Influence of Red Blood Cell Distribution Width on All-Cause Death in Critical Diabetic Patients with Acute Kidney Injury

Figures & data

Table 1 Comparison of Data Between the Death Group and the Survival Group in Critical Diabetic Patients with AKI

Parameters	Death Group	Survival Group	t/χ^2	P value
Basic characteristics
Male/female	560/370	2580/1690	0.014	0.907
Age (year)	73.56±10.80	67.07±13.86	4.974	0.001
ICU LOS (day)	8.90±5.56	9.58±9.20	−0.931	0.353
BMI (kg/m^2)	30.14±6.77	31.79±8.28	−1.499	0.135
Vital signs
Temperature (°C)	37.56±1.13	37.61±0.97	−0.466	0.641
Heart rate (beats/min)	109.52±21.06	107.55±20.73	0.826	0.409
Respiratory (beats/min)	29.79±6.28	28.74±6.70	1.378	0.169
MAP (mmHg)	46.05±13.51	51.61±14.50	−3.392	0.001
CVP (mmHg)	6.89±5.52	6.12±4.04	1.274	0.205
AKI stage			322.565	<0.001
Stage 1	110 (11.8)	1328 (31.1)
Stage 2	220 (23.7)	1512 (35.4)
Stage 3	600 (64.5)	1430 (33.5)
Scoring system
SOFA	9.27±3.94	7.49±3.47	4.358	<0.001
SAPSII	57.18±14.10	46.84±14.19	6.374	<0.001
OASIS	43.19±7.70	37.84±8.86	5.399	<0.001
Selected laboratory test
WBC (×10^9/L)	11.88±6.97	10.77±6.08	1.425	0.157
RBC (× 10^12/L)	3.14±0.70	3.35±0.69	−2.557	0.011
Hb (g/dL)	8.62±1.85	8.86±2.11	−1.531	0.126
Platelet (× 10^9/L)	188.51±130.70	175.53±94.25	0.907	0.366
RDW (%)	16.10±2.14	15.16±1.88	3.897	<0.001
BUN (mg/dL)	44.72±28.71	31.67±21.90	4.130	<0.001
Scr (mg/dL)	2.08±1.39	1.66±1.37	2.676	0.008
RBG (mg/dL)	125.46±49.26	115.35±46.27	1.887	0.060
Lactic acid (mmol/L)	2.06±1.31	1.59±0.96	3.154	0.002
Complications
Sepsis[n (%)]	740 (79.6)	2430 (56.9)	164.778	<0.001
CHF[n (%)]	365 (39.2)	1631 (38.2)	1.457	0.227
ARDS[n (%)]	60 (6.5)	260 (6.1)	0.174	0.677
Respiratory failure[n (%)]	680 (73.1)	2404 (56.3)	89.507	<0.001
Hypertension[n (%)]	700 (75.3)	3181 (74.5)	0.241	0.624
Renal failure[n (%)]	307 (33.0)	1311 (30.7)	1.898	0.168

Note: The bold numbers represent the P values with significant differences.

Abbreviations: AKI, acute kidney injury; ARDS, acute respiratory distress syndrome; BMI, body mass index; BUN, blood urea nitrogen; CHF, congestive heart failure; CVP, central venous pressure; Hb, hemoglobin; ICU LOS, intensive care unit length of stay; MAP, mean arterial pressure; OASIS, oxford acute severity of illness score; RBC, red blood cell; RBG, random blood glucose; RDW, red blood cell distribution width; SAPSII, simplified acute physiology score II; Scr, serum creatinine; SOFA, sequential organ failure assessment; WBC, white blood cell.

Table 2 Risk Factors of All-Cause Death in Critical Diabetic Patients with AKI (Multivariate Cox Regression Analysis)

Parameters	B	SE	Wald	HR	95% CI	P value
Age	0.041	0.010	16.387	1.042	1.021–1.063	<0.001
MAP	−0.017	0.008	4.695	0.984	0.969–0.998	0.030
AKI stage			15.241		–	<0.001
Stage 1
Stage 2	0.176	0.395	0.199	1.193	0.550–2.589	0.656
Stage 3	1.199	0.373	10.355	3.318	1.598–6.890	0.001
SOFA	−0.003	0.048	0.003	0.997	0.907–1.096	0.953
SAPSII	0.023	0.013	2.930	1.023	0.997–1.050	0.087
OASIS	−0.027	0.018	2.221	0.973	0.938–1.009	0.136
Respiratory failure	0.453	0.278	2.666	1.574	0.913–2.712	0.103
Sepsis	0.247	0.300	0.677	1.280	0.711–2.303	0.411
RBC	−0.186	0.291	0.409	0.830	0.470–1.468	0.523
RDW	0.227	0.057	16.068	1.255	1.123–1.403	<0.001
BUN	0.004	0.006	0.532	1.004	0.993–1.015	0.466
Scr	−0.155	0.131	1.390	0.857	0.663–1.108	0.238
Lactic acid	0.181	0.095	3.620	1.198	0.995–1.443	0.057

Note: The bold numbers represent the P values with significant differences.

Abbreviations: 95% CI, 95% confidence interval; AKI, acute kidney injury; B, regression coefficient; BE, standard error; BUN, blood urea nitrogen; HR, hazard rate; MAP, mean arterial pressure; OASIS, oxford acute severity of illness score; RBC, red blood cell; RDW, red blood cell distribution width; SAPSII, simplified acute physiology score II; Scr, serum creatinine; SOFA, sequential organ failure assessment.

Table 3 Differences of All Cause Deaths and Other Adverse Outcomes at Different Levels of RDW

Parameters	RDW>15.3%	RDW≤15.3%	t/χ^2	P value
28-day death[n (%)]	501 (24.2)	429 (13.7)	93.481	<0.001
AKI stage			116.396	<0.001
Stage 1[n (%)]	460 (22.2)	980 (31.3)
Stage 2[n (%)]	621 (30.0)	1111 (35.5)
Stage 3[n (%)]	989 (47.8)	1039 (33.2)
Peak Scr (mg/dL)	2.68±1.89	1.91±1.52	4.940	<0.001
RRT[n (%)]	660 (31.9)	470 (15.0)	208.438	<0.001

Note: The bold numbers represent the P values with significant differences.

Abbreviations: AKI, acute kidney injury; RDW, red blood cell distribution width; RRT, renal replacement therapy; Scr, serum creatinine.

Figure 1 Comparison of survival curves of critical diabetic patients with AKI in different RDW groups (Kaplan–Meier survival curve).

Figure 2 Comparison of survival curves of critical diabetic patients with AKI in different stages (Kaplan–Meier survival curve).