The Role of L-Carnitine in the Improvement of Liver Tests and Glycemic Control among Patients with Non-Alcoholic Fatty Liver Disease: A Meta-Analysis

Abstract

Background:
Population-based cohort studies from Asia have reported rising prevalence of non-alcoholic fatty liver disease (NAFLD) from 10% to 24%. Philippine data report a rate of 12.2% with important co-morbidities such as obesity (56%) and diabetes mellitus (69%). Several interventions for NAFLD have emerged, among which L-carnitine has shown promise. Objective: This meta-analysis aimed to assess the role of carnitine in improving liver function and glycemic control among NAFLD patients.

Methodology:
Electronic search from databases (PubMed, Cochrane Library and Google Scholar) yielded five randomized controlled trials. Studies included adult patients with NAFLD diagnosed through clinical and/or histologic findings. Methodologic assessment of studies and statistical analyses were performed with Review Manager version 5.3. Results: Of 33 studies identified, five fulfilled the inclusion criteria with a total of 340 clinical subjects. Pooled analysis showed significant reduction in serum ALT and AST with mean differences of 34.64 + 14.3 (p value = <0.0001) and 17.49 + 9.88 (p value = 0.0005), respectively. No significant reduction on BMI and fasting blood sugar were demonstrated with mean differences of -0.10 + 0.20 (p value = 0.31) and 2.31 + 13.38 (p value = 0.73), respectively. Subgroup analysis based on treatment dose and duration showed unaltered results except for AST levels, which demonstrated greater reduction at carnitine dose of >500 mg/day.

Conclusion:
The use of L-carnitine resulted in lower ALT and AST levels, with dose-dependent reduction seen for AST. Intake of Lcarnitine had no effect on glycemic control and BMI among NAFLD patients. Further studies involving more clinical subjects with histologic and radiologic assessments as outcomes are highly recommended.