Epidemiological contribution to primary and secondary prevention of diabetes and obesity

The prevalence of both obesity and diabetes is growing at an alarming rate. These conditions and their consequences probably represent the greatest public health challenge of this century. The goal of this programme is to contribute to efforts aimed at preventing the growing burden of diabetes, obesity and related metabolic disorders. To do this we are translating epidemiological knowledge into preventive action, and assessing the effectiveness of different preventive approaches. These approaches range from primary prevention, through earlier detection via screening, to the development and evaluation of interventions for those with the conditions.|The programme has a broad remit. It combines basic research to inform the development of future interventions. To better understand why some people are more active than others and to see how this relates to current health policy. This is illustrated by the following description of two of the research themes. Firstly, our work has demonstrated that higher levels of everyday physical activity reduce risk of diabetes. We are examining individual and environmental influences on physical activity in children and adults (2000 children and 15,000 middle aged adults Norfolk). They are assessed by using geographical information systems and questionnaires, as well as precise measurement of physical activity by accelerometers (measures movement & acceleration). At the same time we are evaluating different interventions to promote physical activity among people with diabetes and those at risk of developing diabetes and the effect of providing individuals with information about their levels of physical activity.|Earlier work from Unit colleagues confirmed that up to half of all people with type 2 diabetes remain undiagnosed. Many patients already have evidence of complications at diagnosis. Consequently, a key question for the health service in the UK and other countries is whether population screening for diabetes would be a cost-effective use of limited healthcare resources. We reviewed the evidence for and against screening on behalf of the National Screening Committee. We developed and tested simple methods of identifying those at high risk of having diabetes that utilise information routinely held in general practice computer records. We then incorporated this method into a trial of screening among 150,000 middle-aged residents of Cambridgeshire and surrounding counties. Preliminary results suggest that screening does not cause anxiety or depression, and patients detected by screening have high levels of modifiable cardiovascular risk factors which are reduced one year later, particularly in general practices being supported to provide intensive treatment.

The growing burden of disease associated with diabetes and obesity represents one of the critical public health challenges of this century. There are significant areas of uncertainty that limit the development of potential solutions. However it is clear that prevention strategies will need to incorporate individual and population-based approaches. In the first quinquennium we established projects spanning this broad prevention agenda from the environmental influences on physical activity and dietary behaviour to intensive multifactorial treatment of people with newly diagnosed diabetes. We identified individual and collective factors associated with physical activity across the life course, synthesised the literature on interventions to promote activity in young people and developed a theory-based intervention to promote activity among individuals at particular risk of the consequences of sedentary behaviour due to their family history of diabetes. In a randomised trial incorporating objective measurement we demonstrated that this intensive intervention was no more effective than brief advice and that relatively small feasible changes in activity were associated with metabolic benefits. We modelled the key uncertainties concerning screening for T2DM and established an international multi-centre trial to resolve them. We developed practical strategies to identify people with undiagnosed diabetes, quantified the cardiovascular risk among screen-detected patients and the potential for reduction of this risk, established that screening was not associated with harmful effects and described the reduction in modelled cardiovascular risk associated with intensive treatment among screen-detected patients.||In the next quinquennium, our studies of the collective, population-level influences on diet and physical activity form the basis of our contribution to UKCRC Public Health Centre of Excellence in Diet and Activity Research through our planned programme on population approaches to diet and physical activity behaviour change. Moving forward, research in the prevention programme will focus on identifying individuals at increased risk of diabetes and its complications, the individual determinants that confer this risk, and the development and evaluation of primary and secondary prevention interventions. The overall goal of this programme is to translate epidemiological knowledge into action to prevent T2DM and related metabolic disorders and to assess the cost-effectiveness of different approaches to disease prevention. Specifically, we aim to:|develop and evaluate effective ways to communicate information about health behaviours, risk factors and disease risk|identify important modifiable individual factors influencing disease risk|develop primary and secondary prevention interventions targeting one or more of these factors and to evaluate their cost-effectiveness.