Association of Neutrophil-Lymphocyte Ratio with Mild Cognitive Impairment in Elderly Chinese Adults: A Case-control Study

Neutrophil to lymphocyte ratio in Alzheimer's disease: A systematic review and meta-analysis

BACKGROUND

The Neutrophil-to-Lymphocyte Ratio (NLR) is a clinical indicator of peripheral inflammation that is easily accessible. It is worth noting that the formation of amyloid-β (Aβ) plaques and neurofibrillary tangles has been linked to inflammation and immune dysregulation. The main objective of this systematic review and meta-analysis is to comprehensively evaluate the existing body of research concerning the NLR in the context of Alzheimer's disease (AD) and mild cognitive impairment (MCI).

METHOD

We conducted a comprehensive online search and included studies that evaluated the NLR in 1) patients with AD or MCI and 2) healthy control (HC) participants. We also pooled mean and standard deviation (SD) data for each group.

RESULTS

Ultimately, 12 studies encompassed 1,309 individuals diagnosed with AD with mean NLR levels of 2.68, 1,929 individuals with MCI with mean NLR levels of 2.42, and 2,064 HC with mean NLR levels of 2.06 were included in this systematic review and meta-analysis. The mean NLR was 0.59 higher in AD patients compared to HC participants (mean difference (MD) = 0.59 [0.38; 0.80]). Similarly, the mean NLR was higher in AD than MCI patients (MD = 0.23 [0.13; 0.33]). Additionally, the mean NLR was higher in individuals with MCI compared to HC participants (MD = 0.37 [0.22; 0.52]). In the subgroup meta-analysis based on the Mini-Mental State Examination (MMSE), AD patients with lower MMSE scores (using a cut-off of 20) exhibited significantly higher mean NLR (3.10 vs. 2.70, with a p-value for subgroup differences < 0.01).

CONCLUSION

The NLR, which serves as a marker of peripheral inflammation, shows increased levels in individuals with AD and MCI compared to HC participants. Furthermore, our study indicates that NLR levels are significantly higher in AD than MCI. Additionally, our novel finding suggests significantly higher NLR levels among AD patients with more severe cognitive decline compared to AD patients with less severe cognitive decline. So, it can be concluded that the higher cognitive decline in humans is accompanied by higher NLR levels. Further longitudinal researches are needed to explore more details about the relationship between inflammation and dementia.

Neuroinflammation in Alzheimer's disease: insights from peripheral immune cells

Alzheimer's disease (AD) is a serious brain disorder characterized by the presence of beta-amyloid plaques, tau pathology, inflammation, neurodegeneration, and cerebrovascular dysfunction. The presence of chronic neuroinflammation, breaches in the blood-brain barrier (BBB), and increased levels of inflammatory mediators are central to the pathogenesis of AD. These factors promote the penetration of immune cells into the brain, potentially exacerbating clinical symptoms and neuronal death in AD patients. While microglia, the resident immune cells of the central nervous system (CNS), play a crucial role in AD, recent evidence suggests the infiltration of cerebral vessels and parenchyma by peripheral immune cells, including neutrophils, T lymphocytes, B lymphocytes, NK cells, and monocytes in AD. These cells participate in the regulation of immunity and inflammation, which is expected to play a huge role in future immunotherapy. Given the crucial role of peripheral immune cells in AD, this article seeks to offer a comprehensive overview of their contributions to neuroinflammation in the disease. Understanding the role of these cells in the neuroinflammatory response is vital for developing new diagnostic markers and therapeutic targets to enhance the diagnosis and treatment of AD patients.

Association between low lung function and the increased risk of age-related macular degeneration: A population-based prospective cohort study

Background

Low lung function is associated with an increased risk of age-related diseases. However, the relationship between age-related macular degeneration (AMD), the leading cause of blindness, and lung function remains unclear. We aimed to investigate whether low lung function increases the risk of AMD and the potential mechanisms behind this association.

Methods

We conducted a prospective cohort analysis of 409 230 UK Biobank participants with completed lung function after excluding individuals with AMD. We used Cox proportional hazards models to estimate the risk of AMD incidence and mediation models to explore potential mechanisms driven by inflammatory markers, erythrocyte-related measures, and metabolites.

