D. W. Dunstan

D. W. Dunstan
Baker Heart and Diabetes Institute · Physical Activity and Behavioural Epidemiology Research Group

Doctor of Philosophy
Currently looking for PhD students

About

556
Publications
123,813
Reads
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37,195
Citations
Introduction
a) Epidemiology of adult sedentary behaviour and physical activity (prevalence, trends and associations with health outcomes) b) Design and implementation of experimental trials investigating the health benefits of regularly breaking up time spent sitting with activity in adults c) Design and implementation of real-world behaviour change trials examining the impacts of interventions targeting sitting less and moving more in adults d) Translation of research evidence into policy

Publications

Publications (556)
Article
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Background TransformUs was a four-arm school-based intervention to increase physical activity and reduce sedentary behaviour among primary school children. Pedagogical and environmental strategies targeted the classroom, school grounds and family setting. The aims of this study were to evaluate program fidelity, dose, appropriateness, satisfaction...
Article
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Background There is a dearth of studies on how neighbourhood environmental attributes relate to the metabolic syndrome (MetS) and profiles of MetS components. We examined the associations of interrelated aspects of the neighbourhood environment, including air pollution, with MetS status and profiles of MetS components. Methods We used socio-demogr...
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Background: Allogeneic stem cell transplantation (allo-SCT) is a potentially lifesaving treatment for high-risk hematological malignancy, but survivors experience markedly elevated rates of cardiovascular disease and associated functional impairment. Mounting evidence suggests regular exercise, combined with a reduction in sedentary time through r...
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Objectives To evaluate the effectiveness of an intervention, with and without a height adjustable desk, on daily sitting time, and to investigate the relative effectiveness of the two interventions, and the effectiveness of both interventions on physical behaviours and physical, biochemical, psychological, and work related health and performance ou...
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Background It is unknown if and how children’s movement behaviour accumulation patterns change as a result of physical activity and/or sedentary behaviour interventions. It is important to establish the effectiveness of interventions targeting changes in such accumulation patterns. This study aimed to investigate the effect of the Transform-Us! sch...
Article
This study investigates the associations of vigorous-intensity gardening time with cardiometabolic health risk markers. This cross-sectional study (AusDiab) analyzed 2011-2012 data of 3,664 adults (55% women, mean [range], age = 59.3 [34-94] years) in Australia. Multiple linear regression models examined associations of time spent participating in...
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BACKGROUND: Time spent sitting is associated adversely with health outcomes in older adults. Nevertheless, it is not clear how sedentary time may be related to appendicular skeletal muscle mass (ASM) – a key attribute of sarcopenia. This cross sectional study examined associations of total sedentary time with ASM among community-dwelling older Japa...
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Introduction: Higher levels of physical activity are associated with lower cardio-metabolic risk. However, the relative contribution of overall activity and the intensity of activity is unclear. Our aim was to determine the relative contribution of overall activity and intensity distribution of activity to cardio-metabolic risk in in a cross-secti...
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Traffic-related air pollution (TRAP) is associated with lower cognitive function and diabetes in older adults, but little is known about whether diabetes status moderates the impact of TRAP on older adult cognitive function. We analysed cross-sectional data from 4141 adults who participated in the Australian Diabetes, Obesity and Lifestyle (AusDiab...
Article
Objective Higher neighbourhood walkability would be expected to contribute to better health, but the relevant evidence is inconsistent. This may be because residents’ dietary attributes, which vary with socio-economic status (SES) and influence their health, can be related to walkability. We examined associations of walkability with dietary attribu...
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Background Clinical practice guidelines recommend that adults with type 2 diabetes (T2D) sit less and move more throughout the day. The 18-month OPTIMISE Your Health Clinical Trial was developed to support desk-based workers with T2D achieve these recommendations. The two-arm protocol consists of an intervention and control arms. The intervention a...
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Background Being overweight or obese may be associated with lower physical and cognitive function, but in late-adulthood (≥ 65 years) evidence is mixed. This study aimed to investigate how being overweight or obese affected interactions between muscle strength, function and cognition in Australians aged ≥ 50 years, and whether interactions varied a...
Article
By 2050, 20% of the world's population will be over the age of 65 years, with projections that 80% of older adults will be living in low- to middle-income countries. Physical inactivity and sedentary time are particularly high in older adults, presenting unique public health challenges. In this article, we first review evidence that points to multi...
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Background Higher levels of time spent sitting (sedentary behavior) contribute to adverse health outcomes, including earlier death. This effect may be modified by other lifestyle factors. We examined the association of television viewing (TV), a common leisure-time sedentary behavior, with all-cause mortality, and whether this is modified by body m...
