Original Article
Copyright ©2014 Baishideng Publishing Group Co.
World J Nephrol. Feb 6, 2014; 3(1): 6-15
Published online Feb 6, 2014. doi: 10.5527/wjn.v3.i1.6
Table 1 Clinical characteristics at renal biopsy n (%)
Totaln = 45
Age (yr) (range)58.3 ± 13.3 (28-84)
Sex (men)32 (71.1)
Diabetes type 238 (84.4)
Diabetes duration (yr) (range)9.6 ± 7.8 (0-35)
BMI (kg/m2) (range)29.3 ± 5.3 (27.8-47.8)
Obesity BMI > 30 kg/m218 (40.9)
Hypertension (yes)42 (93.3)
Smoker, active or past (yes)34 (75.6)
Dyslipidemic (yes)33 (73.3)
Ischemic heart disease (yes)7 (15.6)
CVA (yes)6 (13.3)
Peripheral arterial disease (yes)8 (17.8)
Any CVD16 (35.6)
Hematuria (yes)18 (41.9)
Serum albumin (g/dL) (range)3.4 ± 0.7 (2-5)
HbA1c% (range)6.5 ± 1.4 (4.1-9.3)
Total cholesterol (mg/dL)177.9 ± 58.7
Previous nephrology care (yr) (range)1.21 ± 2.4 (0-12)
RAASI treatment40 (88.9)
Statin treatment33 (73.3)
Antiplatelet drug treatment21 (46.7)
Table 2 Renal parameters and evolution n (%)
Previous renal data (n = 39)Renal biopsy (n = 45)End of follow-up (n = 24)
Time prior to biopsy (mo) (range)7.3 ± 5.2
(1.1-24.1)
Follow-up period (yr) (range)3.4 ± 2.9
(0.2-11.8)
Renal biopsy indicationRPKI8 (17.8)
Nephrotic proteinuria28 (62.2)
CKD9 (20)
Serum creatinine (mg/dL) (range)1.6 ± 0.82.3 ± 1.52.3 ± 1.8
(0.8-4.5)(0.8-6)(0.7-9.1)
eGFR (mL/min per 1.73 m2) (range)51.4 ± 20.939.1 ± 22.540.8 ± 25
(14.7-97.6)(8.1-101.2)(5.1-107.1)
1eGFR categoryG5 < 157 (15.6)24 (53.3)
G4 15-308 (17.8)6 (13.3)
G3b 30-4515 (33.3)5 (11.1)
G3a 45-607 (15.6)7 (15.6)
G2 60-907 (15.6)1 (2.2)
G1 > 901 (2.2)2 (4.4)
> 25% drop in eGFR prior to biopsy13 (33.3)
2Proteinuria (range)3.7 ± 3.44.5 ± 2.7
(0-12.9)(1-8.9)
3Proteinuria categoryA1 < 1503 (8.8)0
A2 150-5002 (5.9)4 (8.9)
A3 > 50029 (85.3)41 (91.1)
RRT2521 (46.7)
4CKD progression7 (15.6)
eGFR improvement > 25%4 (8.9)
Exitus5 (11.1)
Table 3 Clinical and histopathological findings according to glomerular classification of diabetic nephropathy n (%)
I-IIa-IIb (n = 18)III (n = 23)IV (n = 4)
Age (yr)59.9 ± 12.258.1 ± 14.152.3 ± 15.4
Years of diabetes9.1 ± 7.49.3 ± 6.315.1 ± 18
BMI (kg/m2)29 ± 4.930.1 ± 626.8 ± 2.4
Serum creatinine (mg/dL)2 ± 1.22.2 ± 1.44.4 ± 1.9
eGFR (mL/min per 1.73 m2)42.3 ± 21.940.4 ± 22.917.6 ± 12.3
HbA1c (%)6.7 ± 1.46.3 ± 1.36.7 ± 2
Proteinuria (g/d)3.1 ± 2.65.2 ± 44.7 ± 5.6
Serum albumin (g/dL)3.6 ± 0.73.3 ± 0.72.9 ± 0.7
Serum cholesterol (mg/dL)165.4 ± 71.6191.5 ± 34.6213 ± 0
Hypertension16 (88.9)22 (95.7)4 (100)
Diabetic retinopathy7 (38.9)9 (39.1)2 (50)
CVD7 (38.9)6 (26.1)3 (75)
RPKI06 (33.3)7 (30.4)
Patients with renal events9 (50)15 (65.2)4 (100)
RRT6 (33.3)11 (47.8)4 (100)
1Years from biopsy to renal event4.2 ± 1.23.4 ± 1.40.4 ± 0.4
% of global glomerulosclerosis18.1 ± 12.818.4 ± 15.177.3 ± 16.9
Interstitial fibrosis01 (5.6)00
and tubular atrophy110 (55.6)13 (56.5)0
25 (27.8)9 (39.1)1 (25)
32 (11.1)1 (4.3)3 (75)
Interstitial inflammation03 (16.7)00
114 (77.8)22 (95.7)4 (100)
21 (5.6)1 (4.3)0
Arteriolar hyalinosis01 (5.6)1 (4.3)1 (25)
