Circadian variation in gastric vagal afferent mechanosensitivity

Food intake is coordinated to cellular metabolism by clock gene expression with a master clock in the suprachiasmatic nucleus synchronized by light exposure. Gastric vagal afferents play a role in regulating food intake, but it is unknown whether they exhibit circadian variation in their mechanosensitivity. We aimed to determine whether gastric vagal afferents express clock genes and whether their response to mechanical stimuli oscillates throughout the light/dark cycle. Nodose ganglia were collected from 8-week-old female C57BL/6 mice every 3 h starting at lights off (1800 h) to quantify Bmal1, Per1, Per2, and Nr1d1 mRNA by qRT-PCR. Additionally in vitro single-fiber recordings of gastric vagal mechanoreceptors were taken at all time points. Per1, Per2, Bmal1, and Nr1d1 mRNA is expressed in the nodose ganglia and levels oscillated over a 24 h period. In mice fed ad libitum, gastric content was 3 times higher at 0000 h and 0300 h than 1200 h. The response of tension receptors to 3 g stretch was reduced by up to 70% at 2100 h, 0000 h, and 0300 h compared with 1200 h. Gastric mucosal receptor response to stroking with a 50 mg von Frey hair was 3 times greater at 1200 h and 1500 h than the response at 0000 h. Similar findings were obtained in mice fasted for 6 h or maintained in darkness for 3 d before study. Therefore, these changes do not result from food intake or the light/dark cycle. Thus, gastric vagal mechanoreceptors display circadian rhythm, which may act to control food intake differentially at different times of the day.Stephen J. Kentish, Claudine L. Frisby, David J. Kennaway, Gary A. Wittert, and Amanda J. Pag

What do we know about men's help-seeking and health service use?

The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Men seek help and use health services less frequently than women do. Men's help-seeking practices and health service use are complex issues involving biological, psychological and sociological considerations. Most discussion on men's help-seeking positions them as reluctant consumers or "behaving badly" with respect to their health. Few studies have explored whether health service providers are equipped to deal with men's health issues appropriately. The current health system appears not to be tailored to meet the health needs of men. Better collaboration is required across disciplines, to further investigate men's health using both qualitative and quantitative research methods.James A Smith, Annette Braunack-Mayer and Gary Witter

"I feel more comfortable speaking to a male": Aboriginal and Torres Strait Islander men's discourse on utilizing primary health care services

Background: Aboriginal and Torres Strait Islander men have the highest morbidity and mortality rates, and lowest rates of health service utilization in Australia. There is a current perception that Aboriginal and Torres Strait Islander men are disinterested in their health. This study aimed to identify the perceived motivators, barriers and enablers of Aboriginal and Torres Strait Islander men's utilization of primary health care services, explore their experiences and obtain suggestions from them as to how services could be modified to improve utilization. Methods: This study utilized the principles of Indigenist Research Methods. Semi-structured interviews with Aboriginal and Torres Strait Islander men (N = 19) took place in South Australia and far north Queensland. Participants were asked about their experiences with primary health care services, including what they could remember as a child. A thematic analysis of the qualitative data was completed without the use of computer software. Results: Feelings of invincibility, shame, being uncomfortable, fearful, along with long waiting times, having a lack of knowledge, and culturally inappropriate staff/services were all found to be barriers to service utilization. Enabling factors included convenience, the perceived quality of the service, feeling culturally safe and/or a sense of belonging, and having a rapport with staff. Motivation for attending primary health care services included going when feeling sick/unwell, attending a particular service (dental or sexual health), visiting for check-ups and preventative health and family encouragement. This study also highlights strategies surrounding logistical factors, promotion of services and improved communications, having culturally appropriate services and providing gender specific services all of which were suggested by the participants to improve service utilization. Conclusion: Contrary to common misperceptions, this study demonstrated that most of the Aboriginal and Torres Strait Islander men participants were motivated to engage with primary health care services for preventative health care. Even though there were men that fitted the stereo-type who avoid doctors, there were usually underlying reasons and barriers accounting for this reluctance. This study suggests that if primary health care services commit to better understanding the barriers, enablers and motivators their cohort of men face, then utilization could be greatly improved.Kootsy Canuto, Gary Wittert, Stephen Harfield and Alex Brow

Understanding the utilization of primary health care services by Indigenous men: a systematic review

