Vaziri ND, Oveisi F, Reyes GA, Zhou XJ
Dysregulation of melatonin metabolism in chronic renal
insufficiency: Role of erythropoietin induced anemia
Kidney Int
(Aug) 50:653-656 1996

Many dialysis patients suffer from serious sleep disorders such as
sleep apnea syndrome, and many more simply have trouble sleeping. At
every drugstore counter in the United States one can find melatonin
being sold as a sleep aid. So one wonders why no one has studied
melatonin regulation in dialysis patients, and why no one has tried to
give melatonin to dialysis patients to see if it helps them sleep
safely.
The study by Vaziri is a start, although it was
done in rats, not people. Rats with chronic renal failure (5/6
nephrectomy) and associated anemia were found to have marked
attenuation of the normal nocturnal surge in serum melatonin
concentration. Also, the pineal gland melatonin concentration was
significantly depressed. Bright light did, however, suppress
melatonin production as it did in control animals. Interestingly,
correction of the anemia per se using EPO resulted in marked
improvement in the nocturnal increase in serum melatonin
levels.
Comment: As a rule, we don't review rat studies
for HDCN, as the clinical implications of such studies are often
dubious. This is certainly the case for the present study. We are
only reviewing it in the hopes that someone will do some more
definitive studies of melatonin physiology in humans with ESRD. These
results certainly do not support the use of melatonin in patients with
ESRD, but simply suggest an interesting area of future research.
(John T. Daugirdas, M.D., University of Illinois at Chicago)