Sansom Institute for Health Research

Adelaide, Australia

Sansom Institute for Health Research

Adelaide, Australia
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Zahnd G.,CNRS Research Center for Image Acquisition and Processing for Health | Vray D.,CNRS Research Center for Image Acquisition and Processing for Health | Serusclat A.,Louis Pradel Hospital | Alibay D.,Louis Pradel Hospital | And 11 more authors.
Ultrasound in Medicine and Biology | Year: 2012

The recently discovered longitudinal displacement of the common carotid arterial wall (i.e., the motion along the same plane as the blood flow), may be associated with incident cardiovascular events and represents a novel and relevant clinical information. At present, there have only been a few studies that have been conducted to investigate this longitudinal movement. We propose here a method to assess noninvasively the wall bi-dimensional (two-dimensional [2-D], cross-sectional and longitudinal) motion and present an original approach that combines a robust speckle tracking scheme to guidance by minimal path contours segmentation. Our method is well suited to large clinical population studies as it does not necessitate strong imaging prerequisites. The aim of this study is to describe the association between the longitudinal displacement of the carotid arterial wall and cardiovascular risk factors, among which periodontal disease. Some 126 Indigenous Australians with periodontal disease, an emerging risk factor, and 27 healthy age- and sex-matched non-indigenous control subjects had high-resolution ultrasound scans of the common carotid artery. Carotid intima-media thickness and arterial wall 2-D motion were then assessed using our method in ultrasound B-mode sequences. Carotid longitudinal displacement was markedly lower in the periodontal disease group than the control group (geometric mean (IQR): 0.15 mm (0.13) vs. 0.42 mm (0.30), respectively; p < 0.0001), independent of cardiovascular risk factors, cross-sectional distensibility and carotid intima-media thickness (p < 0.0001). A multivariable model indicated that the strongest correlates of carotid longitudinal displacement in adults with periodontal disease were age (β-coefficient = -.235, p = .03), waist (β-coefficient = -.357, p = 0.001), and pulse pressure (β-coefficient = .175, p = 0.07), independent of other cardiovascular risk factors, cross-sectional distensibility and pulse wave velocity. Carotid longitudinal displacement, estimated with our approach, is impaired in the periodontal disease group, independent of established cardiovascular risk factors and other noninvasive measures of arterial stiffness, and may represent an important marker of cardiovascular risk. © 2012 World Federation for Ultrasound in Medicine & Biology.

Thomson R.L.,Sansom Institute for Health Research | Thomson R.L.,CSIRO | Buckley J.D.,Sansom Institute for Health Research | Noakes M.,CSIRO | And 3 more authors.
Fertility and Sterility | Year: 2010

Objective: To determine the effects of weight loss on heart rate recovery (HRR) in overweight women with polycystic ovary syndrome (PCOS). Design: A 10-week prospective clinical intervention. Setting: Clinical research unit. Patient(s): Fifty-seven overweight and obese women with PCOS (age: 29.8 ± 0.8 years; body mass index [BMI] 36.2 ± 0.7 kg/m2). Intervention(s): A dietary plan of 5-6 MJ/day (∼30% energy restricted). Main Outcome Measure(s): Heart rate recovery (defined as the reduction in heart rate after 1 minute from peak heart rate after a graded treadmill test to exhaustion), weight, waist circumference, blood pressure, glucose, insulin, homeostasis model assessment of insulin resistance, and sex steroids before and after the intervention. Result(s): The mean percentage of weight loss was (-6.7 ± 0.4%). There were significant reductions in waist circumference (-6.9 ± 0.6 cm), blood pressure (-4.9/-2.5 ± 1.2/1.2 mm Hg), fasting insulin (-3.4 ± 0.7 mU/L), fasting glucose (-0.17 ± 0.05 mmol/L), homeostasis model assessment of insulin resistance (-0.43 ± 0.09), T (-0.38 ± 0.07 nmol/L), free androgen index (-2.86 ± 0.58), and an increase in sex hormone-binding globulin [SHBG] (5.86 ± 1.12 nmol/L). The HRR improved from 30.9 ± 1.1 to 38.0 ± 1.1 beats/min and that was related to the reduction in body weight (r = -0.34) and waist circumference (r = -0.27). Conclusion(s): Weight loss in overweight and obese women with PCOS is associated with improvements in HRR, which suggests improved autonomic function. This highlights the importance of weight loss to reduce the cardiovascular disease risk in these women. Crown Copyright © 2010.

