Neutrophil-to-lymphocyte ratio predicts poor prognosis in patients with chronic kidney disease-related pulmonary hypertension: A retrospective study

Abstract

Inflammation plays a crucial role in chronic kidney disease (CKD) and pulmonary hypertension (PH). Considering that the neutrophil-to-lymphocyte ratio (NLR) has recently emerged as a powerful predictor of adverse outcomes in many chronic diseases, we aimed to investigate the association between NLR and all-cause mortality in patients with CKD-related PH. A total of 176 hospitalized patients with predialysis CKD-related PH were recruited retrospectively from January 2012 to June 2020 by reviewing electronic medical records. The NLR and clinical characteristics of the patients were included in the current analysis. The Kaplan-Meier method and univariate and multivariate Cox regression analyses were performed to identify the association between NLR and the incidence of all-cause mortality. Baseline NLR values were associated with hemoglobin, estimated glomerular filtration rate and C-reactive protein. During a median follow-up period of 32.5 (11.3-53.0) months, 23 patients died. Regardless of whether the NLR acted as a continuous variable with a hazard ratio of 1.408 (95% confidence interval: 1.124-1.763) or a categorical variable (NLR ≤4.3 vs NLR >4.3) with a hazard ratio of 3.100 (95% confidence interval: 1.299-7.402), an elevated NLR was significantly associated with all-cause mortality in different models. A greater NLR at baseline was remarkably associated with a higher all-cause mortality in hospitalized patients with CKD-related PH.