Comparison of different preoperative objective nutritional indices for evaluating 30-d mortality and complications after liver transplantation

Table 1 Patient characteristics

Characteristics	Total (n = 162)
Age, yr	53.0 (45.0-57.0)
Male/female	133/29
BMI	23.0 (21.1-25.1)
Hypertension, yes/no	18/144
Diabetes, yes/no	22/140
HBsAg-positive, yes/no	118/44
Operation time (min)	535.0 (440.0-600.0)
Anhepatic phase (min)	58.0 (47.3-66.0)
Donor age, yr	45.0 (36.0-55.0)
Total ischemia time (min)	305.0 (250.5-372.6)
Graft weight (kg)	1.4 (1.3-1.7)
Split LT/whole LT	20/142
Blood loss (mL)	1750.0 (975.0-3925.0)
Intraoperative urine volume (mL)	2650.0 (1600.0-4000.0)
Prealbumin (mg/L)	95.0 (89.7-101.8)
NRI	95.1 (89.7-101.8)
CONUT	6.0 (4.0-6.0)
PNI	42.6 (38.7-46.4)
ALB (g/L)	37.2 (33.6-40.7)
Lymphocyte count (× 109 /mL)	0.9 (0.6-1.5)
Alanine aminotransferase (U/L)	31.0 (19.0-53.3)
Aspartate aminotransferase (U/L)	46.5 (31.0-90.1)
Total bilirubin (μmol/L)	30.8 (15.2-107.2)
Creatinine (umol/L)	71.0 (58.8-85.3)
Preoperative MELD score	12.0 (8.0-22.0)
Total cholesterol (mmol/L)	3.4 (2.2-4.6)
Prothrombin time (s)	16.4 (14.1-20.8)
Platelet (× 109/mL)	67.0 (44.0-150.3)
Death, yes/no	14/148

The data are presented as the median (25^th-75^th percentile) or n. BMI: Body mass index; HBsAg: Hepatitis B surface antigen; CONUT: Control nutritional status; PNI: Prognostic nutritional index; NRI: Nutritional risk index; MELD: Model for end-stage liver disease; LT: Liver transplantation; ALB: Albumin.

Table 2 Univariate and multivariate analyses of predictors of 30-d mortality

Variables	Univariable OR (95%CI)	P value	Multivariable OR (95%CI)	P value
Age	1.054 (0.996-1.114)	0.066
Male	0.781 (0.204-2.999)	0.719
BMI	0.772 (0.616-0.967)	0.024	0.720 (0.336-1.542)	0.397
Hypertension	2.418 (0.606-9.648)	0.211
Diabetes	1.067 (0.222-5.124)	0.936
HBsAg-positive	0.644 (0.203-2.040)	0.454
Operation time	1.005 (1.002-1.009)	0.008	1.004 (0.996-1.011)	0.367
Anhepatic phase	1.039 (1.010-1.069)	0.091
Donor age	1.004 (0.995-1.020)	0.475
Total ischemia time	1.000 (0.996-1.005)	0.984
Graft weight	1.002 (0.999-1.004)	0.253
Split LT	0.938 (0.195-4.503)	0.936
Blood loss	1.003 (1.001-1.004)	< 0.001	1.001 (1.000-1.002)	0.034
Intraoperative urine volume	0.999 (0.999-1.000)	0.004	0.999 (0.998-1.000)	0.295
Prealbumin	0.988 (0.977-0.999)	0.040	0.975 (0.929-1.023)	0.310
NRI	0.258 (0.082-0.811)	0.020	0.665 (0.446-0.991)	0.045
CONUT	5.756 (1.695-19.540)	0.005	2.088 (1.016-4.291)	0.045
PNI	0.160 (0.051-0.500)	0.002	0.920 (0.848-0.997)	0.042
ALB	0.798 (0.706-0.903)	< 0.001
Lymphocyte count	0.723 (0.301-1.736)	0.468
Alanine aminotransferase	1.002 (1.000-1.004)	0.045	1.002 (0.993-1.011)	0.639
Aspartate aminotransferase	1.001 (1.000-1.002)	0.231
Total bilirubin	1.007 (1.003-1.012)	0.001	1.004 (0.988-1.021)	0.606
Creatinine	1.003 (0.999-1.007)	0.173
Preoperative MELD score	1.099 (1.042-1.158)	< 0.001	1.003 (0.517-1.946)	0.994
Total cholesterol	0.694 (0.452-1.065)	0.095
Prothrombin time	1.114 (1.042-1.191)	0.001	0.773 (0.309-1.931)	0.773
Platelet	1.002 (0.997-1.007)	0.432

BMI: Body mass index; HBsAg: Hepatitis B surface antigen; CONUT: Control nutritional status; PNI: Prognostic nutritional index; NRI: Nutritional risk index; MELD: Model for end-stage liver disease; OR: Odds ratio; LT: Liver transplantation; ALB: Albumin.

