{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,30]],"date-time":"2026-06-30T20:26:26Z","timestamp":1782851186523,"version":"3.54.5"},"reference-count":30,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2024,6,3]],"date-time":"2024-06-03T00:00:00Z","timestamp":1717372800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Fibroblast growth factor (FGF)-23 is a phosphaturic hormone. An association between increasing FGF-23 levels and progression of chronic kidney disease (CKD) was documented in cats, dogs, and humans. The information regarding reference intervals (RIs) of FGF-23 in cats is limited. We aimed to establish RIs in a large cohort of clinically healthy cats and to investigate correlations with sex and age. A total of 118 cats with unremarkable complete blood count and serum chemistry profile were included. Clinically sick cats, cats with concurrent diseases, suspicion of CKD, or receiving renal diets were excluded. FGF-23 concentrations were measured with the FGF-23 ELISA Kit. RIs were calculated using the reference interval advisor software 2.1 (Microsoft Excel). FGF-23 concentrations were correlated with sex and age. The RI for FGF-23 concentrations spanned 85.8 to 387.0 pg\/mL (90% confidence interval: lower limit 40.5 to 103.9 pg\/mL, upper limit: 354.6 to 425.0 pg\/mL). No significant relationships (r2 = 0.044) were detected with age (p = 0.081) or sex (p = 0.191). Other studies of the same diagnostic assay calculated RIs of 56 to 700 pg\/mL in 79 cats and &lt;336 pg\/mL in 108 cats, and in concordance with the present study, did not detect any correlation with sex or age.<\/jats:p>","DOI":"10.3390\/ani14111670","type":"journal-article","created":{"date-parts":[[2024,6,3]],"date-time":"2024-06-03T10:08:38Z","timestamp":1717409318000},"page":"1670","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Establishing a Reference Interval for Fibroblast Growth Factor (FGF)-23 in Cats"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8635-1327","authenticated-orcid":false,"given":"Sandra","family":"Lapsina","sequence":"first","affiliation":[{"name":"LABOKLIN GmbH and Co. KG, Steubenstra\u00dfe 4, 97688 Bad Kissingen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jennifer","family":"von Luckner","sequence":"additional","affiliation":[{"name":"LABOKLIN GmbH and Co. KG, Steubenstra\u00dfe 4, 97688 Bad Kissingen, Germany"},{"name":"AniCura Ahlen, Bunsenstra\u00dfe 20, 59229 Ahlen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicole","family":"Nagler","sequence":"additional","affiliation":[{"name":"LABOKLIN GmbH and Co. KG, Steubenstra\u00dfe 4, 97688 Bad Kissingen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5429-0088","authenticated-orcid":false,"given":"Simon Franz","family":"M\u00fcller","sequence":"additional","affiliation":[{"name":"LABOKLIN GmbH and Co. KG, Steubenstra\u00dfe 4, 97688 Bad Kissingen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elisabeth","family":"M\u00fcller","sequence":"additional","affiliation":[{"name":"LABOKLIN GmbH and Co. KG, Steubenstra\u00dfe 4, 97688 Bad Kissingen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9264-6607","authenticated-orcid":false,"given":"Ingo","family":"Sch\u00e4fer","sequence":"additional","affiliation":[{"name":"LABOKLIN GmbH and Co. KG, Steubenstra\u00dfe 4, 97688 Bad Kissingen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,6,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1336","DOI":"10.2460\/javma.1999.214.09.1336","article-title":"Health status and population characteristics of dogs and cats examined at private veterinary practices in the United States","volume":"214","author":"Lund","year":"1999","journal-title":"J. Am. Vet. Med. Assoc."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"286","DOI":"10.1016\/j.tvjl.2014.08.004","article-title":"Prevalence of disorders recorded in cats attending primary-care veterinary practices in England","volume":"202","author":"Church","year":"2014","journal-title":"Vet. J."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"806","DOI":"10.1111\/j.1939-1676.2009.0339.x","article-title":"Evaluation of predictors of the development of azotemia in cats","volume":"23","author":"Jepson","year":"2009","journal-title":"J. Vet. Intern. Med."