Maple-Brown L.J.,Charles Darwin University | Maple-Brown L.J.,Royal Darwin Hospital | Cunningham J.,Charles Darwin University | Nandi N.,Royal Darwin Hospital | And 2 more authors.
Cardiovascular Diabetology | Year: 2010

Background: Epidemiological evidence suggests that fibrinogen and CRP are associated with coronary heart disease risk. High CRP in Indigenous Australians has been reported in previous studies including our 'Diabetes and Related diseases in Urban Indigenous population in Darwin region' (DRUID) Study. We studied levels of fibrinogen and its cross-sectional relationship with traditional and non-traditional cardiovascular risk factors in an urban Indigenous Australian cohort.Methods: Fibrinogen data were available from 287 males and 628 females (aged ≥ 15 years) from the DRUID study. Analysis was performed for associations with the following risk factors: diabetes, HbA1c, age, BMI, waist circumference, waist-hip ratio, total cholesterol, triglyceride, HDL cholesterol, C-reactive protein, homocysteine, blood pressure, heart rate, urine ACR, smoking status, alcohol abstinence.Results: Fibrinogen generally increased with age in both genders; levels by age group were higher than those previously reported in other populations, including Native Americans. Fibrinogen was higher in those with than without diabetes (4.24 vs 3.56 g/L, p < 0.001). After adjusting for age and sex, the following were significantly associated with fibrinogen: BMI, waist, waist-hip ratio, systolic blood pressure, heart rate, fasting triglycerides, HDL cholesterol, HbA1c, CRP, ACR and alcohol abstinence. On multivariate regression (age and sex-adjusted) CRP and HbA1c were significant independent predictors of fibrinogen, explaining 27% of its variance; CRP alone explained 25% of fibrinogen variance. On factor analysis, both CRP and fibrinogen clustered with obesity in women (this factor explained 20% of variance); but in men, CRP clustered with obesity (factor explained 18% of variance) whilst fibrinogen clustered with HbA1c and urine ACR (factor explained 13% of variance).Conclusions: Fibrinogen is associated with traditional and non-traditional cardiovascular risk factors in this urban Indigenous cohort and may be a useful biomarker of CVD in this high-risk population. The apparent different associations of fibrinogen with cardiovascular disease risk markers in men and women should be explored further. © 2010 Maple-Brown et al; licensee BioMed Central Ltd.

PubMed | Charles Darwin University, South Australian Health and Medical Research Institute, University of Adelaide, University of Sydney and 2 more.
Type: | Journal: International journal of dental hygiene | Year: 2016

Diabetes mellitus and periodontal disease are highly prevalent among Indigenous Australian adults. Untreated periodontitis impacts glycaemic control in people with diabetes. The aim of this study was to report on the effect of periodontal therapy on glycaemic control among people with obesity.This subgroup analysis is limited to 62 participants with diabetes from the original 273 Aboriginal Australian adults enrolled into the PerioCardio study. Intervention participants received full-mouth non-surgical periodontal scaling during a single, untimed session while controls were untreated. Endpoints of interest included change in glycated haemoglobin (HbA1c), C-reactive protein (CRP) and periodontal status at 3 months post-intervention.There were more females randomized to the treatment group (n = 17) than control (n = 10) while the control group had a higher overall body mass index (BMI) [mean (SD)] 33.1 (9.7 kg mNon-surgical periodontal therapy did not significantly reduce glycated haemoglobin in participants with type 2 diabetes. Reasons are likely to be multifactorial and may be influenced by persistent periodontal inflammation at the follow-up appointments. Alternatively, the BMI of study participants may impact glycaemic control via alternative mechanisms involving the interplay between inflammation and adiposity meaning HbA1c may not be amenable to periodontal therapy in these individuals.

Grieger J.A.,University of South Australia | Johnson B.J.,University of South Australia | Wycherley T.P.,University of South Australia | Golley R.K.,University of South Australia | Golley R.K.,Sansom Institute for Health Research
Nutrients | Year: 2017

