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


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 <0.001). Similar improvements were observed for claudication onset time. Propionyl-L-carnitine treatment significantly improved walking distance and walking speed (by the Walking Impairment Questionnaire), and enhanced physical role functioning, reduced bodily pain, and resulted in a better health transition score (by the Medical Outcome Study SF-36 Questionnaire). The incidence of adverse events and study discontinuations were similar in the two treatment groups.


CONCLUSIONS
Propionyl-L-carnitine safely improved treadmill exercise performance and enhanced functional status in patients with claudication.
Hiatt
W R
WR
Department of Medicine, Section of Vascular Medicine, Divisions of Geriatrics and Cardiology, University of Colorado Health Sciences Center, Denver 80203, USA.
Regensteiner
J G
JG
Creager
M A
MA
Hirsch
A T
AT
Cooke
J P
JP
Olin
J W
JW
Gorbunov
G N
GN
Isner
J
J
Lukjanov
Y V
YV
Tsitsiashvili
M S
MS
Zabelskaya
T F
TF
Amato
A
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D002331:Carnitine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D004311:Double-Blind Method; D017079:Exercise Tolerance / Q000187:drug effects*; D005260:Female; D006801:Humans; D007383:Intermittent Claudication / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged
D000894:Anti-Inflammatory Agents, Non-Steroidal; C003223:propionylcarnitine; D002331:Carnitine