BACKGROUND:Aboriginal and Torres Strait Islander men experience worse health outcomes and are the most marginalized and disadvantaged population group in Australia. Primary health care services are critical to providing both clinical and social and emotional support, however, remain underutilized by Aboriginal and Torres Strait Islander men. This review aims to better understand the utilization of primary health care services by Indigenous men and assess the effectiveness of strategies implemented to improve utilization. METHODS:A four-step search strategy was employed across four databases to find peer-reviewed publications and grey literature from Australia, New Zealand, Canada and America. The search began in March 2015 and included the following databases PubMed, CINAHL, Informit (Indigenous collection) and Embase. Additional databases and websites were also searched for grey literature, reference lists of included publications were searched for additional studies and relevant experts were consulted. RESULTS:The literature search found seven articles that met the inclusion criteria; four describing three research projects, plus three expert opinion pieces. The search was unable to find published research on strategies implemented to improve primary health care utilization by Indigenous men. There is limited published research focused on the utilization of primary health care by Indigenous men. From the identified papers Indigenous men described factors impacting utilization which were categorized into three primary organizing themes; those related to health services, the attitudes of Indigenous men and knowledge. It is evident from the identified papers that improvements in Indigenous health can only occur if future programs are developed in collaboration with health services and Indigenous men to address differing requirements. CONCLUSIONS:Currently, health systems in Australia are limited in their ability to improve the health and wellbeing of Aboriginal and Torres Strait Islander males without such strategies. Future research should focus on evaluating the implementation of men specific utilization strategies. It is through evidence-based research that subsequent policies and programs can be made and implemented to improve Indigenous men's health.Kootsy Canuto, Alex Brown, Gary Wittert and Stephen Harfiel

Dietary enrichment with fish oil prevents high fat-induced metabolic dysfunction in skeletal muscle in mice

High saturated fat (HF-S) diets increase intramyocellular lipid, an effect ameliorated by omega-3 fatty acids in vitro and in vivo, though little is known about sex- and muscle fiber type-specific effects. We compared effects of standard chow, HF-S, and 7.5% HF-S replaced with fish oil (HF-FO) diets on the metabolic profile and lipid metabolism gene and protein content in red (soleus) and white (extensor digitorum longus) muscles of male and female C57BL/6 mice (n = 9-12/group). Weight gain was similar in HF-S- and HF-FO-fed groups. HF-S feeding increased mesenteric fat mass and lipid marker, Oil Red O, in red and mixed muscle; HF-FO increased interscapular brown fat mass. Compared to chow, HF-S and HF-FO increased expression of genes regulating triacylglycerol synthesis and fatty acid transport, HF-S suppressed genes and proteins regulating fatty acid oxidation, whereas HF-FO increased oxidative genes, proteins and enzymes and lipolytic gene content, whilst suppressing lipogenic genes. In comparison to HF-S, HF-FO further increased fat transporters, markers of fatty acid oxidation and mitochondrial content, and reduced lipogenic genes. No diet-by-sex interactions were observed. Neither diet influenced fiber type composition. However, some interactions between muscle type and diet were observed. HF-S induced changes in triacylglycerol synthesis and lipogenic genes in red, but not white, muscle, and mitochondrial biogenesis and oxidative genes were suppressed by HF-S and increased by HF-FO in red muscle only. In conclusion, HF-S feeding promotes lipid storage in red muscle, an effect abrogated by the fish oil, which increases mediators of lipolysis, oxidation and thermogenesis while inhibiting lipogenic genes. Greater storage and synthesis, and lower oxidative genes in red, but not white, muscle likely contribute to lipid accretion encountered in red muscle. Despite several gender-dimorphic genes, both sexes exhibited a similar HF-S-induced metabolic and gene expression profile; likewise fish oil was similarly protective in both sexes.Lisa K. Philp, Leonie K. Heilbronn, Alena Janovska, Gary A. Witter

Obesity alone or with type 2 diabetes is associated with tissue specific alterations in DNA methylation and gene expression of PPARGC1A and IGF2

