Inflammatory Markers and Risk of Parkinson's Disease: A Population-Based Analysis

Objected: Parkinson's disease (PD) is an important cause of neurological dysfunction, and the aim of this study was to explore whether neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), systemic inflammatory response (SIRI), and systemic immune inflammation (SII) are associated with the risk of developing PD. Based on this, we may identify people at high risk for PD and intervene early. Method: Our study included 31,480 participants from the National Health and Nutrition Examination Survey (NHANES) between 2001 and 2018. Basic information and inflammation-related indicators were obtained by questionnaires and laboratory tests, respectively. NLR, PLR, LMR, SIRI, SII, and PD risk were analyzed using weighted logistic regression models. Results: There were 261 and 31,219 in the PD and non-PD groups, respectively, and the prevalence of PD was 0.83%. Separate analyses of NLR and PLR were conducted after fully adjusting for confounding factors. According to our analysis, there was an increased risk of PD for both NLR and PLR in the higher level group (Q4) as compared with the lower level group (Q1) (OR = 1.83 and 95% confidence interval (CI) = 1.09-3.07, and OR = 1.92 and 95% CI = 1.20-3.08). However, we did not find similar relationships in LMR, SIRI, and SII. Conclusions: There was a significant association between elevated levels of NLR, PLR, and PD risk, while LMR, SIRI, and SII were not statistically significant. It suggests that NLR or PLR could be used to screen people at risk of PD at an early stage. It is essential to conduct more large-scale prospective studies to investigate the role that NLR and PLR play in PD.