C-reactive protein-to-albumin ratio and six-month mortality in incident hemodialysis patients

Figures & data

Figure 1. Flow-chart of patient selection.

Table 1. Baseline characteristics and according to six-month mortality.

Characteristics	Total (n = 787)	Six-month mortality (n = 109)	Surival (n = 678)	p-value
Age (year)	68.3 ± 15.5	76.5 ± 11.4	67.3 ± 15.5	<0.001
Sex (Male) – n (%)	477 (60.6)	65 (59.6)	412 (60.7)	0.822
Race (Caucasian) – n (%)	661 (83.9)	99 (90.8)	562 (82.9)	0.036
Comorbidities – n (%)
Hypertension	701 (89.1)	93 (85.3)	608 (89.6)	0.176
Diabetes	359 (45.6)	48 (44.0)	311 (45.9)	0.721
Heart failure	282 (35.8)	57 (52.3)	225 (33.1)	<0.001
Ischemic cardiopathy	186 (23.6)	33 (30.3)	153 (22.6)	0.079
COPD	79 (10.0)	14 (12.8)	65 (9.6)	0.294
Cerebrovascular disease	126 (16.0)	22 (20.1)	104 (15.3)	0.200
Dementia	40 (5.1)	9 (8.3)	31 (4.6)	0.105
Cardiovascular disease	383 (48.7)	71 (65.1)	312 (46.0)	<0.001
Cancer	159 (20.2)	29 (26.6)	130 (19.2)	0.073
Peripheral artery disease	134 (17.0)	25 (22.9)	109 (16.1)	0.077
Chronic liver disease	33 (4.2)	4 (3.7)	29 (4.3)	0.767
Laboratory at HD start
Hemoglobin (g/dL)	9.7 ± 1.7	9.6 ± 1.6	9.7 ± 1.64	0.554
Serum Creatinine (mg/dL)	6.8 ± 3.1	5.7 ± 2.4	7.0 ± 3.1	<0.001
eGFR (ml/min/1.73m2)	9.3 ± 5.8	11.0 ± 9.0	9.1 ± 5.0	0.002
Albumin (g/dL)	3.4 ± 0.7	3.0 ± 0.7	3.5 ± 0.7	<0.001
PTH (pg/mL)	353.2 ± 188.6	229.4 ± 170.5	365.9 ± 215.8	0.006
Ferritin (ng/mL)	527.4 ± 394.4	544.8 ± 368.7	537.5 ± 359.6	0.972
C-RP (mg/dL)	4.4 ± 2.6	6.9 ± 3.0	4.0 ± 2.5	<0.001
Urea (mg/dL)	196.9 ± 80.8	179.3 ± 73.5	198.2 ± 73.8	0.014
CRP/Alb	1.6 ± 0.7	2.9 ± 1.9	1.4 ± 0.4	<0.001
Central venous catheter at HD start – n (%)	486 (61.8)	91 (83.5)	395 (58.3)	<0.001

Acronym: COPD: Chronic Obstructive Pulmonary Disease; PTH: Parathyroid Hormone; C-RP: C Reactive Protein; CRP/Alb: C-reactive protein to albumin ratio.

Table 2. Univariate and Multivariate analysis of factors predictive of six-month mortality.

