Preventing type 2 diabetes in at risk people - the evidence from trials
An editorial in the Annals of Internal Medicine discusses recent trials that studied four potential drug interventions to delay the onset of type 2 diabetes in people at risk.
The drugs studied are rosiglitazone, metformin, ramipril, and acarbose.
Metformin and Acarbose were shown to reduce the onset of diabetes in trials published in 2002 and the recently published DREAM trial found that rosiglitazone also seemed to do so but ramipril did not. This editorial primarily discusses DREAM.
The authors briefly describe the study, and noted that it showed rosiglitazone to be effective in reducing progression to diabetes while ramipril was not. They are concerned, however, over the adverse effect profile of rosiglitazone, with an increased incidence of peripheral oedema, weight gain, and heart failure.
Overall, they emphasized that lifestyle changes remain the first line for prevention of diabetes, as those that work also have many other health benefits. Where patients cannot adopt or maintain such changes, drug treatment may be considered: in this situation, the chosen drug must be safe, as it will be taken long term by many people who will not actually benefit. It must also be more cost-effective than delaying treatment until diabetes develops.
On these criteria, rosiglitazone fails and other medications must be considered. Acarbose is associated with a high incidence of withdrawal due to adverse effects, therefore the authors suggest that METFORMIN is the best option, being effective, generally well tolerated, and relatively low cost.
They warn, however, that the long term benefits and cost-effectiveness of this approach are unproven, and thus more trials are needed.