Serum myoglobin in patients on intermittent and continuous ambulatory peritoneal dialysis.

Serum myoglobin levels were determined in patients maintained on chronic peritoneal dialysis. Eleven intermittent peritoneal dialysis patients had a mean serum myoglobin of 174 +/- 29 ng/ml. In 7 patients tested serially, there was no consistent change in serum myoglobin: the mean level was 154 +/- 36 ng/ml pre-dialysis and 170 +/- 20 ng/ml post-dialysis. Seventeen patients on continuous ambulatory peritoneal dialysis had a mean serum myoglobin of 215 +/- 18 ng/ml. Two patients given oral carnitine supplements had a substantial decrease in their serum myoglobin levels. Patients on peritoneal dialysis, like those on hemodialysis, tend to have elevated serum myoglobin levels, and neither form of dialysis affects serum myoglobin concentration. This hypermyoglobinemia may be due to metabolic changes in muscle.