Association between Serum Uric Acid Levels, Nutritional and Antioxidant Status in Patients on Hemodialysis

• Published in: Nutrients Vol. 12; no. 9; p. 2600
• Main Authors: Domínguez-Zambrano, Etna, Pedraza-Chaverri, José, López-Santos, Ana Laura, Medina-Campos, Omar Noel, Cruz-Rivera, Cristino, Bueno-Hernández, Francisco, Espinosa-Cuevas, Angeles
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 27.08.2020; MDPI
• Subjects: Adult; Antioxidants; Antioxidants - metabolism; appearance (quality); blood serum; Body composition; Body mass index; cachexia; Creatinine; Cross-Sectional Studies; dialysis; Dielectric properties; Disease; Female; Fistula; height; Hemodialysis; Humans; hyperuricemia; Male; malondialdehyde; Metabolism; Middle Aged; nitrogen; Nutrition research; Nutritional Status; oxidants; Oxidative stress; oxygen radical absorbance capacity; patients; Population; Potassium; Proteins; Renal Dialysis; risk; Software; Uric acid; Uric Acid - blood; Values; United States > US; nutritional status; oxygen radical absorbance capacity; malondialdehyde; 2,2-diphenyl-1-picrilhydrazyl; uric acid; oxidative stress; renal dialysis
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu12092600

Purpose: To determine the relationship between uric acid (UA) and nutritional and antioxidant status in hemodialysis (HD) patients, given that hyperuricemia could be an indicator of good nutritional status possibly because of the antioxidant properties of UA. Methods: Cross-sectional study with 93 patients on HD. Hyperuricemia was considered as UA ≥6.0 mg/dL in females and ≥7.0 mg/dL in males. Nutritional variables were registered. Blood samples were taken before the dialysis session to determine oxidative damage as plasma malondialdehyde (MDA) content, and antioxidant capacity measuring 2,2-diphenyl-piclrylhidrazil radical (DPPH●) scavenging activity and oxygen radical absorbance capacity (ORAC) value. Results: Patients with hyperuricemia had higher creatinine (11.9 vs. 10.5 mg/dL; p = 0.004), potassium (5.5 vs. 5.0 mg/dL; p = 0.014) levels; phase angle (5.8 vs. 4.9; p = 0.005), protein consumption (normalized protein nitrogen appearance, nPNA, 1.03 vs. 0.83; p = 0.013) than normouricemic patients. DPPH● scavenging activity was higher in hyperuricemic subjects (1.139 vs. 1.049 mM Trolox equivalents; p = 0.007); likewise, hyperuricemic subjects had less oxidant damage measured by MDA (10.6 vs. 12.7 nmol/mL; p = 0.020). Subjects with normouricemia were at higher risk of having a reactance to height (Xc/H) ratio less than 35 (OR 2.79; 95% CI, 1.1–7.017, p = 0.028); nPNA < 1.0 (OR 3.78; 95% CI, 1.4–10.2, p = 0.007), diagnosis of cachexia (OR 2.95; 95% CI, 1156–7.518, p = 0.021), potassium levels <5 (OR 2.97; 95% CI, 1.136–7.772, p = 0.023) and PA < 5.5° (OR 3.38; 95% CI, 1.309–8.749, p = 0.012.) Conclusions: Patients with hyperuricemia had higher antioxidant capacity and better nutritional status. Purines and protein restrictions in HD patients with hyperuricemia need to be reviewed individually for each patient. More studies are needed to stablish a cut point of UA levels in renal population.