Study of aerobic capacity in chronic hemodialized patients: effect of L-carnitine supplementation

BACKGROUND AND OBJECTIVE: Chronic hemodialyzed patients have a low level of aerobic capacity, caused by the pathologies concomitant to renal insufficiency, according with a low level of physical activity. One of the factors that would contribute to this level of aerobic capacity is the L-carnitine deficit on skeletal muscle. However, the value of the supplementation of L-carnitine to improve the physical fitness has been controversial. The objective of this work was to evaluate the effect of the administration of L-carnitine on VO2 max in hemodialyzed patients. PATIENTS AND METHODS: A group of 21 patients (20-50 years old) on a program of chronic hemodialysis was studied. During 12 weeks, 13 of them received L-carnitine, 7 men and 6 women, 38.8 (9.5) years old; BMI 24.2 (2.1) Kg/m(2); 8 of them received placebo, 4 men and 4 women, 35.8 (11.4) years old; BMI 24.5 (5.8) Kg/m(2). RESULTS: There was an increase in VO2 peak on L-carnitine group from 16.3 (2.8) mL x Kg(-1) x min(-1) to 19.5 (3.3) mL x Kg(-1) x min(-1), and the same was seen in the placebo group (increase in VO2peak from 14.8 (3.8) mL x Kg(-1) x min(-1) to 18.9 (4.8) mL x Kg(-1) X min(-1)). The L-carnitine and placebo groups did not show statistical differences at the end of this study (all values above p > 0.05). CONCLUSION. In this group of patients, the intravenous supplementation of L-carnitine during 12 weeks did not have an impact on the improvement of the VO2peak.