Table 1 Characteristics for AKI patients treated with EPO vs no EPO treatment

Parameters at baseline T1

 Age, mean ± SD

 Median (IQR)

78.82 ± 12.04

81 (73, 86)

76.42 ± 12.98

79 (69, 86)

0.269^a

 Gender M/F, n(%)

34/33 (50.7/49.3)

37/30 (55.2/44.8)

0.604^b

 BMI, median (IQR)

27.26 (23.79, 30.79)

26.12 (24.40, 30.66)

0.723^c

 Diabetes, n(%)

33 (49.3)

37 (55.2)

0.489^b

 Smoking status, n(%)

12 (17.9)

27 (40.3)

0.005^b

 Hypertension, n(%)

63 (94.0)

60 (89.6)

0.531^d

 Hyperlipidemia, n(%)

44 (65.7)

50 (74.6)

0.257^b

 Previous CVD, n(%)

35 (52.2)

40 (59.7)

0.384^b

 COPD, n(%)

11 (16.4)

20 (29.9)

0.072^b

 Chronic inflammation, n(%)

20 (29.9)

19 (28.4)

0.849^b

 RAASi intake, n(%)

28 (41.8)

26 (38.8)

0.723^b

 Home altitude in meters, mean ± SD

615.44 ± 405.89

623.56 ± 356.98

0.916^a

 Presumed cause of AKI

  ATN/Sepsis

18 (26.9)

20 (29.9)

0.066^b

  ATN/Hypovolemia

13 (19.4)

5 (7.5)

  ATN/Nephrotoxic agents

4 (6.0)

2 (3.0)

  Cardiorenal

10 (14.9)

15 (22.4)

  Other

22 (32.8)

25 (37.3)

 Baseline eGFR (mL/min/1.73m2), mean ± SD

53.86 ± 21.82

50.52 ± 25.75

0.423^a

 Baseline eGFR < 60 mL/min, n(%)

41 (61.2)

44 (65.7)

0.591^b

 Serum creatinine T1 (mg/dL), median (IQR)

2.3 (1.7, 4.2)

2.6 (2, 4.4)

0.224^c

  AKI stage 1, n(%)

29 (43.3)

34 (50.7)

0.428^b

  AKI stage 2, n(%)

12 (17.9)

15 (22.4)

  AKI stage 3, n(%)

21 (31.3)

16 (23.9)

  Missing baseline creatinine, n(%)

5 (7.5)

2 (3)

 Hemoglobin T1 (g/dL), median (IQR)

9.7 (8.8, 10.5)

9.4 (8.4, 10.0)

0.034^c

 Serum albumin T1 (g/L), median (IQR)

32.0 (28.8, 36.0)

31.0 (27.0, 35.0)

0.360^c

 Serum calcium T1 (mg/dL), median (IQR)

8.8 (8.3, 9.1)

8.8 (7.8, 9.2)

0.554^c

 Serum phosphate T1 (mg/dL), median (IQR)

4.2 (3.4, 5.6)

4.6 (3.9, 6.3)

0.077^c

 Serum bicarbonate T1 (meq/L), median (IQR)

22.0 (19.0, 25.0)

21.0 (18.0, 24.0)

0.337^c

 Ferritin (ng/mL), median (IQR)

181.75 (61.63, 366.25)

247.0 (99.75, 368.27)

0.564^c

 TSAT (%), median (IQR)

12.5 (8.0, 24.3)

10.5 (7.3, 17.4)

0.222^c

 CRP level T1 (mg/L), median (IQR)

74.0 (12.0, 168.0)

59.85 (20.8, 148.25)

0.752^c

 Vitamin B12 (pg/mL), median (IQR)

322.0 (201.5, 809.5)

347.5 (226.0, 756.75)

0.705^c

 Folic acid (ng/mL), median (IQR)

10.5 (6.6, 20.0)

7.9 (5.9, 12.3)

0.163^c

 LDH (U/L), median (IQR)

186.5 (164.0, 248.0)

214.5 (174.75, 273.5)

0.088^c

 Vasopressor use, n(%)

4 (6)

14 (20.9)

0.021^b

 Corticosteroid use, n(%)

21 (31.3)

23 (34.3)

0.666^b

 Iron intake, n(%)

13 (19.7)

22 (32.8)

0.067^b

 Anticoagulation, n(%)

37 (55.2)

41 (61.2)

0.419^b

 Oligoanuria, n(%)

11 (16.4)

18 (26.9)

0.142^b

 Total dose of EPO UI/Kg, median (IQR)

0

150 (88.5, 220.5)

 < 0.001

Parameters after follow-up T2

 Serum creatinine T2, median (IQR)

1.4 (1.1, 2.5)

1.8 (1.2, 2.91)

0.167^c

 Hemoglobin T2, median (IQR)

9.95 (9.1, 10.6)

9.7 (9.0, 10.5)

0.492^c

 Percentage of increase in hemoglobin level, mean ± SD

2.19 ± 0.01

6.4 ± 0.01

0.092^a

 CRP level T2, median (IQR)

30.0 (14.0, 72.0)

24.5 (12.5, 52.75)

0.381^c

 Length of stay in days, median (IQR)

8 (6, 13)

9 (6, 14)

0.342^c

 Number of units of packed red blood cells transfused, median (IQR)

0 (0,2)

0 (0, 1.5)

0.991^c