A team led by Ravindra L. Mehta, MD, of the University of California San Diego, studied 1,946 patients hospitalized at an academic medical center over 24 months. The researchers defined AKI has a serum creatinine rise greater than 0.3 mg/dL within 48 hours.
Of the 1,946, 348 (18%) experienced AKI during their hospital stay. Compared with patients who did not have AKI, the AKI group had significantly lower average hemoglobin (Hb) levels throughout hospitalization. A significantly greater percentage of patients in the AKI than non-AKI group had average Hb levels below 10 mg/dL (51.1% vs. 20.7%).
Worsening of anemia was more significant in AKI than non-AKI patients from admission to discharge (decline of 1.05 vs. 0.69 mg/dL). Of the 348 patients, 69% recovered completely, 23% had a partial recovery, and 8% had no recovery. Increasing quintiles of Hb level at baseline was associated with increased likelihood of complete or partial recovery. Compared with patients in the lowest quintile (9.24 mg/dL or less), those in the third, fourth, and fifth quintiles (10.51–11.60, 11.61–12.80, and 12.81 mg/dL or higher, respectively) had a significant 5.0, 4.9, and 5.6 times increased odds of complete or partial recovery.
In adjusted analyses, the researchers found that Hb levels below 10 mg/dL independently predicted a significant 82% increased odds of AKI.