title: Serum carnitine as an independent biomarker of malnutrition in patients with impaired oral intake.
abstract: Carnitine is a vitamin-like compound that plays important roles in fatty acid β-oxidation and the control of the mitochondrial coenzyme A/acetyl-CoA ratio. However, carnitine is not added to ordinary enteral nutrition or total parenteral nutrition. In this study, we determined the serum carnitine concentrations in subjects receiving ordinary enteral nutrition (EN) or total parenteral nutrition (TPN) and in patients with inflammatory bowel diseases to compare its levels with those of other nutritional markers. Serum samples obtained from 11 EN and 11 TPN patients and 82 healthy controls were examined. In addition, 10 Crohn's disease and 10 ulcerative colitis patients with malnutrition who were barely able to ingest an ordinary diet were also evaluated. Carnitine and its derivatives were quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The carnitine concentrations in EN and TPN subjects were significantly lower compared with those of the control subjects. Neither the serum albumin nor the total cholesterol level was correlated with the carnitine concentration, although a significant positive correlation was found between the serum albumin and total cholesterol levels. Indeed, patients with CD and UC showed significantly reduced serum albumin and/or total cholesterol levels, but their carnitine concentrations remained normal. In conclusion, only a complete blockade of an ordinary diet, such as EN or TPN, caused a reduction in the serum carnitine concentration. Serum carnitine may be an independent biomarker of malnutrition, and its supplementation is needed in EN and TPN subjects even if their serum albumin and total cholesterol levels are normal.
authors.affiliation: Department of Gastroenterology, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Ami-machi Chuo, Inashiki-gun, Ibaraki 300-0395, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Iwamoto
authors.affiliation: Department of Gastroenterology, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Ami-machi Chuo, Inashiki-gun, Ibaraki 300-0395, Japan ; Joint Research Center, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Ami-machi Chuo, Inashiki-gun, Ibaraki 300-0395, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Honda
authors.affiliation: Department of Nephrology, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Ami-machi Chuo, Inashiki-gun, Ibaraki 300-0395, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Miyamoto
authors.affiliation: Joint Research Center, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Ami-machi Chuo, Inashiki-gun, Ibaraki 300-0395, Japan.
authors.forename: Teruo
authors.initials: T
authors.lastname: Miyazaki
authors.affiliation: Department of Gastroenterology, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Ami-machi Chuo, Inashiki-gun, Ibaraki 300-0395, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Murakami
authors.affiliation: Department of Gastroenterology, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Ami-machi Chuo, Inashiki-gun, Ibaraki 300-0395, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Saito
authors.affiliation: Department of Gastroenterology, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Ami-machi Chuo, Inashiki-gun, Ibaraki 300-0395, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ikegami
authors.affiliation: Miyamoto Hospital, 1247 kouda, Inashiki-shi, Ibaraki 300-0605, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Miyamoto
authors.affiliation: Department of Gastroenterology, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Ami-machi Chuo, Inashiki-gun, Ibaraki 300-0395, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Matsuzaki
keywords: carnitine; enteral nutrition (EN); inflammatory bowel diseases; total parenteral nutrition (TPN)