A meta-analysis comparing clinical effects of short- or long-acting GLP-1 receptor agonists versus insulin treatment from head-to-head studies in type 2 diabetic patients

Abstract

Aims: To study differences in clinical outcomes between initiating glucagon-like peptide-1 receptor agonist (GLP-1 RAs) vs insulin treatment in patients with type 2 diabetes treated with oral glucose-lowering medications (OGLM).

Methods: Prospective, randomized trials comparing GLP-1 RA and insulin treatment head-to-head as add-on to OGLM were identified (PubMed). Differences from baseline values were compared for HbA1c, fasting plasma glucose, bodyweight, blood pressure, heartrate and lipoproteins. Proportions of patients reporting hypoglycaemic episodes were compared.

Results: Of 712 publications identified, 23 describing 19 clinical trials were included in the meta-analysis. Compared to insulin, GLP-1 RAs reduced HbA1c more effectively (Δ -.12%, P < .0001). Basal insulin was more effective in reducing fasting plasma glucose (Δ -1.8 mmol/L, P < .0001). GLP-1 RAs reduced bodyweight more effectively (Δ -3.71 kg; P < .0001). The proportion of patients experiencing hypoglycaemic episodes was 34% lower with GLP-1 RAs ( P < .0001), with a similar trend for severe hypoglycaemia. Systolic blood pressure was lower and heartrate was higher with GLP-1 RAs ( P < .0001). Triglycerides and LDL cholesterol were significantly lower with GLP-1 RAs. Long-acting GLP-1 RAs were better than short-acting GLP-1 RAs in reducing HbA1c and fasting glucose, but were similar regarding bodyweight.

Conclusions: Slightly better glycaemic control can be achieved by adding GLP-1 RAs to OGLM as compared to insulin treatment, with added benefits regarding bodyweight, hypoglycaemia, blood pressure and lipoproteins. These differences are in contrast to the fact that insulin is prescribed far more often than GLP-1 RAs.

Keywords: GLP-1 receptor agonists; basal insulin; bodyweight; incretin-based glucose-lowering medications; lipoproteins; meta-analysis; type 2 diabetes.