Impact of Simultaneous Versus Sequential Initiation of Basal Insulin and Glucagon-like Peptide-1 Receptor Agonists on HbA1c in Type 2 Diabetes: A Retrospective Observational Study

INTRODUCTION: When and how to intensify treatment in patients with type 2 diabetes (T2D) not achieving glycated hemoglobin (HbA1c) targets with oral antidiabetic drugs (OADs) in clinical practice remains a matter of clinical preference. This pilot study was conducted using the retrospective observational data from such patients to evaluate the impact on HbA1c of three treatment sequences: simultaneous initiation of basal insulin (BI) and a glucagon-like peptide-1 receptor agonist (GLP-1 RA; Cohort 1); BI followed by GLP-1 RA initiation within a 90-day timeframe (Cohort 2); or BI followed by GLP-1 RA initiation beyond 90 days (Cohort 3). METHODS: Data from the regional US electronic medical records database, Research Action for Health Network (REACHnet), were extracted for all patients with T2D aged ≥ 18 years who had encounter dates between January 2011 and August 2017 and ≥ 1 HbA1c laboratory value(s) < 90 days before BI initiation and ≥ 2 HbA1c laboratory values within 1 year after BI initiation and who met the inclusion criteria for GLP-1 RA initiation set for Cohorts 1, 2, or 3. The primary endpoints were the proportion of patients achieving HbA1c < 7.0%, which was estimated via Kaplan–Meier analysis, and change in HbA1c within 12 months. RESULTS: Overall, 869 patients were analyzed, of whom 109 were in Cohort 1, 301 in Cohort 2, and 459 in Cohort 3. Baseline HbA1c was 10.3 ± 2.1, 10.3 ± 2.0, and 10.2 ± 2.1% for these three cohorts, respectively. Statistically significantly more patients in Cohort 1 than in Cohort 3 achieved HbA1c < 7.0% (33.4 vs. 20.9%, respectively; p = 0.0186). Mean observed reductions in HbA1c at 12 months were − 1.7% (Cohort 1), − 1.5% (Cohort 2), and − 1.3% (Cohort 3). CONCLUSIONS: Simultaneous initiation of BI and GLP-1 RA achieves glycemic control more effectively than sequential initiation of BI with GLP-1 RA added beyond 90 days.