Erythrocyte metabolism and renal anemia in hemodialyzed patients supplemented with L-carnitine

Background and Aims: Potential role of L-carnitine in anemia adjuvant treatment is still a matter of concern. The aim of the study was to determine the influence of L-carnitine on renal anemia and erythrocyte metabolism in haemodialyzed (HD) patients.Methods: We studied 26 patients (13 male and 13 female) aged from 13 to 65, (mean age 38) and 30 healthy volunteers (12 male, 18 female) aged from 25 to 65, (mean age 40). HD patients showed stable hemoglobin (Hb) levels and low plasma free carnitine (FC) levels. Laboratory markers of: carnitine metabolism, hematological status, iron stores as well as erythrocyte metabolism were measured. L-carnitine (500 mg/day) was administered orally for 12 months (dose from 5.3 to 16.7 mg/kg of body weight, mean dose 9 mg/kg).

Results: After six months of oral low doses administration of L-carnitine, plasma total (TC) and FC levels increased and reached a plateau (at almost two times the initial levels) being at 12 months significantly higher than in the controls. During L-carnitine treatment a significant increase of mean Hb concentration was observed. Patients who responded (14/26) to L-carnitine differed from those who did not respond, with significantly longer dialysis time and lower both initial FC concentrations and FC/TC ratio. The following changes in erythrocyte metabolism were noticed: 1) glycolytic enzymes: significant increase of erythrocyte sodium, potassium ATPase, hexokinase and lactate dehydrogenase activities, 2) glycolytic intermediates: increase of 2,3-diphosphoglycerate and decrease of adenosine triphosphate concentrations, 3) decrease of the glucose uptake and lactate production by erythrocytes.

Conclusions: 1. L-carnitine may ameliorate anemia in some hemodialysis patients. 2. L-carnitine induces metabolic changes in erythrocytes. 3. Long-term maintenance hemodialysis patients may benefit most from L-carnitine supplementation. 4. Low doses of L-carnitine are effective in restoring the plasma carnitine pool.