Table 3 Factors that predict a Clavien-Dindo grade ≥ 3

Variables	Univariable OR (95%CI)	P value	Multivariable OR (95%CI)	P value
Age	0.997 (0.968-1.028)	0.852
Male	0.518 (0.222-1.212)	0.129
BMI	0.918 (0.819-1.028)	0.138
Hypertension	1.073 (0.359-3.210)	0.900
Diabetes	1.044 (0.380-2.868)	0.934
HBsAg-positive	0.813 (0.377-1.754)	0.598
Operation time	1.004 (1.001-1.006)	0.004	1.003 (1.000-1.006)	0.078
Anhepatic phase	1.019 (0.999-1.041)	0.069
Donor age	1.010 (0.998-1.022)	0.113
Total ischemia time	1.001 (0.999-1.003)	0.350
Graft Weight	1.065 (0.978-1.158)	0.146
Split LT	1.515 (0.477-4.812)	0.582
Blood loss	1.004 (1.002-1.005)	< 0.001	1.003 (1.001-1.005)	0.004
Intraoperative urine volume	0.998 (0.996-1.000)	0.042	0.999 (0.995-1.002)	0.382
Prealbumin	0.995 (0.990-1.001)	0.089
NRI	0.945 (0.904-0.988)	0.013	0.942 (0.901-0.986)	0.011
CONUT	1.037 (0.984-1.094)	0.169
PNI	0.856 (0.738-0.994)	0.041	0.994 (0.989-0.999)	0.013
ALB	0.910 (0.848-0.977)	0.009
Lymphocyte count	1.113 (0.814-1.522)	0.502
Alanine aminotransferase	1.002 (0.999-1.004)	0.138
Aspartate aminotransferase	1.000 (1.000-1.001)	0.314
Total bilirubin	1.004 (1.002-1.006)	< 0.001	1.005 (0.999-1.010)	0.079
Creatinine	1.001 (0.997-1.004)	0.685
Preoperative MELD score	1.057 (1.020-1.097)	0.003	0.894 (0.763-1.047)	0.165
Total cholesterol	0.886 (0.721-1.088)	0.886
Prothrombin time	1.075 (1.019-1.134)	0.009	1.075 (0.923-1.252)	0.354
Platelet	1.001 (0.998-1.005)	0.422

BMI: Body mass index; HBsAg: Hepatitis B surface antigen; CONUT: Control nutritional status; PNI: Prognostic nutritional index; NRI: Nutritional risk index; MELD: Model for end-stage liver disease; LT: Liver transplantation; ALB: Albumin.

Table 4 Values of different preoperative objective nutritional indicators for predicting 30-d mortality

	AUC	Sensitivity	Specificity	95%CI	Optimal threshold value	P value
CONUT	0.724	0.58	0.80	0.646-0.794	6	0.015
NRI	0.861	0.70	0.83	0.765-0.958	88	< 0.001
PNI	0.781	0.64	0.80	0.682-0.829	38	0.001
Prealbumin	0.666	0.76	0.60	0.589-0.754	79	0.003

AUC: Area under the curve; CONUT: Control nutritional status; PNI: Prognostic nutritional index; NRI: Nutritional risk index.

Table 5 Comparisons of the area under the curve of various nutritional indicators for predicting severe complications and 30-d mortality

ROC	Severe complications		30-d mortality
	Z value	P value	Z value	P value
CONUT vs NRI	1.851	0.064	1.550	0.121
CONUT vs PNI	1.945	0.051	0.832	0.405
CONUT vs Prealbumin	0.818	0.413	0.490	0.623
NRI vs PNI	0.749	0.454	1.061	0.288
NRI vs Prealbumin	0.582	0.560	2.337	0.019
PNI vs Prealbumin	0.176	0.860	1.062	0.288

CONUT: Control nutritional status; PNI: Prognostic nutritional index; NRI: Nutritional risk index; ROC: Receiver operating characteristic.

Table 6 Values of different preoperative objective nutritional indicators for predicting severe complications

	AUC	Sensitivity	Specificity	95%CI	Optimal threshold value	P value
CONUT	0.547	0.17	0.96	0.463-0.627	8	0.410
NRI	0.643	0.50	0.72	0.555-0.712	91	0.011
PNI	0.615	0.23	0.94	0.522-0.678	34	0.047
Prealbumin	0.603	0.63	0.61	0.533-0.695	82	0.027

AUC: Area under the curve; CONUT: Control nutritional status; PNI: Prognostic nutritional index; NRI: Nutritional risk index.

