Improvement of myocardial fatty acid metabolism through L-carnitine administration to chronic hemodialysis patients.
The concentration of carnitine, which is essential to fatty acid metabolism, can decrease markedly in patients on long-term hemodialysis coincident with life-threatening cardiac damage. However, administration of L-carnitine improves the myocardial function of these patients. To evaluate the underlying events of this phenomenon, we used recently developed technology, (123)I-labeled beta-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) myocardial scintigraphy, as a test of myocardial fatty acid metabolism. Our results showed that the free carnitine concentration (19.2 +/- 6.5 micromol/l) was lower in 11 chronically dialyzed patients than in 8 healthy controls (49.3 +/- 7.7 micromol/l, p < 0. 0001). Additionally the heart to mediastinal ratio (H/M) of BMIPP was higher for these patients than for the controls (1.91 +/- 0.19 vs. 1.52 +/- 0.24, p < 0.005), and the patients' washout rate (WOR) of BMIPP was lower (17.2 +/- 6.0 vs. 22.8 +/- 4.2%, p < 0.05). After L-carnitine was administered orally to the patients at doses of 1 g/day for 1 month and 0.5 g/day for the following month, the concentration of free carnitine in their sera increased to 85.4 +/- 27.0 micromol/l (p < 0.0001). Although the H/M ratio did not change (1.89 +/- 0.20) with this treatment, their WOR increased to 21.9 +/- 6.6% (p < 0.001), similar to that of controls. The left ventricular end-diastolic dimension and left ventricular fractional shortening remained unchanged, as shown by echocardiography. The results presented here denote that a carnitine deficiency in chronically hemodialyzed patients disrupts their myocardial fatty acid metabolism, which is improved by L-carnitine supplementation.
Sakurabayashi
T
T
Kidney Center of Shinraku-en Hospital, Niigata-shi, Yamanashi Medical College, Yamanashi, Japan. fm6y-kud@asahi-net.or.jp
Takaesu
Y
Y
Haginoshita
S
S
Takeda
T
T
Aoike
I
I
Miyazaki
S
S
Koda
Y
Y
Yuasa
Y
Y
Sakai
S
S
Suzuki
M
M
Takahashi
S
S
Hirasawa
Y
Y
Nakamura
T
T
D002331:Carnitine / Q000172:deficiency / Q000627:therapeutic use*; D016022:Case-Control Studies; D004452:Echocardiography; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D006435:Renal Dialysis; D015899:Tomography, Emission-Computed, Single-Photon
D005227:Fatty Acids; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; C049338:iodofiltic acid; D002331:Carnitine