Cardiovascular Research

Physical Activity and Behavioural Epidemiology

Professor David Dunstan
Head, Physical Activity
ARC Future Fellow
david.dunstan@bakeridi.edu.au
Phone: +61 3 8532 1873

Professor Neville Owen
Head, Behavioural Epidemiology
NHMRC Senior Principal Research Fellow
neville.owen@bakeridi.edu.au
Phone: +61 3 8532 1874

The Physical Activity and Behavioural Epidemiology laboratories are concerned with the primary prevention of diabetes, heart disease and cancer. Our research deals with the health consequences of physical inactivity and sedentary behaviours; the measurement and analysis of environmental, social and personal-level determinants of behavioral risk factors (television viewing, sitting in automobiles, desk- and screen-bound work) and lack of physical activity; and, gathering and interpreting evidence from trials of broad-reaching interventions. The aim is to better understand how variations in behaviour can influence health outcomes and to identify the factors that can influence behavioural change.

The ultimate goal of our combined program is to contribute unique insights relevant to public health policy. We aim to identify environmental and social innovations that can increase physical activity and reduce sitting time.

The two laboratories are building comprehensive scientific links between epidemiological evidence; clinical/experimental investigations; behavioural intervention trials on changing sitting time in real-world settings; and large-scale population studies of environment/behaviour relationships. This integration aims to provide much-needed evidence to inform new policy directions in public health in order to reduce Australia's disease burden from excessive sedentary time and physical inactivity.

Research Focus

The integrated program of studies on physical activity, sedentary behaviour and health conducted by the Physical Activity and Behavioural Epidemiology laboratories includes:

Laboratory-based investigations of behaviour-biomarker relationships, dose-response and mechanisms
Cross-sectional and prospective epidemiologic observational studies
Measurement development studies using state-of-the-art accelerometer and inclinometer devices
Studies on the multiple levels of influence on physical activity and sedentary behaviour, focused on understanding environmental determinants
Field-based intervention trials on the feasibility and outcomes of changing physical activity and sedentary behaviour
The ongoing refinement of conceptual models to integrate the evidence and explain multiple levels of influence on physical activity and sedentary behaviour
Addressing research-translation implications
Informing clinical practice and public health policy.

Research Projects

CEREBRA study: Cognitive Effects from REpeated BReAks

Group leaders: Dr Patrik Wennberg and Professor David Dunstan

The CEREBRA study is an experimental trial in older overweight adults using the experimental model previously developed in the Physical Activity laboratory at Baker IDI Heart and Diabetes Institute. The aims of the CEREBRA study are to investigate the acute effects of a single bout of prolonged sitting on long-term memory and executive functions with and without intermittent bouts of light-intensity physical activity in older (45-65 years) overweight adults. Furthermore, the study will examine the acute effect of interrupting prolonged sitting with intermittent short bouts of light-intensity physical activity on potential mediating pathways (glucose, insulin, BDNF, and markers of inflammation and the sympathetic nervous system) with respect to cognitive function.

Reducing prolonged sitting in office workers: the Stand Up Victoria study

Group leaders: Professor David Dunstan with Dr Genevieve Healy and Dr Glen Wiesner

The aim of the Stand Up Victoria study is to determine the effectiveness of an intervention program aimed at reducing prolonged workplace sitting time in office workers. It also is evaluating the effect of the intervention on markers of diabetes and heart health. An important and novel aspect of this study is the use of devices to objectively measure sitting time and physical activity levels rather than the self-report approach used in previous studies.

Baker IDI Heart and Diabetes Institute, in collaboration with researchers from the University of Queensland, the University of Melbourne and Deakin University, are conducting this 3-year trial within the Australian Government Department of Human Services (DHS). It aims to recruit 320 DHS employees from a number of offices around Victoria. Physical activity levels and sitting time will be measured at three time-points over 12 months. In addition, various markers of health and disease such as blood pressure, blood glucose, insulin and lipids, and body composition will be assessed.

Stand Up Victoria is generously supported by NHMRC and VicHealth

Sedentary behaviour and cancer

Group leaders: Professor Neville Owen with Professor David Dunstan and Dr Brigid Lynch

Sedentary behaviour has been proposed as an independent risk factor for cancer. Biologically plausible mechanisms exist, however few studies have examined sedentary behaviour in a cancer context. We are developing a program of research in this emerging field of enquiry. Opportunities exist for epidemiological studies examining associations of sedentary behaviour with cancer risk and with intermediary endpoints in large, prospective cohort studies. We also wish to better understand the underlying biological mechanisms by which sedentary behaviour affects cancer risk. We plan to examine the effect of acute bouts of prolonged sitting on cancer biomarkers such as endogenous sex hormones and adipokines in laboratory-based experiments. Finally, we are interested in rigorously characterising the sedentary behaviour of cancer survivors, and investigating how it contributes to health outcomes in this population.

Physical activity and the environment: domain-specific examination

Group leaders: Professor Neville Owen with Dr Takemi Sugiyama and Dr Javad Koohsari

In examining environmental attributes associated with physical activity, studies have focused on neighbourhood environments. A number of instruments have been developed to capture residential environmental factors that may be relevant to physical activity participation. However, physical activity has been measured without specifying where it occurs. In order to accurately assess the role of environments, it is important to examine specific behaviours (eg, walking, cycling, sitting) taking place in a specific context. At Baker IDI, we use this principle to examine how environments in different domains influence specific health behaviours.

- Physical Activity - Domain-specific examination

In AusDiab3 (the third round of the Australian Diabetes, Obesity and Lifestyle study), we will measure walking (for transport and for recreation) in one's neighbourhood and car use for transport, and examine if they are related to objectively-determined neighbourhood environmental attributes (using Geographic Information Systems). Stand Up Victoria study will investigate office environmental attributes associated with workers' sedentary behaviour.