Reevaluation of serum carnitine status in patients with liver cirrhosis

Background:Carnitine (CA) is an important key substance for lipid metabolism and serum CA levels change in patients with various diseases. Although liver cirrhosis (LC) is known as a representative cause of secondary CA deficiencies, the exact levels of serum CA in LC patients remains a controversial issue. The aim of the present study was to reevaluate the serum CA levels in LC patients, with a particular focus on the relationship between serum CA levels and liver and renal function. Methods:Seventy-one patients with LC (51 males, 20 females; median age 63.0 years) were examined. Fasting serum Total-CA (T-CA), Free-CA (F-CA) and Acyl-CA (Ac-CA) levels were measured using an enzymatic cycling method and were evaluated according to their relationships with liver and renal dysfunction. Results:The levels (mean ± standard deviation, μmol/L) of serum T-CA, F-CA and Ac-CA (72.9±19.1, 55.3±14.0 and 17.6±7.2 respectively) in LC patients were almost within normal range (T-CA: 45.0-91.0; F-CA: 36.0-74.4 and Ac-CA: 6.0-23.0 respectively). Approximately 11% of patients had serum T-CA levels <45μmol/L. These serum CAs levels did not correlate with severity of liver damage based on the Child-Pugh classification and the Model for End-stage Liver Disease, but serum T-CA and Ac-CA levels significantly correlated with serum creatinine and/or the estimated glomerular filtration rate. Blood ammonia levels did not correlate with these serum CA levels. Among nutritional parameters, only serum free fatty acid levels strongly correlated with serum Ac-CA levels and the Ac-CA to T-CA ratio. Conclusion:Our results suggest that the rate of secondary CA deficiency may be low and that serum CA levels are almost within normal range in LC patients, although serum Ac-CA levels are closely associated with renal dysfunction. Furthermore, the Ac-CA to T-CA ratio may be useful as a marker of malnutrition (299).