Dietary strategies to reduce discretionary choice intake are commonly utilized in practice, but evidence on their relative efficacy is lacking. The aim was to compare the potential impact on nutritional intake of three strategies to reducing discretionary choices intake in the Australian adult (19-90 years) population. Dietary simulation modelling using data from the National Nutrition and Physical Activity Survey 2011-2012 was conducted (n = 9341, one 24 h dietary recall). Strategies modelled were: moderation (reduce discretionary choices by 50%, with 0%, 25% or 75% energy compensation), substitution (replace 50% of discretionary choices with core choices), reformulation (replace 50% SFA with unsaturated fats, reduce added sugars by 25%, and reduce sodium by 20%). Compared to the base case (observed) intake, modelled intakes in the moderation scenario showed: −17.3% lower energy (sensitivity analyses, 25% energy compensation −14.2%, 75% energy compensation −8.0%), −20.9% lower SFA (−17.4%, −10.5%), −43.3% lower added sugars (−41.1%, −36.7%) and 17.7% lower sodium (−14.3%, −7.5%). Substitution with a range of core items, or with fruits, vegetables and core beverages only, resulted in similar changes in energy intake (−13.5% and −15.4%), SFA (−17.7% and −20.1%), added sugars (−42.6% and −43%) and sodium (−13.7% and −16.5%), respectively. Reformulating discretionary choices had minimal impact on reducing energy intake but reduced SFA (−10.3% to −30.9%), added sugars (−9.3% to −52.9%), and alcohol (−25.0% to −49.9%) and sodium (−3.3% to −13.2%). The substitution and reformulation scenarios minimized negative changes in fiber, protein and micronutrient intakes. While each strategy has strengths and limitations, substitution of discretionary choices with core foods and beverages may optimize the nutritional impact. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.

Rowlands A.V.,Sansom Institute for Health Research | Rowlands A.V.,University of South Australia | Fraysse F.,University of South Australia | Catt M.,Newcastle University | And 5 more authors.
Medicine and Science in Sports and Exercise | Year: 2015

Background: Accelerometers that provide triaxial measured acceleration data are now available. However, equivalence of output between brands cannot be assumed and testing is necessary to determine whether features of the acceleration signal are interchangeable. Purpose: This study aimed to establish the equivalence of output between two brands of monitor in a laboratory and in a free-living environment. Methods: For part 1, 38 adults performed nine laboratory-based activities while wearing an ActiGraph GT3X+ and GENEActiv (Gravity Estimator of Normal Everyday Activity) at the hip. For part 2, 58 children age 10-12 yr wore a GT3X+ and GENEActiv at the hip for 7 d in a free-living setting. Results: For part 1, the magnitude of time domain features from the GENEActiv was greater than that from the GT3X+. However, frequency domain features compared well, with perfect agreement of the dominant frequency for 97%-100% of participants for most activities. For part 2, mean daily acceleration measured by the two brands was correlated (r = 0.93, P < 0.001, respectively) but the magnitude was approximately 15% lower for the GT3X+ than that for the GENEActiv at the hip. Conclusions: Frequency domain-based classification algorithms should be transferable between monitors, and it should be possible to apply time domain-based classification algorithms developed for one device to the other by applying an affine conversion on the measured acceleration values. The strong relation between accelerations measured by the two brands suggests that habitual activity level and activity patterns assessed by the GENE and GT3X+ may compare well if analyzed appropriately. Copyright © 2014 by the American College of Sports Medicine.

Wong R.H.X.,Sansom Institute for Health Research | Berry N.M.,Sansom Institute for Health Research | Coates A.M.,Sansom Institute for Health Research | Buckley J.D.,Sansom Institute for Health Research | And 4 more authors.
Journal of Hypertension | Year: 2013

Background: We have previously demonstrated acute dose-dependent increases of flow-mediated dilatation (FMD) in the brachial artery after resveratrol consumption in mildly hypertensive, overweight/obese adults. Resveratrol supplementation has also been shown to increase cerebral blood flow acutely, without affecting cognition. Objectives: To evaluate the effects of chronic resveratrol supplementation on both FMD and cognitive performance. Method: Twenty-eight obese but otherwise healthy adults (BMI: 33.3±0.6kg/m 2) were randomized to take a single 75 mg capsule of trans-resveratrol (Resvida) or placebo daily for 6 weeks each in a double-blind crossover supplementation trial. Blood pressure, arterial compliance, FMD, and performance on the Stroop Color-Word Test were assessed at the end of each 6-week intervention period while fasted and at least 18 h after taking the last daily capsule. An additional capsule of the same supplement was then taken. FMD assessment was repeated 1 h later. Results: Chronic resveratrol supplementation for 6 weeks was well tolerated and resulted in a 23% increase in FMD compared with placebo (P = 0.021, paired t-test). The extent of increase correlated negatively with baseline FMD (r= -0.47, P=0.01). A single dose of resveratrol (75 mg) following chronic resveratrol supplementation resulted in a 35% greater acute FMD response than the equivalent placebo supplementation. These FMD improvements remained significant after adjusting for baseline FMD. Blood pressure, arterial compliance, and all components of the Stroop Color-Word Test were unaffected by chronic resveratrol supplementation. Conclusion: Daily resveratrol consumption was well tolerated and has the potential to maintain healthy circulatory function in obese adults. © 2013 Wolters Kluwer Health Lippincott Williams & Wilkins.

