Patient characteristics
A total of 1252 patients with chronic hepatitis C were followed up for a mean of 5.2 years. Baseline characteristics are shown in Table 1. Median age was 58 years, and 54.7% of the patients were male. Rates of hypertension and diabetes were 25.6% and 22.8%, respectively. At entry, CH was diagnosed in 1008 patients (80.5%); Com-LC, 123 patients (9.8%); and Decom-LC or HCC, 121 patients (9.7%).
Table 1. Baseline characteristics according to acute kidney injury
|
All patients (n=1252)
|
AKI (n=285)
|
No AKI (n=967)
|
Age, year a
|
58.0 (49.0-67.8)
|
65.0 (54.0-71.0)
|
57.0 (48.0-66.0)
|
Male sexa
|
685 (54.7%)
|
176 (61.8%)
|
509 (52.6%)
|
Hypertension a
|
321 (25.6%)
|
112 (39.3%)
|
209 (21.6%)
|
Diabetes a
|
286 (22.8%)
|
108 (37.9%)
|
178 (18.4%)
|
Alcohol > 40 g/day
|
244 (19.5%)
|
65 (22.8%)
|
179 (18.5%)
|
Diagnosis at entry a
|
|
|
|
CH
|
1008 (80.5%)
|
186 (18.5%)
|
822 (81.5%)
|
Com-LC
|
123 (9.8%)
|
34 (27.6%)
|
89 (72.4%)
|
Decom-LC or HCC
|
121 (9.7%)
|
65 (53.7%)
|
56 (46.3%)
|
Genotype
|
|
|
|
1
|
545 (43.5%)
|
108 (37.9%)
|
437 (45.2%)
|
2
|
603 (48.2%)
|
150 (52.6%)
|
453 (46.8%)
|
3
|
101 (8.1%)
|
26 (9.1%)
|
75 (7.8%)
|
Others
|
3 (0.2%)
|
1 (0.4%)
|
2 (0.2%)
|
Extrahepatic malignancy a
|
90 (7.2%)
|
35 (12.3%)
|
55 (5.7%)
|
SVR a
|
606 (48.4%)
|
49 (17.2%)
|
557 (57.7%)
|
HCV RNA > 600,000 IU/mL
|
202 (16.1%)
|
42 (14.7%)
|
160 (16.5%)
|
Albumin, g/dL a
|
4.1 (3.7-4.4)
|
3.7 (3.1-4.1)
|
4.2 (3.9-4.5)
|
Bilirubin, mg/dL a
|
0.69 (0.50-1.00)
|
0.77 (0.50-1.25)
|
0.67 (0.50-0.94)
|
Platelet, ×109/L a
|
183.0 (131.0-232.0)
|
151.0 (102.0-215.0)
|
190.0 (142.0-233.0)
|
PT-INR a
|
1.03 (0.99-1.11)
|
1.09 (1.02-1.22)
|
1.01 (0.98-1.09)
|
Child-Pugh B or C at entry a
|
112 (8.9%)
|
66 (58.9%)
|
46 (41.1%)
|
MELD score at entry a
|
7.0 (6.0-8.0)
|
8.0 (7.0-10.0)
|
7.0 (6.0-8.0)
|
Follow-up period (year)
|
4.2 (2.1-7.9)
|
4.6 (2.1-8.0)
|
4.1 (2.0-7.8)
|
Abbreviations: CH, chronic hepatitis; Com-LC, compensated cirrhosis; Decom-LC, decompensated cirrhosis; HCC, hepatocellular carcinoma; SVR, sustained virologic response; HCV, hepatitis C virus; PT-INR, prothrombin time-international normalized ratio; MELD score, Model For End-Stage Liver Disease score.
a p < 0.05 AKI vs No AKI using the Mann-Whitney U test and Chi-squared test.
Data are presented as median (interquartile range) for continuous data and percentages for categorical data.
Characteristics of subjects with AKI
Of the 1252 patients, 285 (22.8%) developed AKI. Patients with AKI were older than those without AKI. The proportions of male sex, hypertension, diabetes, and extrahepatic malignancy were higher in patients with AKI than in those without AKI. As liver disease progressed (from CH to Com-LC and Decom-LC or HCC), the frequency of AKI increased. Interestingly, the frequency of AKI was lower in patients with SVR than in those without SVR.
