Clinical and Pathological Features of Chinese Patients with Type 2 Diabetes, Biopsy-Proven Diabetic Kidney Disease, and Rapid eGFR Decline

Figures & data

Figure 1 Flowchart of study participants.

Table 1 Baseline Clinical Features of Rapid eGFR Decliners Overall and Divided into Non-ESRD and ESRD Groups

Variables	All (n = 96)	Non-ESRD (n = 44)	ESRD (n = 52)	p-value
Male gender, n (%)	66 (68.8)	30 (68.2)	36 (69.2)	0.912
Age (years)	48.6 ± 10.6	47.4 ± 11.7	49.6 ± 9.4	0.3
Body mass index (kg/m^2)	25.72 ± 4.15	26.15 ± 4.21	25.36 ± 4.13	0.446
Current Smoker, n (%)	44 (45.8)	18 (40.9)	26 (50.0)	0.468
Hypertension, n (%)	85 (88.5)	38 (86.4)	47 (90.4)	0.538
Systolic blood pressure (mmHg)	145 ± 25	145 ± 24	145 ± 26	0.96
Diastolic blood pressure (mmHg)	86 ± 13	87 ± 12	85 ± 14	0.583
Diabetic duration (months)	108 [53, 144]	108 [60, 153]	114 [36, 141]	0.632
Diabetic retinopathy, n (%)	53 (55.2)	20 (45.5)	33 (63.5)	0.077
Fasting blood glucose (mmol/L)	7.4 [5.4, 9.7]	7.6 [5.5, 9.4]	7.0 [5.3, 9.7]	0.62
Serum albumin (g/L)	33.1 ± 7.2	35.4 ± 6.9	31.1 ± 7.0	0.003
Glycosylated hemoglobin(%)	7.0 [5.7, 8.4]	7.3 [6.0, 8.5]	6.8 [5.6, 8.3]	0.588
Cystatin-C (mg//L)	1.56 [1.21, 1.94]	1.32 [1.08, 1.66]	1.77 [1.46, 2.15]	<0.001
Serum creatinine (μmol/L)	119 [86, 158]	98 [69, 121]	145 [109, 174]	<0.001
eGFR (mL/min/1.73 m^2)	58 [43, 90]	79 [57, 99]	49 [35, 65]	<0.001
Albumin to creatinine ratio	2648 [1227, 4956]	2130 [744, 3473]	3675 [1822, 5453]	0.015
(mg/g)	(n=53)	(n=25)	(n=28)
Proteinuria (g/24 h)	4.8 [2.6, 8.4]	2.9 [1.8, 6.8]	6.1 [3.6, 9.6]	0.002
Proteinuria subgroups, n (%)				0.011
0–3.5	35 (36.5)	22 (50)	13 (25)
>3.5	61 (63.5)	22 (50)	39 (75)
Triglyceride (mmol/L)	1.80 [1.24, 2.26]	1.92 [1.21, 2.25]	1.76 [1.24, 2.37]	0.686
Total cholesterol (mmol/L)	5.34 ± 1.59	5 ± 1.20	5.63 ± 1.82	0.046
HDL-C (mmol/L)	1.3 [1.01, 1.62]	1.17 [1.01, 1.44]	1.35 [1.02, 2.03]	0.079
LDL-C(mmol/L)	3.07 [2.26, 4.05]	2.98 [2.28, 3.63]	3.15 [2.22, 4.22]	0.396
Uric acid (mmol/L)	378 ± 80	382 ± 90	374 ± 72	0.31
Hemoglobin (g/L)	114 ± 26	125 ± 27	106 ± 20	<0.001
Stage 1, 2, 3, 4 CKD (KDIGO), n	24/20/41/11	16/14/13/1	8/6/28/10	<0.001
Use of RAAS inhibitors, n (%)	77 (80.2)	39 (88.6)	38 (73.1)	0.057
Insulin use, n (%)	79 (82.3)	36 (81.8)	43 (82.7)	0.911
Statins use, n (%)	55 (57.3)	24 (54.5)	31 (59.6)	0.617

Notes: Data are presented as a mean ± SD, or median [IQR], or count (percentage). A two-tailed p< 0.05 was considered statistically significant.

Abbreviations: ESRD, end-stage renal disease; eGFR, estimated glomerular filtration rate; HDL-C, high-density lipoprotein-cholesterol; LDL-C, low-density lipoprotein-cholesterol; RAAS, renin-angiotensin-aldosterone system.