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Background Strong evidence indicates that excessive time spent sitting (sedentary behaviour) is detrimentally associated with multiple chronic diseases. Sedentary behaviour is prevalent among adults in Australia and has increased during the COVID-19 pandemic. Estimating the potential health benefits and healthcare cost saving associated with reduct...
Article
OBJECTIVE The primary aim was to assess associations between total steps per day and incident diabetes, whereas the secondary aim was to assess whether the intensity and/or cadence of steps is associated with incident diabetes. RESEARCH DESIGN AND METHODS Women without physician-diagnosed diabetes (n = 4,838; mean [SD] age 78.9 [6.7] years) were f...
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Aims •Sedentary behaviour is an established risk factor for several diseases; however, its economic impacts are less understood. This study systematically reviews the literature on the economic costs associated with excessive sedentary behaviour and the cost-effectiveness of interventions targeting sedentary time. Methods •A systematic search wa...
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Background :Screen-based device use could increase the risk of adolescent depression. Distinct modalities of screen-use may have differential effects on mental health. We used compositional data analysis to examine how theoretically replacing different screen-uses with exercise might influence future adolescent emotional distress. Methods : In 4,5...
Preprint
BACKGROUND Lockdown restrictions reduce COVID-19 community transmission; however, they may pose challenges for non-communicable disease management. A 112-day hard lockdown in Victoria, Australia (commencing March 23, 2020), which affected an intervention trial of reducing and breaking up sitting time in desk workers with type 2 diabetes who were us...
Article
Background: Lockdown restrictions reduce COVID-19 community transmission; however, they may pose challenges for non-communicable disease management. A 112-day hard lockdown in Victoria, Australia (commencing March 23, 2020), coincided with an intervention trial of reducing and breaking up sitting time in desk workers with type 2 diabetes who were...
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Background : Hip-worn accelerometers are commonly used, but data processed using the 100 counts per minute cut point do not accurately measure sitting patterns. We developed and validated a model to accurately classify sitting and sitting patterns using hip-worn accelerometer data from a wide age range of older adults. Methods : Deep learning model...
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Background Sedentary behaviour (SB; time spent sitting) is associated with musculoskeletal pain (MSP) conditions; however, no prior systematic review has examined these associations according to SB domains. We synthesised evidence on occupational and non-occupational SB and MSP conditions. Methods Guided by a PRISMA protocol, eight databases (MEDL...
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Background Recent evidence suggests that prolonged sitting and its adverse impact on glycaemic indicators appear to be proportional to the degree of insulin resistance. To investigate this finding in a free-living context, we aimed to examine associations of device-measured 24-h time-use compositions of sitting, standing, stepping, and sleeping wit...
Article
Exercise is a treatment in rheumatoid arthritis but participation in moderate-to-vigorous exercise is challenging for some patients. Light-intensity breaks in sitting could be a promising alternative. We compared the acute effects of active breaks in sitting with those of moderate-to-vigorous exercise on cardiometabolic risk markers in patients wit...
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Desk-based workers are highly sedentary; this has been identified as an emerging work health and safety issue. To reduce workplace sitting time and promote physical activity it is important to understand what factors are already present within workplaces to inform future interventions. This cross-sectional study examined the prevalence of supportiv...
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This feasibility study explored the contextual factors influencing office workers’ adherence to an e-health intervention targeting total and prolonged sedentary time over 12 weeks. A three-arm quasi-randomized intervention included prompts at 30 or 60 min intervals delivered via a smartphone application, and a no-prompt comparison arm. Fifty-six of...
Article
Recently, sedentary behavior recommendations have been included in the public health guidelines of multiple countries, pointing to new opportunities for prevention of chronic disease as well as a potential strategy for initiating long-term behavior change. Objective: To propose an evidence-informed approach to physical activity counseling that st...
Article
Objective: To determine the dose-response relationship between prolonged sitting and vascular function in healthy individuals and those with metabolic disturbances. To investigate the acute effects, on vascular function, of interventions that target interrupting prolonged sitting. Design: Systematic review with meta-analysis. Data sources: Ovi...
Article
National guidelines recommend physically active interruptions to sitting time, however, the characteristics of these interruptions are broadly stated and ill-defined. A robust methodology for population surveillance for such interruptions is needed. Purpose: To describe the frequency and characteristics (i.e., duration, stepping time, and estimat...
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Background & Aims Whether the frequency of interruptions to sitting time involving simple resistance activities (SRAs), compared to uninterrupted sitting, differentially affected 22 h glycemic control in adults with medication-controlled type 2 diabetes (T2D). Methods & Results Twenty-four participants (13 men; mean±SD age 62±8 years) completed th...
