Positive correlations between cerebral choline and renal dysfunction in chronic renal failure.
BACKGROUND
Cerebral metabolism in chronic renal failure (CRF) patients has not been fully evaluated. This study examined cerebral metabolites in CRF, using proton magnetic resonance spectroscopy (MRS).


METHODS
Subjects comprised 19 CRF patients and 21 healthy volunteers. Spectra were acquired from voxels of interest positioned in the parietal gray and white matter, and concentrations of the following cerebral metabolites were measured: N-acetyl group (NA), creatine + phosphocreatine (Cr), choline-containing compounds (Cho), myo-inositol and glutamate + glutamine. Among the 19 CRF patients, 9 who were started on hemodialysis (HD) underwent careful follow-up. Proton MRS was performed before and about 2 weeks after starting HD. In six patients in whom follow-up was possible, a third MRS was performed after about 18 months.


RESULTS
The NA/Cr ratio was not significantly changed in CRF. However, elevations in the Cho/Cr ratio were found in both gray and white matter compared with controls. To the best of our knowledge, this is the first report of positive correlations between the Cho/Cr ratio in both regions and serum osmotic pressure. Compared with baseline data, no significant changes in cerebral metabolite ratios were found about 2 weeks after starting HD. About 18 months after starting HD, however, the elevated Cho/Cr ratio was significantly reduced in the gray matter and tended to be reduced in the white matter.


CONCLUSIONS
Cho appear to play an important role in the regulation of cerebral metabolism to compensate for alterations in serum osmotic pressure in CRF, and HD may correct this abnormal cerebral metabolism.
Division of Hypertension and Nephrology, Department of Internal Medicine, National Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan. osasaki815@hotmail.com
Osamu
O
Sasaki
Noriaki
N
Hattori
Hajime
H
Nakahama
Noriko
N
Inoue
Satoko
S
Nakamura
Takashi
T
Inenaga
Shigeru
S
Kohno
Tohru
T
Sawada
Yuhei
Y
Kawano
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism*; D002794:Choline / Q000378:metabolism*; D003401:Creatine / Q000378:metabolism; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D007677:Kidney Function Tests; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity
D001224:Aspartic Acid; D018698:Glutamic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline