Glycemic Control Following GLP-1 RA or Basal Insulin Initiation in Real-World Practice: A Retrospective, Observational, Longitudinal Cohort Study

Abstract

Introduction: Injectable therapies such as glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and basal insulin (BI) are well-established agents for people with type 2 diabetes (T2D). This study aimed to investigate real-world effectiveness of GLP-1 RAs or BI in adults with T2D poorly controlled on oral antihyperglycemic drugs (OADs).

Methods: This was a retrospective, observational, longitudinal cohort study of adults with T2D from the US Optum Humedica® database and UK Clinical Practice Research Datalink, who initiated either injectable between January 1, 2010, and June 30, 2016. Baseline characteristics, glycated hemoglobin (HbA1c) change, and cumulative percentage reaching HbA1c < 7% in 24 months after initiation were analyzed in four patient cohorts.

Results: In the US and UK databases, respectively, 20,836 and 5508 patients initiated GLP-1 RAs and 60,598 and 5083 initiated BI. Baseline mean HbA1c at initiation ranged between 8.8% and 10.3% across all cohorts. In all cohorts, a decrease of HbA1c occurred 3-6 months after initiation. The cumulative percentage of patients reaching HbA1c < 7% showed the greatest probability in the first 12 months (15-40% of patients across cohorts at 12 months), particularly in the first 6 months after initiation. The probability of reaching glycemic control diminished after the second quarter. The proportion of patients reaching HbA1c < 7% in both GLP-1 RA and BI cohorts at 12 months was < 25% if baseline HbA1c was ≥ 9%.

Conclusions: For adults with T2D inadequately controlled on OADs, this analysis reveals an unmet clinical need. Initiation of first injectable therapy did not occur until HbA1c was considerably above target, when control is harder to achieve. Results suggest that in individuals with baseline HbA1c ≥ 9.0%, only a minority are likely to achieve an HbA1c < 7% with a GLP-1 RA or BI alone.

Keywords: Basal insulin; GLP-1; Type 2 diabetes.

Fig. 1

Monthly HbA1c distributions from 12 months before to 24 months after initiation of GLP-1 RA or BI in the US (a, b) and UK (c, d). BI basal insulin, GLP-1 RA glucagon-like peptide-1 receptor agonist, HbA1c glycated hemoglobin

Fig. 2

Proportion of all patients achieving HbA1c < 7% by baseline HbA1c (≥ 7% to < 8% vs. ≥ 8% to < 9% vs. ≥ 9%) for patients initiated on GLP-1 RAs in the US (a) and UK (b), and for patients initiated on BI in the US (c) and UK (d), and for the overall population in the US and UK initiated on GLP-1 RAs (e) and those initiated on BI (f). BI basal insulin, GLP-1 RA glucagon-like peptide-1 receptor agonist, HbA1c glycated hemoglobin, UK United Kingdom, US United States

Fig. 3

Probability of reaching first HbA1c < 7% within each quarter post-initiation of either injectable (a, c: US; b, d: UK). GLP-1 RA glucagon-like peptide-1 receptor agonist, HbA1c glycated hemoglobin, Q quarter, UK United Kingdom, US United States