Neutrophil-lymphocyte ratio as a predictor of delirium in older internal medicine patients: a prospective cohort study

Abstract

Backgrounds Delirium is a common neuropsychiatric syndrome in older hospitalized patients. Previous studies have suggested that inflammation and oxidative stress contribute to the pathophysiology of delirium. However, it remains unclear whether neutrophil-lymphocyte ratio (NLR), an indicator of systematic inflammation, is associated with delirium. This study aimed to investigate the value of NLR as an independent risk factor for delirium among older hospitalized patients. Methods We conducted a prospective study of 740 hospitalized patients aged ≥ 70 years in the geriatric ward of West China Hospital of Sichuan University. Neutrophil and lymphocyte counts were collected within 24 h after hospital admission. Delirium was assessed on admission and every 48 h thereafter. We used the receiver operating characteristic analysis to assess the ability of the NLR for predicting delirium. The optimal cut-point value of the NLR was determined based on the highest Youden index (sensitivity + specificity − 1). Patients were categorized according to the cut-point value and quartiles of NLR, respectively. We then used logistic regression to identify the unadjusted and adjusted associations between NLR as a categorical variable and delirium. Results The optimal cut-point value of NLR for predicting delirium was 3.626 (sensitivity: 75.2 %; specificity: 63.4 %; Youden index: 0.386). The incidence of delirium was significantly higher in patients with NLR > 3.626 than NLR ≤ 3.626 (24.5 % vs. 5.8 %; P < 0.001). Significantly fewer patients in the first quartile of NLR experienced delirium than in the third (4.3 % vs. 20.0 %; P < 0.001) and fourth quartiles of NLR (4.3 % vs. 24.9 %; P < 0.001). Results from the multivariable logistic regression models showed that NLR was independently associated with delirium. Conclusions NLR is a simple and practical marker that can predict the development of delirium in older internal medicine patients.

Neutrophil-Lymphocyte Ratio as a Potential Biomarker for Delirium in the Intensive Care Unit

“…This can be interpreted as the NLR may be the more effective inflammatory marker in early detection of delirium occurrence, compared to CRP (Figure 5). This result is in line with recent studies using NLR for prediction of delirium (31,32).…”

Prospective Analysis Between Neutrophil-to-Lymphocyte Ratio on Admission and Development of Delirium Among Older Hospitalized Patients With COVID-19

“…Another systemic inflammation biomarker (SII) –which considers together neutrophil, platelet, and lymphocyte– did not predict delirium development in this study, in spite of the relationship between an increase of platelets levels and delirium ( Oyama et al, 2021 ). Notably, NLR levels are less costly to obtain than cellular mediators and acute phase reactants ( Zhao et al, 2021 ) and neutrophil and lymphocyte counts are part of basic routine determinations in most patients considered for hospital admission due to medical conditions. In addition, our findings expand the increasing use of NLR levels to classify patients’ risk of a variety of outcomes, including risk of depression following hemorrhagic stroke and risk of all-cause mortality in hospitalized COVID-19 patients ( Gong et al, 2020 ; Haghjooy Javanmard et al, 2020 ).…”

“…Neutrophil-to-lymphocyte ratio (NLR) is an indicator of the immune-inflammatory response available from routine blood tests performed at hospital admission. NLR is a good predictor of poor prognosis of COVID-19 ( Yang et al, 2020 ; Kerboua, 2021 ; Pandurangan et al, 2021 ); a non-specific transdiagnostic marker for neuropsychiatric disorders ( Mazza et al, 2018 ; Brinn and Stone, 2020 ) including delirium ( Egberts and Mattace-Raso, 2017 ; Oh et al, 2017 ; Zhao et al, 2021 ); and a prognosis marker in cardiovascular disease ( Wang et al, 2014 ), kidney disease ( Solak et al, 2013 ), and sepsis ( Huang et al, 2020 ). To our knowledge, no study has examined the link between NLR and delirium in COVID-19 hospitalized patients.…”

Credibility of the Neutrophil-to-Lymphocyte Count Ratio in Severe Traumatic Brain Injury

“…Inflammatory regulators recruit microglia and immune cells to the brain by activating the expression of chemokines and cell adhesion molecules. Thus, NLR may be a useful, low cost marker, showing the peripheral inflammation and its correspondance with neurodegeneration [120][121][122][123]. In addition, chronic neuroinflammation may become a potential target for novel therapy as a select method of conversion from proinflammatory to anti-inflammatory reactions.…”