Table 2.

Selected baseline clinicopathological data in initially nonazotemic hyperthyroid cats that developed azotemia within 4 months of successful treatment of hyperthyroidism (pre‐azotemic), hyperthyroid cats that remained nonazotemic throughout the study period (nonazotemic), nonhyperthyroid cats with azotemic CKD, and healthy older cats

Variable	Hyperthyroid		Nonhyperthyroid Azotemic CKD	Healthy Older Cat
	Pre‐azotemic	Nonazotemic
Age (years)	15.1 [12.3, 16.2]	14.8 [12.9, 16.2]	12.5 [11.3, 16.1]	12.0 [10.5, 14.0]
Serum total thyroxine concentrations (nmol/L)	82.1 [62.4, 117.9]	108.8 [73.0, 177.8]	23.0 [18.6, 27.5]	21.2 [17.6, 24.8]
Serum/plasma blood urea nitrogen concentrations (mg/dL)	34.7 [29.7, 46.2]	25.2 [23.0, 31.6]	42.3 [29.7, 58.5]	28.3 [24.9, 34.4]
Serum/plasma creatinine concentrations (mg/dL)	1.4 [1.1, 1.6]	1.1 [0.9, 1.3]	2.2 [1.9, 2.8]	1.4 [1.2, 1.6]
Urine specific gravity	1.027 [1.020, 1.039]	1.031 [1.019, 1.041]	1.022 [1.017, 1.028]	1.044 [1.034, >1.050]

Normal reference interval for serum total thyroxine concentrations is 7–45 nmol/L.10 Data are presented as median [25th, 75th percentiles].