Propionyl-L-carnitine improves exercise performance and functional status in patients with claudication

PURPOSE: We tested the hypothesis that propionyl-L-carnitine would improve peak walking time in patients with claudication. Secondary aims of the study were to evaluate the effects of propionyl-L-carnitine on claudication onset time, functional status, and safety. SUBJECTS AND METHODS: In this double-blind, randomized, placebo-controlled trial, 155 patients with disabling claudication from the United States (n = 72) or Russia (n = 83) received either placebo or propionyl-L-carnitine (2g/day orally) for 6 months. Subjects were evaluated at baseline and 3 and 6 months after randomization with a graded treadmill protocol at a constant speed of 2 miles per hour, beginning at 0% grade, with increments in the grade of 2% every 2 minutes until maximal symptoms of claudication forced cessation of exercise. Questionnaires were used to determine changes in functional status. RESULTS: At baseline, peak walking time was 331 ± 171 seconds in the placebo group and 331 ± 187 seconds in the propionyl-L-carnitine group. After 6 months of treatment, subjects randomly assigned to propionyl-L-carnitine increased their peak walking time by 162 ± 222 seconds (a 54% increase) as compared with an improvement of 75 ± 191 seconds (a 25% increase) for those on placebo ( P