Obesity, acute kidney injury and mortality in patients with sepsis: a cohort analysis

Figures & data

Table 1. Kidney disease improving global outcomes (KDIGO) classification.

Stage	SCr/GFR	UO
1	↑ SCr ≥26.5 μmol/l (≥0.3 mg/dl) or ↑ SCr ≥150–200% (1.5–1.9X)	<0.5 ml/kg/h (>6 h)
2	↑ SCr >200–300% (>2–2.9X)	<0.5 ml/kg/h (>12 h)
3	↑ SCr >300% (≥3X) or ↑ SCr to ≥353.6 μmol/l (≥4 mg/dl) or initiation of renal replacement therapy	<0.3 ml/kg/h (24 h) or anuria (12 h)

Table 2. Patients’ baseline characteristics.

Characteristics	Value
Age (year)	64.1 ± 16.4
Gender (Male) – n (%)	264 (57.9)
Race (Caucasian) – n (%)	433 (94.7)
Obese (IMC> =30) – n (%)	125 (27.4)
Underweight (IMC <18.5) – n (%)	9 (2)
Hypertension – n (%)	212 (46.5)
Comorbidities – n (%)
Diabetes	103 (22.6)
CVD	125 (27.4)
COPD	38 (8.3)
Cirrhosis	18 (3.9)
Neoplasia	109 (23.9)
Medical admission – n (%)	253 (55.5)
Infection source – n (%)
Abdominal	187 (41.0)
Respiratory	138 (30.3)
Kidney	57 (12.5)
Skin	34 (7.5)
Others	26 (5.7)
Unknown	14 (3.1)
SAPS II	49.4 ± 17.3
Baseline SCr (mg/dl)	1.3 ± 0.6
Admission SCr (mg/dl)	2.3 ± 1.5
Hemoglobin (g/dl)	10.4 ± 2.0
Serum albumin (g/dl)	1.9 ± 0.6
Mechanical ventilation – n (%)	350 (76.8)
Vasopressors – n (%)	316 (369.3)
Fluid balance (l)	4.5 ± 5.7
RRT – n (%)	108 (23.7)
LOS in hospital (days)	37.1 ± 39.4
LOS in ICU (days)	10.0 ± 10.0
ICU mortality – n (%)	108 (23.7)
In-hospital mortality – n (%)	153 (33.6)

Table 3. Demographic and clinical characteristics of patients according to the development of acute kidney injury defined by the KDIGO classification.

	KDIGO
Characteristics	No AKI (n = 57)	AKI (n = 399)	p Value
Age (year)	64.1 ± 17.4	64.1 ± 16.0	.994
Gender (Male) – n (%)	35 (61.4)	229 (57.4)	.566
Race (Caucasian) – n (%)	54 (94.7)	379 (95.0)	.936
Obesity – n (%)	9 (15.7)	116 (29.1)	.035
Underweight – n (%)	3 (5.3)	6 (1.5)	.242
Co-morbidities – n (%)
Hypertension	30 (50.2)	182 (45.6)	.320
Diabetes	15 (26.3)	88 (22.1)	.472
CVD	14 (24.6)	111 (27.8)	.606
COPD	5 (8.8)	33 (8.3)	.898
Cirrhosis	1 (1.8)	17 (4.3)	.363
Neoplasia	13 (22.8)	96 (24.1)	.836
Medical admission – n (%)	31 (54.4)	222 (55.6)	.859
Infection source – n (%)
Abdominal	19 (33.3)	168 (42.1)	.208
Respiratory	16 (28.3)	122 (30.6)	.700
Kidney	14 (24.6)	43 (10.8)	.003
Skin	2 (3.5)	32 (8.0)	.225
Others	6 (10.5)	20 (5.0)	.093
Unknown	0 (0.0)	14 (3.5)	.151
SAPS II	42.8 ± 15.6	50.4 ± 17.3	.002
Baseline SCr (mg/dl)	1.4 ± 0.7	1.3 ± 0.6	.185
Hemoglobin (g/dl)	10.0 ± 1.7	10.5 ± 2.0	.078
Serum albumin (g/dl)	2.1 ± 0.6	1.9 ± 0.6	.003
Mechanical ventilation – n (%)	41 (71.9)	309 (77.4)	.357
Vasopressors – n (%)	26 (45.6)	290 (72.7)	<.001
RRT – n (%)		108 (27.1)
LOS in hospital (days)	39.5 ± 44.8	36.7 ± 38.6	.625
LOS in ICU (days)	9.8 ± 10.3	10.0 ± 10.0	.881
ICU mortality – n (%)	7 (12.3)	101 (25.3)	.030
Hospital mortality – n (%)	10 (17.5)	143 (87.5)	.006

