Metformin monotherapy is not associated with a reduced risk of AF in patients with newly diagnosed type 2 diabetes, according to an observational study.

Although the 10-year cumulative risk of AF was lower in metformin users than those given other glucose-lowering agents, this was not statistically significant, US researchers found.

In comparison, both dipeptidyl peptidase-4 (DPP4) inhibitors and thiazolidinediones (TZDs) have been shown to reduce AF incidence through specific anti-inflammatory and antioxidant mechanisms, they said.

“Given lack of concrete evidence in the literature, prospective and randomised clinical trials are imperative to reveal such protective effects of metformin and other antihyperglycaemic agents, if [they exist],” the authors wrote.