The Effect of L-Carnitine on Mortality Rate in Septic Patients: A Systematic Review and Meta-Analysis on Randomized Clinical Trials

L-carnitine ameliorates myocardial injury by alleviating endoplasmic reticulum stress via inhibition of PERK pathway in exertional heatstroke rats

Exertional heatstroke (EHS) is a life-threatening condition with potential for tissues and organs injury, including heart. Effective drug strategies to treat patients with EHS are warranted to unlock the therapeutic potential. Considering the cardioprotective effects of L-carnitine (LC), this study aimed to investigate the effects of LC on EHS-induced myocardial injury in rats and to explore the underlying mechanisms. Here, we found that LC exerted a greater protective effect on EHS-induced cardiac dysfunction and mortality, which also significantly attenuated certain negative effects, including increased myocardial apoptosis, pathological changes, and ultrastructural impairment, enhanced activity levels of such serum enzymes as AST, LDH, CK, and CK-MB, reduced BCL-2 expression, increased the expression of cleaved caspase-3 and the critical endoplasmic reticulum stress (ERS) indices like CHOP and GRP78 in EHS rats. Besides, pretreatment of EHS rats with PBA (4-Phenyl butyric acid), a chemical chaperone that attenuates ERS, restored BCL-2 expression, reduced the protein levels of cleaved caspase-3, CHOP, and GRP78. Furthermore, thapsigargin (TG), which induces ERS, enhanced the expression of BAX, cleaved caspase-3, CHOP, and GRP78, attenuated BCL-2 expression, and enhanced mitochondrial impairment in EHS + LC rats. Mechanismly, the protective effects of LC were mediated, at least partly, by inhibiting the activation of PERK pathway against ERS-associated myocardial damage. These results indicate that supplementation of LC might be a potential strategy to reduce myocardial injury by affecting ERS via inhibiting the PERK pathway against EHS.

The supplementation of L-carnitine in critically ill patients with sepsis: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

The evidence suggests that L-carnitine may reduce mortality in critically ill patients with sepsis. However, the conclusions of different studies are inconsistent. A meta-analysis was conducted to evaluate the effect of L-carnitine compliance on mortality in patients with sepsis.

METHODS

A search of the PubMed, Embase, and Cochrane Library databases was conducted on 1 June 2024. The risk ratio (RR) was pooled with a 95% confidence interval (CI) for dichotomous data. The publications were subjected to a review in accordance with the guidelines set forth in the Cochrane Handbook and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). This study has been registered with INPLASY (number INPLASY202460086).

RESULTS

A total of 356 patients were included in four randomized controlled trials. The results indicated that L-carnitine supplementation was not associated with 28-day mortality in sepsis patients (RR: 0.65; 95% CI 0.33-1.28; I2 = 70%; P = 0.21). And there was no significant effect on 12-month mortality (RR: 0.72; 95% CI 0.47-1.11; I2 = 0%; P = 0.14) compared to placebo.

CONCLUSIONS

The use of L-carnitine was not found to be significantly correlated with 28-day or 12-month mortality in patients with sepsis.

The effects of L-carnitine supplementation on inflammatory factors, oxidative stress, and clinical outcomes in patients with sepsis admitted to the intensive care unit (ICU): study protocol for a double blind, randomized, placebo-controlled clinical trial

BACKGROUND

Sepsis is a common cause for admission to the intensive care unit (ICU), and its incidence has been increasing. It is associated with a significant increase in serum inflammatory biomarkers such as C-reactive protein (CRP) and cytokines such as interleukin 1 (IL-1), IL-6, and tumor necrosis factor (TNF). Sepsis is also associated with pathophysiological changes that include fluid accumulation in the lungs, eventually leading to acute respiratory distress syndrome (ARDS), tissue edema, hypotension, and acute kidney injury (AKI). Conventional therapies include antibiotics, but these may have important adverse effects, so novel therapeutic approaches are required. In animal studies, L-carnitine improves antioxidant status, and in some clinical trials, it has been shown to reduce inflammation. It has also been shown to improve respiratory distress and help maintain coenzyme A homeostasis, metabolic flexibility, promoting the normal function of the tricarboxylic acid (TCA) cycle, and oxidation of fatty acids by peroxisomes. We aim to determine the effects of very high doses of L-carnitine on inflammatory factors, oxidative stress, and clinical outcomes of patients with sepsis in ICU.

METHOD AND DESIGN

In this double-blind, randomized controlled clinical trial, we will use block randomization of 60 patients with sepsis, aged between 20 and 65 years from Al-Zahra Hospital, Isfahan, Iran. The intervention group (n = 30) will receive three capsules of L-carnitine (each capsule contains 1000 mg L-carnitine; totally 3000 mg/day) for 7 days, and a control group (n = 30) will receive a placebo with the same dose and for the same duration in addition to usual care. At baseline, scores for clinical and nutritional status (Acute Physiology and Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA), Quick SOFA (qSOFA), and NUTRIC Score) will be assessed. At beginning and end point of the study, inflammatory markers (CRP, erythrocyte sedimentation rate (ESR)), oxidative stress status (total oxidative stress (TOS), total antioxidant capacity (TAC)), and clinical variables will be evaluated also. The mortality rate will be assessed within 28 days of the beginning of the intervention.

DISCUSSION

Because of the anti-inflammatory and antioxidant properties of L-carnitine, it is possible that using a high dose of 3000 mg daily of this nutritional supplement may reduce inflammation and oxidative stress and improve subsequent mortality of critically ill patients with sepsis.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials IRCT20201129049534N1 . Registered on 2 May 2021.

L-carnitine: Searching for New Therapeutic Strategy for Sepsis Management

In this review, we discussed the biological targets of carnitine, its effects on immune function, and how L-carnitine supplementation may help critically ill patients. L-carnitine is a potent antioxidant. L-carnitine depletion has been observed in prolonged intensive care unit (ICU) stays, while L-carnitine supplementation has beneficial effects in health promotion and regulation of immunity. It is essential for the uptake of fatty acids into mitochondria. By inhibiting the ubiquitin-proteasome system, down-regulation of apelin receptor in cardiac tissue, and reducing β-oxidation of fatty acid, carnitine may decrease vasopressor requirement in septic shock and improve clinical outcomes of this group of patients. We also have an overview of animal and clinical studies that have been recruited for evaluating the beneficial effects of L-carnitine in the management of sepsis/ septic shock. Additional clinical data are required to evaluate the optimal daily dose and duration of L-carnitine supplementation.