG (a change in weight z‐scores > 0.67) during infancy (from birth to age 2 years) and subsequent adiposity outcomes were included. Random effects meta‐analysis was conducted to obtain the weighted‐pooled estimates of the odds of overweight/obesity for those with RWG. Seventeen studies were eligible for inclusion with the majority of studies (15/17) being of high/acceptable quality and reporting positive associations between RWG during infancy and later adiposity outcomes. RWG in infancy was associated with overweight/obesity from childhood to adulthood (pooled odds ratio = 3.66, 95% confidence interval: 2.59–5.17, I2 > 75%). Subgroup analyses revealed that RWG during infancy was associated with higher odds of overweight/obesity in childhood than in adulthood, and RWG from birth to 1 year was associated with higher odds of overweight/obesity than RWG from birth to 2 years. The present study supports that RWG during infancy is a significant predictor of adiposity in later life.

The outcomes of health-promoting communities: being active eating well initiative—a community-based obesity prevention intervention in Victoria, Australia

Objective:The aim of this study is to evaluate the impact of the Health-Promoting Communities: Being Active Eating Well (HPC:BAEW, 2007–2010) initiative, which comprised community-based multi-component interventions adapted to community context in five separate communities. The intervention aimed to promote healthy eating, physical activity and stronger, healthier communities.Methods:A mixed method and multilevel quasi-experimental evaluation of the HPC:BAEW initiative captured process, impact and outcome data. The evaluation involved both cross-sectional (children and adolescents) and longitudinal designs (adults) with data collected pre- and post-intervention in intervention (n=2408 children and adolescents from 18 schools, n=501 adults from 22 workplaces) and comparison groups (n=3163 children and adolescents from 33 schools, n=318 adults from seven workplaces). Anthropometry, obesity-related behavioural and environmental data, information regarding community context and implementation factors were collected. The primary outcomes were differences in anthropometry (weight, waist, body mass index (BMI) and standardised BMI (BMI z-score)) over time compared with comparison communities. Baseline data was collected 2008/2009 and post-intervention collected in 2010 with an average intervention time frame of approximately 12 months.Results:The strategies most commonly implemented were related to social marketing, stakeholder engagement, network and partnership development, community-directed needs assessment and capacity building. Analysis of post-intervention data showed gains in community capacity, but few impacts on environments, policy or individual knowledge, skills, beliefs and perceptions. Relative to the comparison group, one community achieved a lower prevalence of overweight/obesity, lower weight, waist circumference and BMI (P<0.005). One community achieved a higher level of healthy eating policy implementation in schools; two communities achieved improved healthy eating-related behaviours (P<0.03); one community achieved lower sedentary behaviours; and one community achieved higher levels of physical activity in schools (P<0.05). All effect sizes were in the small-to-moderate range.Conclusions:This was a complex and ambitious initiative, which attempted to expand a previously successful community-based intervention in Victoria into five new contexts and communities. Overall, project success was quite inconsistent, and some significant differences were in the unanticipated direction. However, there are many important learnings that should inform future health-promotion activities. The heterogeneity of outcomes of HPC:BAEW communities reflects the reality of life whereby effectiveness of intervention strategies is dependent on individual and community factors. Future health promotion should consider a systems approach whereby existing systems are modified rather than relying heavily on the addition of new activities, with longer time frames for implementation.

A map of community-based obesity prevention initiatives in Australia following obesity funding 2009-2013.

Objective: Obesity is the single biggest public health threat to developed and developing economies. In concert with healthy public policy, multi‐strategy, multi‐level community‐based initiatives appear promising in preventing obesity, with several countries trialling this approach. In Australia, multiple levels of government have funded and facilitated a range of community‐based obesity prevention initiatives (CBI), heterogeneous in their funding, timing, target audience and structure. This paper aims to present a central repository of CBI operating in Australia during 2013, to facilitate knowledge exchange and shared opportunities for learning, and to guide professional development towards best practice for CBI practitioners.

Expanding a successful community-based obesity prevention approach into new communities: Challenges and achievements

OBJECTIVE A previously successful community-based obesity prevention intervention with a focus on school settings was expanded into new communities with varying contexts. In order to understand the complexities involved in implementing health promotion activities in schools, this study examined experiences of school staff and project officers including barriers, contextual factors and achievements. METHODS School environment assessments were conducted in schools across four Victorian communities with school staff (n=1-5 staff plus a trained researcher per group in 9 primary and 8 secondary schools) 12-18 months post-intervention. Process reports from project officers were also reviewed and analysed (n=4). RESULTS School staff commonly reported time pressures as a barrier to implementation and project officers working within schools reported competing priorities and limited health promotion experience of staff; lack of stakeholder engagement; low participation in some activities and insufficient implementation time. Contextual factors included community socioeconomic status, student ethnicity and living rurally. Achievements included student and staff enjoyment from programme activities, staff capacity building, partnerships, embedding activities into existing infrastructure and programmes, and having consistent health-related messages repeated through a variety of strategies. CONCLUSIONS Community-based interventions with a focus on school settings need to consider system level, organisational and contextual (i.e. socioeconomic, ethnicity, family and town characteristics) factors when expanding previously effective strategies into new communities. Implementation benefits may have added whole of school benefits in addition to child health. Focussing on overcoming the challenges experienced in this complex initiative is required for future interventions. TRIAL REGISTRATION ACTRN12609000892213.

A snapshot of the scope of obesity prevention practice in Australia

Community-based initiatives (CBIs) that build capacity and promote healthy environments hold promise for preventing obesity and non-communicable disease, however their characteristics remain poorly understood and lessons are learned in isolation. This limits understanding of likely effectiveness of CBIs; the potential for actively supporting practice; and the translation of community-based knowledge into policy. Building on an initial survey (2010), an online survey was launched (2013) with the aim to describe the reach and characteristics of Australian CBIs and identify and evaluate elements known to contribute to best practice, effectiveness and sustainability. Responses from 104 CBIs were received in 2013. Geographic location generally reflected population density in Australia. Duration of CBIs was short-term (median 3 years; range 0.2–21.0 years), delivered mostly by health departments and local governments. Median annual funding had more than doubled since the 2010 survey, but average staffing had not increased. CBIs used at least two strategy types, with a preference for individual behaviour change strategies. Targeting children was less common (31%) compared with the 2010 survey (57%). Logic models and theory were used in planning, but there was low use of research evidence and existing prevention frameworks. Nearly, all CBIs had an evaluation component (12% of budget), but dissemination was limited. This survey provides information on the scope and varied quality of the current obesity prevention investment in Australia. To boost the quality and effectiveness of CBIs, further support systems may be required to ensure that organizations adopt upstream, evidence-informed approaches; and integrate CBIs into systems, policies and environments.

Evaluation of a Knowledge Translation and Exchange Platform to Advance Non-Communicable Disease Prevention.

Coordinated systems are required to ensure evidence-informed practice and evaluation of community-based interventions (CBIs). Knowledge translation and exchange (KTE) strategies show promise, but these require evaluation. This paper describes implementation and evaluation of COOPS, a national KTE platform to support best practice in obesity prevention CBIs. A logic model guides KTE activities including knowledge brokering, networking, tailored communications, training, and needs assessments. A mixed-methods evaluation includes communications data, knowledge brokering database, annual survey of CBIs, pre- and post-event questionnaires, interviews, social network analysis, and case studies. This evaluation will contribute to understanding the process of implementing a KTE platform with CBIs and its reach, quality and effectiveness.