The effects of L-carnitine supplementation on inflammatory and anti-inflammatory markers in adults: a systematic review and dose-response meta-analysis.
- 2023-09-01
- Inflammopharmacology 31(5)
- Samira Rastgoo
- Sahand Tehrani Fateh
- Mahlagha Nikbaf-Shandiz
- Niloufar Rasaei
- Yasaman Aali
- Mohammad Zamani
- Farideh Shiraseb
- Omid Asbaghi
- PubMed: 37656233
- DOI: 10.1007/s10787-023-01323-9
Study Design
- Type
- Meta-Analysis
- Sample size
- n = 3,255
- Population
- adults
- Methods
- systematic review and meta-analysis; random-effects model; search in PubMed, ISI Web of Science, the Cochrane Library, and Scopus up to October 2022; included 48 RCTs (n = 3255) with 51 effect sizes
- Duration
- not stated explicitly for the meta-analysis; subgroup analyses mention trial duration ≥ 12 weeks
L-carnitine supplementation may be beneficial in improving inflammatory conditions and reducing the level of inflammatory cytokines. Therefore, according to the finding of randomized controlled trials (RCTs), the systematic review and meta-analysis aimed to investigate the effect of L-carnitine supplementation on inflammation in adults. To obtain acceptable articles up to October 2022, a thorough search was conducted in databases including PubMed, ISI Web of Science, the Cochrane Library, and Scopus. A random-effects model was used to estimate the weighted mean difference (WMD). We included the 48 RCTs (n = 3255) with 51 effect sizes in this study. L-carnitine supplementation had a significant effect on C-reactive protein (CRP) (p < 0.001), interleukin-6 (IL-6) (p = 0.001), tumor necrosis factor-α (TNF-α) (p = 0.002), malondialdehyde (MDA) (p = 0.001), total antioxidant capacity (TAC) (p = 0.029), alanine transaminase (ALT) (p < 0.001), and aspartate transaminase (AST) (p < 0.001) in intervention, compared to the placebo group. Subgroup analyses showed that L-carnitine supplementation had a lowering effect on CRP and TNF-α in trial duration ≥ 12 weeks in type 2 diabetes and BMI ≥ 25 kg/m2. L-carnitine supplementation reduced ALT levels in overweight and normal BMI subjects at any trial dose and trial duration ≥ 12 weeks and reduced AST levels in overweight subjects and trial dose ≥ 2 g/day. This meta-analysis revealed that L-carnitine supplementation effectively reduces the inflammatory state by increasing the level of TAC and decreasing the levels of CRP, IL-6, TNF-α and MDA in the serum.
Research Insights
L-carnitine supplementation had a significant effect on … total antioxidant capacity (TAC) (p = 0.029)
- Effect
- Beneficial
- Effect size
- Small
- Dose
- not specified in abstract
L-carnitine supplementation had a significant effect on … alanine transaminase (ALT) (p < 0.001)
- Effect
- Beneficial
- Effect size
- Small
- Dose
- not specified in abstract
L-carnitine supplementation had a significant effect on … aspartate transaminase (AST) (p < 0.001)
- Effect
- Beneficial
- Effect size
- Small
- Dose
- not specified in abstract
L-carnitine supplementation had a significant effect on C-reactive protein (CRP) (p < 0.001)
- Effect
- Beneficial
- Effect size
- Moderate
- Dose
- not specified in abstract
L-carnitine supplementation had a significant effect on … interleukin-6 (IL-6) (p = 0.001)
- Effect
- Beneficial
- Effect size
- Small
- Dose
- not specified in abstract
L-carnitine supplementation had a significant effect on … malondialdehyde (MDA) (p = 0.001)
- Effect
- Beneficial
- Effect size
- Small
- Dose
- not specified in abstract
L-carnitine supplementation had a significant effect on … tumor necrosis factor-α (TNF-α) (p = 0.002)
- Effect
- Beneficial
- Effect size
- Small
- Dose
- not specified in abstract