Serum carnitine levels in patients with tumoral cachexia

Abstract

Background Cachexia is a serious complication of many cancers that is common in cancer and AIDS patients. However, the key factors and mechanisms involved in the development of cachexia are not yet understood. There is little data currently available regarding carnitine metabolism in patients with neoplasm and cachexia. Methods Forty-six neoplastic patients with different localizations of their primary disease gave signed, informed consent before enrolling in the present study. They underwent routine laboratory investigation, including examination of the levels of the various forms of carnitine present in serum (i.e., long-chain acylcarnitine, short-chain acylcarnitine, soluble acid acylcarnitine, free carnitine, and total carnitine). These values were compared with those found in 30 cancer patients in good nutritional status as well as with those of 30 healthy control subjects. Results In the comparison of serum plasma carnitine of cachectic patients versus controls, the difference in free carnitine was − 8.20 μmol/L ( p = 0.000); the difference in short-chain acylcarnitine − 2.60 μmol/L ( p = 0.029); the difference in soluble acid carnitine − 10.80 μmol/L ( p = 0.000); the difference in long-chain acylcarnitine − 0.40 μmol/L ( p = 0.036); and the difference in total carnitine −11.20 μmol/L ( p = 0.000). In the comparison of serum plasma carnitine of cachectic versus neoplastic patients in good nutritional status, the difference in free carnitine was −5.80 μmol/L ( p = 0.006); the difference in soluble acid carnitine − 7.20 μmol/L ( p = 0.000); and the difference in total carnitine − 7.50 μmol/L ( p = 0.000). Conclusion Our study showed that, in the multifactorial pathogenesis of cachexia, the low serum levels of carnitine in terminal neoplastic patients, which are due to a decreased dietary intake as well as to an impaired endogenous synthesis of this substance, could play an important role. These low serum carnitine levels may also contribute to the development of cachexia in cancer patients.