Combination of basal insulin and GLP-1 receptor agonist: is this the end of basal insulin alone in the treatment of type 2 diabetes?

Glycemic control has been considered a major therapeutic goal within the scope of diabetes management, as supported by robust observational and experimental evidence. However, the coexistence of micro and macrovascular disease is associated with the highest cardiovascular risks which highlights the importance that pharmacological treatment of type 2 diabetes mellitus provides not only glycemic control, but also cardiovascular safety. Basal insulin is a highly effective treatment in reducing fasting blood glucose, but it is associated with considerable risk of hypoglycemia and weight gain. Glucagon like peptide 1 receptor agonists (GLP-1 RAs) are also effective in terms of glycemic control and associated with weight loss and low risk of hypoglycemia. The potential benefits of combining GLP-1RAs with basal insulin are contemplated in the current position statement of several different position statement and guidelines. This article reviews the efficacy and safety of different strategies to initiate and intensify basal insulin, with focus on new fixed ratio combinations of basal insulin with GLP-1 RAs available for use in a single injection pen (insulin degludec/liraglutide and insulin glargine/lixisenatide).