Metformin disappoints in peripheral artery disease

Treatment with metformin does not appear to improve the walking ability of patients with peripheral artery disease (PAD) but no diabetes, according to a study.

The study included 202 PAD patients who had no diabetes (mean age 69.6 years, 28 percent female, 39 percent Black). These patients were randomly assigned to receive either metformin (n=97) or placebo (n=105) for 6 months.

The 6-month change in 6-min walk distance (minimum clinically important difference, 8–20 m) was assessed as the primary outcome. Secondary outcomes included maximal treadmill walking time, pain-free treadmill walking time, the Walking Impairment Questionnaire distance and speed scores, the Short-Form 36 physical functioning score, and brachial artery flow-mediated dilation.

Of the patients, 179 (89 percent) completed 6-month follow-up. At 6 months, the change in 6-min walk distance from baseline did not significantly differ between metformin and placebo (−5.4 vs −5.3 m; adjusted between-group difference, 1.1 m, 95 percent confidence interval [CI], −16.3 to 18.6 m; p=0.90).

Likewise, metformin had no significant effect on any of the secondary outcomes compared with placebo.

The most common serious adverse events (AEs) were cardiovascular events (3.1 percent with metformin, 1.9 percent with placebo), while the most common nonserious AEs were indigestion/stomach upset (64.9 percent with metformin, 40.6 percent with placebo) and headache (37.2 percent with metformin, 49.5 percent with placebo).

The findings do not support metformin for improving walking performance in patients with PAD, according to researchers.