Supplementation of vitamin E as an addition to a commercial renal diet does not prolong survival of cats with chronic kidney disease

• Published in: BMC veterinary research Vol. 20; no. 1; pp. 308 - 13
• Main Authors: Krofič Žel, Martina, Tavčar Kalcher, Gabrijela, Vovk, Tomaž, Žegura, Bojana, Lusa, Lara, Tozon, Nataša, Nemec Svete, Alenka
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 10.07.2024; BioMed Central; BMC
• Subjects: Analysis; Anemia; Animal euthanasia; Animal Feed - analysis; Animals; Antioxidants; Biomarkers; Cat Diseases - diet therapy; Cat Diseases - drug therapy; Cats; Chronic kidney disease; Chronic kidney failure; Clinical trials; Diet - veterinary; Dietary Supplements; Diseases; DNA damage; DNA Damage - drug effects; Dosage and administration; Double-Blind Method; Female; Genetic aspects; Growth; Hemodialysis; Kidney diseases; Lipid peroxidation; Lipids; Lymphocytes; Male; Malondialdehyde - blood; Mineral oils; Mortality; Oxidative stress; Oxidative Stress - drug effects; Physiology, Pathological; Placebos; Plasma; Prevention; Protein Carbonylation - drug effects; Renal Insufficiency, Chronic - diet therapy; Renal Insufficiency, Chronic - drug therapy; Renal Insufficiency, Chronic - veterinary; Risk factors; Statistical analysis; Survival; Vitamin E; Vitamin E - administration & dosage; Vitamin E - therapeutic use; Slovenia; Oxidative stress; Chronic kidney disease; Vitamin E; Survival
• ISSN: 1746-6148; 1746-6148
• DOI: 10.1186/s12917-024-04176-8

The aim of this double-blind, placebo-controlled study was to investigate the effect of vitamin E supplementation as an addition to a commercial renal diet on survival time of cats with different stages of chronic kidney disease (CKD). In addition, we were interested whether vitamin E supplementation affects selected oxidative stress and clinical parameters. Thirty-four cats with CKD and 38 healthy cats were included in the study. Cats with CKD were classified according to the IRIS Guidelines; seven in IRIS stage 1, 15 in IRIS stage 2, five in IRIS stage 3 and seven in IRIS stage 4. Cats with CKD were treated according to IRIS Guidelines. Cats with CKD were randomly assigned to receive vitamin E (100 IU/cat/day) or placebo (mineral oil) for 24 weeks in addition to standard therapy. Plasma malondialdehyde (MDA) and protein carbonyl (PC) concentrations, DNA damage of peripheral lymphocytes and plasma vitamin E concentrations were measured at baseline and four, eight, 16 and 24 weeks thereafter. Routine laboratory analyses and assessment of clinical signs were performed at each visit. Vitamin E supplementation had no effect on the survival time and did not reduce the severity of clinical signs. Before vitamin E supplementation, no significant differences in vitamin E, MDA and PC concentrations were found between healthy and CKD cats. However, plasma MDA concentration was statistically significantly higher (p = 0.043) in cats with early CKD (IRIS stages 1 and 2) than in cats with advanced CKD (IRIS stages 3 and 4). Additionally, DNA damage was statistically significantly higher in healthy cats (p ≤ 0.001) than in CKD cats. Plasma vitamin E concentrations increased statistically significantly in the vitamin E group compared to the placebo group four (p = 0.013) and eight (p = 0.017) weeks after the start of vitamin E supplementation. During the study and after 24 weeks of vitamin E supplementation, plasma MDA and PC concentrations and DNA damage remained similar to pre-supplementation levels in both the placebo and vitamin E groups. Vitamin E supplementation as an addition to standard therapy does not prolong survival in feline CKD.