BACKGROUND: Epigenetic modifications of key genes have been linked to the development of aging related diseases, such as type 2 diabetes, with increased DNA methylation of the transcriptional co-activator, peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A) in islets and skeletal muscle of patients with type 2 diabetes. Here, we examined DNA methylation and gene expression of PPARGC1A and insulin like growth factor-2 (IGF2) in adipose tissue and skeletal muscle of lean and morbidly obese individuals with or without type 2 diabetes. METHODS: Adipose tissue and skeletal muscle biopsies were collected from 24 lean, obese, and obese patients with type 2 diabetes (n=8/group). DNA methylation and gene expression of PPARGC1A and IGF2 were measured using pyrosequencing and quantitative real-time PCR respectively. RESULTS: DNA methylation and expression of both genes varied in a tissue specific manner (P<0.05). The highest levels of PPARGC1A methylation were observed in subcutaneous adipose tissue and lowest in muscle (P≤0.001), whereas IGF2 methylation was lowest in subcutaneous adipose tissue as compared with visceral adipose tissue and muscle (P≤0.04). Expression of PPARGC1A and IGF2 was highest in muscle and lowest in subcutaneous adipose tissue (P≤0.001) and PPARGC1A expression was conversely correlated with DNA methylation in skeletal muscle (r=-0.54, P=0.008). Obese patients with type 2 diabetes had higher PPARGC1A methylation in subcutaneous adipose tissue (P=0.01) and lower IGF2 DNA methylation in muscle (P=0.01) as compared with lean individuals. Obese patients with and without type 2 diabetes had reduced expression of both genes in subcutaneous adipose tissue (P≤0.04) as compared to lean individuals. CONCLUSIONS: This study showed tissue specific DNA methylation and gene expression of PPARGC1A and IGF2, which may also be associated with obesity and type 2 diabetes. Further study of the effects of tissue specific DNA methylation on risk of obesity and type 2 diabetes in a larger cohort is now warranted.Miaoxin Chen, Anne Macpherson, Julie Owens, Gary Wittert and Leonie K. Heilbron

Tea consumption is inversely related to 5-year blood pressure change among adults in Jiangsu, China: a cross-sectional study

BACKGROUND: Data relating to the association between tea consumption and blood pressure change are inconsistent. The aim of this analysis was to investigate the association between tea consumption and the change in blood pressure (BP) in Chinese adults over a 5-year period. METHODS: Data from 1109 Chinese men (N= 472) and women (N= 637) who participated in the Jiangsu Nutrition Study (JIN) were analysed. BP was measured in 2002 and 2007. Tea (green, black and total tea) consumption was quantitatively assessed at the follow-up survey in 2007. RESULTS: Total tea and green tea consumption were inversely associated with 5-year diastolic BP (DBP) but not systolic BP (SBP) change. In the multivariable analysis, compared with no consumption of tea, those with daily total tea/green tea consumption of at least10 g had 2.41 mmHg and 3.68 mmHg smaller increase of DBP respectively. There was a significant interaction between smoking and total tea/green tea consumption and DBP change. The inverse association between total tea/green tea consumption and DBP change was significant only in non-smokers. Green tea consumption was inversely associated with SBP change only in non-smokers and those without central obesity. CONCLUSION: The consumption of green tea is inversely associated with 5-year BP change among Chinese adults, an effect abrogated by smoking.Xiaoliang Tong, Anne W Taylor, Lynne Giles, Gary A Wittert and Zumin Sh

Optimising web-based computer-tailored physical activity interventions for prostate cancer survivors: a randomised controlled trial examining the impact of website architecture on user engagement

Background: Web-based computer-tailored interventions can assist prostate cancer survivors to become more physically active by providing personally relevant behaviour change support. This study aimed to explore how changing the website architecture (free choice vs. tunnelled) impacted engagement within a physical activity computer-tailored intervention targeting prostate cancer survivors. Methods: On a 2:2:1 ratio, 71 Australian prostate cancer survivors with local or locally advanced disease (mean age: 66.6 years ± 9.66) were randomised into either a free-choice (N = 27), tunnelled (N = 27) or minimal intervention control arm (N =17). The primary outcome was differences in usage of the physical activity self-monitoring and feedback modules between the two intervention arms. Differences in usage of other website components between the two intervention groups were explored as secondary outcomes. Further, secondary outcomes involving comparisons between all study groups (including the control) included usability, personal relevance, and behaviour change. Results: The average number of physical activity self-monitoring and feedback modules accessed was higher in the tunnelled arm (M 2.6 SD 1.3) compared to the free-choice arm (M 1.5 SD 1.4), p = 0.01. However, free-choice participants were significantly more likely to have engaged with the social support (p = 0.008) and habit formation (p = 0.003) 'once-off' modules compared to the standard tunnelled arm. There were no other between-group differences found for any other study outcomes. Conclusion: This study indicated that website architecture influences behavioural engagement. Further research is needed to examine the impact of differential usage on mechanisms of action and behaviour change.Amy Finlay, Holly Evans, Andrew Vincent, Gary Wittert, Corneel Vandelanotte and Camille E Shor