Table 4. Demographic and clinical characteristics of patients according to obesity.

Characteristics	Non-obese patients (n = 331)	Obese patients (n = 125)	p Value
Age (year)	63.9 ± 16.5	64.4 ± 14.8	.779
Gender (Male) – n (%)	203 (61.3)	61 (48.8)	.016
Race (Caucasian) – n (%)	309 (93.4)	124 (99.2)	.011
AKI – n (%)	283 (85.5)	116 (92.8)	.035
Comorbidities – n (%)
Hypertension	141 (43)	71 (56.8)	.007
Diabetes	63 (19)	40 (32)	.003
CVD	98 (29.6)	27 (21.6)	.087
COPD	32 (9.7)	6 (4.8)	.093
Cirrhosis	12 (3.6)	6 (4.8)	.566
Neoplasia	93 (28.1)	16 (12.8)	.001
Medical admission – n (%)	188 (56.8)	65 (52)	.398
Infection source – n (%)
Abdominal	132 (56.8)	55 (44)	.425
Respiratory	111 (33.5)	27 (21.6)	.013
Kidney	37 (11.2)	20 (16)	.165
Skin	25 (7.6)	9 (7.2)	.898
Others	18 (5.4)	8 (6.4)	.693
Unknown	8 (2.4)	6 (4.8)	.188
SAPS II	48.4 ± 17.3	52.1 ± 17.1	.043
Baseline SCr (mg/dl)	1.3 ± 0.58	1.3 ± 0.67	.524
Hemoglobin (g/dl)	10.2 ± 2	10.8 ± 2	.005
Serum albumin (g/dl)	1.9 ± 0.6	1.9 ± 0.5	.896
Mechanical ventilation – n (%)	256 (77.3)	94 (75.2)	.629
Vasopressors – n (%)	228 (68.9)	88 (70.4)	.754
RRT – n (%)	64 (19.3)	44 (35.2)	<.001
LOS in hospital (days)	38.8 ± 39.3	32.6 ± 39.3	.136
LOS in ICU (days)	10 ± 9.8	10 ± 10.7	.91
ICU mortality – n (%)	81 (24.5)	27 (21.6)	.520
Hospital mortality – n (%)	113 (34.1)	40 (32)	.666

Table 6. Univariate and multivariate analysis of factors predictive of outcomes.

