Valproic Acid-associated Hypoalbuminemia in Medically Fragile Patients
关键词
抽象
描述
Valproic acid (VPA) is a long-chain fatty acid frequently used as an antiepileptic agent in pediatric and adult seizure patients. Other adverse effects that have been associated with VPA use include hepatic steatosis, altered mitochondrial function and decreased concentrations of serum proteins. The exact mechanism or mechanisms by which VPA induces these associated adverse drug effects are not fully understood though multiple theories have been postulated including impaired vesicle transport within the hepatocyte, inhibition of hepatic synthetic metabolic pathways and renal protein loss. Decreased serum albumin concentrations with concomitant VPA use have been identified in multiple studies. Albumin synthesis is sensitive to tryptophan concentrations (other amino acids are also able to stimulate albumin synthesis), oncotic pressure near the synthetic site, and energy supply while albumin release from the hepatocyte is sensitive to intrahepatocellular potassium concentrations. Based on available literature, VPA appears to inhibit an enzyme(s) either directly or indirectly involved with albumin synthesis or albumin gene expression. VPA is known to inhibit the urea cycle, including patients with ornithine-transcarbamylase (OTC) deficiency, possibly by inhibiting mitochondrial carbamoyl-phosphate synthase. Oratz et al discussed the potential correlation between the urea cycle and albumin synthesis identified after the administration of various amino acids increased both albumin and urea synthesis. Ornithine is an intermediate amino acid within the urea cycle and it is also a precursor to polyamines which have been shown to increase the degree of aggregation of polysomes, responsible for protein synthesis, bound to the endoplasmic reticulum. Thus, VPA may indirectly inhibit protein synthesis by interfering with the urea cycle leading to decreased ornithine concentrations and subsequently a decrease in polyamine concentrations and a decrease in the number of bound polysomes resulting in alterations in albumin synthesis and release. The purpose of this study is to investigate potential mechanisms of VPA-associated hypoalbuminemia in medically fragile pediatric and young adult epileptic patients of a long-term care facility.
日期
最后验证: | 02/28/2011 |
首次提交: | 07/24/2008 |
提交的预估入学人数: | 07/27/2008 |
首次发布: | 07/28/2008 |
上次提交的更新: | 03/07/2011 |
最近更新发布: | 03/09/2011 |
实际学习开始日期: | 01/31/2009 |
预计主要完成日期: | 11/30/2009 |
预计完成日期: | 11/30/2010 |
状况或疾病
干预/治疗
Procedure: 1
相
手臂组
臂 | 干预/治疗 |
---|---|
1 Resident of Hattie Larlham long-term care facility receiving VPA | Procedure: 1 A blood sample and a spot urine sample will be obtained from all eligible patients receiving VPA at the start of the study. |
2 Control AED patients will be recruited based on similar AED regimens excluding VPA, length of time on AED (number of months to >1 year), age, and gender; one control patient per VPA patient. | |
3 Control non-AED patients will be recruited based on age and gender; one control patient per VPA patient. |
资格标准
有资格学习的性别 | All |
取样方式 | Non-Probability Sample |
接受健康志愿者 | 是 |
标准 | Inclusion Criteria: - Resident of Hattie Larlham long-term care facility receiving VPA for > 3 months at the start of the study - Resident of Hattie Larlham long-term care facility matched to a resident receiving VPA for > 3 month based on concomitant AED, length of time on AED, age, and gender - Resident of Hattie Larlham long-term care facility not receiving AED matched to a resident receiving VPA for > 3 month based on age and gender Exclusion Criteria: - Received albumin products within the past 1 month - Receiving VPA for < 3 months or discontinuation of VPA therapy within the past four weeks - Medical need for specific protein supplementation - Diagnosed with protein-losing nephropathy or enteropathy |
结果
主要结果指标
1. The primary outcome will be serum albumin concentrations at baseline in the patients receiving VPA. [Baseline]
次要成果指标
1. Secondary outcome variables will include serum amino acid concentrations, total protein, AST, ALT, alkaline phosphatase, ammonia, BUN, and sCr and urine albumin, protein, and urea. [Baseline]