The association of socio-demographic status, lifestyle factors and dietary patterns with total urinary phthalates in Australian men

Published: April 15, 2015OBJECTIVE: To investigate the associations between socio-demographic status, lifestyle factors, dietary patterns and urinary total phthalate concentration in a cohort of South Australian men. METHOD: We randomly selected 1527 males aged 39 to 84 from wave two of the Men Androgen Inflammation Lifestyle Environment and Stress (MAILES) study. Total phthalate concentration was examined in fasting morning urine samples. Socio-demographic and lifestyle factors were assessed by questionnaire. Food intake was assessed by food frequency questionnaire (FFQ). Dietary patterns were constructed using factor analysis. RESULTS: Total phthalates were detected in 99.6% of the urine samples. The overall geometric mean (95% CI) of total phthalate concentration was 112.4 (107.5-117.5) ng/mL. The least square geometric means (LSGMs) of total phthalate concentration were significantly higher among people who were obese (127.8 ng/mL), consuming less than two serves fruit per day (125.7 ng/mL) and drinking more than one can (375mL) of carbonated soft drink per day (131.9 ng/mL). Two dietary patterns were identified: a prudent dietary pattern and a western dietary pattern. Both the western dietary pattern (p = 0.002) and multiple lifestyle risk factors including smoking, obesity, insufficient physical activity and the highest quartile of the western dietary pattern (p<0.001), were positively associated with total phthalate levels. There was no significant relationship between total phthalate concentration and socio-demographic status. CONCLUSION: Phthalate exposure is ubiquitous and positively associated with lifestyle risk factors in urban dwelling Australian men.Peter Y. Bai, Gary A. Wittert, Anne W. Taylor, Sean A. Martin, Robert W. Milne, Zumin Sh

Lower urinary tract symptoms, depression, anxiety and systemic inflammatory factors in men: a population-based cohort study

The relationship between lower urinary tract symptoms (LUTS) and common mental health disorders such as depression and anxiety in men remains unclear. Inflammation has recently been identified as an independent risk factor for LUTS and depression. This study aimed to assess the association between depression, anxiety and LUTS, and the moderating influence of systemic inflammation, in the presence of other biopsychosocial confounders.Participants were randomly-selected from urban, community-dwelling males aged 35-80 years at recruitment (n = 1195; sample response rate:67.8%). Of these, 730 men who attended baseline (2002-5) and follow-up clinic visits (2007-10), with complete outcome measures, and without prostate or bladder cancer and/or surgery, neurodegenerative conditions, or antipsychotic medications use, were selected for the present study. Unadjusted and multi-adjusted regression models of incident storage and voiding LUTS and incident depression and anxiety were combined with serum inflammatory markers (high-sensitive C-reactive protein (hsCRP), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), myeloperoxidase (MPO), soluble e-selectin (e-Sel)) and socio-demographic, lifestyle, and health-related factors. Hierarchical multiple regression was used to assessed the moderating effect of inflammatory markers.The incidence of storage, voiding LUTS, depression and anxiety was 16.3% (n = 108), 12.1% (n = 88), 14.5% (n = 108), and 12.2% (n = 107). Regression models demonstrated that men with depression and anxiety at baseline were more likely to have incident storage, but not voiding LUTS (OR: 1.26, 99%CI: 1.01-4.02; and OR:1.74; 99%CI:1.05-2.21, respectively). Men with anxiety and storage LUTS at baseline were more likely to have incident depression (OR: 2.77, 99%CI: 1.65-7.89; and OR:1.45; 99%CI:1.05-2.36, respectively), while men with depression and voiding LUTS were more likely to have anxiety at follow-up (OR: 5.06, 99%CI: 2.81-9.11; and OR:2.40; 99%CI:1.16-4.98, respectively). CRP, TNF-α, and e-Sel were found to have significant moderating effects on the development of storage LUTS (1.06, 0.91-1.96, R2 change: 12.7%), depression (1.17, 1.01-1.54, R2 change: 9.8%), and anxiety (1.35, 1.03-1.76, R2 change: 10.6%), respectively.There is a bidirectional relationship between storage, but not voiding, LUTS and both depression and anxiety. We observed variable moderation effects for selected inflammatory markers on the development of depression, anxiety and storage LUTS.Sean Martin, Andrew Vincent, Anne W. Taylor, Evan Atlantis, Alicia Jenkins, Andrzej Januszewski, Peter O, Loughlin, Gary Witter