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Table 2 Outcomes

From: Effects of preoperative high-oral protein loading on short- and long-term renal outcomes following cardiac surgery: a cohort study

  Control group
(n = 214)
Protein-loading group
(n = 110)
p-value (unadjusted) p-value (adjusted)a
Serum creatinine, mg/dLb     
 Hospital admission 0.85 (0.72 – 0.96) 0.84 (0.73 – 0.96) 0.998 0.930
 Preoperative 0.84 (0.72 − 0.95) 0.83 (0.72 − 0.96) 0.956 0.883
 Postoperative day 1 0.77 (0.65 − 0.89) 0.79 (0.70 − 0.88) 0.181 0.148
 Postoperative day 2 0.84 (0.70 − 0.96) 0.82 (0.70 − 0.96) 0.308 0.251
 Hospital discharge 0.8 (0.67 − 0.92) 0.78 (0.69 − 0.93) 0.990 0.924
 3-month follow-up 0.90 (0.76 − 1.00) 0.83 (0.72 − 0.95) 0.088 0.048
 1-year follow-up 0.95 (0.81 – 1.09) 0.87 (0.76 – 0.93)  < 0.001  < 0.001
eGFR, mL/min/1.73 m2 c     
 Hospital admission 90 (80 − 98) 91 (82 − 100) 0.886 0.823
 Preoperative 91 (80 − 98) 92 (82 − 100) 0.886 0.823
 Hospital discharge 94 (85 − 102) 93 (85 − 102) 0.774 0.767
 3-month follow-up 87 (77 − 95) 91 (82 − 100) 0.033 0.028
 1-year follow-up 81 (70 − 88) 88 (78 − 96)  < 0.001  < 0.001
Albuminuria, mg/g creatinine     
 Hospital admission 7.0 (3.6 − 24.1) 6.5 (3.3 − 21.0) 0.273 0.265
 3-month follow-up 14.1 (4.3 − 62.1) 7.9 (1.6 − 43.9) 0.076 0.065
 1-year follow-up 20.9 (4.3 − 62.1) 10.0 (1.8 − 26.0) 0.024 0.020
 Postoperative day 1 urine output/hour, mL 2.7 (2 – 3.7) 2.33 (1.86 − 3.11) 0.021 0.031
 Postoperative day 2 urine output/hour, mL 1.42 (1.13 – 1.72) 1.48 (1.2 − 1.87) 0.324 0.277
 AKI, n (%)    0.945 0.945
  Stage 1 18 (8.5%) 10 (9.1%)   
  Stage 2 6 (2.8%) 4 (3.6%)   
  Stage 3 2 (0.9%) 1 (0.9%)   
  Postoperative kidney replacement therapy, n (%) 2 (0.9%) 0 (0%) 0.550 0.550
 Type of AKI    0.110 0.110
  Serum creatinine criteria 19 (9.0%) 15 (13.6%)   
  Urine output criteria 4 (1.9%) 0 (0%)   
  Both criteria 3 (1.4%) 0 (0%)   
 AKI reversal state at discharge, n (%) d    0.139 0.139
  Reversal 21/26 (80.8%) 15/15 (100%)   
  Non-reversal 5/26 (19.2%) 0 (0%)   
  1. Summaries of quantitative variables are presented as median and interquartile range (in parentheses). For categorical variables, the absolute and relative frequencies (as %, in parentheses) are presented for the categories
  2. AKI acute kidney injury; eGFR estimated glomerular filtration rate
  3. aP-values were taken from linear models, including age, sex, body mass index, hypertension, and diabetes as covariables
  4. bTo convert the values for serum creatinine to micromoles per liter, multiply it by 88.4
  5. cThe eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation [15]
  6. dAKI reversal was defined as the absence of any stage of AKI based on either the serum creatinine or urine output criteria at hospital discharge [22]