Evaluation ofserum free carnitine/acylcarnitine levels and left ventricular systolic functions in children with idiopathic epilepsy receiving valproic acid

Cardiac structural and functional abnormalities in epilepsy: A systematic review and meta-analysis

OBJECTIVE

Epilepsy is associated with an increased risk of cardiovascular disease and mortality. Whether cardiac structure and function are altered in epilepsy remains unclear. To address this, we conducted a systematic review and meta-analysis of studies evaluating cardiac structure and function in patients with epilepsy.

METHODS

We searched the electronic databases MEDLINE, PubMed, COCHRANE, and Web of Science from inception to 31 December 2021. Primary outcomes of interest included left ventricular ejection fraction (LVEF) for studies reporting echocardiogram findings and cardiac weight and fibrosis for postmortem investigations. Study quality was assessed using the National Heart, Lung, and Blood Institute (NHLBI) assessment tools.

RESULTS

Among the 10 case-control studies with epilepsy patients (n = 515) and healthy controls (n = 445), LVEF was significantly decreased in epilepsy group compared with controls (MD: -1.80; 95% confidence interval [CI]: -3.56 to -0.04; P = 0.045), whereas A-wave velocity (MD: 4.73; 95% CI: 1.87-7.60; P = 0.001), E/e' ratio (MD: 0.39; 95% CI: 0.06-0.71; P = 0.019), and isovolumic relaxation time (MD: 10.18; 95% CI: 2.05-18.32; P = 0.014) were increased in epilepsy, compared with controls. A pooled analysis was performed in sudden unexpected death in epilepsy (SUDEP) cases with autopsy data (n = 714). Among SUDEP cases, the prevalence of cardiac hypertrophy was 16% (95% CI: 9%-23%); cardiac fibrosis was 20% (95% CI: 15%-26%). We found no marked differences in cardiac hypertrophy, heart weight, or cardiac fibrosis between SUDEP cases and epilepsy controls.

SIGNIFICANCE

Our findings suggest that epilepsy is associated with altered diastolic and systolic echocardiogram parameters compared with healthy controls. Notably, SUDEP does not appear to be associated with a higher incidence of structural cardiac abnormalities, compared with non-SUDEP epilepsy controls. Longitudinal studies are needed to understand the prognostic significance of such changes. Echocardiography may be a useful noninvasive diagnostic test in epilepsy population.

The correlation between carbamazepine and valproic acid monotherapy with serum adiponectin and carnitine

Antiepileptic drugs may cause systemic and metabolic side effects. The aim of our study was to investigate the effects of valproic acid and carbamazepine monotherapy used in the treatment of epilepsy patients on serum adiponectin and carnitine levels. The study included 60 patients, of which 30 patients receiving valproic acid monotherapy and 30 patients receiving carbamazepine monotherapy, who were followed up by the epilepsy outpatient clinic with the diagnosis of idiopathic epilepsy, and 30 healthy volunteers. Patients, who used drugs for at least 6 months, were selected. Venous blood samples were collected from the patients and healthy volunteers after their consent was obtained. Serum carnitine and adiponectin levels in the collected samples were measured using the ELISA method. Serum carnitine levels were 5166.55 ng/ml (± 1954.92) in patients receiving carbamazepine, 4224.56 ng/ml (± 2055.54) in patients using valproic acid, and 5802.64 ng/ml (± 3422.57) in the control group. Serum adiponectin levels were 13,606.51 ng/ml (± 5915.92) in patients using carbamazepine, 11,986.58 ng/ml (± 5367.82) in patients receiving valproic acid, and 14,033.43 ng/ml (± 5646.34) in the control group. In both groups, both serum carnitine and serum adiponectin levels were lower than the control group. There was a negative but insignificant correlation between the duration and dose of carbamazepine and valproic acid drug use and serum adiponectin and carnitine levels. There is a need for more extensive studies with larger sample size to investigate the effect of antiepileptic drugs used on serum adiponectin and carnitine levels.

Valproic Acid and the Liver Injury in Patients with Epilepsy: An Update

BACKGROUND

Valproic acid (VPA) as a widely used primary medication in the treatment of epilepsy is associated with reversible or irreversible hepatotoxicity. Long-term VPA therapy is also related to increased risk for the development of non-alcoholic fatty liver disease (NAFLD). In this review, metabolic elimination pathways of VPA in the liver and underlying mechanisms of VPA-induced hepatotoxicity are discussed.

METHODS

We searched in PubMed for manuscripts published in English, combining terms such as "Valproic acid", "hepatotoxicity", "liver injury", and "mechanisms". The data of screened papers were analyzed and summarized.

RESULTS

The formation of VPA reactive metabolites, inhibition of fatty acid β-oxidation, excessive oxidative stress and genetic variants of some enzymes, such as CPS1, POLG, GSTs, SOD2, UGTs and CYPs genes, have been reported to be associated with VPA hepatotoxicity. Furthermore, carnitine supplementation and antioxidants administration proved to be positive treatment strategies for VPA-induced hepatotoxicity.

CONCLUSION

Therapeutic drug monitoring (TDM) and routine liver biochemistry monitoring during VPA-therapy, as well as genotype screening for certain patients before VPA administration, could improve the safety profile of this antiepileptic drug.

Mass Spectrometric Analysis of L-carnitine and its Esters: Potential Biomarkers of Disturbances in Carnitine Homeostasis

PURPOSE

After a golden age of classic carnitine research three decades ago, the spread of mass spectrometry opened new perspectives and a much better understanding of the carnitine system is available nowadays. In the classic period, several human and animal studies were focused on various distinct physiological functions of this molecule and these revealed different aspects of carnitine homeostasis in normal and pathological conditions. Initially, the laboratory analyses were based on the classic or radioenzymatic assays, enabling only the determination of free and total carnitine levels and calculation of total carnitine esters' amount without any information on the composition of the acyl groups. The introduction of mass spectrometry allowed the measurement of free carnitine along with the specific and sensitive determination of different carnitine esters. Beyond basic research, mass spectrometry study of carnitine esters was introduced into the newborn screening program because of being capable to detect more than 30 metabolic disorders simultaneously. Furthermore, mass spectrometry measurements were performed to investigate different disease states affecting carnitine homeostasis, such as diabetes, chronic renal failure, celiac disease, cardiovascular diseases, autism spectrum disorder or inflammatory bowel diseases.

RESULTS

This article will review the recent advances in the field of carnitine research with respect to mass spectrometric analyses of acyl-carnitines in normal and various pathological states.

CONCLUSION

The growing number of publications using mass spectrometry as a tool to investigate normal physiological conditions or reveal potential biomarkers of primary and secondary carnitine deficiencies shows that this tool brought a new perspective to carnitine research.