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1177\/1098612X13511446","article-title":"Prevalence and classification of chronic kidney disease in cats randomly selected from four age groups and in cats recruited for degenerative joint disease studies","volume":"16","author":"Marino","year":"2014","journal-title":"J. Feline Med. Surg."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1177\/1098612X16631234","article-title":"ISFM consensus guidelines on the diagnosis and management of feline chronic kidney disease","volume":"18","author":"Sparkes","year":"2016","journal-title":"J. Feline Med. Surg."},{"key":"ref_6","unstructured":"International Renal Interest Society (IRIS) (2023, March 18). IRIS Staging of CKD (Modified in 2023). Available online: http:\/\/iris-kidney.com\/pdf\/2_IRIS_Staging_of_CKD_2023.pdf."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"37419","DOI":"10.1074\/jbc.M304544200","article-title":"Regulation of fibroblastic growth factor 23 expression but not degradation by PHEX","volume":"278","author":"Liu","year":"2003","journal-title":"J. Biol. Chem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1161","DOI":"10.1016\/j.bone.2009.08.008","article-title":"Patterns of FGF-23, DMP1, and MEPE expression in patients with chronic kidney disease","volume":"45","author":"Pereira","year":"2009","journal-title":"Bone"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"429","DOI":"10.1359\/JBMR.0301264","article-title":"FGF-23 is a potent regulator of vitamin D metabolism and phosphate homeostasis","volume":"19","author":"Shimada","year":"2004","journal-title":"J. Bone Miner. Res."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2543","DOI":"10.1074\/jbc.M408903200","article-title":"Circulating FGF-23 is regulated by 1alpha,25-dihydroxyvitamin D3 and phosphorus in vivo","volume":"280","author":"Saito","year":"2005","journal-title":"J. Biol. Chem."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1637","DOI":"10.1681\/ASN.2007010068","article-title":"How fibroblast growth factor 23 works","volume":"18","author":"Liu","year":"2007","journal-title":"J. Am. Soc. Nephrol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1159\/000365787","article-title":"Fibroblast growth factor 23\/klotho axis in chronic kidney disease","volume":"128","author":"Nitta","year":"2014","journal-title":"Nephron Clin. Pract."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1370","DOI":"10.1038\/ki.2011.47","article-title":"Fibroblast growth factor 23 is elevated before parathyroid hormone and phosphate in chronic kidney disease","volume":"79","author":"Isakova","year":"2011","journal-title":"Kidney Int."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"993","DOI":"10.1093\/ndt\/gfp699","article-title":"Fibroblast growth factor-23 and early decrements in kidney function: The Heart and Soul Study","volume":"25","author":"Ix","year":"2010","journal-title":"Nephrol. Dial. Transplant."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"234","DOI":"10.1111\/jvim.12044","article-title":"Fibroblast growth factor 23 in feline chronic kidney disease","volume":"27","author":"Geddes","year":"2013","journal-title":"J. Vet. Intern. Med."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"686","DOI":"10.1111\/jvim.15457","article-title":"The association of indoxyl sulfate with fibroblast growth factor-23 in cats with chronic kidney disease","volume":"33","author":"Liao","year":"2019","journal-title":"J. Vet. Intern. Med."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1111\/jvim.12036","article-title":"Fibroblast growth factor 23 (FGF-23) concentrations in cats with early nonazotemic chronic kidney disease (CKD) and in healthy geriatric cats","volume":"27","author":"Finch","year":"2013","journal-title":"J. Vet. Intern. Med."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2657","DOI":"10.1111\/jvim.15590","article-title":"Fibroblast growth factor 23 and symmetric dimethylarginine concentrations in geriatric cats","volume":"33","author":"Sargent","year":"2019","journal-title":"J. Vet. Intern. Med."