Does Exercise plus Colony-Stimulating Factor Improve Walking Distance in Peripheral Artery Disease?

A pilot trial of granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients with peripheral artery disease (PAD) reported improved walking distance. Its premise was that exercise in PAD causes ischemia-induced production of progenitor cells, which may favorably affect performance.

To further test the hypothesis, investigators randomized 210 participants (mean age, 67; 39% women) with PAD. The study arms were supervised exercise plus GM-CSF, supervised exercise plus placebo, attention control (weekly health lectures) plus GM-CSF, and attention control plus placebo. Treadmill exercise occurred three times a week with an exercise physiologist. The primary outcome was the change from baseline in 6-minute walk distance at 12 weeks (195…