Achieving A1c Levels Below 7% Early May be Predictive of Long-term Glycemic Control in Patients with T2D

Early attainment of a hemoglobin A1c (A1c) level below 7% may be predictive of long-term glycemic control in patients with type 2 diabetes (T2D) initiating second-line glucose-lowering therapy, according to a new analysis published in Diabetes, Obesity and Metabolism.

“Our results suggest that patients with an elevated HbA1c level after 6 months following initiation of second-line glucose-lowering therapy should be considered as being at high risk of persistent poor glycaemic [sic] control, and therefore should have their treatment intensified in a timely manner to minimize therapeutic inertia,” wrote study authors led by Fabrice Bonnet, MD, PhD, chair of endocrinology, University of Rennes, France.

Researchers used data from the global, 3-year observational DISCOVER study of patients with T2D in order to examine the factors associated with achieving good long-term glycemic control (A1c <7%) in a subset of patients with elevated blood glucose levels (A1c ≥7%) at initiation of second-line glucose-lowering therapy (baseline).

In order to assess the differences between patients with moderately elevated A1c levels and those with severely elevated A1c levels, participants were separated into 2 cohorts: those with baseline A1c ≥7% and <9% (group 1), and those with baseline A1c ≥9% (group 2).

Among the 14 691 DISCOVER participants assessed, 5342 (56.6% men; mean age, 58.7 years) were included in group 1 and 2233 (58% men; mean age, 54.4 years) were included in group 2.

Researchers found that after 6 months of second-line therapy, 43.7% and 24.2% of patients had an A1c level <7% in group 1 and 2, respectively. At 3 years, these proportions had increased slightly to 45.8% and 29.3%.

The proportion of participants with A1c levels ≥9% at 3 years was 6.1% in group 1 and 18.6% in group 2.

In both groups, the most common first-line treatment was metformin monotherapy, followed by dual therapy. Second-line therapy with insulin, alone or in combination with other agents, was initiated in 3.3% of patients in group 1 and in 14.5% of patients in group 2.

Having A1c <7% at 6 months, compared to ≥7%, was the strongest predictor of having A1c <7% at 3 years in both cohorts (odds ratio [95% confidence interval]: 2.01 [1.77–2.27] and 2.68 [2.10–3.41], respectively).

Also, a shorter time since T2D diagnosis and lower A1c at baseline were associated with an increased likelihood of having an A1c level <7.0% at 3 years, according to study authors.

“These findings are in line with previous studies, which have also demonstrated an association between earlier initiation of second-line therapy and improved glycaemic control,” researchers concluded. “Together, these results emphasize the importance of early glycaemic control with timely treatment intensification, as recommended by clinical guidelines.”