Table 2.

Association of biomarkers and AKI

Quintile (Cut Points)aSevere AKIbAKI RIFLE Rc
AKI Cases (%)dAdjusted OR Demographics (95% CI)eAdjusted OR Full (95% CI)fAKI Cases (%)dAdjusted OR Demographics (95% CI)eAdjusted OR Full (95% CI)f
Urine IL-18 (pg/ml)
    Q1 (<16)4.91 (referent)1 (referent)19.71 (referent)1 (referent)
    Q2 (17, 43)8.11.5 (0.3, 6.8)1.1 (0.2, 5.3)43.52.7 (1.2, 6.2)2.3 (0.9, 5.8)
    Q3 (44,123)13.12.9 (0.7, 11.8)2.5 (0.6, 10.6)41.02.7 (1.1, 6.2)2.2 (0.9, 5.3)
    Q4 (124, 362)25.86.5 (1.7, 24.8)4.3 (1.0, 18.1)50.03.5 (1.5, 8.2)2.4 (0.9, 6)
    Q5 (>362)32.89.4 (2.5, 35.5)6.9 (1.7, 28.8)54.14.2 (1.8, 9.9)2.6 (1.0, 6.7)
Urine NGAL (ng/ml)
    Q1 (<3)6.61 (referent)1 (referent)23.01 (referent)1 (referent)
    Q2 (3,8)11.31.6 (0.4, 6.1)1.4 (0.4, 5.5)33.91.5 (0.6, 3.4)1.3 (0.5, 3.1)
    Q3 (9,19)9.81.3 (0.3, 5.2)1.2 (0.3, 5.1)36.11.6 (0.7, 3.8)1.4 (0.5, 3.4)
    Q4 (20,70)21.03.1 (0.9, 10.5)2.1 (0.5, 7.8)56.53.5 (1.6, 7.9)2.1 (0.8, 5.2)
    Q5 (>70)36.16.7 (2.1, 21.7)4.1 (1.0, 16.3)59.04.0 (1.7, 9.0)2.1 (0.8, 5.7)
Plasma NGAL (ng/ml)
    Q1 (<81)15.81 (referent)1 (referent)38.61 (referent)1 (referent)
    Q2 (82,123)12.30.8 (0.3, 2.3)0.5 (0.2, 1.8)40.41.1 (0.5, 2.4)1.0 (0.4, 2.3)
    Q3 (124,175)15.51.0 (0.3, 2.7)0.8 (0.2, 2.5)43.11.3 (0.6, 2.7)1.2 (0.5, 2.8)
    Q4 (176, 259)19.31.3 (0.5, 3.6)1.3 (0.4, 3.9)33.30.8 (0.4, 1.9)0.7 (0.3, 1.7)
    Q5 (>259)22.81.9 (0.7, 5.1)2.2 (0.7, 6.9)50.92.3 (1.0, 5.0)2.3 (1.0, 5.5)
  • aThe number of patients per quintile (Q): urine IL-18, n = 61 or 62; urine NGAL, n = 61 or 62; plasma NGAL, n = 57 or 58.

  • bSevere AKI is defined as the receipt of dialysis or a doubling of serum creatinine during hospitalization.

  • cAKI RIFLE R is defined as a rise of 50% or higher in serum creatinine during hospitalization.

  • dPercentage AKI cases within each quintile.

  • eAdjusted for age (per year), gender, Caucasian race, and site.

  • fAdjusted for age (per year), gender, Caucasian race, site, CPB time >120 min, nonelective surgery, RACHS ≥3, and preoperative eGFR percentile and site.