The Journal of the American Medical Association has published the results of a meta-analysis that aimed to assess the comparative efficacy, risk of weight gain and risk of hypoglycaemia associated with non-insulin hypoglycaemic agents when used in addition to metformin.
The study analysed data from 27 randomised controlled studies involving 11,198 participants. Comparisons were made between sulphonylureas, glinides (nateglinide, rapeglinide), glitazones (pioglitazone, rosiglitazone), alpha-glucosidase inhibitors (acarbose), GLP-1 analogs (exenatide, liraglutide) and DPP-4 inhibitors (sitagliptin, vildagliptin, saxagliptin). The studies varied in duration from 12-52 weeks.
All of the treatments were associated with similar reductions in HbA1c but there were differences in the risk of weight gain and hypoglycaemia. Sulphonylureas, glitazones and glinides were all associated with weight gain. Sulphonylureas and glinides were associated with hypoglycaemia.
The authors conclude that, "these factors and other considerations should be taken into account when selecting a second-line treatment to add to stable, maximum metformin".
Action: These results are not surprising and the recommendations are in keeping with the current NICE Guideline for diabetes. Clinicians should consider the relative benefits of the second-line agents with due regard for patient factors and acquisition cost.