Objective: Assess evidence describing the effect of Sodium-Glucose Cotransporter-2 (SGLT2) inhibitors on total daily insulin (TDI) requirements in insulin-dependent patients with type 2 diabetes.
Data sources: A scoping review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Protocols and Scoping Reviews (PRISMA-ScR) guidelines. The search was conducted in PubMed; citation mapping was completed in Web of Science. Filters for human studies, English language, and a publication date, from January 1, 2005 to April 12, 2021, were applied.
Study selection and data extraction: Studies assessing insulin dose requirements with concurrent use of an SGLT2 inhibitor for patients with type 2 diabetes were included.
Data synthesis: Sixteen studies were included and demonstrated that addition of an SGLT2 inhibitor typically reduced TDI requirements. Insulin reductions were often statistically significant, occurring in studies evaluating (1) within subjects who received SGLT2 inhibitors, and (2) between subjects receiving SGLT2 inhibitors versus placebo. Compared with placebo, insulin dose reduction ranged from -0.72 to -19.2 units. However, studies were relatively small, not designed to assess TDI change, and some utilized fixed dose insulin protocols or empiric insulin dose reductions.
Conclusions: Lowering insulin requirements may have benefits, such as decreased hypoglycemia risk, insulin resistance, and cost. Addition of an SGLT2 inhibitor may modestly reduce TDI requirements for patients with type 2 diabetes. Evidence indicating SGLT2 inhibitor use reduces TDI may lead to additional implementation in practice and inform future research. Further research is needed to clarify insulin type (i.e., basal or prandial) and degree of TDI reduction expected with addition of an SGLT2 inhibitor.
Keywords: SGLT-2 inhibitor; diabetes; insulin; insulin requirements; insulin resistance.