Table 7 Comparation of the clinical characteristics among different nutritional risk index groups

Characteristics	Low NRI (n = 30)	High NRI (n = 132)	P value
Age, yr	53.0 (44.0-56.0)	52.5 (46.0-58.0)	0.587
Male/female	26/4	107/25	0.602
BMI	21.5 (19.0-23.4)	23.3 (21.4-25.4)	0.012
Hypertension, yes/no	4/26	14/118	0.747
Diabetes, yes/no	5/25	17/115	0.563
HBsAg-positive, yes/no	21/9	97/35	0.820
Operation time (min)	540.0 (452.5-650.3)	520.0 (440.0-600.0)	0.344
Anhepatic phase (min)	58.0 (48.5-65.0)	57.0 (47.0-66.0)	0.719
Donor age, yr	46.5 (39.0-59.6)	43.0 (35.1-53.0)	0.651
Total ischemia time (min)	329.5 (271.4-395.0)	286.5(234.7-356.2)	0.323
Graft weight (kg)	1.3 (1.2-1.6)	1.5 (1.4-1.8)	0.409
Split LT/whole LT	2/28	18/114	0.373
Blood loss (mL)	2000.0 (850.0-5000.0)	1650.0 (925.0-3500.0)	0.305
Intraoperative urine volume (mL)	2600.0 (1650.0-3225.0)	2800.0 (1600.0-4000.0)	0.636
Prealbumin (mg/L)	56.0 (33.0-82.0)	109.5 (54.5-172.0)	< 0.001
NRI	83.8 (81.2-85.5)	98.8 (93.1-103.5)	< 0.001
CONUT	8.0 (7.0-9.8)	5.0 (4.0-6.0)	< 0.001
PNI	34.9 (31.7-38.9)	43.7 (40.3-47.6)	< 0.001
ALB (g/L)	29.8 (27.4-31.2)	39.0 (35.6-41.4)	< 0.001
Lymphocyte count (× 109/mL)	0.9 (0.5-1.6)	0.9 (0.6-1.4)	0.978
Alanine aminotransferase (U/L)	41.5 (19.8-62.5)	29.5 (19.0-45.8)	0.154
Aspartate aminotransferase (U/L)	64.5 (38.8-126.3)	42.0 (29.3-77.5)	0.008
Total bilirubin (μmol/L)	53.0 (20.4-250.4)	28.4 (14.8-87.8)	0.047
Creatinine (umol/L)	73.0 (57.0-86.3)	70.0 (59.3-85.0)	0.848
Preoperative MELD score	15.0 (11.8-24.8)	11.0 (7.3-20.8)	0.028
Total cholesterol (mmol/L)	2.7 (2.0-4.4)	3.6 (2.3-4.6)	0.050
Prothrombin time (s)	17.8 (16.2-23.4)	15.9 (14.1-20.0)	0.037
Platelet (× 109/mL)	63.5 (32.5-143.0)	67.5 (47.0-152.8)	0.386

BMI: Body mass index; HBsAg: Hepatitis B surface antigen; CONUT: Control nutritional status; PNI: Prognostic nutritional index; NRI: Nutritional risk index; MELD: Model for end-stage liver disease; LT: Liver transplantation; ALB: Albumin.

Table 8 Comparison of postoperative complications between the low nutritional risk index group and the high nutritional risk index group, n (%)

	Total (n = 162)	Low NRI (n = 30)	High NRI (n = 132)	P value
Pneumonia	37 (22.8)	8 (26.7)	29 (22.0)	0.631
Intra-abdominal infection	20 (12.3)	4 (13.3)	16 (12.1)	0.767
Intra-abdominal bleeding	14 (8.6)	6 (20.0)	8 (6.1)	0.025
Graft rejection	6 (3.7)	2 (6.7)	4 (3.0)	0.308
Primary graft nonfunction	5 (3.1)	3 (10.0)	2 (1.5)	0.044
Early graft dysfunction	4 (2.5)	0 (0.0)	4 (3.0)	1.000
Mortality	14 (8.6)	6 (20.0)	8 (6.1)	0.025
Clavien-Dindo grade ≥ 3	43 (26.5)	12 (40)	31 (23.5)	0.071
Biliary leakage	3 (1.9)	1 (3.3)	2 (1.5)	0.461
Biliary stricture	4 (2.5)	2 (6.7)	2 (1.5)	0.156

NRI: Nutritional risk index.