Biguanides vs DPP-4 Inhibitors in Type 2 Diabetes: Efficacy, Safety, and Costs

Biguanides vs dipeptidyl peptidase-4 (DPP-4) inhibitors have a similar incidence of cardiac and cerebrovascular events, as well as disease-related complications, but are less costly to use in patients with type 2 diabetes (T2D) initiating pharmacotherapy, according to study results published in PLOS One.

While both DPP-4 inhibitors and biguanides have been recommended as first-line treatment for diabetes, few studies have compared their effectiveness, long-term safety, and costs.

Researchers conducted a retrospective study to compare the outcomes and costs associated with biguanides vs DPP-4 inhibitors in patients with T2D.

Eligible participants were adults with T2D with a prescription for a biguanide or DPP-4 inhibitor.

Patients were then allocated into 2 groups based on the treatment administered. Index date was defined as the date when the initial treatment was prescribed.

Primary study outcome was the interval between index date and occurrence of a cardiac or cerebrovascular event, or death — as a composite outcome. Secondary outcomes were intervals between index date and onset of a diabetes-related event, such as nephropathy, neuropathy, retinopathy, or kidney failure.

A total of 3084 patients with T2D (514 receiving a biguanide and 2570 receiving a DPP-4 inhibitor) were included in the study. After adjusting for variables, the majority of participants in both groups were men, and mean age was 68.

In the biguanide and DPP-4 groups, the rate of cardiac events (4.5% and 5.8%; cumulative incidence after 5 years, 5.2 and 6.3, respectively; P =.825) and cerebrovascular events (3.3% and 3.3%; cumulative incidence, 3.9 and 3.1, respectively; P =.538) were similar.

The mortality rate was also observed to be similar (3.1% vs 3.5%; cumulative incidence, 3.3 and 3.7, respectively; P =.860).

Overall, the composite outcome occurred in 9.5% of the biguanide group and 10.4% of the DPP-4 group, showing no significant differences between the groups (P =.544). Results of a sensitivity analyses were consistent with these results at the 9- and 12-month follow-up.

The researchers observed that 15.4% and 17.1% of patients in the biguanide and DPP-4 group, respectively, developed diabetic complications (P =.290), with no significant differences between groups in cumulative incidence of diabetic retinopathy, nephropathy, neuropathy, and other conditions (P =.579, P =.894, P =.491, and P =.891, respectively).

However, there was a significant difference in mean daily costs in biguanide vs DPP-4 inhibitor use (60.5±70.9 vs 123.6±64.3 yen; mean difference, 63.1 yen; 95% CI, 56.9-69.3 yen; P <.001).

Limitations of the analysis included the lack of generalizability, the limited geographic specificity of the database, and the retrospective nature of the study.

“These findings underscore the therapeutic effectiveness and financial benefits of administering biguanides as the initial treatment for T2DM [type 2 diabetes mellitus],” the researchers concluded.