In SLE, Metformin Might Reduce Infection Rates

Metformin significantly reduces infection rates among patients with systemic lupus erythematous (SLE), according to a new study.

Metformin is an anti-diabetic medication for the treatment of type 2 diabetes mellitus and can regulate systemic and cellular metabolism. Because immunometabolism is involved in the pathogenesis of SLE, the researchers aimed to determine whether repurposing metformin could control the immunometabolic processes in SLE.

To conduct their study, the researchers enrolled 140 patients with SLE, who did not have diabetes, in a double-blind trial conducted at 3 hospitals in Shanghai, China. Participants were randomly assigned to receive either metformin, 0.5 g, daily (n=67) or placebo (n=73) in addition to their standard SLE therapy for a maximum of 12 months.

After follow-up, the researchers found that the incidence of SLE flares was not significantly different between the metformin (21%) and placebo (34%) groups.

Gastrointestinal adverse events were more common among participants taking metformin (4%) vs placebo (1%); however, the incidence of nonflare-related serious adverse events was similar between the metformin (1%) and placebo (4%) groups.

Metformin also significantly lowered the frequency of infection events among participants taking metformin (25%) vs those taking placebo (44%).

“This trial was underpowered to draw a sound conclusion on the efficacy of metformin to reduce disease flares as an add-on treatment to standard care in patients with SLE,” the researchers concluded. “Nonetheless, metformin had a favourable safety profile, and our data present a basis for larger trials to investigate its potential effect on reducing the frequency of flares for patients with SLE with low-grade disease activity who are at risk of relapse.”

—Amanda Balbi

Reference:

Sun F, Wang HJ, Liu Z, et al. Safety and efficacy of metformin in systemic lupus erythematosus: a multicentre, randomised, double-blind, placebo-controlled trial. Lancet Rheumatol. 2020;2(4):E210-E216. https://doi.org/10.1016/S2665-9913(20)30004-7