Results

Overall, 6477 AMD cases were diagnosed across an average of 12.4 years of follow-up. Participants with low lung function had an increased risk of developing AMD compared to those with high lung function (forced vital capacity: adjusted hazard ratio (aHR) = 1.20 (95% confidence interval (CI) = 1.07-1.34); forced expiratory volume in one second: aHR = 1.32 (95% CI = 1.18-1.47); peak expiratory flow: aHR = 1.32 (95% CI = 1.20-1.45)). Inflammatory markers and erythrocyte-related measures mediated this relationship, acting as a pathway through which low lung function influenced AMD. The interactions of body mass index (BMI), sex, and smoking were significant and the effect of lung function on AMD was higher in men, obese, and smoking populations.

Conclusions

The increased risk of AMD was associated with low lung function, with inflammatory and erythrocyte-related markers mediating this relationship. This suggests that improvements in lung function could reduce the risk of AMD, thereby promoting health and longevity.

Higher remnant cholesterol is associated with an increased risk of amnestic mild cognitive impairment: a community-based cross-sectional study

Background and aims

Amnestic mild cognitive impairment (aMCI) is the most common subtype of MCI, which carries a significantly high risk of transitioning to Alzheimer's disease. Recently, increasing attention has been given to remnant cholesterol (RC), a non-traditional and previously overlooked risk factor. The aim of this study was to explore the association between plasma RC levels and aMCI.

Methods

Data were obtained from Brain Health Cognitive Management Team in Wuhan (https://hbtcm.66nao.com/admin/). A total of 1,007 community-dwelling elders were recruited for this project. Based on ten tools including general demographic data, cognitive screening and some exclusion scales, these participants were divided into the aMCI (n = 401) and normal cognitive groups (n = 606). Physical examinations were conducted on all participants, with clinical indicators such as blood pressure, blood sugar, and blood lipids collected.

Results

The aMCI group had significantly higher RC levels compared to the normal cognitive group (0.64 ± 0.431 vs. 0.52 ± 0.447 mmol/L, p < 0.05). Binary logistics regression revealed that occupation (P<0.001, OR = 0.533, 95%CI: 0.423-0.673) and RC (p = 0.014, OR = 1.477, 95% CI:1.081-2.018) were associated factors for aMCI. Partial correlation analysis, after controlling for occupation, showed a significant negative correlation between RC levels and MoCA scores (r = 0.059, p = 0.046), as well as Naming scores (r = 0.070, p = 0.026). ROC curve analysis demonstrated that RC levels had an independent predictive efficacy in predicting aMCI (AUC = 0.580, 95%CI: 0.544 ~ 0.615, P < 0.001).

Conclusion

Higher RC levels were identified as an independent indicator for aMCI, particularly in the naming cognitive domain among older individuals. Further longitudinal studies are necessary to validate the predictive efficacy of RC.

Communication Regarding the Myocardial Ischemia/Reperfusion and Cognitive Impairment: A Narrative Literature Review

Coronary artery disease is a prevalent ischemic disease that results in insufficient blood supply to the heart muscle due to narrowing or occlusion of the coronary arteries. Various reperfusion strategies, including pharmacological thrombolysis and percutaneous coronary intervention, have been developed to enhance blood flow restoration. However, these interventions can lead to myocardial ischemia/reperfusion injury (MI/RI), which can cause unpredictable complications. Recent research has highlighted a compelling association between MI/RI and cognitive function, revealing pathophysiological mechanisms that may explain altered brain cognition. Manifestations in the brain following MI/RI exhibit pathological features resembling those observed in Alzheimer's disease (AD), implying a potential link between MI/RI and the development of AD. The pro-inflammatory state following MI/RI may induce neuroinflammation via systemic inflammation, while impaired cardiac function can result in cerebral under-perfusion. This review delves into the role of extracellular vesicles in transporting deleterious substances from the heart to the brain during conditions of MI/RI, potentially contributing to impaired cognition. Addressing the cognitive consequence of MI/RI, the review also emphasizes potential neuroprotective interventions and pharmacological treatments within the MI/RI model. In conclusion, the review underscores the significant impact of MI/RI on cognitive function, summarizes potential mechanisms of cardio-cerebral communication in the context of MI/RI, and offers ideas and insights for the prevention and treatment of cognitive dysfunction following MI/RI.

Association between the neutrophil-to-lymphocyte ratio and cognitive impairment: a meta-analysis of observational studies

Background

Systemic inflammation is one of the underlying mechanisms of cognitive impairment. The neutrophil-to-lymphocyte ratio (NLR) has emerged as a systemic inflammation indicator. This meta-analysis aimed to evaluate the association between high NLR and cognitive impairment (CI) risk.

