The objective of this study is to compare the efficacy and safety of sitagliptin and saxagliptin with placebo and other hypoglycaemic medications in adults with type 2 diabetes. We searched MEDLINE®, Embase, the Cochrane Library and the International Pharmaceuticals from their inception through 3 February 2011. Studies were included of adults with type 2 diabetes that were 12 weeks or more in duration. Meta-analyses were conducted when included studies were homogenous enough to justify combining their results. A total of 32 articles met inclusion criteria. Sitagliptin 100 mg monotherapy and saxagliptin 5 mg resulted in greater HbA1c reduction compared to placebo [weighted mean difference (WMD) -0.82%, 95% CI -0.95 to -0.70 and WMD -0.70, 95% CI -0.84 to -0.56, respectively]. Sitagliptin was similar to sulfonylureas for HbA1c reduction (WMD 0.08%, 95% CI 0-0.16, 3 trials) and to saxagliptin in one head-to-head trial. There was no statistically significant difference in hypoglycaemia between sitagliptin (pooled RR 1.55, 95% CI 0.55-4.36) or saxagliptin (pooled RR 1.04, 95% CI 0.28-3.81) and placebo. Sitagliptin and saxagliptin result in similar modest HbA1c reductions and do not increase the risk of hypoglycaemia unless combined with other therapies. Their role in the long-term treatment of type 2 diabetes remains unclear given the lack of long-term data on efficacy, harms and health outcomes.
© 2011 Blackwell Publishing Ltd.