We have studied the changes in the lipid profile of 14 chronic hemodialysis patients receiving a 6-month cycle of nandrolone decanoate as treatment for anemia. Nandrolone decanoate was administered in a weekly intramuscular dose of 200 mg and resulted in an increase in the hemoglobin concentration (baseline, 7.9 +/- 0.9 g/dL; month 6, 10.8 +/- 1.7 g/dL; P < 0.001, ANOVA) and also produced relevant modifications in the lipid concentrations. The most significant finding was a decrease in the concentration of lipoprotein(a) [Lp(a)]: baseline, 19.8 mg/dL (median), month 2, 10.6 mg/dL; month 4, 8.7 mg/dL; and month 6, 7.1 mg/dL (P < 0.001, Friedman). Other lipid changes induced by nandrolone decanoate were an increase in the concentrations of apolipoprotein B (P < 0.02, ANOVA) and triglyceride (P = NS, ANOVA) and a decrease of high-density lipoprotein (HDL) cholesterol (P < 0.001, ANOVA) and apolipoprotein A-I (P = NS, ANOVA). The decrease in HDL cholesterol was at the expense of the HDL2 cholesterol subfraction, whereas HDL3 remained unchanged. These lipid modifications were reversible; 4 months after nandrolone decanoate withdrawal, the lipid concentrations were similar to the basal values. The changes in Lp(a) levels did not correlate with those of hemoglobin or the other lipid parameters, suggesting that the underlying mechanisms are unrelated. Our findings could be clinically relevant if confirmed by further studies.