News from the world of cardiology
A new review of oral hypoglycaemic agents supports the choice of metformin as first-line therapy but also finds that the long-term benefits and harms of diabetes medications remain unclear.
For the review, published online in the Annals of Internal Medicine on March 14th 2011, the authors reviewed 140 randomised clinical trials and 26 observational studies of oral hypoglycaemic agents. Most of the medications reduced HbA1c levels by approximately 1%, but metformin was more effective than the new DPP-4 inhibitors.
All of the drugs also were associated with weight gain, with the exception of metformin, which was consistently associated with weight reduction or neutrality. Sulphonylureas were associated with a fourfold increased risk for hypoglycaemia versus metformin alone. Glitazones increased the risk for congestive heart failure versus sulphonylureas and the risk for bone fractures relative to metformin. The main side effect of metformin was gastrointestinal-tract effects, particularly diarrhoea.
There was limited difference among various two-drug combinations in impact on HbA1c levels, but the combination of metformin with sulphonylureas was associated with a particularly high risk of hypoglycaemia.