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1494","DOI":"10.1111\/jvim.13625","article-title":"Relationship between plasma fibroblast growth Factor-23 concentration and survival time in cats with chronic kidney disease","volume":"29","author":"Geddes","year":"2015","journal-title":"J. Vet. Intern. Med."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"288","DOI":"10.1177\/1040638720985563","article-title":"Serum fibroblast growth factor 23 (FGF-23): Associations with hyperphosphatemia and clinical staging of feline chronic kidney disease","volume":"33","author":"Lin","year":"2021","journal-title":"J. Vet. Diagn. Investig."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Grelova, S., Karasova, M., Tothova, C., Kiskova, T., Baranova, D., Lukac, B., Fialkovicova, M., Michalova, A., Kunay, L., and Svoboda, M. (2022). Relationship between FGF 23, SDMA, urea, creatinine and phosphate in relation to feline chronic kidney disease. Animals, 12.","DOI":"10.3390\/ani12172247"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1292\/jvms.21-0566","article-title":"Assessment of the measurement of canine and feline serum fibroblast growth factor-23 concentrations by automated chemiluminescence immunoassay","volume":"84","author":"Miyakawa","year":"2022","journal-title":"J. Vet. Med. Sci."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Lapsina, S., Nagler, N., M\u00fcller, S.F., Holtdirk, A., Kottmann, T., M\u00fcller, E., von Luckner, J., and Sch\u00e4fer, I. (2023). Comparison of three different diagnostic assays for Fibroblast growth factor-23 (FGF-23) measurements in cats: A pilot study. Animals, 13.","DOI":"10.3390\/ani13111853"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1111\/vcp.12006","article-title":"ASVCP reference interval guidelines: Determination of de novo reference intervals in veterinary species and other related topics","volume":"41","author":"Friedrichs","year":"2012","journal-title":"Vet. Clin. Pathol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1111\/j.1939-165X.2011.00287.x","article-title":"Reference Value Advisor: A new freeware set of macroinstructions to calculate reference intervals with Microsoft Excel","volume":"40","author":"Geffre","year":"2011","journal-title":"Vet. Clin. Pathol."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Lapsina, S., Nagler, N., M\u00fcller, S.F., Holtdirk, A., Kottmann, T., M\u00fcller, E., and Sch\u00e4fer, I. (2023). Fibroblast Growth Factor-23 (FGF-23) in dogs-Reference interval and correlation with hematological and biochemical parameters. Animals, 13.","DOI":"10.3390\/ani13203202"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1018523","DOI":"10.3389\/fendo.2022.1018523","article-title":"Determination of iFGF23 upper reference limits (URL) in healthy pediatric population, for its better correct use","volume":"13","author":"Brescia","year":"2022","journal-title":"Front. Endocrinol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2345","DOI":"10.1007\/s00198-016-3543-5","article-title":"Stability and degradation of fibroblast growth factor 23 (FGF23): The effect of time and temperature and assay type","volume":"27","author":"Dumitrescu","year":"2016","journal-title":"Osteoporos. Int."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"48","DOI":"10.1089\/bio.2020.0073","article-title":"The effects of storage time and repeated freeze-thaw cycles on Intact Fibroblast Growth Factor 23 levels","volume":"19","author":"Tang","year":"2021","journal-title":"Biopreserv. Biobank."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1098612X241234984","DOI":"10.1177\/1098612X241234984","article-title":"Blood fibroblast growth factor 23 concentration in cats with and without chronic kidney disease: A scoping review","volume":"26","author":"Summers","year":"2024","journal-title":"J. Feline Med. Surg."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/14\/11\/1670\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T14:53:05Z","timestamp":1760107985000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/14\/11\/1670"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,6,3]]},"references-count":30,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2024,6]]}},"alternative-id":["ani14111670"],"URL":"https:\/\/doi.org\/10.3390\/ani14111670","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,6,3]]}}}