Adams W H, Daniel G B, Legendre A M, Gompf R E, Grove C A
Department of Small Animal Clinical Sciences, University of Tennessee, College of Veterinary Medicine, Knoxville 37901-1071, USA.
Vet Radiol Ultrasound. 1997 May-Jun;38(3):231-8. doi: 10.1111/j.1740-8261.1997.tb00846.x.
Changes in renal function of twenty-two cats treated for hyperthyroidism using radioiodine were evaluated. Serum thyroxine (T4), serum creatinine, blood urea nitrogen (BUN) and urine specific gravity were measured before treatment and 6 and 30 days after treatment. Twenty-two cats had pretreatment and 21 cats had 6 day posttreatment measurement of glomerular filtration rate (GFR) using nuclear medicine imaging techniques. There were significant declines in serum T4 at 6 days following treatment, but the changes in GFR, serum creatinine and BUN were not significant. At 30 days following treatment, there were significant increases in BUN and serum creatinine and further significant declines in serum T4. Nine cats were in renal failure prior to treatment and 13 cats were in renal failure 30 days following treatment. Renal failure was defined as BUN greater than 30 mg/dl and/or serum creatinine greater than 1.8 mg/dl with concurrent urine specific gravity less than 1.035. These 13 cats included eight of 9 cats in renal failure prior to treatment and 5 cats not previously in renal failure. Follow up information beyond 30 days following treatment on 9 of these 13 cats indicated that all remained in renal failure. Based on receiver operating curve analysis of pretreatment glomerular filtration rate (GFR) in predicting posttreatment renal failure, a value of 2.25 ml/kg/min as a point of maximum sensitivity (100%) and specificity (78%) was derived. Fifteen of 22 cats had pretreatment GFR measurements of less than 2.25 ml/kg/min. These 15 cats included all 9 cats in renal failure and 5 cats with normal renal clinicopathologic values prior to treatment. At 30 days following treatment, 13 of these 15 cats were in renal failure. The 2 cats not in renal failure had persistently increased serum T4 values. Seven of 22 cats had pretreatment GFR measurements greater than 2.25 ml/kg/min. None of these 7 cats was in renal failure at 30 days following treatment, all cats having normal BUN, serum creatinine, and urine specific gravity values. It was concluded that significant declines in renal function occur after treatment of hyperthyroidism and this decline is clinically important in cats with renal disease. Pretreatment measurement of GFR is valuable in detecting subclinical renal disease and in predicting which cats may have clinically important declines in renal function following treatment.
评估了22只接受放射性碘治疗甲状腺功能亢进症的猫的肾功能变化。在治疗前以及治疗后6天和30天测量血清甲状腺素（T4）、血清肌酐、血尿素氮（BUN）和尿比重。22只猫进行了治疗前测量，21只猫在治疗后6天使用核医学成像技术测量了肾小球滤过率（GFR）。治疗后6天血清T4显著下降，但GFR、血清肌酐和BUN的变化不显著。治疗后30天，BUN和血清肌酐显著升高，血清T4进一步显著下降。9只猫在治疗前处于肾衰竭状态，13只猫在治疗后30天处于肾衰竭状态。肾衰竭定义为BUN大于30mg/dl和/或血清肌酐大于1.8mg/dl，同时尿比重小于1.035。这13只猫包括治疗前9只肾衰竭猫中的8只和5只之前未患肾衰竭的猫。对这13只猫中的9只在治疗后30天以上的随访信息表明，所有猫仍处于肾衰竭状态。基于治疗前肾小球滤过率（GFR）预测治疗后肾衰竭的受试者工作特征曲线分析，得出2.25ml/kg/min的值为最大敏感性（100%）和特异性（78%）的点。22只猫中有15只治疗前GFR测量值小于2.25ml/kg/min。这15只猫包括所有9只肾衰竭猫和5只治疗前肾脏临床病理值正常的猫。治疗后30天，这15只猫中有13只处于肾衰竭状态。2只未患肾衰竭的猫血清T4值持续升高。22只猫中有7只治疗前GFR测量值大于2.25ml/kg/min。治疗后30天，这7只猫中没有一只处于肾衰竭状态，所有猫的BUN、血清肌酐和尿比重值均正常。得出结论，甲状腺功能亢进症治疗后肾功能显著下降，这种下降在患有肾脏疾病的猫中具有临床重要性。治疗前测量GFR对于检测亚临床肾脏疾病以及预测哪些猫在治疗后可能出现具有临床重要性的肾功能下降很有价值。
