Prospective controlled study of androgen therapy in the anemia of chronic renal disease: effects on iron kinetics.

Ferrokinetic and RBC mass determinations were made at 3-month intervals in iron-replete hemodialysis patients randomized to a control group or to nandrolone decanoate therapy. After 3 months, RBC mass increased in two of 4 androgen-treated patients. Erythron iron turnover, an index of RBC production, increased in the one responder studied but not in the two nonresponders. Similarly, in a fifth subject, who was not restudied until 6 months of androgen therapy were completed, an increase in RBC mass was associated with an increase in erythron iron turnover. However, between 3 and 6 months, RBC mass increased in all 4 androgen-treated patients studied even though erythron iron turnovers remained unchanged and dialysis-associated blood losses did not decrease. Thus, at least two androgen-treated patients had increases in RBC mass without ever increasing their erythron iron turnover. Two of three control subjects also had increased erythron iron turnovers, which in one case was related to increased dialysis-associated blood losses. Changes in RBC mass were not consistently paralleled by changes in Hb. These findings suggest that increases in RBC mass during nandrolone decanoate therapy result from two mechanisms: increased erythropoiesis (shown by simultaneous increases in RBC mass and erythron iron turnover) and increased RBC survival (indirectly shown by increases in RBC mass without increases in erythron iron turnover). The importance of control groups, RBC mass determinations and the monitoring of dialysis-associated blood losses in studying the effects of androgens on erythropoiesis in chronic hemodialysis patients is also demonstrated.