Method

A comprehensive systematic search was conducted to identify eligible studies published until May 30, 2023. The reference group comprised patients with the lowest NLR level, whereas the exposure group comprised those with the highest NLR level. The main outcome was to examine the relationship between NLR and CI risk. The secondary outcome included the association between patient characteristics or comorbidities and CI risk.

Results

This meta-analysis included 11 studies published between 2018 and 2023, involving 10,357 patients. Patients with CI had a higher NLR than those without (mean difference=0.35, 95% confidence interval [CI]: 0.26-0.44, p < 00001, I2 = 86%). Consistently, pooled results revealed an association between high NLR and CI risk (odds ratio [OR]=2.53, 95% CI:1.67-3.82, p<0.0001, I2 = 84%). Furthermore, aging (mean difference =4.31 years, 95% CI:2.83-5.8, p < 0.00001, I2 = 92%), diabetes (OR=1.59, 95% CI:1.35-1.88, p < 0.00001, I2 = 66%), and hypertension (OR=1.36, 95% CI:1.19-1.57, p < 0.00001, I2 = 0%) were significant risk factors for CI. However, no significant associations were observed between CI and male gender (OR = 0.84, 95% CI:0.64-1.11, p = 0.22, I2 = 81%), body mass index (mean = -0.32 kg/m2, 95% CI: -0.82, 0.18, p = 0.2, I2 = 82%), alcohol consumption (OR = 1.11, 95% CI:0.95-1.3, p = 1.35, I2 = 0%), and smoking (OR = 0.99, 95% CI:0.87-1.13, p = 0.86, I2 = 0%). Meta-regression found that diabetes and hypertension, but not age, significantly moderated the association between NLR and CI.

Conclusion

This meta-analysis showed a significant association between high NLR and increased CI risk. Moreover, meta-regression identified diabetes and hypertension, but not age, as significant moderating factors in the relationship between NLR and CI. To validate and strengthen these findings, further large-scale studies are required.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023430384, identifier CRD42023430384.

Neutrophil-Mediated Progression of Mild Cognitive Impairment to Dementia

Cognitive impairment is a serious condition that begins with amnesia and progresses to cognitive decline, behavioral dysfunction, and neuropsychiatric impairment. In the final stage, dysphagia and incontinence occur. There are numerous studies and developed drugs for cognitive dysfunction in neurodegenerative diseases, such as Alzheimer's disease (AD); however, their clinical effectiveness remains equivocal. To date, attempts have been made to overcome cognitive dysfunction and understand and delay the aging processes that lead to degenerative and chronic diseases. Cognitive dysfunction is involved in aging and the disruption of inflammation and innate immunity. Recent reports have indicated that the innate immune system is prevalent in patients with AD, and that peripheral neutrophil markers can predict a decline in executive function in patients with mild cognitive impairment (MCI). Furthermore, altered levels of pro-inflammatory interleukins have been reported in MCI, which have been suggested to play a role in the peripheral immune system during the process from early MCI to dementia. Neutrophils are the first responders of the innate immune system. Neutrophils eliminate harmful cellular debris via phagocytosis, secrete inflammatory factors to activate host defense systems, stimulate cytokine production, kill pathogens, and regulate extracellular proteases and inhibitors. This review investigated and summarized the regulation of neutrophil function during cognitive impairment caused by various degenerative diseases. In addition, this work elucidates the cellular mechanism of neutrophils in cognitive impairment and what is currently known about the effects of activated neutrophils on cognitive decline.

The neutrophil-to-lymphocyte ratio is associated with mild cognitive impairment in community-dwelling older women aged over 70 years: a population-based cross-sectional study

Background

The neutrophil-to-lymphocyte ratio (NLR) is a marker of inflammation that can be obtained quickly, conveniently, and cheaply from blood samples. However, there is no research to explore the effects of sex and age on the relationship between the NLR and mild cognitive impairment (MCI) in community-dwelling older adults.

Methods

A total of 3,126 individuals aged over 60 years in Shanghai were recruited for face-to-face interviews, and blood samples were collected. MCI was assessed by the Mini-Mental State Examination (MMSE) and the Instrumental Activities of Daily Living (IADL) scale, and neutrophil count and lymphocyte counts were measured in fasting blood samples. The NLR was calculated by dividing the absolute neutrophil count by the absolute lymphocyte count.

