Metformin showed superior glycemic durability compared with sulfonylurea and meglitinide in a nationwide observational study in Sweden, according to a report published online in BMJ Open Diabetes Research & Care.

To study glycemic durability in real-world patients, researchers analyzed data from five Swedish national registries of diabetes care, prescribed drugs, causes of death, hospital discharges, and health insurance. They examined the medical records of 69,667 adults who had heretofore untreated type 2 diabetes and were initially prescribed metformin, sulfonylurea, or meglitinide during a 4-year period. They also analyzed medication use in a subset of propensity-matched patients who were well balanced for numerous covariates that can impact diabetes progression, such as age, gender, hemoglobin A1c level, eGFR, and CVD history.

Each medication’s glycemic durability was judged according to whether these patients continued using their initial diabetes drug, switched to a different drug, or added a second drug during 5.5 years of follow-up, said Dr. Nils Ekstrom of the University of Gothenburg (Sweden) and his associates.

Mean patient age was 71 years, mean duration of diabetes was 5 years, and mean body mass index was 28 kg/m2. Overall, almost half of these patients discontinued their initial medication, switched to a different medication, or required a second diabetes drug be added to their regimen during follow-up.

Compared with metformin, sulfonylurea and meglitinide showed a significantly increased risk of monotherapy failure (hazard ratio, 1.74). Sulfonylurea and meglitinide had an even greater risk of requiring a switch to a new agent (HR, 2.81) and of requiring an add-on agent (HR, 3.14). These results from the main analyses were confirmed in two sensitivity analyses involving approximately 60,000 participants, the investigators said (BMJ Open Diab. Res. Care 2015 [doi:10.1136/bmjdrc-2014-000059]).

Patients who continued on their initial monotherapy throughout follow-up showed improved HbA1c levels of approximately 10%, regardless of which medication they used. This group represents treatment responders. In contrast, patients who discontinued, switched, or added a new agent to their initial medication showed stable or slightly increasing HbA1c levels over time, which represented deteriorating glycemic control.

“These results strengthen the current evidence of a superior durability with metformin compared with sulfonylureas” in the real-world setting, and suggest that the same is true regarding meglitinide, Dr. Ekstrom and his associates said.