13 (16.7)2 (8.7)0
214 (77.8)20 (87)3 (75)
Large vessel arteriosclerosis (yes)17 (94.4)19 (86.4)4 (100)
Table 4 Clinical differences at the time of biopsy between silent and non-silent diabetic nephropathy n (%)
Non-silent DN (n = 20)Silent DN (n = 25)P value
Age (yr)55.8 ± 12.260.3 ± 14.1
Sex (women)5 (25)8 (32)
BMI (kg/m2)30.9 ± 6.328 ± 4.1
T2 DM17 (85)21 (84)
Duration of diabetes (year)12.5 ± 5.37 ± 8.90.005
Follow-up period (year)3.4 ± 3.53.5 ± 2.7
Smoking, active or past16 (80)18 (72)
Retinopathy8 (40)10 (40)
CVD6 (30)10 (40)
HbA1c (%)7 ± 1.26.2 ± 1.50.03
Serum creatine at biopsy (mg/dL)1.8 ± 12.7 ± 1.60.03
eGFR at biopsy (mL/min per 1.73 m2)47 ± 22.532.9 ± 20.80.04
Proteinuria (g/d)3.5 ± 2.65 ± 4.3
Hematuria8 (44.4)10 (40)
RPKI3 (15)12 (48)0.03
CKD progression3 (15)10 (50)0.04
Renal events8 (40)20 (80)0.01
Histopathological class AP III-IV9 (45)18 (72)
Glomerular sclerosis percentage18.8 ± 14.327.2 ± 26.4
IFTA 0-112 (60)12 (48)
IFTA 27 (35)8 (32)
IFTA 31 (5)5 (20)
Severe arteriolar hyalinosis15 (75)22 (88)
Large vessel arteriosclerosis18 (94.7)22 (88)
RAASI treatment18 (90)22 (88)
Statins treatment15 (75)18 (72)
Table 5 Multivariate Cox proportional model of renal end point by the variable silent diabetic nephropathy
Variables in the equationHR95%CI
LowerUpper
CVD3.9431.6499.429
HbA1c%0.7240.5161.016
Silent DN2.1370.8195.573
Table 6 Univariate Cox proportional hazard analysis of renal end point, according to clinical variables
HR95%CI
P value
LowerUpper
Age (yr)1.000.971.03
Sex (men)1.190.502.85
Diabetes type (2/1)0.760.311.91
Diabetes duration (years)1.010.951.07
BMI < 30 (yes/no)2.941.097.690.03
Smoker (yes/no)0.920.342.50
Hypertension (yes/no)1.010.137.69
CVD (yes/no)4.561.9410.690.000
Retinopathy (yes/no)1.240.562.75
Baseline Serum creatinine (mg/dL)2.181.144.160.02
Baseline eGFR (mL/min per 1.73 m2)0.980.951.00
1Baseline proteinuria (g/g)1.120.981.27
eGFR drop > 25% before biopsy3.961.5410.180.004
Serum creatinine (mg/dL) at biopsy2.971.914.610.000
eGFR (mL/min per 1.73 m2) at biopsy0.940.920.970.000
RPKI2.741.216.240.02
2Proteinuria at biopsy (g/d)1.090.971.23
Hematuria1.650.723.82
Serum albumin (g/dL)0.750.411.35
HbA1c % (< 7/≥ 7)3.371.239.250.02
Total cholesterol (mg/dL)0.980.961.01
RAASI treatment (yes/no)0.590.221.59
Statin treatment0.660.271.62
Silent DN3.041.267.30.02
Table 7 Univariate Cox proportional hazard analysis of renal end point, according to histological variables
HR95%CIP value
Glomerular classIII/I-IIa-IIb1.20.52.9
IV/I-IIa-IIb5.61.619.70.007
IV/III4.61.415.10.01
% of global glomerulosclerosis1.01.01.00.01
IFTA(> 25 ≤ 25%)1.20.52.5
Arteriolar hyalinosisSevere/mild0.70.22.2
Large vessel arteriosclerosis (yes)1-2/01.20.44.1
Table 8 Multivariate Cox proportional hazard model of renal end point, adjusted for age and sex
HR95%CI for HR
P value
LowerUpper
CVD2.751.077.110.036
RPKI1.290.463.640.626
eGFR (10 mL/min per 1.73 m2)1.961.283.000.001
HbA1c% (< 7/≥ 7)2.880.988.440.054