Results

In females, the NLR in the MCI group was significantly higher than that in the cognitively normal group (2.13 ± 0.94 vs. 1.85 ± 0.83, p < 0.001) but not in men. Logistic regression showed that a higher NLR was an independent risk factor for MCI in women [odds ratio (OR) = 1.33; 95% confidence interval (CI) = 1.14-1.55]. In addition, the elevated NLR quartile was associated with an increased risk of MCI, especially in women older than 70 years (p value for trend = 0.012).

Conclusion

Compared with males, female MCI patients had a significantly higher NLR than cognitively normal controls. In addition, elevated NLR was found to be significantly associated with MCI risk in women older than 70 years. Therefore, elderly Chinese women with a higher NLR value may be the target population for effective prevention of MCI.

Decrease in cognitive performance and increase of the neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios with higher doses of antipsychotics in women with schizophrenia: a cross-sectional study

BACKGROUND

We explored the relationship between symptoms, cognitive performance, neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR) (three markers of inflammation), and antipsychotic dose (in chlorpromazine units) in male and female patients with schizophrenia.

METHODS

We conducted a cross-sectional analysis in patients with schizophrenia of the complete blood count and the results of neuropsychological testing, using the Welch t-test to compare groups and the Pearson test for correlations.

RESULTS

We found that the NLR and the PLR are higher among women with schizophrenia when compared with men. In women, the NLR and the PLR correlate positively with antipsychotic drug dose and inversely with a working memory test (Direct Digit Span). Higher doses of antipsychotics are associated with worse working and semantic memory and mental flexibility in the women in our sample.

CONCLUSION

Higher doses of antipsychotics were associated with worse working and semantic memory and mental flexibility in women with schizophrenia. No such correlations were present in men, suggesting that, in female patients, cognitive performance deteriorates as the antipsychotic dose is increased, a finding that could be mediated by inflammatory mechanisms, given the demonstrated relationship to biomarkers of inflammation - e.g., the NLR and the PLR.

TRIAL REGISTRATION

NCT03788759 (ClinicalTrials.gov).

Neutrophil-Lymphocyte Ratio as a Predictor of Cerebral Small Vessel Disease in a Geriatric Community: The I-Lan Longitudinal Aging Study

Cerebral Small Vessel Disease (CSVD) frequently affects the elderly, with inflammation playing a crucial role in related health complications, including dementia, stroke, and SVD. Studies, including animal experiments, indicate a strong link between inflammation and SVD progression. The Neutrophil-Lymphocyte Ratio (NLR) serves as a possible biomarker for ongoing inflammatory risks. A total of 720 adults aged 50 years or older from the community-based I-Lan Longitudinal Aging Study were included in this study. General linear regression and ordinally logistic regression analyses were performed to evaluate the association between NLR and CSVD. We further examined the presence of lacune, microbleed, and white matter hyperintensity (WMH) on brain MRI, which were used to construct a combined CSVD score. The NLR was positively associated with WMH (adjusted r = 0.109, p = 0.003), microbleed (adjusted r = 0.102, p = 0.006), and lacune (adjusted r = 0.100, p = 0.008). After adjustments for smoking, drinking, and physical activity in the ordinal logistic regression analysis, age, gender, brachial Systolic Blood Pressure (SBP), fasting glucose, LDL-cholesterol, and Hs-CRP were compared among subjects with low tertile (T1), medium tertile (T2) and high tertile (T3) NLR. The results showed that T2 vs. T1 had an odds ratio of 1.23 (0.86-1.77); and T3 vs. T1 had an odds ratio of 1.87 (1.29-2.71) of CSVD scores in four groups (zero (reference group), one, two, and three or more). NLR could be used to assess the state of inflammation in cerebral vessels. A significant and positive correlation between NLR and CSVD was verified in this study. However, the practical clinical application of NLR in CSVD patients and prognosis prediction should be validated through more scientific attempts.

Altered neutrophil-to-lymphocyte ratio in patients with non-affective first episode psychosis and its relationship with symptom severity and cognitive impairment

Signatures of immune dysregulation as clinical biomarker for psychosis have remained unclear. We aimed to compare the Neutrophil-to-lymphocyte ratio (NLR) of patients with acute non-affective first-episode psychosis (FEP) with healthy controls after accounting for emotional states. We also explored the associations of NLR with symptom severity, onset profile and cognitive functions. The NLR was enumerated from complete blood count taken within a week of assessment. All FEP patients were rated on the Positive and Negative Syndrome Scale (PANSS) and the Clinician Global Impression-Severity (CGI-S) with verbal memory and executive functions assessed with the Cambridge Neuropsychological Test Automated Battery. Prevailing emotional state was measured with Beck Depression Inventory-II and Beck Anxiety Inventory. Out of seventy-nine consecutive FEP patients presenting to the study site, twenty-seven subjects were eligible and recruited. Twenty-seven age-/sex-matched controls were recruited. FEP patients had an NLR of 1.886 over the controls after accounting for scores on emotional states. The NLR of FEP patients was positively associated with CGI-S scores, PANSS positive symptom, disorganization and excitation scores. There was no significant correlation between NLR with the duration of untreated psychosis and cognitive performances. These findings support using NLR as a clinical biomarker in FEP, purporting further prospective study to measure NLR changes in the course of treatment.

