Barr EL, Zimmet PZ, Welborn TA et al. Circulation 2007 Jun 18 (Epub ahead of print)
Evidence is mounting for the significance of impaired glucose regulation (IGR) as an independent CVD risk factor. This large project involved 10,428 participants of the Australian Diabetes, Obesity and Lifestyle Study whose glucose tolerance status was tested at baseline and who were followed up for a median of 5.2 years to record CVD and all-cause mortality.
A strong association between abnormal glucose metabolism, cardiovascular and all-cause mortality was found.
The current focus on diabetes alone (excluding IGR) as the target for cardiovascular prevention measures in the quality framework misses an opportunity for significant improvements to public health through the systematic targeting of people with more borderline dysglycaemia for cardiovascular risk reduction.
Cardiovascular risk correlates seamlessly with glucose levels throughout the borderline range, so the cut-off at the diabetes diagnostic threshold is artificial if one is considering macrovascular disease. Nevertheless, the practical implications of identifying, monitoring and following up such people are significant and require policy development and consultation.
IGR is not a diagnosis in itself and the maintenance of disease registers linked to remunerative targets, such as those for diabetes, therefore seem less appropriate, but might be required to make the targeting process effective.
Current UK guidelines recommend the identification of individuals with IGR through blood glucose testing as part of cardiovascular risk assessment. In the primary CVD prevention scenario, it is suggested that CVD risk estimates take this risk factor into account.
This policy falls short of recommending preventive drug therapies, such as lipid-lowering agents, to all individuals with IGR. Such a policy would require further cost-benefit analysis. In the meantime, the benefits of lifestyle interventions to all of those identified is clear, to reduce cardiovascular risk and the risk of progression to diabetes.
- Dr Tim Holt is a GP and clinical lecturer, University of Warwick