Preliminary evaluation of fecal fatty acid concentrations in cats with chronic kidney disease and correlation with indoxyl sulfate and p‐cresol sulfate

• Published in: Journal of veterinary internal medicine Vol. 34; no. 1; pp. 206 - 215
• Main Authors: Summers, Stacie, Quimby, Jessica M., Phillips, Robert Kyle, Stockman, Jonathan, Isaiah, Anitha, Lidbury, Jonathan A., Steiner, Joerg M., Suchodolski, Jan
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.01.2020; Wiley
• Subjects: Aging; Animals; Appetite; Blood levels; Blood pressure; branched‐chain fatty acids; Case-Control Studies; Cat Diseases - metabolism; Cats; Chain branching; Chromatography; chronic renal failure; Creatinine; Cresol; Cresols - chemistry; Diet; Dilution; Fatty acids; Fatty Acids, Nonesterified - chemistry; Feces; Feces - chemistry; feline; Food; Gas chromatography; Geriatrics; Indican - chemistry; isovaleric acid; Kidney diseases; Kidneys; Laboratories; Liquid chromatography; Mass spectrometry; Mass spectroscopy; Medical records; Microbiota; Motility; Muscles; Prospective Studies; Proteins; Renal Insufficiency, Chronic - metabolism; Renal Insufficiency, Chronic - veterinary; short‐chain fatty acids; SMALL ANIMAL; Stable isotopes; Sulfates; Sulfuric Acid Esters - chemistry; Teaching hospitals; Urea; uremic toxins; Urine; Veterinary medicine; Vomiting; United States > US; Colorado; isovaleric acid; feline; uremic toxins; branched-chain fatty acids; short-chain fatty acids; chronic renal failure
• ISSN: 0891-6640; 1939-1676
• DOI: 10.1111/jvim.15634

Background Straight‐ and branched‐chain (BCFA) short‐chain fatty acids (SCFAs) are produced by colonic microbiota and have both beneficial and deleterious effects in humans with chronic kidney disease (CKD). Fecal SCFAs in cats with CKD have not been described. Objective To characterize fecal SCFA concentrations in cats with CKD as compared to healthy geriatric cats and correlate SCFA to serum indoxyl sulfate (IS) and p‐cresol sulfate (pCS) concentrations. Animals Twenty‐eight cats with CKD (International Renal Interest Society [IRIS] stages 2, 3, and 4) and 11 older (≥ 8 years) healthy geriatric cats. Methods Prospective, cross‐sectional study. Voided feces were analyzed using stable isotope dilution gas chromatography‐mass spectrometry to determine fecal concentrations of SCFAs. Serum concentrations of IS and pCS were measured using liquid chromatography tandem mass spectrometry. Results Fecal isovaleric acid concentrations were significantly higher in CKD cats(P = .02) Cats with IRIS CKD stage 3 and 4 had significantly higher fecal isovaleric acid concentrations compared to healthy geriatric cats (P = .03), but not compared to IRIS CKD stage 2 cats. Total fecal concentrations of BCFAs were found to correlate weakly with serum creatinine concentration (rho, 0.33; P = .05), blood urea nitrogen concentration (rho, 0.40; P = .01), and pCS concentration (rho, 0.35; P = .04). Conclusions and Clinical Importance Fecal isovaleric acid concentrations were higher in CKD cats, particularly in late stage disease, compared to healthy geriatric cats. Fecal BCFA concentrations correlated with pCS and were higher in cats with muscle wasting, providing evidence for malassimilation of protein in CKD cats.