Investigating the Prognostic Role of Peripheral Inflammatory Markers in Mild Cognitive Impairment

Growing evidence suggests that neuroinflammation plays a critical role in the pathogenesis of neurodegenerative diseases. Peripheral markers of inflammation, including blood cell counts and their ratios, such as the neutrophil-to-lymphocyte ratio (NLR), have been reported as an easily accessible and reliable proxy of central nervous system inflammation. However, the role of peripheral inflammation in dementia and Mild Cognitive Impairment (MCI) still needs to be clarified. In the current study, we aimed to assess the prognostic role of the NLR and other peripheral markers of inflammation in a sample of 130 amnestic MCI, followed up for two to five years. The Mini-Mental state examination (MMSE) score at baseline and follow-up visits was used to assess global cognitive status at each visit and the degree of cognitive decline over time. Baseline peripheral markers of inflammation included blood cell counts and ratios, specifically the NLR, the platelet-to-lymphocyte ratio (PLR), the monocyte-to-lymphocyte ratio (MLR), and the systemic immune inflammation index (SII). After classifying subjects into CONVERTERS and non-CONVERTERS (respectively, patients converting to dementia and subjects showing stability at the last available follow-up), we compared peripheral markers of inflammation among groups ed correlated them with cognitive measures, testing the ability of significant factors to predict conversion to dementia. In our cohort, CONVERTERS showed lower baseline MMSE scores (p-value = 0.004) than non-CONVERTERS. In addition, CONVERTERS had statistically elevated NLR (p-value = 0.005), PLR (p-value = 0.002), and SII levels (p-value = 0.015), besides a lower number of lymphocytes (p-value = 0.004) compared with non-CONVERTERS. In a logistic regression analysis, baseline MMSE scores and NLR predicted conversion to dementia. Tertiles analysis showed that MCI with the highest NLR values had a higher conversion risk. Our study supports the hypothesis that a dysregulation of peripheral inflammation involving both lymphocytes and neutrophils may play a role in the pathogenesis of dementia, even at the early stages of neurodegeneration, as in the MCI condition.

Physiological stress level and screening for malnutrition as preoperative predictors of postoperative complications in pancreatic surgery: a retrospective study

BACKGROUND

Assessment of 'physiological stress levels' and 'nutritional status' before surgery is important for predicting complications and indirect interventions on the pancreas. The aim of this study was to determine neutrophil-lymphocyte ratio (NLR) and nutritional risk index (NRI) indicators before surgery to predict 90-day complications and mortality in a cohort of patients with complicated chronic pancreatitis and cancer of the head of the pancreas.

METHODS

We evaluated preoperative levels of NLR and NRI among 225 subjects treated at different centres located in three countries. Short-term outcomes included length of hospital stay, postoperative complications, and mortality at 90 days and were appreciated based on NLR and NRI. The level of physiological stress was divided according by the formulas: neutrophil-lymphocyte ratio (NLR) = (neutrophil count, %)/(lymphocyte count, %). The nutritional state of the patients was divided according to the INR: NRI = (1.519 × serum albumin, g/L) + (41.7 × present weight, kg / usual weight, kg)].

RESULTS

All patients were operated. An analysis of the operations performed in three institutions demonstrated mortality in chronic pancreatitis and pancreatic pseudocysts in 1.4%, in chronic pancreatitis and the presence of an inflammatory mass mainly in the pancreatic head in 1.2%, and in cancer of the pancreatic head in 5.9%. The mean preoperative NLR was normal in 33.8% of the patients, the mild physiologic stress level was 54.7%, and the moderate was 11.5% before surgery. 10.2% of patients had a normal nutritional status, 20% had mild, 19.6% had moderate, and 50.2% had severe malnutrition. In a univariate analysis, at the cutoff of NLR ≥ 9.5 (AUC = 0.803) and the cutoff of NRI ≤ 98.5 (AUC = 0.801), increasing the risk of complications was observed (hazard ratio, 2.01; 95% CI, 1.247-3.250, p = 0.006), but at the cutoff of NRI ≤ 83.55 (AUC = 0.81), we observed a survival difference in operated patients (hazard ratio, 2.15; 95% CI, 1.334-3.477, p = 0.0025).