Characteristic	Mortality
	Unadjusted HR (95% CI)	p-value	Adjusted HR (95% CI)	p-value
Age	1.06 (1.04–1.07)	<0.001	1.06 (1.03–1.09)	<0.001
Sex (Male)	0.95 (0.63–1.44)	0.822
Race (Caucasian)	2.043 (1.04–4.04)	0.040	0.66 (0.21–1.52)	0.258
Co-morbidities
Hypertension	0.67 (0.37–1.20)	0.179
Diabetes	0.93 (0.62–1.40)	0.721
Heart failure	2.21 (1.47–3.32)	<0.001
Peripheral artery disease	1.55 (0.95–2.54)	0.079
Cerebrovascular disease	1.40 (0.39–2.33)	0.202
Ischemic Cardiopathy	1.49 (0.94–2.33)	0.080
Dementia	1.88 (0.87-–4.06)	0.110
CVD	2.20 (1.44–3.34)	<0.001	2.21 (1.21–4.04)	0.010
COPD	1.39 (0.75–2.58)	0.295
CLD	0.85 (0.29–2.47)	0.767
Cancer	1.53 (0.96–2.44)	0.074
Central venous catheter at HD start	3.62 (2.136–6.142)	<0.001	3.09 (1.58–6.03)	0.001
Laboratory findings
Hemoglobin	0.96 (0.85–1.09)	0.553
Serum Creatinine	0.82 (0.74–0.90)	<0.001
Urea	1.00 (0.993–0.999)	0.013	1.00 (0.996–1.004)	0.895
eGFR	1.05 (1.01–1.08)	0.004	1.03 (0.98–2.00)	0.269
Albumin	0.31 (0.22–0.43)	<0.001
PTH	1.00 (0.996–0.999)	0.002	1.00 (0.997–1.000)	0.014
Ferritin	1.00 (1.00–1.00)	0.97
C-RP	1.05 (1.03–1.08)	<0.001
CAR	1.16 (1.09–1.24)	<0.001	1.13 (1.02–1.24)	0.015
CAR ≥ 0.5	5.36 (3.21–8.96)	<0.001

Acronym: CVD: Cardiovascular Disease; COPD: Chronic Obstructive Pulmonary Disease; CLD: Chronic Liver Disease; PTH: Parathyroid Hormone; C-RP: C Reactive Protein; CAR: C-reactive protein to albumin ratio.

Figure 2. Receiver operating curve of C-reactive protein, albumin, and C-reactive protein-to-albumin ratio to predict six-month mortality.

Table 3. Characteristics according to CAR ≥ 0.5.

Characteristics	CAR < 0.5 (n = 427)	CAR ≥ 0.5 (n = 360)	p-value
Age (year)	65.0 ± 16.5	72.1 ± 13.6	<0.001
Sex (Male) – n (%)	259 (60.7)	219 (60.8)	0.877
Race (Caucasian) – n (%)	342 (80.1)	318 (88.3)	0.005
Comorbidities – n (%)
Hypertension	378 (88.5)	327 (90.8)	0.556
Diabetes	202 (47.3)	151 (41.9)	0.097
Heart failure	124 (29.0)	152 (0.42)	<0.001
Ischemic cardiopathy	86 (20.1)	93 (25.8)	0.070
COPD	29 (6.8)	54 (15.0)	<0.001
Cerebrovascular disease	59 (13.8)	64 (17.8)	0.146
Dementia	18 (4.2)	23 (6.4)	0.187
Cardiovascular disease	172 (40.3)	201 (55.8)	<0.001
Cancer	65 (15.2)	93 (25.8)	<0.001
Peripheral artery disease	58 (13.6)	73 (20.3)	0.015
Chronic liver disease	14 (3.3)	18 (5.0)	0.233
Laboratory at HD start
Hemoglobin (g/dL)	10.0 ± 1.7	9.4 ± 1.5	<0.001
Serum Creatinine (mg/dL)	6.9 ± 2.7	6.9 ± 3.7	0.926
eGFR (ml/min/1.73m2)	9.0 ± 4.3	9.8 ± 7.2	0.066
Albumin (g/dL)	3.7 ± 0.6	3.1 ± 0.6	<0.001
PTH (pg/mL)	376.4 ± 100.1	312.3 ± 143.2	0.036
Ferritin (ng/mL)	371.6 ± 199.8	745.2 ± 563.1	0.007
C-RP (mg/dL)	0.6 ± 0.6	8.9 ± 1.8	<0.001
Urea (mg/dL)	200.5 ± 79.0	193.4 ± 85.9	0.231
Central venous catheter at HD start – n (%)	231 (54.1)	258 (71.7)	<0.001
Six-month mortality	20 (4.7)	83 (23.1)	<0.001

Figure 3. Cumulative survival of patients who started maintenance HD according to CAR ≥ 0.5.

Data availability statement

Please contact author for data requests.