Addition of Insulin Glargine to GLP-1 RA Therapy Improved T2D Glycemic Control

Timothy S Bailey, MD

New findings suggest the addition of insulin glargine 300 U/ml (Gla-300) to glucagon-like peptide 1 receptor agonist (GLP-1 RA) therapy significantly improved glycemic control in patients with type 2 diabetes (T2D), without significantly increasing hypoglycemia.

These observations found improvement in glycemic control was seen regardless of the use of daily or weekly GLP-1 RAs, or the baseline HbA1c of the patient.

“Observations support [American Diabetes Association/European Association for the Study of Diabetes] guidelines, noting that insulin should be added to GLP-1 RA for people with T2DM with inadequate glycaemic control requiring treatment intensification,” wrote study author Timothy S Bailey, MD, AMCR Institute.

Although previous clinical studies have identified improved glycemic control and low risk of hypoglycemia with combination of insulin and GLP-1 RA, there remains a gap in knowledge from their use in real-world clinical practice, according to the study authors. Investigators additionally noted a lack of data on outcomes for those who received basal insulins after experiencing suboptimal glycemic control during GLP-1 RA therapy.

The current retrospective analysis of US electronic medical record data sources took place between March 2014 - March 2020, including more than 4 million individuals with T2D from outpatient, inpatient, and post-acute care settings. Investigators identified insulin-naive adults receiving GLP-1 RA therapy and Gla-300 between March 3015 - September 2019. They were required to have data for ≥12 months before index date and ≥6 months following the index date, with a validated glycated HbA1c of 3 - 15%.

A total of 271 patients with a mean age of 57.9 years and a baseline HbA1c of 9.16% were identified. The investigators observed 156 (57.6%) patients received daily GLP-1 RAs and 115 (42.4%) received weekly GLP-1 RAs before treatment intensification with Gla-300.

Data show HbA1c was significantly reduced after treatment intensification with the addition of Gla-300 (-0.97 ± 1.6%; P <.0001). Investigators additional found a significant increase in the proportion of patients with T2D achieving HbA1c after the addition of Gla-300 (HbA1c <7.0%: 4.80% vs 22.14%; P <.0001; HbA1c <8.0%: 19.56% vs 51.29%, P <.0001).

Investigators noted no changes in overall incidence or event rate of hypoglycemia were observed following the addition of Gla-300. The incidence of overall (8.49% vs 9.59%, P = .513) and inpatient/emergency department-associated hypoglycemia (0.37% vs 0.74%, P = 1.000) were similar before and after the addition of Gla-300. Additionally, the incidence of overall (0.33 vs. 0.46 per person per year [PPPY], P = .170) and inpatient/ED-associated hypoglycemia events (0.01 vs 0.04 PPPY, P = .466) were similar before and after the addition of Gla-300, investigators found.

“The findings from this real-world study warrant further assessment of the effect of adding Gla-300 to GLP-1 RA therapy in patients with T2D,” Bailey concluded.

The study, “Real-world outcomes of addition of insulin glargine 300 U/mL (Gla-300) to GLP-1 RA therapy in people with type 2 diabetes: The DELIVER-G study,” was published in Diabetes, Obesity and Metabolism.