The present study examined the serum and urinary
carnitine concentrations of 21
cancer patients with metastatic disease and 13 healthy age-matched controls by taking three consecutive samples during an 8-week period. The serum concentrations of all fractions of
carnitine were significantly lower in the female
cancer patients than in the female controls. The concentrations of urinary
carnitine fractions were relatively higher in the total
cancer population; however, only
acid-insoluble
acylcarnitine (AIAC) was statistically significant. The renal clearance of
acid-soluble
acylcarnitine (ASAC) and AIAC was significantly greater in
cancer subjects than in controls. Significant inverse relationships were established between the ASAC and AIAC clearances and their respective serum concentrations. The renal tubular reabsorption of AIAC was significantly less in
cancer patients than in control subjects as indicated by the fractional excretion of
carnitine. The increased clearance of
acylcarnitine and excretion of large amounts of AIAC are proposed to be a response to
chemotherapy and represent a loss of energy to the
cancer patient.