Grzeskowiak L.E.,Sansom Institute for Health Research | Gilbert A.L.,Sansom Institute for Health Research | Morrison J.L.,Sansom Institute for Health Research
European Journal of Clinical Pharmacology | Year: 2012

Purpose: The aim of this systematic review was to examine and compare differences in the way medication exposures are classified in studies using linked administrative data to investigate outcomes following medication use during pregnancy. This was undertaken with a focus on studies investigating specific neonatal outcomes following prenatal exposure to selective serotonin reuptake inhibitors (SSRIs). Methods: We searched Medline and Embase to identify studies that used linked administrative data to investigate specific neonatal outcomes (congenital malformations, birth weight, gestational age) following prenatal exposure to SSRIs. Results: Key factors such as dose, duration and timing of exposure were inconsistently addressed in the studies identified. In addition, there was a great deal of variability in the way medication exposures were classified and how women who stop taking their medication before or during early pregnancy are handled in analyses. Furthermore, there are issues in assuming how and when women who receive a dispensing for a medication actually take it during pregnancy. This creates a great deal of uncertainty around medication exposure during pregnancy in studies using linked administrative data, potentially resulting in biased risk estimates. Conclusions: There is a need for greater focus on determining the most effective and accurate way of using linked administrative data to investigate outcomes following medication use during pregnancy in an effort to minimise potential biases. © Springer-Verlag 2011.

Golley R.K.,Sansom Institute for Health Research | Hendrie G.A.,CSIRO | McNaughton S.A.,Deakin University
Journal of Nutrition | Year: 2011

Diet quality indices reflect overall dietary patterns better than single nutrients or food groups. The study aims were to develop a measure of adherence with dietary guidelines applicable to child and adolescent populations in Australia and determine the association between index scores and food and nutrient intake, socio-demographic characteristics, and measures of adiposity. Data were analyzed from 4- to 16-y-old participants of the 2007 Australian Children's Nutrition and Physical Activity Survey (n = 3416). The Dietary Guideline Index for Children and Adolescents (DGI-CA) comprises 11 components: 5 core food groups, wholegrain bread, reduced-fat dairy foods, extra foods (nutrient poor and high in fat, salt, and added sugar), healthy fats/oils, water, and diet variety (possible score of 100). The index criteria were age specific. The mean DGI-CA score was low (53.6 ± 0.4), similar between boys and girls, and differed by age; the youngest children scored higher than the oldest children (P<, 0.0001). Higher DGI-CA scores were associated with lower energy intake, energy density, total and saturated fat, and sugar intake; higher protein, carbohydrate, fiber, calcium, iron, vitamin C, vitamin A, folate, phosphorous, magnesium, zinc, and iodine intakes; and a higher polyunsaturated:saturated fat ratio (P<, 0.0001). DGI-CA scores were associated with socio-economic characteristics and measures of family circumstance. Weak positive associations were observed between DGI-CA score and BMI or waist circumference Z-scores in the 4- to 10-y and 12- to 16-y age groups only. This index is the first validated index in Australia and one of the few international indices to describe the diet quality of children and adolescents. © 2011 American Society for Nutrition.

Fung K.Y.C.,CSIRO | Ooi C.C.,CSIRO | Ooi C.C.,Sansom Institute for Health Research | Zucker M.H.,CSIRO | And 4 more authors.
International Journal of Molecular Sciences | Year: 2013

The current models for colorectal cancer (CRC) are essentially linear in nature with a sequential progression from adenoma through to carcinoma. However, these views of CRC development do not explain the full body of published knowledge and tend to discount environmental influences. This paper proposes that CRC is a cellular response to prolonged exposure to cytotoxic agents (e.g., free ammonia) as key events within a sustained high-risk colonic luminal environment. This environment is low in substrate for the colonocytes (short chain fatty acids, SCFA) and consequently of higher pH with higher levels of free ammonia and decreased mucosal oxygen supply as a result of lower visceral blood flow. All of these lead to greater and prolonged exposure of the colonic epithelium to a cytotoxic agent with diminished aerobic energy availability. Normal colonocytes faced with this unfavourable environment can transform into CRC cells for survival through epigenetic reprogramming to express genes which increase mobility to allow migration and proliferation. Recent data with high protein diets confirm that genetic damage can be increased, consistent with greater CRC risk. However, this damage can be reversed by increasing SCFA supply by feeding fermentable fibre as resistant starch or arabinoxylan. High protein, low carbohydrate diets have been shown to alter the colonic environment with lower butyrate levels and apparently greater mucosal exposure to ammonia, consistent with our hypothesis. Evidence is drawn from in vivo and in vitro genomic and biochemical studies to frame experiments to test this proposition. © 2013 by the authors; licensee MDPI, Basel, Switzerland.

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