What are the long-term outcomes with second-line treatments in type 2 diabetes?

This study investigated the long-term glycemic (blood sugar) control of type 2 diabetes patients receiving second-line medications with or without metformin (Glucophage). This study concluded that GLP-1 receptor agonists, DPP-4 inhibitors and thiazolidinedione-based therapies offer a higher chance of long-term glycemic control compared to other treatment options.

Metformin is generally the first-line treatment for patients with type 2 diabetes. However, most patients eventually require second-line medications. There is a wide variety of second-line treatments available, including sulfonylureas, GLP-1 receptor agonists, DPP-4 inhibitors, and thiazolidinediones (TZDs). Few studies have directly compared the short- and long-term effectiveness of these therapies.

This study analyzed the medical records of 163,081 patients with type 2 diabetes. At the start of treatment, patients had an average HbA1c (average blood glucose over 3 months) level of 8.4%. All patients received a second-line treatment for at least 6 months. The average follow-up time was 3.93 years.

Patients with a starting HbA1c between 7.5% and 7.9% were more likely to reach an HbA1c less than 7% at 6 months with GLP-1 receptor agonists (57%) or TZDs (57%). Of those who reached an HbA1c less than 7% without adding a third treatment, 68% maintained control at 12 months, and 58% at 24 months.

GLP-1 receptor agonists, DPP-4 inhibitors, and TZDs were most likely to lead to glycemic control in patients with starting HbA1c levels of 8% or higher. In patients who reached HbA1c levels of 7.5% or less after 6 months, 58% to 67% maintained control at 24 months.

At follow-up, 52% of all patients had a third-line treatment prescribed. Third-line treatments were prescribed an average of 15 months after the start of a second-line treatment. The most popular third-line treatment was insulin (28%), followed by DPP-4 inhibitors (24%).

This study concluded that GLP-1 receptor agonists, DPP-4 inhibitors and thiazolidinedione-based therapies offer a higher chance of long-term glycemic control compared to other treatment options.

Information about medication adherence was not available for this study, so these results may not be representative of those from controlled clinical trials. Also, this study only focused on patients who continued second-line therapy for at least 6 months.