Fasting and Post-Methionine Loading Concentrations of Homocysteine, Vitamin B2, and Vitamin B6 in Patients on Antiepileptic Drugs

[摘要] Patients on antiepileptic drugs (AEDs) frequently have low serum folate and high plasma total homocysteine (tHcy) (1)(2)(3)(4). This metabolic disturbance has been implicated in an increased rate of cardiovascular disease, fetal malformations, dementia, and neuropsychiatric symptoms among patients on AEDs (5)(6)(7). Homocysteine metabolism is dependent on four B vitamins as cofactors: The methylation of homocysteine to methionine requires folate and vitamin B12, and the irreversible transsulfuration to cysteine requires vitamin B6 (8). The recycling of folate cofactors is dependent on vitamin B6 and B2, and vitamin B2 is necessary for activating vitamin B6 to pyridoxal 5′-phosphate (PLP) (9). Vitamin B2 and B6 status thus may have an impact on tHcy concentrations in patients taking AEDs, but few studies have reported on this matter (3)(4)(10)(11). The methionine loading test detects individuals with impaired homocysteine metabolism not detected by fasting Hcy concentrations alone and is often considered primarily a test of the transsulfuration pathway (1)(8)(12). We therefore determined the fasting and 6 h post-methionine loading (postload) plasma concentrations of thiols and B vitamins in patients taking AEDs.We recruited 101 patients with symptomatic, cryptogenic, or primary generalized epilepsy from our outpatient clinic. None of them had epilepsy secondary to ischemic stroke or other conditions considered to be associated with high tHcy, and none were on prescribed vitamin supplements. We recruited 101 controls among blood donors and hospital employees. All participants gave written informed consent before entering the study, and The Regional Ethics Committee (University of Bergen, Norway) approved the study. The number of male patients and controls was identical (n = 53), as was the mean (SD) age [37.9 (15.0) and 37.3 …

[学科分类] 过敏症与临床免疫学