Plasma oxalic acid and cardiovascular risk in end-stage renal disease patients: a prospective, observational cohort pilot study

Background/Aims: It was hypothesized that oxalate might be strongly involved in atherogenesis and the inflammatory pathway that could result in an increased risk of cardiovascular disease (CVD) in end-stage renal disease (ESRD) patients. Therefore, this study aimed to address two primary research questions: to characterize the lipid profile and the pattern of pro-inflammatory cytokines according to plasma oxalic acid (POx) concentration in ESRD patients; to evaluate the potential role of elevated POx concentration in the development of CVD risk. Methods: A total of 73 participants were enrolled in this prospective, observational cohort pilot study. Among them, there were 50 ESRD patients and 23 healthy volunteers. The lipid profile and the pro-inflammatory cytokines were analyzed according to the distribution of POx concentration into tertiles. After the clinical examination, 29 hemodialysis patients and 21 peritoneal dialysis patients without prevalent CVD were observed for CVD events for 2 years. The Cox regression analysis and a set of different types of sensitivity analyses were used to determine whether elevated POx was associated with an increased risk of CVD. Results: An increasing trend in the atherogenic lipoprotein fractions and the pro-inflammatory markers as well as a linear decrease in high-density lipoprotein was significantly associated with elevated POx. POx concentration >= 62.9 mu mol/L was significantly associated with CVD events independently of other examined CVD risk factors. Conclusions: This pilot study firstly demonstrated a potential contribution of POx to atherogenesis, inflammation and CVD risk in ESRD patients.