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Background: Interrupting prolonged sitting acutely lowers blood pressure in nonstroke populations. However, the dose-response effect in stroke survivors is unknown. The authors investigated different doses of light-intensity standing exercises that interrupt prolonged sitting and reduce blood pressure immediately and over 24 hours in stroke surviv...
Article
OBJECTIVE To determine whether interrupting prolonged sitting improves glycemic control and the metabolic profile of free-living adults with obesity. METHODS Sixteen sedentary individuals (10 women/6 men; median [IQR] age 50 [44-53] years, BMI 32 [32-35.8] kg/m ² ) were fitted with continuous glucose and activity monitors for 4 weeks. After a 1-wee...
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Time spent sitting is positively correlated with endothelial dysfunction and cardiovascular disease risk. The underlying molecular mechanisms are unknown. MicroRNAs contained in extracellular vesicles (EVs) reflect cell/tissue status and mediate intercellular communication. We explored the association between sitting patterns and microRNAs isolated...
Article
Sedentary behaviour — put simply, too much sitting, as a distinct concept from too little exercise — is a novel determinant of cardiovascular risk. This definition provides a perspective that is complementary to the well-understood detrimental effects of physical inactivity. Sitting occupies the majority of the daily waking hours in most adults and...
Article
Background: Interrupting prolonged sitting can attenuate postprandial glucose responses in overweight adults. The dose-response effect in stroke survivors is unknown. The authors investigated the effects of interrupting 8 hours of prolonged sitting with increasingly frequent bouts of light-intensity standing-based exercises on the postprandial glu...
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Sedentary behaviour (sitting) is a risk factor for adverse health outcomes. The classroom environment has traditionally been associated with prolonged periods of sitting in children. The aim of this study was to examine the potential impact of an environmental intervention, the addition of sit–stand desks in the classroom, on school children’s sitt...
Article
Objective: To determine whether interrupting sitting with brief bouts of simple resistance activities (SRAs) at different frequencies improves postprandial glucose, insulin, and triglycerides in adults with medication-controlled type 2 diabetes (T2D). Research design and methods: Participants (n = 23, 10 of whom were female, with mean ± SD age 6...
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This study aimed to investigate the theoretical impact of reallocating a specific amount of sedentary time with an equal amount of (a) total, and (b) ≥1min‐bout‐accumulated time spent in different activity intensities, on inflammatory biomarkers in 8‐9 year old children. Accelerometry and inflammatory biomarker baseline data from the Transform‐Us!...
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Purpose: The study aimed to describe youth time-use compositions, focusing on time spent in shorter and longer bouts of sedentary behavior and physical activity (PA), and to examine associations of these time-use compositions with cardiometabolic biomarkers. Methods: Accelerometer and cardiometabolic biomarker data from 2 Australian studies invo...
Article
Background TV viewing is associated with elevated plasma glucose, but it’s not clear whether such associations can be modified by dietary patterns. Methods We examined the interactions of TV viewing time and dietary patterns in relation to fasting and 2‐h plasma glucose. Cross‐sectional analyses were performed among participants (n= 3081; 44.7% ma...
Article
Office spatial design can affect the way workers move and interact in the workplace, which can have implications for health and productivity. This systematic review examined office spatial design attributes associated with sitting and face-to-face interactions (FTFIs) at work. The initial search using six databases (Art and Architecture Source; Bus...
Article
Aim: To determine the effect of whey-protein plus vitamin D supplementation combined with progressive resistance training (PRT) on glycemic control, body composition, muscle function and cardiometabolic risk factors in middle-aged and older adults with type 2 diabetes (T2D). Materials and methods: In this 24-week, randomized controlled trial, 19...
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Background: Postprandial glucose, insulin, and triglyceride metabolism is impaired by prolonged sitting, but enhanced by exercise. The aim of this study was to assess the effects of a continuous exercise bout with and without intermittent active interruptions to prolonged sitting on postprandial glucose, insulin, and triglycerides. Methods: Seden...
Article
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This feasibility study evaluated the effects of an individual-level intervention to target office workers total and prolonged sedentary behaviour during working hours, using an e-health smartphone application. A three-arm (Prompt-30 or 60 min Intervention arm and a No-Prompt Comparison arm), quasi-randomised intervention was conducted over 12 weeks...
Article
Introduction Time spent sitting in cars is a prevalent form of sedentary behaviour. Overall time spent sitting and specific sedentary behaviours such as TV viewing have been shown to be associated with cardiovascular disease – a major contributor to premature death. A previous review found that motor vehicle use (including public transport) was ass...