A total of 149 (52.3%), 80 (28.1%), and 56 (19.6%) of the 285 patients had initial AKI stage 1, stage 2, and stage 3, respectively. During hospitalization, 121 (42.5%) patients had a peak AKI stage 1, 76 (26.7%) patients had a peak AKI stage 2, and 88 (30.9%) patients had a peak AKI stage 3. A resolution of AKI occurred in 77.7%, 53.9%, and 31.8% of the patients with peak AKI stages 1, 2, and 3, respectively (Supp. Fig. 1). Dialysis-requiring AKI was observed in 26 (2.1%) patients.
The causes of AKI were: (1) pre-renal AKI in 127 (44.6%) patients, (2) HRS-AKI in 44 (15.4%) patients, (3) intrinsic-renal AKI in 108 (37.9%) patients, and (4) post-renal AKI in 6 (2.1%) patients.
Incidence of AKI
Over the follow-up of 6551.0 person-years, 285 of the 1252 patients developed new AKI, with an incidence rate of 4.35 per 100 person-years. The incidence rate of AKI would increase as liver disease progressed from CH to Com-LC and Decom-LC or HCC. Of the 1008 patients with CH at entry, 896 remained with CH, with an incidence rate of 3.17 per 100 person-years; 47 progressed to Com-LC, with an incidence rate of 0.53 per 100 person-years; and 65 progressed to Decom-LC or HCC, with an incidence rate of 6.74 per 100 person-years. Of the 123 patients with Com-LC at entry, 75 progressed to Com-LC, with an incidence rate of 1.90 per 100 person-years; and 48 progressed to Decom-LC or HCC, with an incidence rate of 9.13 per 100 person-years. The remaining 121 patients with Decom-LC or HCC at entry had an incidence rate of 17.28 per 100 person-years (Fig. 1). The overall incidence of AKI was higher in patients with Decom-LC or HCC (17.28 per 100 person-years, 95% CI = 13.09–21.49; P < 0.001) and with Com-LC (5.86 per 100 person-years, 95% CI = 3.88–7.81; P = 0.001) than in patients with CH (3.32 per 100 person-years, 95% CI = 2.87–3.83) (Fig. 2).
Risk factors for AKI
The associated risk factors for the development of AKI in univariate analysis were male sex (HR, 1.32; P = 0.022), age (HR, 1.03 per year; P < 0.001), hypertension (HR, 1.58; P < 0.001), diabetes mellitus (HR, 1.97; P < 0.001), platelet count (HR, 0.99 per 109/L; P < 0.001), Model For End-Stage Liver Disease (MELD) score at entry (HR, 1.15 per point; P < 0.001), Child-Pugh score at entry (HR, 1.72 per point; P < 0.001), SVR (HR, 0.21; P < 0.001), extrahepatic malignancy (HR, 1.73; P = 0.002), Com-LC at entry (HR, 1.83; P < 0.001), and Decom-LC or HCC at entry (HR, 5.49; P < 0.001). In the final multivariate analysis for the development of AKI, the risk factors included age (HR, 1.01 per year; P = 0.041), hypertension (HR, 1.49; P = 0.003), diabetes mellitus (HR, 1.31; P = 0.041), MELD score at entry (HR, 1.06 per point; P = 0.035), Child-Pugh score at entry (HR, 1.26 per point; P < 0.001), SVR (HR, 0.31; P < 0.001), extrahepatic malignancy (HR, 1.65; P = 0.009), and Decom-LC or HCC at entry (HR, 2.47; P < 0.001) (Table 2).
