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Evidence-Based Supplement Research
Evidence-Based Supplement Research

Effect of L-carnitine on quality of life in covert hepatic encephalopathy: a randomized, double-blind, placebo-controlled study.

  • 2022-07-01
  • The Korean journal of internal medicine 37(4)
    • Eileen L Yoon
    • Sang Bong Ahn
    • Dae Won Jun
    • Yong Kyun Cho
    • Do Seon Song
    • Jae Yoon Jeong
    • Hee Yeon Kim
    • Young Kul Jung
    • Myeong Jun Song
    • Sung Eun Kim
    • Hyoung Su Kim
    • Soung Won Jeong
    • Sang Gyune Kim
    • Tae Hee Lee

Study Design

Type
Randomized Controlled Trial (RCT)
Sample size
n = 150
Population
150 patients with liver cirrhosis and covert HE
Methods
investigator-initiated, prospective, multi-center, double-blind, randomized phase III trial, L-carnitine (2 g/day) vs placebo for 24 weeks
Blinding
Double-blind
Duration
24 weeks
Funding
Unclear
  • Large Human Trial

Background/aims

L-carnitine is potentially beneficial in patients with hepatic encephalopathy (HE). We aimed to evaluate the impact of L-carnitine on the quality of life and liver function in patients with liver cirrhosis and covert HE.

Methods

We conducted an investigator-initiated, prospective, multi-center, double- blind, randomized phase III trial in patients with covert HE. A total of 150 patients were randomized 1:1 to L-carnitine (2 g/day) or placebo for 24 weeks. Changes in quality of life and liver function were assessed at 6 months. The model for end-stage liver disease (MELD), the 36-Item Short Form Survey (SF-36), the psychometric hepatic encephalopathy score (PHES), and the Stroop Test were evaluated in all patients.

Results

The total SF-36 score significantly improved in the L-carnitine group after 24 weeks (difference: median, 2; interquartile range, 0 to 11; p < 0.001); however, these values were comparable between the two groups. Furthermore, there was a significant ordinal improvement in PHES scores among patients with minimal HE who were in the L-carnitine group (p = 0.007). Changes in the total carnitine level also positively correlated with improvements in the Stroop test in the L-carnitine group (color test, r = 0.3; word test, r = 0.4; inhibition test, r = 0.5; inhibition/switching test, r = 0.3; all p < 0.05). Nevertheless, the MELD scores at week 24 did not differ between the groups.

Conclusion

Twenty-four weeks of L-carnitine supplementation was safe but ineffective in improving quality of life and liver function.

Research Insights

  • Changes in the total carnitine level also positively correlated with improvements in the Stroop test in the L-carnitine group (... inhibition/switching test, r = 0.3; all p < 0.05).

    Effect
    Beneficial
    Effect size
    Moderate
    Dose
    2 g/day
  • Changes in the total carnitine level also positively correlated with improvements in the Stroop test in the L-carnitine group (... inhibition test, r = 0.5; ...; all p < 0.05).

    Effect
    Beneficial
    Effect size
    Moderate
    Dose
    2 g/day
  • there was a significant ordinal improvement in PHES scores among patients with minimal HE who were in the L-carnitine group (p = 0.007).

    Effect
    Beneficial
    Effect size
    Small
    Dose
    2 g/day
  • total SF-36 score significantly improved in the L-carnitine group after 24 weeks ... however, these values were comparable between the two groups.

    Effect
    Neutral
    Effect size
    Small
    Dose
    2 g/day
  • Changes in the total carnitine level also positively correlated with improvements in the Stroop test in the L-carnitine group (color test, r = 0.3; ...; all p < 0.05).

    Effect
    Beneficial
    Effect size
    Moderate
    Dose
    2 g/day
  • Changes in the total carnitine level also positively correlated with improvements in the Stroop test in the L-carnitine group (... word test, r = 0.4; ...; all p < 0.05).

    Effect
    Beneficial
    Effect size
    Moderate
    Dose
    2 g/day
  • the MELD scores at week 24 did not differ between the groups.

    Effect
    Neutral
    Effect size
    Small
    Dose
    2 g/day
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