Higher Neutrophil-to-lymphocyte Ratio is Association with an Increased Risk of Fatal Stroke Occurrence in Older Chinese

Background: The neutrophil-to-lymphocyte ratio (NLR) has linked to a mortality risk of coronary heart disease. However, it is unclear whether the NLR is related to the risk of fatal stroke in a relatively healthy elderly population. Aims: : To evaluate the association between the NLR and the risk of fatal stroke in elderly populations. Methods: : In total, 27811 participants without a stroke history at baseline were included and followed up for a mean of 11.5 (standard deviation=2.3) years. After review of available records, 503 stroke deaths (ischaemic 227, haemorrhagic 172 and unclassified 104) were recorded. Cox proportional hazards regression was used to assess the relationship between the NLR and future risk of fatal stroke, fatal ischaemic stroke or fatal haemorrhagic stroke. Results: : (1) Compared with those in the 1 st quartile and after adjustments for a series of factors, those in the highest neutrophil (NEUT) quartile had a 45% and a 65% increased risk of fatal stroke (adjusted hazard ratio (aHR)=1.45, 95% confidence interval (CI) 1.10-1.89, P =0.008) and fatal ischaemic stroke (aHR=1.65, 95% CI 1.10-2.47, P =0.02), respectively; while no significant relationship was obtained between the lymphocyte (LYM) and the risk of fatal stroke. (2) The restricted cubic splines showed an increased trend of relationship between the NLR and the risk of fatal stroke occurrence. Compared with those in the lowest quartile (≤ 1.39), the participants with the highest NLR (≥ 2.24) had a 76% and a 115% increased risk of fatal stroke (aHR=1.76, 95% CI 1.33-2.32) and fatal ischaemic stroke (aHR=2.15, 95% CI 1.41-3.28), respectively; Similar associations for stroke and ischaemic stroke were obtained after further adjustment for C-reactive protein. (3) Compared with those in NLR ≤ 1.75, the participants in NLR > 1.75 had a 57% and a 91% increased risk of fatal stroke (aHR=1.57, 95%CI 1.20-2.06) and fatal ischaemic stroke (aHR=1.91, 95%CI 1.27-2.88), respectively. (3) As a continuous variable, the NLR presented an increased risk of fatal stroke (aHR=1.11 95%CI 1.06-1.17) and fatal ischaemic stroke (aHR=1.15 95%CI 1.09-1.21), respectively. Conclusions: : Higher NLR was associated with an increased risk of fatal stroke and fatal ischaemic stroke occurrence in a relatively healthy elderly population.The clinicians should pay more attention to asymptomatic inflammatory characteristics in relatively healthy older population.