Background: Inflammation plays a significant role in the pathophysiology of cognitive impairment
in previous studies. Neutrophil-lymphocyte ratio (NLR) is a reliable measure of systemic inflammation.
Objectives: The aim of this study was to investigate the association between NLR and mild cognitive
impairment (MCI), and further to explore the diagnostic potential of the inflammatory markers NLR for
the diagnosis of MCI in elderly Chinese individuals.
Methods: 186 MCI subjects and 153 subjects with normal cognitive function were evaluated consecutively
in this study. Neutrophil (NEUT) count and Lymphocyte (LYM) count were measured in fasting
blood samples. The NLR was calculated by dividing the absolute NEUT count by the absolute LYM
count. Multivariable logistic regression was used to evaluate the potential association between NLR and
MCI. NLR for predicting MCI was analyzed using Receiver Operating Characteristic (ROC) curve
Results: The NLR of MCI group was significantly higher than that of subjects with normal cognitive
function (2.39 ± 0.55 vs. 1.94 ± 0.51, P < 0.001). Logistic regression analysis showed that higher NLR
was an independent risk factor for MCI (OR: 4.549, 95% CI: 2.623-7.889, P < 0.001). ROC analysis
suggested that the optimum NLR cut-off point for MCI was 2.07 with 73.66% sensitivity, 69.28% specificity,
74.48% Positive Predictive Values (PPV) and 68.36% negative predictive values (NPV). Subjects
with NLR ≥ 2.07 showed higher risk relative to NLR < 2.07 (OR: 5.933, 95% CI: 3.467-10.155, P <
Conclusion: The elevated NLR is significantly associated with increased risk of MCI. In particular,
NLR level higher than the threshold of 2.07 was significantly associated with the probability of MCI.