Screen and treat policies to preventing type 2 diabetes are unlikely to have a substantial impact on the growing numbers of people developing the condition, new research has found.
The approach where people are identified as being at a high risk and offered individual intervention, and a population wide approach in which everyone is targeted via public health policies are increasingly popular.
But research from the University of Oxford in England concludes that this kind of approach will only be effective if it if fulfils certain criteria; a test that correctly identifies those at high risk, that is those with insulin sensitivity, as well as excluding those at low risk and an intervention exists that is acceptable to patients and clinicians.
The team of researchers, led by Professor Trish Greenhalgh, assessed the diagnostic accuracy of screening tests for pre-diabetes and effectiveness of interventions in preventing onset of type 2 diabetes in people with pre-diabetes and analysed the results of 49 studies of screening tests and 50 intervention trials.
The diagnostic accuracy of tests used to detect pre-diabetes in screening programmes was low ad they found that fasting glucose is specific but not sensitive and HbA1c is neither sensitive nor specific, suggesting that large numbers of people will be unnecessarily treated or falsely reassured depending on the test used.
Lifestyle interventions lasting three to six years showed a 37% reduction in relative risk of type 2 diabetes, equating to 151 out of 1,000 people developing diabetes compared with 239 of 1000 in the control group. This fell to 20% in follow up studies.
Use of metformin showed a relative risk reduction of 26% while participants were taking this drug, translating to 218 out of 1000 developing diabetes while taking metformin compared with 295 of 1000 not receiving it.
They concluded that screen and treat policies will benefit some but not all people at high risk of developing diabetes and they should be complemented by population wide approaches for effective diabetes prevention.
According to Professor Norman Waugh from Warwick Medical School, lifestyle changes across whole populations is the key to prevention of type 2 diabetes and he pointed out that pre-diabetes is an unsatisfactory term because many people so labelled do not develop diabetes.
He believes there is a balance to be struck between the medical model of screening and treating of individuals of individuals, and the public health model of changing behaviour in the whole population at risk.
Waugh said that public health measures targeted at the whole population at risk could include interventions to help weight control, such as changes to taxation of foodstuffs and interventions to make physical activity easier or safer.
However, he acknowledges that adherence to lifestyle advice remains poor, and concludes that preventing or delaying type 2 diabetes ‘requires effective measures to motivate the general population to protect their own health.’
The opinions expressed in this article do not necessarily reflect the views of the DiabetesForum.com Community and should not be interpreted as medical advice. Please see your doctor before making any changes to your diabetes management plan.