L-Carnitine Shows No Overall Cardiometabolic Benefit in Hemodialysis Patients: Study
Iran: Researchers found in a new study that oral L-carnitine supplementation did not significantly improve cardiometabolic risk factors among patients undergoing hemodialysis (HD).
While exploratory subgroup analyses suggested possible benefits for triglycerides (TG), HDL cholesterol (HDL-C), total cholesterol (TC), systolic blood pressure (SBP), and diastolic blood pressure (DBP) in certain patient groups, these findings are considered hypothesis-generating. Due to the risk of Type I error, small subgroup sizes, and substantial heterogeneity, the results should be interpreted cautiously and require confirmation in future well-designed studies.
The findings are from a systematic review and meta-analysis published in BMC Nephrology by Mahdi Vajdi from the Student Research Committee, Department of Clinical Nutrition, Isfahan University of Medical Sciences, Isfahan, Iran, and colleagues.
Patients undergoing long-term hemodialysis are at increased risk of metabolic and cardiovascular complications. L-carnitine, a compound involved in fatty acid metabolism and energy production, has been studied as a potential therapeutic supplement in this population, but previous studies have reported mixed results.
To clarify the evidence, researchers conducted a systematic review and meta-analysis of clinical trials identified through searches of the Web of Science, Scopus, PubMed, and Cochrane databases up to January 2026, without restrictions on language or publication date.
The analysis included 16 clinical trials involving 699 hemodialysis patients and examined the effects of L-carnitine supplementation on body weight, BMI, lipid parameters, blood pressure, albumin, and hemoglobin levels.
The researchers reported the following findings:
- L-carnitine supplementation had no significant effect on body weight in hemodialysis patients.
- No significant changes were observed in body mass index (BMI) following supplementation.
- Triglyceride (TG) levels were not significantly affected overall.
- L-carnitine did not significantly alter LDL cholesterol (LDL-C) levels.
- Total cholesterol (TC) levels showed no significant overall change.
- No significant effect was observed on HDL cholesterol (HDL-C) levels.
- Albumin concentrations remained unchanged with supplementation.
- Hemoglobin levels were not significantly affected.
- Overall, oral L-carnitine supplementation did not significantly improve cardiometabolic risk factors in patients undergoing hemodialysis.
- Exploratory analyses suggested that doses of 1,000 mg/day or higher may reduce triglyceride levels.
- Participants younger than 50 years showed a potential reduction in total cholesterol.
- Doses below 1,000 mg/day were associated with lower systolic blood pressure.
- Lower-dose supplementation was also linked to increased HDL cholesterol levels.
- Supplementation lasting more than 12 weeks was associated with reduced diastolic blood pressure.
- Interventions lasting 12 weeks or less were associated with improved HDL cholesterol levels.
- These subgroup findings are hypothesis-generating and should be interpreted cautiously pending confirmation in future studies.
The authors cautioned that the subgroup findings should be interpreted carefully, as small sample sizes, study heterogeneity, and the potential for chance findings limit their reliability.
Overall, the researchers concluded that current evidence does not support significant cardiometabolic benefits of oral L-carnitine supplementation in hemodialysis patients. They called for larger, well-designed clinical trials to determine whether specific patient subgroups may benefit from the intervention.
Reference:
Vajdi, M., Adeli, S., Noshadi, N. et al. Effect of L-carnitine supplementation on cardiac-metabolic risk factors in hemodialysis patients: a systematic review and meta-analysis of clinical trials. BMC Nephrol (2026). https://doi.org/10.1186/s12882-026-05068-9
