Plasma inflammatory factors in older people predict acute kidney injury: a case-control study

To investigate whether inflammatory factors are predictors of acute kidney injury (AKI) in older people in the intensive care unit (ICU).

We performed a case-control study that included 98 older people (≥ 65 years) who were admitted to ICU from 2013 to 2017. The contents of plasma pro-inflammatory factors [interleukin (IL)-1b, IL-6, IL-8, tumor necrosis factor-a (TNF-α)] and the anti-inflammatory factor IL-10 were determined at the first day of admission. Patients were assessed based on the Kidney Disease Improving Global Outcomes (KDIGO) criteria and were divided into AKI and non-AKI (control) groups (n = 49 for each). T test was applied for differences comparisons in the levels of inflammatory factors between the two groups. Logistic regression was used to identify independent predictors of AKI.

AKI patients had significantly elevated plasma contents of IL-6, IL-8 and IL-10, relative to the control group. A strong correlation was observed between IL-6 and IL-8 with AKI (OR 36.4 and 18.2, respectively). For each increase in the natural log unit in the levels of IL-6 and IL-8, the risk of developing AKI augmented by 36.4% and 18.2%, respectively. Moreover, the higher the tertile value of IL-6 and IL-8, the higher the risk of developing AKI. The area under the receiver operating characteristic curve for IL-6 and IL-8 was, respectively, 87% and 83% for predicting AKI.

Plasma inflammatory contents of IL-6 and IL-8 can predict AKI in older people. Management of inflammatory factors should take into consideration the age of AKI patients.