Value of Neutrophil Counts in Predicting Surgery-Related Acute Kidney Injury and the Interaction of These Counts With Diabetes in Chronic Kidney Disease Patients With Hypertension: A Cohort Study

As a component of routine blood cell analyses, the quantity of neutrophils present is a proven predictor of morbidity and mortality in several clinical settings. However, whether episodes of acute kidney injury (AKI) are associated with higher neutrophil counts in vulnerable groups, such as chronic kidney disease (CKD) patients with hypertension, are unknown. This study was conducted to investigate the relationship between neutrophil counts and the incidence of surgery-related AKI in CKD patients with hypertension. This was a retrospective cohort study of the relationship between neutrophils and surgery-related AKI. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using logistic regression models. In total, 119 (11.9%) of 998 patients experienced surgery-related AKI during hospitalization from October 2008 to February 2013. We divided patients into 4 quartiles according to their neutrophil counts. After adjusting for multiple covariates, the patients in the 4th quartile of neutrophil counts had greater ORs for AKI compared to those in the 1st quartile. The incidence of AKI increased 1.59-fold for those patients with neutrophil counts ≥6.30 × 10(9)/L. There was a positive linear association between the neutrophil count upon admission and the predicted probability of AKI. The cross-validation revealed a statistically significant predictive accuracy for AKI (area under the curve (AUC) = 0.68, 95% CI, 0.67–0.69). The interaction analyses revealed that higher neutrophil counts are associated with a heightened risk of AKI in the presence of diabetes (OR = 3.38, 95% CI, 1.06–10.80). There were no interactions between neutrophil counts and age (P = 0.371), sex (P = 0.335), estimated glomerular filtration rate (P = 0.487), systolic blood pressure (P = 0.950), diastolic blood pressure (P = 0.977), the presence of chronic heart failure (P = 0.226), or sepsis (P = 0.796). The neutrophil count upon admission, an index that is easily and rapidly measured, is valuable for the prediction of surgery-related AKI in CKD patients with hypertension, especially in those with diabetes.