Study;Low carnitine levels linked to fatigue severity in chronic hepatitis C patients

Low carnitine levels linked to fatigue severity in chronic hepatitis C patients

By Lauretta Ihonor

01 April 2011
Aliment Pharmacol Ther 2011; Advance online publication MedWire News:

Study findings suggest that plasma carnitine levels are inversely correlated with fatigue severity in patients with chronic hepatitis C (CHC).

But this association does not appear to occur in patients with irritable bowel syndrome (IBS), even though, like CHC, it is a condition in which chronic fatigue is a prominent symptom.

"Although the mechanisms involved in the occurrence of carnitine deficiency in CHC have not been investigated in the present study, it could be cautiously speculated that [hepatitis] virus C infection may alter the physiological process of carnitine biosynthesis in the liver," note the authors in the journal Alimentary Pharmacology and Therapeutics.

They explain that carnitine - an amino acid involved in energy production - is known to improve chronic fatigue states, such as those occurring in cancer and multiple sclerosis, and thus it is feasible that a carnitine deficiency may worsen fatigue in conditions like CHC.

The study, led by Thierry Piche, from Centre Hospitalier Universitaire of Nice in France, involved 44 healthy controls, 70 CHC, and 42 IBS patients.

All participants completed a 40-question Fatigue Impact Scale questionnaire, grading fatigue severity out of a maximum score of 160.

Bioelectrical impedance analysis was used to determine the body fat composition of all participants and plasma samples were taken to measure their carnitine levels.

Analysis of the participants' fatigue scores showed that CHC and IBS patients reported more severe fatigue than controls, with respective mean scores of 56.0, 68.4, and 15.5.

Piche and team also report that CHC patients had significantly lower plasma carnitine (total and free) levels than healthy controls, even after adjustment for fat mass, with mean concentrations of 2.7 and 4.5 ng/ml/kg, respectively.

No significant difference was observed in the plasma carnitine levels of IBS patients and controls.

When the team assessed the relationship between fatigue scores and carnitine levels, they found that in patients with CHC, fatigue scores were significantly and inversely correlated with plasma carnitine levels.

No such association was found among patients with IBS, which the authors say is an indication that "the underlying mechanism of fatigue in IBS does not seem to involve carnitine."

Piche et al conclude: "Given the fact that emerging evidence from an uncontrolled study has suggested that CHC patients treated with interferon in association with carnitine (2 g daily) showed a marked early significant reduction of fatigue levels, our findings provide good reasons to pursue larger trials on the possible benefit of carnitine supplementation in CHC patients reporting fatigue."

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