Table 2 Baseline Pathological Features of Rapid eGFR Decliners

Variables	All (n = 96)	Non-ESRD (n = 44)	ESRD (n = 52)	p-value
Glomerular class, n (%)				0.084
I	3 (3.1)	3 (6.8)	0 (0)
IIa	17 (17.7)	10 (22.7)	7 (13.5)
IIb	11 (11.5)	7 (15.9)	4 (7.7)
III	45 (46.9)	16 (36.4)	29 (55.8)
IV	20 (20.8)	8 (18.2)	12 (23.1)
IFTA, n (%)				0.475
0	2 (2.1)	2 (4.5)	0 (0)
1	39 (40.6)	19 (43.2)	20 (38.5)
2	40 (41.7)	16 (36.4)	24 (46.2)
3	15 (15.6)	7 (15.9)	8 (15.4)
Interstitial inflammation, n (%)				0.023
0	5 (5.2)	5 (11.4)	0 (0)
1	65 (67.7)	30 (68.2)	35 (67.3)
2	26 (27.1)	9 (20.5)	17 (32.7)
Arteriolar hyalinosis, n (%)				0.402
0	9 (9.4)	5 (11.4)	4 (7.7)
1	54 (56.3)	27 (61.4)	27 (51.9)
2	33 (34.4)	12 (27.3)	21 (40.4)
Immunofluorescence features, n (%)
IgM	14 (14.6)	5 (11.4)	9 (17.3)	0.411
IgA	8 (8.3)	2 (4.5)	6 (11.5)	0.282
IgG	14 (14.6)	6 (13.6)	8 (15.4)	0.809
C1q	7 (7.3)	2 (4.5)	5 (9.6)	0.447
C3	13 (13.5)	4 (9.1)	9 (17.3)	0.241
C4	8 (8.3)	2 (4.5)	6 (11.5)	0.282

Notes: Data are presented as percentages for categorical variables. A two-tailed p< 0.05 was considered statistically significant.

Abbreviations: IFTA, interstitial fibrosis and tubular atrophy; C3, complement 3; C4, complement 4.

Table 3 Logistic Regression Analyses of Patients with Diabetic Kidney Disease

Variables	Univariate			Multivariable
	Odds Ratio	95% CI	p value	Odds Ratio	95% CI	p value
Age	0.962	0.935–0.991	0.01	0.969	0.938–1.002	0.063
Male	1.088	0.587–2.016	0.79	0.822	0.408–1.655	0.582
eGFR	1.001	0.991–1.010	0.917	1.012	0.998–1.026	0.097
Proteinuria	1.143	1.055–1.239	0.001	1.151	1.054–1.256	0.002
Glomerular class	1.319	0.940–1.852	0.11	1.314	0.819–2.108	0.257
IFTA	1.265	0.861–1.859	0.231	1.184	0.660–2.126	0.571
Interstitial inflammation	1.773	1.015–3.096	0.044	1.421	0.661–3.053	0.368
Arteriosclerosis	1.132	0.724–1.769	0.587	1.013	0.592–1.734	0.963

Note: A two-tailed p< 0.05 was considered statistically significant.

Abbreviations: eGFR, estimated glomerular filtration rate; IFTA, interstitial fibrosis and tubular atrophy; CI, confidence interval.

Table 4 Univariable and Multivariable Cox Proportional Hazard Analyses for the Prediction of ESRD in Rapid eGFR Decliners

Variables	Univariate HR (95% CI)	p value	Multivariable HR (95% CI)	p value
Age	1.013 (0.985, 1.041)	0.370	0.998 (0.967, 1.030)	0.916
Male	1.209 (0.669, 2.184)	0.530	0.606 (0.276, 1.333)	0.213
eGFR	0.960 (0.946, 0.974)	<0.001	0.973 (0.956, 0.989)	0.001
Proteinuria	1.140 (1.078, 1.204)	<0.001	1.125 (1.030, 1.228)	0.009
Serum albumin	0.928 (0.893, 0.964)	<0.001	1.004 (0.946, 1.065)	0.899
Hemoglobin	0.974 (0.963, 0.986)	<0.001	0.987 (0.969, 1.005)	0.166
Hypertension	1.352 (0.537, 3.405)	0.522
Glycosylated hemoglobin	0.893 (0.781, 1.020)	0.096
Total cholesterol	1.107 (0.927, 1.323)	0.261
LDL-C	1.088 (0.866, 1.366)	0.470
Pathology characteristics
Glomerular class	2.211 (1.129, 4.332)	0.021	1.446 (0.605, 3.458)	0.407
IFTA	1.374 (0.784, 2.410)	0.267	0.747 (0.363, 1.537)	0.428
Interstitial inflammation	2.228 (1.234, 4.022)	0.008	0.953 (0.444, 2.045)	0.901
Arteriosclerosis	1.543 (0.884, 2.692)	0.127	1.419 (0.707, 2.847)	0.324

Note: Multivariable model was adjusted for age, sex, eGFR, proteinuria, serum albumin, hemoglobin, and all pathological parameters.

Abbreviations: HR, hazard ratio; eGFR, estimated glomerular filtration rate; LDL-C, low-density lipoprotein-cholesterol; IFTA, interstitial fibrosis and tubular atrophy.

Figure 2 Renal survival curves for end-stage renal disease according to proteinuria subgroups. Proteinuria ≤ 3.5g/24 h (n = 35) and Proteinuria > 3.5 g/24 h (n = 61).