Correlation Between C-reactive Protein and Non-enzymatic Antioxidants (Albumin, Ferritin, Uric Acid and Bilirubin) in Hemodialysis Patients

Introduction: Increased levels of C-Reactive Protein are found in 30-60% on hemodialysis patients and it is closely associated with the progression of atherosclerosis, cardiovascular morbidity and mortality. Non enzymatic antioxidants are antioxidants which primarily retain potentially dangerous ions of iron and copper in their inactive form and thereby prevent its participation in the production of free radicals. Aim: The aim of the study was to examine the relationship of CRP and non enzymatic antioxidants (albumin, ferritin, uric acid and bilirubin) i.e. examine the importance of CRP as a serum biomarker in assessing the condition of inflammation and its relationship to antioxidant protection in patients on hemodialysis. Methods: The study was cross-sectional, clinical, comparative and descriptive. The study involved 100 patients (non diabetic) on chronic hemodialysis. The control group consisted of 50 subjects without subjective and objective indicators of chronic renal disease. In all patients, the concentration of CRP as well as concentrations of non enzymatic antioxidants were determined. Results: In the group of hemodialysis patients 60% were men and 40% women. The average age of hemodialysis patients was 54.13 ± 11.8 years and the average age of the control group 41.72 ± 9.8 years. The average duration of hemodialysis treatment was 91.42 ± 76.2 months. In the group of hemodialysis patients statistically significant, negative linear correlation was determined between the concentration of CRP in and albumin concentration (rho = -0.251, p = 0.012) as well as negative, statistics insignificant, linear correlation between serum CRP and the concentration of uric acid (r = -0.077, p = 0.448). Furthermore, the positive, linear correlation was determined between serum CRP and ferritin (r = 0.159, p = 0.114) and positive linear correlation between CRP and total serum bilirubin (r = 0.121, p = 0.230). In the control group was determined a statistically significant, positive, linear correlation between serum CRP and uric acid concentration (rho = 0.438, p = 0.001) and statistically significant, positive, linear correlation between serum CRP and total serum bilirubin (rho = 0.510, p = 0.0001) A statistically significant, negative linear correlation was determined between CRP and albumin concentration (rho= -0.393, p = 0.005) as well as statistically significant, negative linear correlation between serum CRP and ferritin control group (rho = -0.391, p = 0.005). Conclusion: Elevated CRP level is a strong and independent predictor of low levels of serum albumin, which indicates that the hypoalbuminemia in hemodialysis patients could be more due to inflammation than malnutrition. There was no statistically significant correlation between CRP and other non enzymatic antioxidants (uric acid, ferritin, bilirubin), which shows that indicators of antioxidant defense in hemodialysis patients must be individually measured to determine their actual stocks and activity.