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 stud y were to evaluate the effects of propionyl-L-carnitine on claudication ons et 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 (2 g/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 gr ade of 2% every 2 minutes until maximal symptoms of claudication forced ces sation of exercise. Questionnaires were used to determine changes in functi onal status. RESULTS: At baseline, peak walking lime was 331 +/- 171 seconds in the plac ebo group and 331 +/- 187 seconds in the proplonyl-L-carnitine group. After 6 months of treatment, subjects randomly assigned to proponyl-L-carnitine increased their peak walking time by 162 +/- 222 seconds (a 54% increase) a s compared with an improvement of 75 +/- 191 seconds (a 25% increase) for t hose on placebo (P <0.001). Similar improvements were observed for claudica tion onset time. Propionyl-L-carnitine treatment significantly improved wal king distance and walking speed (by the Walking Impairment Questionnaire), and enhanced physical role functioning, reduced bodily pain, and resulted i n a better health transition score (by the Medical Outcome Study SF-36 Ques tionnaire). The incidence of adverse events and study discontinuations were similar in the two treatment groups. CONCLUSIONS: Proyionyl-L-carnitine safely improved treadmill exercise perfo rmance and enhanced functional status in patients with claudication. (C) 20 01 by Excerpta Medica, Inc.