GLP-1 receptor agonists and HBA1c target of <7% in type 2 diabetes: meta-analysis of randomized controlled trials

Objective: Glucagon-like peptide-1 (GLP-1) receptor agonists are available for the treatment of type 2 diabetes. We assessed the efficacy of exenatide and liraglutide to reach the HbA(1c) target of <7% in people with type 2 diabetes. Research design and methods: We conducted an electronic search for randomized controlled trials (RCTs) involving GLP-1 agonists through September 2010. RCTs were included if they lasted at least 12 weeks, included 30 patients or more, and reported the proportion of patients reaching the HbA(1c) target of < 7%. Results: A total of 25 RCTs reporting 28 comparisons met the selection criteria, which included 9771 study participants evaluated for the primary endpoint, 5083 treated with a GLP-1 agonist and 4688 treated with placebo or a comparator drug. GLP-1 agonists showed a statistically significant reduction in HbA(1c) compared to placebo and the proportion of participants achieving the HbA(1c) goal <7% was 46% for exenatide, 47% for liraglutide, and 63% for exenatide LAR (long-acting release). Moreover, the reduction of the HbA(1c) level and the rate of HbA(1c) goal attainment were higher for both exenatide LAR and liraglutide, as compared to comparator drugs. Higher rates of hypoglycemia with exenatide b.i.d. and liraglutide compared to placebo were associated with the concomitant use of a sulfonylurea. Exenatide b.i.d. and liraglutide were associated with weight loss compared to placebo or other antidiabetic drugs. Baseline HbA(1c) was the best predictor for achievement of A(1c) target (overall weighted R-2 value = 0.513, p<0.001). Conclusions: A greater proportion of patients with type 2 diabetes can achieve the HbA(1c) goal <7% with GLP-1 agonists compared to placebo or other antidiabetic drugs; in absolute terms, exenatide LAR was best for the attainment of the HbA(1c) goal.