Improvement in exercise tolerance in isovaleric acidaemia with L-carnitine therapy.
The effect of 4 weeks' treatment with oral-L-carnitine (100 mg/kg per day) on carnitine status and metabolic parameters during an incremental ramp exercise test in a 12-year-old girl with isovaleric acidaemia was examined to determine its possible therapeutic role. The maximum work rate achieved increased from 110 to 120 watts; oxygen consumption at anaerobic threshold from 600 to 800 L/min; peak oxygen consumption from 1270 to 1450 L/min; and oxygen pulse, a measure of cardiac output, from 7.0 to 8.1 L/beat. These changes were associated with increases in plasma and urinary free and acyl carnitine concentrations but no change in physical activity. This observed effect of L-carnitine on exercise performance may be on cardiac or skeletal muscle function or both. We conclude that, in this single patient with isovaleric acid-aemia, L-carnitine supplementation had objective benefits and further studies on more patients are warranted.
Lee
P J
PJ
Department of Child Health, St George's Hospital Medical School, London, UK.
Harrison
E L
EL
Jones
M G
MG
Chalmers
R A
RA
Leonard
J V
JV
Whipp
B J
BJ
D000592:Amino Acid Metabolism, Inborn Errors / Q000188:drug therapy* / Q000503:physiopathology; D002331:Carnitine / Q000627:therapeutic use*; D002648:Child; D015444:Exercise; D005260:Female; D045782:Hemiterpenes; D006801:Humans; D007930:Leucine / Q000378:metabolism*; D010421:Pentanoic Acids / Q000097:blood*
D045782:Hemiterpenes; D010421:Pentanoic Acids; C008216:isovaleric acid; D007930:Leucine; D002331:Carnitine