Body mass index and its association with clinical outcomes in acute liver failure

Table 2 Biochemical comparison between groups stratified by body mass index, n (%)

Baseline characteristics	Overall (n = 196)	Normal weight1 (n = 69)	Overweight1 (n = 62)	Obese1 (n = 65)	P value
Age (years), median (IQR)	44 (29-57)	36 (25-51)	45 (37-60)	48 (33-57)	0.006
Sex, female	124 (63.3)	49 (71)	36 (58.1)	39 (60)	0.36
Ethnicity	189 (96.4)	70 (100)	50 (88.7)	60 (92.3)	0.004
Non-Hispanic	189 (96.4)	70 (100)	50 (88.7)	60 (92.3)	0.004
Race
White	117 (59.7)	41(59.4)	39 (62.9)	37(59.9)	0.60
African American	59 (30.1)	24 (34.8)	13 (21.1)	22 (33.8)
Asian	7 (3.6)	2 (2.9)	2 (3.2)	3 (4.6)
Etiology of acute liver failure
Viral hepatitis	17 (8.7)	6 (8.7)	5 (8.1)	6 (9.2)	0.85
Acetaminophen toxicity	89 (45.4)	30 (49.3)	26 (45.2)	24 (41.5)
Drug-related hepatitis	21 (10.7)	8 (11.6)	5 (8.1)	8 (12.3)
Other	69 (35.2)	25 (36.2)	19 (31)	25 (38.5)
Charlson comorbidity score
0	32 (16.3)	12 (17.4)	9 (14.5)	11 (16.9)	0.94
1–3	122 (62.2)	47 (68.1)	37 (60.1)	39 (60)
> 3	42 (21.4)	14 (20.3)	13 (21)	15 (23.1)
Grade of hepatic encephalopathy
I-II	84 (42.9)	36 (52.2)	29 (46.8)	19 (29.2)	0.04
III-IV	112 (57.1)	34 (49.3)	33 (51.6)	46 (70.2)
Liver chemistries, median (IQR)
Alanine aminotransferases (IU/L)	1983 (353-4497)	2115 (753-4560)	2571 (809-5691)	703 (108-2920)	0.001
Aspartate aminotransferase (IU/L)	2436 (453-5383)	3100 (1007-6223)	3090 (675-7400)	989 (208-3321)	0.003
Alkaline phosphatase (IU/L)	134 (88-208)	134 (88-204)	148 (97-236)	122 (86-206)	0.45
Total bilirubin (mg/dL)	3.9 (1.6-10.8)	3.5 (1.7-9.9)	4.6 (2.2-8.6)	4.5 (1.2-16.6)	0.81
Albumin (g/dL)	3.1 (2.6-3.7)	3.4 (2.7-4)	3.2 (3-3.7)	2.7 (2.3-3.1)	< 0.001
Total protein (g/dL)	5.5 (4.6-6.2)	5.8 (4.6-6.5)	5.5 (4.9-6.2)	5 (4.2-5.7)	0.007
Ammonia (μmol/L)	64 (45.5-105)	56 (44-98)	62 (51-116)	67.5 (45-115)	0.41
Coagulation test, median (IQR)
prothrombin time	21.4 (16.1-34.3)	21.4 (15.1-38.1)	20.4 (16.3-27.5)	21.4 (16.8-31.5)	0.78
Activated partial thromboplastin time	34.8 (29.2-45.2)	34.5 (28.1-45.4)	34.1 (28.7-41.9)	35.3 (29.8-47.7)	0.76
International normalized ratio	2.2 (1.7-3.6)	2.20 (1.70-3.82)	2.4 (1.7-3.2)	2.1 (1.7-3.2)	0.90
Renal function tests, median (IQR)
Creatinine (mg/dL)	1.6 (0.9-3.1)	1.1 (0.6-1.8)	1.7 (1-3.1)	2.1 (1-3.31)	0.005
Blood urea nitrogen (mg/dL)	19 (9-39)	15 (8-39)	21 (11-34)	24 (10-43)	0.19
Estimated glomerular filtration rate (mL/minute/1.73 m2)	49 (21-60)	60 (38-60)	46 (22-60)	30 (18-60)	0.004
Fasting glucose (mg/dL)	108 (88-150)	109 (93-150)	105 (89-134)	108 (88-153)	0.71
Alpha-fetoprotein (ng/mL)	3.2 (2-8)	3.5 (0.9-9)	3.6 (2-7)	3.2 (2-7.3)	0.97
Lactate (mmol/L)	2.8 (1.9-5.4)	2.8 (1.6-5.3)	2.8 (2.2-8)	2.75 (1.8-4.8)	0.41
CT abdomen
Presence of fatty liver	32 (16.3)	10 (14.5)	12 (19.2)	10 (15.3)	0.84
CT/magnetic resonance imaging brain
Presence of cerebral/brain edema	84 (42.9)	24 (34.8)	25 (40.2)	35 (53.8)	0.11
Organ support
Vasopressors	21 (17.2)	8 (25)	4 (12.5)	9 (18.4)	0.02
Renal replacement therapy	13 (10.7)	3 (9.4)	5 (15.6)	5 (10.2)
Mechanical ventilation	32 (16.6)	10 (31.3)	5 (15.6)	5 (15.6)
Prognostic scores
KCC (Acetaminophen)	1 (0-2)	0.5 (0-1.5)	0 (0-2)	1 (0-2)	0.55
KCC (non-acetaminophen)	2 (1-2)	1 (1-2)	1 (1-2)	2 (1-2)	0.11
MELD	28 (21-36)	25 (21-34)	26 (22-36)	30 (23-38)	0.15
MELD-Na	29 (22-37)	27 (22-34)	28 (24-36)	31 (23-38)	0.22
Overall survival
< 21 days	69 (35.2)	13 (20)	24 (45.3)	27 (44.3)	0.004
Outcome
Spontaneous survival	94 (48)	39 (56.5)	26 (41.9)	29 (44.6)	0.004
Liver transplantation or death	102 (52)	29 (42)	34 (54.8)	39 (60)
Length of hospital stay (days), median (IQR)	7 (4-19)	8 (4-19)	5 (3-13)	9 (4-23)	0.08

¹Based on the World Health Organization criteria used for body mass index (BMI) categories: (1) Normal weight: BMI between 18.5 kg/m² and 24.9 kg/m²; (2) Overweight: BMI between 25.0 kg/m² and 29.9 kg/m²; and (3) Obese: BMI ≥ 30 kg/m².

CT: Computed tomography; IQR: Interquartile range; KCC: King's college criteria; MELD: Model for end-stage liver disease.