Effectiveness of monitoring free carnitine levels for L-carnitine supplementation in hemodialysis patients to maintain carnitine sufficiency and nutritional factors

We investigated the effectiveness of monitoring serum carnitine levels in hemodialysis patients receiving L-carnitine supplementation. One-hundred forty-five hemodialysis patients were divided into three groups. Group 1 consisted of patients (n = 30) who had been receiving supplementation before this study and then discontinued at the beginning. The remaining patients were divided into Group 2 (n = 13) and Group 3 (n = 102) based on their baseline free carnitine (FC) level, <20 or ≥ 20 μmol/L. Group 2 was started on supplementation, and Groups 1 and 3 were observed without any intervention for the first 6 months. FC was measured every 6 months in all three groups up to 18 months. All patients in whom FC was less than 20 μmol/L at 6 and 12 months were prescribed supplementation. After the first 6 months, the mean ± SD of FC changed from 262.5 ± 87.5 μmol/L at baseline to 70.8 ± 33.6 μmol/L (P < 0.001) in Group 1, from 17.4 ± 1.9 to 193.9 ± 43.3 μmol/L (P < 0.001) in Group 2, and from 49.2 ± 24.6 to 44.2 ± 19.8 μmol/L (P < 0.05) in Group 3. The acyl/free carnitine changed from 0.62 to 0.59 in Group 1 (P = 0.287), from 0.76 to 0.66 in Group 2 (P = 0.054) and from 0.57 to 0.60 in Group 3 (P < 0.05). Of the 145 patients, 126 continued follow-up for the full 18 months. FC remained in the normal range (36-74 μmol/L) within the 95% CI. FC was considered a strong predictor of carnitine deficiency after 6 months (AUC: 0.9146, cut-off value: 33.8 μmol/L). FC monitoring is essential for appropriate carnitine supplementation in hemodialysis patients.

Antimyopathic effects of carnitine and nicotine

PURPOSE OF REVIEW

The clinical course of most chronic diseases is associated with declined energy intake and nutrient-resistant progressive myopathy, characterized by accelerated proteolysis and impaired function. This anorexia/cachexia syndrome leads to deterioration of quality of life, and increased morbidity and mortality. The clinical efficacy of currently available therapeutic strategies is limited and more effective treatments are needed.

RECENT FINDINGS

Chronic systemic inflammation, triggered and sustained by cytokines, and increased oxidative stress contribute to the pathogenesis of the anorexia/cachexia syndrome. Carnitine and nicotine have recently been tested as immunomodulating and antioxidant agents. In particular, carnitine supplementation has been shown to reduce chronic inflammation and oxidative stress in hemodialysis patients and, in cancer patients, yielding to reduced fatigue and improved outcome. Nicotine is able to induce the anti-inflammatory activity of the vagus nerve. In animal models of sepsis and cancer, the nicotine-induced supplementation resulted in better protection of nutritional status and improved survival.

SUMMARY

In the continuous effort to develop more efficacious strategies against the anorexia/cachexia syndrome, carnitine and nicotine may represent a further therapeutic tool. More clinical studies are needed, however, before their use can be routinely suggested.