	AKI				Mortality
	Unadjusted HR (95% CI)	p Value	Adjusted HR (95% CI)	p Value	Unadjusted HR (95% CI)	p Value	Adjusted HR (95% CI)	p Value
Demographics
Age	1.00 (0.98–1.02)	.094			1.02 (1.08–1.04)	.001	1.02 (1.00–1.03)	.026
Male	0.85 (0.48–1.50)	.567			1.20 (0.81–1.18)	.375
Caucasian	1.053 (0.30–3.66)	.936			0.64 (0.27–1.50)	.304
Obesity	2.19 (1.04–4.60)	.039	2.31 (1.07–5.02)	.034	0.91 (0.59–1.41)	.666
Underweight	−1.2 (−0.29–0.07)	.243			0.38 (−0.2–0.31)	.704
Comorbidities
Hypertension	0.76 (0.43–1.32)	.321			0.88 (0.60–1.31)	.534
Diabetes	0.79 (0.42–1.50)	.473			0.97 (0.61–1.54)	.894
CVD	1.18 (0.62–2.25)	.606			0.91 (0.59–1.41)	.666
COPD	0.94 (0.35–2.51)	.898			1.68 (0.86–3.29)	.131
Cirrhosis	2.492 (0.33–19.09)	.379			1.27 (0.48–3.35)	.625
Neoplasia	1.04 (0.75–1.44)	.836			1.42 (1.14–1.77)	.002	1.2 (0.93–1.55)	.166
Medical admission	1.05 (0.60–1.84)	.859			1.00 (0.68–1.49)	.982
Infection source
Abdominal	1.45 (0.81–2.61)	.210			1.18 (0.80–1.76)	.391
Respiratory	1.13 (0.61–2.09)	.700			1.08 (0.71–1.65)	.714
Kidney	0.37 (0.19–0.73)	.004	0.39 (0.19–0.82)	.013	0.38 (0.19–0.78)	.008	0.40 (0.17–0.93)	.034
Skin	2.40 (0.56–10.29)	.239			1.25 (0.61–2.56)	.548
Others	0.45 (0.17–1.17	.101			1.05 (0.46–2.42)	.906
SAPS II	1.03 (1.01–1.05)	.002	1.01 (0.99–1.03)	.187	1.05 (1.04–1.06)	.000	1.04 (1.02–1.06)	.000
Baseline SCr	0.76 (0.50–1.15)	.188			0.89 (0.64–1.23)	.469
Hemoglobin	1.14 (0.99–1.32)	.078			0.80 (0.72–0.89)	.000	0.79 (0.70–0.89)	.000
Serum albumin	0.51 (0.33–0.81)	.004	0.67 (0.41–1.09)	.105	0.56 (0.39–0.81)	.002	0.91 (0.60–1.39)	.661
Mechanical ventilation	1.34 (0.72–2.50)	.358			3.07 (1.77–5.33)	.000	1.78 (0.94–3.40)	.079
Vasopressors	3.17 (1.80–5.59)	.000	2.63 (1.37–5.04)	.004	2.34 (1.47–3.71)	.000	1.1 (0.62–1.94)	.749
AKI					2.63 (1.29–5.35)	.008	2.44 (1.07–5.57)	.035

Table 5. Demographic and clinical characteristics of patients according to in-hospital mortality.

Characteristics	No in-hospital mortality 303	In-hospital mortality 153	p Value
Age (year)	62.32 ± 15.9	67.54 ± 15.8	.001
Gender (Male) – n (%)	171 (56.4)	93 (60.8)	.374
Race (Caucasian) – n (%)	290 (95.7)	143 (93.5)	.301
Obesity – n (%)	85 (28.1)	40 (26.1)	.739
Comorbidities – n (%)
Hypertension	144 (47.5)	68 (44.4)	.533
Diabetes	69 (22.8)	34 (22.2)	.894
CVD	85 (28.1)	40 (26.1)	.666
COPD	21 (6.9)	17 (11.1)	.127
Cirrhosis	11 (3.6)	7 (4.6)	.625
Neoplasia	59 (19.5)	50 (32.7)	.002
Medical admission – n (%)	168 (55.4)	85 (55.6)	.982
Infection source – n (%)
Abdominal	120 (39.6)	67 (43.8)	.391
Respiratory	90 (29.7)	48 (31.4)	.714
Kidney	47 (15.5)	10 (6.5)	.006
Skin	21 (5.9)	13 (8.5)	.574
Others	17 (5.6)	9 (6)	1.000
Unknown	8 (2.6)	6 (3.9)	.566
SAPS II	45.13 ± 15.4	57.94 ± 16.7	<.001
Baseline SCr (mg/dl)	1.3 ± 0.64	1.25 ± 0.54	.47
Hemoglobin (g/dl)	10.7 ± 2	9.9 ± 2	<.001
Serum albumin (g/dl)	1.98 ± 0.57	1.79 ± 0.6	.002
Mechanical ventilation – n (%)	215 (71)	135 (88.2)	<.001
Vasopressors – n (%)	193 (63.7)	123 (80.4)	<.001
RRT – n (%)	43 (14.2)	65 (42.5)	<.001
AKI – n (%)	256 (84.5)	143 (93.5)	.006
LOS in hospital (days)	37.97 ± 38	35.3 ± 41.9	.494
LOS in ICU (days)	9.6 ± 9.6	10.7 ± 10.9	.261