Article
In healthy and overweight/obese adults, interrupting prolonged sitting with activity bouts mitigates impairment in vascular function. However, it is unknown whether these benefits extend to those with type 2 diabetes (T2D); nor, whether an optimal frequency of activity interruptions exist. We examined the acute effects on vascular function in T2D o...
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Paired associative stimulation (PAS) can induce plasticity in the motor cortex, as measured by changes in corticospinal excitability (CSE). This effect is attenuated in older and less active individuals. Although a single bout of exercise enhances PAS-induced plasticity in young, physically inactive adults, it is not yet known if physical activity...
Article
Objectives To estimate the extent of measurement error in the Active Australia questionnaire, and to examine the impact of measurement error on the association of moderate-vigorous physical activity (MVPA) with obesity. Design Accelerometer Validation Study, cross-sectional; data from the third wave of a prospective cohort (Australian Diabetes, Ob...
Article
This cross-sectional study examined theoretical effects of reallocating sedentary time (SED) with total physical activity, and physical activity bouts of varying intensities, on children's cardiometabolic biomarkers. Baseline data from the Transform-Us! trial (Melbourne, Australia) was used. Participant data were included if accelerometer and blood...
Article
Study objectives: Uncertainty exists over whether continuous positive airway pressure (CPAP) treatment improves moderate to vigorous physical activity levels in those with obstructive sleep apnea (OSA). We aimed to determine effects of CPAP on moderate to vigorous physical activity among participants with co-occurring cardiovascular disease and OS...
Article
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Background: There is increasing concern about the time people spend in sedentary behaviour, including screen time, leisure and occupational sitting. The number of both primary research studies (published trials) and reviews has been growing rapidly in this research area. A summary of the highest level of evidence that provides a broader quantitati...
Article
Purpose: In healthy adults, the impairment of vascular function associated with prolonged sitting can be mitigated with intermittent brief bouts of activity. It is unknown whether these benefits extend to women with polycystic ovary syndrome (PCOS), in whom vascular function is typically impaired and sitting time is high. We examined the acute imp...
Preprint
Full-text available
Background: Social distancing measures designed to contain the COVID-19 pandemic can explicitly and implicitly restrict physical activity, a particular concern for high-risk patient groups. Using a within-subjects design with objective measurement (via validated accelerometers), we assessed rheumatoid arthritis patients' physical activity and seden...
Preprint
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Time spent sitting in different settings can pose different risks to health. In Australian adults either with higher and lower diabetes risk, this study examined the differing compositions of self-reported sitting time accumulated in five contexts (occupational, transport, TV viewing, leisure computer-use and other). Participants (n = 3927; 60 ± 11...
Article
Studies examining associations of sitting time at work with obesity measures have produced inconsistent findings. Different sample characteristics across studies, e.g., the composition of different occupational groups, may be one explanation for the mixed findings. We examined cross-sectional associations of workplace sitting time with waist circum...
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This study demonstrates a novel data-driven method of summarising accelerometer data to profile physical activity in three diverse groups, compared with cut-point determined moderate-to-vigorous physical activity (MVPA). GGIR was used to generate average daily acceleration, intensity gradient, time in MVPA and MX metrics (acceleration above which t...
Article
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Orthopaedic injury can lead to decreased physical activity. Valid measures for assessing physical activity are therefore needed in this population. The aim of this study was to determine the agreement and concordance between the International Physical Activity Questionnaire–Short Form (IPAQ) and device-measured physical activity and sitting time in...
Article
Introduction: Long-term effects of physical activity and TV viewing on mortality have been inferred from observational studies. The associations observed do not allow inferences about the effects of population interventions and could be subject to bias due to time-varying confounding. Methods: Using data from the Australian Diabetes, Obesity and...
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Elevated levels of cardiovascular disease (CVD) risk markers are highly prevalent in people with a spinal cord injury (SCI). Breaking up prolonged sedentary time with short, regular bouts of physical activity can reduce postprandial glucose and lipid levels in able‐bodied individuals. The effects in people with paraplegia are unknown. The study aim...
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Background: Subjective measures of sedentary behaviour (SB) (i.e. questionnaires and diaries/logs) are widely implemented, and can be useful for capturing type and context of SBs. However, little is known about comparative validity and reliability. The aim of this systematic review and meta-analysis was to: 1) identify subjective methods to assess...
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Background: Physical inactivity and sedentary behaviour (too much sitting) can contribute to renal dysfunction. However, the potential benefits of behavioural change (e.g. replacing sedentary behaviour with physical activity) on renal function are not well understood. We used isotemporal substitution to model potential impacts of behaviours on ren...