Table 2. Univariate and multivariate analyses showing significant predictive factors of acute kidney injury (n=1252)
Variable
|
Univariate analysis
|
Multivariate analysis
|
P
|
HR (95% CI)
|
P
|
HR (95% CI)
|
Male
|
0.022
|
1.32 (1.04-1.68)
|
0.057
|
1.28 (0.99-1.64)
|
Age per year
|
<0.001
|
1.03 (1.02-1.04)
|
0.041
|
1.01 (1.00-1.02)
|
Hypertension
|
<0.001
|
1.58 (1.24-2.00)
|
0.003
|
1.49 (1.14-1.94)
|
Diabetes
|
<0.001
|
1.97 (1.55-2.51)
|
0.041
|
1.31 (1.01-1.69)
|
Platelet per 109/L
|
<0.001
|
0.99 (0.99-1.00)
|
0.348
|
0.99 (0.99-1.01)
|
MELD score per point
|
<0.001
|
1.15 (1.13-1.18)
|
0.035
|
1.06 (1.00-1.11)
|
Child-Pugh score per point
|
<0.001
|
1.72 (1.59-1.86)
|
<0.001
|
1.26 (1.09-1.46)
|
SVR
|
<0.001
|
0.21 (0.16-0.29)
|
<0.001
|
0.31 (0.23-0.43)
|
Extrahepatic malignancy
|
0.002
|
1.73 (1.22-2.47)
|
0.009
|
1.65 (1.13-2.41)
|
CH (diagnosis at entry)
|
Reference
|
Reference
|
Com-LC
|
0.001
|
1.83 (1.26-2.65)
|
0.102
|
1.40 (0.94-2.09)
|
Decom-LC or HCC
|
<0.001
|
5.49 (4.10-7.35)
|
<0.001
|
2.47 (1.72-3.57)
|
Abbreviations: HR, hazard ratio; CI, confidence interval; MELD score, model for end-stage liver disease score; SVR, sustained virologic response; Com-LC, compensated cirrhosis; Decom-LC, decompensated cirrhosis; HCC, hepatocellular carcinoma.
Overall mortality
During the study period, 137 patients died (10.9%). The causes of mortality in patients with chronic hepatitis C were hepatic failure (n=57), HCC (n=25), extrahepatic malignancy (n=23), sepsis (n=23), and others (n=9). The cumulative survival rate at 14 years was higher for patients without AKI (94.2%) than for patients with AKI (26.3%, P < 0.001) (Fig. 3).
The factors associated with overall mortality in univariate analysis were male sex (HR, 1.63; P = 0.007), age (HR, 1.03 per year; P < 0.001), platelet count (HR, 0.99 per 109/L; P < 0.001), MELD score at entry (HR, 1.17 per point; P < 0.001), Child-Pugh score at entry (HR, 1.85 per point; P < 0.001), SVR (HR, 0.13; P < 0.001), extrahepatic malignancy (HR, 3.96; P < 0.001), Com-LC at entry (HR, 2.69; P < 0.001), Decom-LC or HCC at entry (HR, 12.13; P < 0.001), and AKI (HR, 13.60; P < 0.001). The factors associated with overall mortality in the final multivariate analysis included SVR (HR, 0.33; P < 0.001), extrahepatic malignancy (HR, 4.25; P < 0.001), Decom-LC or HCC at entry (HR, 5.63; P < 0.001), and AKI (HR, 6.66; P < 0.001) (Table 3).
Table 3. Univariate and multivariate analyses showing significant predictive factors of overall mortality (n=1252)
Variable
|
Univariate analysis
|
Multivariate analysis
|
P
|
HR (95% CI)
|
P
|
HR (95% CI)
|
Male
|
0.007
|
1.63 (1.14-2.34)
|
0.097
|
1.38 (0.94-2.00)
|
Age per year
|
<0.001
|
1.03 (1.02-1.05)
|
0.813
|
1.00 (0.99-1.02)
|
Platelet per 109/L
|
<0.001
|
0.99 (0.98-0.99)
|
0.590
|
0.99 (0.99-1.01)
|
MELD score per point
|
<0.001
|
1.17 (1.14-1.20)
|
0.126
|
1.06 (0.98-1.14)
|
Child-Pugh score per point
|
<0.001
|
1.85 (1.67-2.05)
|
0.436
|
1.08 (0.89-1.30)
|
SVR
|
<0.001
|
0.13 (0.08-0.22)
|
<0.001
|
0.33 (0.19-0.59)
|
Extrahepatic malignancy
|
<0.001
|
3.96 (2.35-6.69)
|
<0.001
|
4.25 (2.64-6.82)
|
CH (diagnosis at entry)
|
Reference
|
Reference
|
Com-LC
|
<0.001
|
2.69 (1.60-4.53)
|
0.108
|
1.60 (0.90-2.84)
|
Decom-LC or HCC
|
<0.001
|
12.13 (8.27-17.79)
|
<0.001
|
5.63 (3.39-9.37)
|
AKI
|
<0.001
|
13.60 (8.92-20.73)
|
<0.001
|
6.66 (4.26-10.41)
|
Abbreviations: HR, hazard ratio; CI, confidence interval; MELD score, model for end-stage liver disease score; SVR, sustained virologic response; Com-LC, compensated cirrhosis; Decom-LC, decompensated cirrhosis; HCC, hepatocellular carcinoma; AKI, acute kidney injury.