title: Association between urinary vascular endothelial growth factor excretion and chronic kidney disease in hyperthyroid cats.
abstract: Many hyperthyroid cats develop azotaemic chronic kidney disease (aCKD) following treatment, which has led to the hypothesis that hyperthyroidism might be detrimental to renal function. Renin-angiotensin-aldosterone system (RAAS) activation occurs in hyperthyroidism, which could cause peri-tubular hypoxia, tubular damage and the development of aCKD. Urinary vascular endothelial growth factor:creatinine ratio (VEGFCR) is postulated to be a marker of tubular hypoxia. VEGFCR was correlated with plasma renin activity (PRA) and compared between hyperthyroid cats that did and did not develop aCKD following treatment (pre-azotaemic and non-azotaemic groups respectively). PRA was positively correlated with VEGFCR (rs = 0.382; P = 0.028); however, pre-azotaemic hyperthyroid cats had significantly lower VEGFCR than non-azotaemic cats at baseline (median 122.3 fg/g versus 167.0 fg/g; P < 0.001). RAAS activation in hyperthyroidism is associated with increased VEGFCR; however, increased VEGFCR was not correlated with the development of aCKD. Therefore, tubular hypoxia may not be a mechanism for renal damage in hyperthyroid cats.
authors.affiliation: Department of Veterinary Clinical Sciences, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK. Electronic address: timwilliams@cantab.net.
authors.forename: T L
authors.initials: TL
authors.lastname: Williams
authors.affiliation: Department of Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, Camden, London NW1 0TU, UK.
authors.forename: J
authors.initials: J
authors.lastname: Elliott
authors.affiliation: Department of Veterinary Clinical Sciences, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK.
authors.forename: H M
authors.initials: HM
authors.lastname: Syme
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000378:metabolism* / Q000652:urine; D002415:Cats; D003404:Creatinine / Q000652:urine; D005260:Female; D006980:Hyperthyroidism / Q000150:complications / Q000378:metabolism / Q000652:urine / Q000662:veterinary*; D008297:Male; D051436:Renal Insufficiency, Chronic / Q000150:complications / Q000378:metabolism / Q000652:urine / Q000662:veterinary*; D012083:Renin / Q000097:blood; D018709:Statistics, Nonparametric; D013974:Thyroxine / Q000097:blood; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism* / Q000652:urine
chemical_list: D042461:Vascular Endothelial Growth Factor A; D003404:Creatinine; D012083:Renin; D013974:Thyroxine
keywords: NAG; PRA; RAAS; azotaemia; hypoxia; proteinuria