The Relationship between Timing of Initiation on a Glucagon-like Peptide-1 Receptor Agonist and Glycosylated Hemoglobin Values Among Patients with Type 2 Diabetes



This study examines the relationship between timing of initiation on a glucagon-like peptide-1 receptor agonist (GLP-1 RA) and glycosylated hemoglobin (HbA1c) values.


The IBM MarketScan databases were used to identify adults with type 2 diabetes mellitus (T2DM) who initiated GLP-1 RA therapy and had multiple recorded HbA1c results. Time to GLP-1 RA initiation was proxied by the number of classes of glucose-lowering agents prescribed in the 2 years before GLP-1 RA initiation, with fewer glucose-lowering agents indicating initiation of a GLP-1 RA earlier in disease progression. Paired t tests examined differences in HbA1c values from preperiod to 2-year postperiod. Multivariable analyses examined the relationship between time to GLP-1 RA initiation and postperiod HbA1c values.


Initiation on a GLP-1 RA was associated with a 0.6% reduction in HbA1c values over 2 years (P < 0.0001). Earliest starts were associated with a 1.3% reduction in HbA1c levels (P < 0.0001) and the highest likelihood of achieving a postperiod HbA1c level <7% (odds ratio, 4.9; 95% CI, 3.0–8.1).


Results indicate that although initiation on a GLP-1 RA is generally associated with reduced HbA1c levels, there may be additional clinical benefits associated with earlier initiation of a GLP-1 RA.

Key words


For patients with type 2 diabetes (T2DM), pancreatic beta cells cease to produce enough insulin to control blood sugar.

Beta cells—what they do, role in insulin.