Table 2.

Spearman correlations of clinical characteristics, kidney function, biopsy measures, and macroscopic measures with diameters of proximal and distal tubules by cortex depth

Characteristics	Mean Proximal Tubular Diameter						Mean Distal Tubular Diameter
	Superficial Cortex		Middle Cortex		Deep Cortex		Superficial Cortex		Middle Cortex		Deep Cortex
	Rs	P Value	Rs	P Value	Rs	P Value	Rs	P Value	Rs	P Value	Rs	P Value
Clinical characteristics
Age	0.03	0.34	0.01	0.68	0.03	0.24	0.06	0.04	0.07	0.009	0.06	0.04
Male	0.08	0.004	0.03	0.32	0.04	0.14	0.11	<0.0001	0.12	<0.0001	0.08	0.005
BMI	0.19	<0.0001	0.19	<0.0001	0.16	<0.0001	0.11	<0.0001	0.09	0.0008	0.10	0.0001
Hypertension	0.14	<0.0001	0.14	<0.0001	0.15	<0.0001	0.08	0.003	0.13	0.0003	0.10	0.0001
Diabetes mellitus	0.13	<0.0001	0.11	<0.0001	0.09	0.0005	0.08	0.005	0.09	0.0009	0.11	<0.0001
Kidney function
Prenephrectomy eGFR	−0.04	0.18	−0.05	0.08	−0.07	0.007	−0.12	<0.0001	−0.16	<0.0001	−0.11	<0.0001
24-h urine proteina	0.12	<0.0001	0.10	0.0007	0.11	0.0001	0.13	<0.0001	0.15	<0.0001	0.12	<0.0001
Other biopsy measures
% Luminal stenosis	0.05	0.07	0.03	0.21	0.06	0.02	0.07	0.006	0.07	0.008	0.08	0.002
% Glomerulosclerosis	0.17	<0.0001	0.15	<0.0001	0.18	<0.0001	0.17	<0.0001	0.20	<0.0001	0.19	<0.0001
% IFTA	0.12	<0.0001	0.09	0.0008	0.11	<0.0001	0.12	<0.0001	0.17	<0.0001	0.15	<0.0001
IFTA foci density	0.04	0.16	0.03	0.26	0.03	0.24	−0.01	0.74	0.03	0.30	0.04	0.13
Contralateral kidney sizeb
Cortex volume	0.13	0.001	0.10	0.009	0.11	0.006	0.12	0.003	0.12	0.003	0.09	0.02
Medulla volume	0.01	0.71	0.02	0.67	0.01	0.75	0.03	0.38	0.04	0.25	0.06	0.15
Ipsilateral kidney tumor sizec
Tumor volume	0.07	0.01	0.09	0.002	0.08	0.007	0.06	0.04	0.06	0.047	0.08	0.004

None of correlations between characteristics and proximal and distal tubular diameters clearly differed by depth (tests of interaction >0.01 for all), except the correlation between proximal tubule diameter and male (P = 0.005 for test of interaction). BMI, body mass index; IFTA, interstitial fibrosis and tubular atrophy.

^an = 24-h urine protein available in 1184 patients.

^bCortex and medulla volumes available in 663 patients.

^cTumor volume available in 1195 patients.