CONCLUSIONS

Our study demonstrated that NLR and NRI were predictors of postoperative complications, but only NRI was a predictor of 90-day mortality in patients after surgery.

Effects of Hydrogen Gas Inhalation on Community-Dwelling Adults of Various Ages: A Single-Arm, Open-Label, Prospective Clinical Trial

Molecular hydrogen (H₂) is a versatile therapeutic agent. H₂ gas inhalation is reportedly safe and has a positive impact on a range of illnesses, including Alzheimer's disease (AD). Herein, we investigated the effects of 4 weeks of H₂ gas inhalation on community-dwelling adults of various ages. Fifty-four participants, including those who dropped out (5%), were screened and enrolled. The selected participants were treated as a single group without randomization. We evaluated the association between total and differential white blood cell (WBC) counts and AD risk at individual levels after 4 weeks of H₂ gas inhalation treatment. The total and differential WBC counts were not adversely affected after H₂ gas inhalation, indicating that it was safe and well tolerated. Investigation of oxidative stress markers such as reactive oxygen species and nitric oxide showed that their levels decreased post-treatment. Furthermore, evaluation of dementia-related biomarkers, such as beta-site APP cleaving enzyme 1 (BACE-1), amyloid beta (Aβ), brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor A (VEGF-A), T-tau, monocyte chemotactic protein-1 (MCP-1), and inflammatory cytokines (interleukin-6), showed that their cognitive condition significantly improved after treatment, in most cases. Collectively, our results indicate that H₂ gas inhalation may be a good candidate for improving AD with cognitive dysfunction in community-dwelling adults of different ages.

The Association Between Neutrophil-Lymphocyte Ratio and Variability with New-Onset Dementia: A Population-Based Cohort Study

BACKGROUND

Previous studies identified that neutrophil-to-lymphocyte ratio (NLR) may be a predictor of dementia. However, the associations between NLR and dementia at the population level were less explored.

OBJECTIVE

This retrospective population-based cohort study was designed to identify the associations between NLR and dementia among patients visiting for family medicine consultation in Hong Kong.

METHODS

The patients were recruited from January 1, 2000, to December 31, 2003, and followed up until December 31, 2019. The demographics, prior comorbidities, medications, and laboratory results were collected. The primary outcomes were Alzheimer's disease and related dementia and non-Alzheimer's dementia. Cox regression and restricted cubic spline were applied to identify associations between NLR and dementia.

RESULTS

A cohort of 9,760 patients (male: 41.08% ; baseline age median: 70.2; median follow-up duration: 4756.5 days) with complete NLR were included. Multivariable Cox regression identified that patients with NLR >5.44 had higher risks of developing Alzheimer's disease and related dementia (hazard ratio [HR]: 1.50, 95% Confidence interval [CI]: 1.17-1.93) but not non-Alzheimer's dementia (HR: 1.33; 95% CI: 0.60-2.95). The restricted cubic splines demonstrated that higher NLR was associated with Alzheimer's disease and related dementia. The relationship between the NLR variability and dementia was also explored; of all the NLR variability measures, only the coefficient of variation was predictive of non-Alzheimer's dementia (HR: 4.93; 95% CI: 1.03-23.61).

CONCLUSION

In this population-based cohort, the baseline NLR predicts the risks of developing dementia. Utilizing the baseline NLR during family medicine consultation may help predict the risks of dementia.

Association between the neutrophil to lymphocyte ratio and mild cognitive impairment in patients with type 2 diabetes

AIM

Evidence indicates that type 2 diabetes (T2D) is associated with mild cognitive impairment (MCI). Inflammation is a recognized sign of many neurodegenerative diseases. The neutrophil-to-lymphocyte ratio (NLR) is a novel and inexpensive marker of inflammation. The purpose of this study was to investigate the relationship between the NLR and MCI in patients with T2D.

METHODS

The sample for this study comprised 787 patients with T2D, including 411 patients with normal cognitive function and 376 patients with MCI. Blood biochemical parameters and routine blood indicators were determined by an automatic analyzer. The NLR was calculated as the neutrophil count divided by the lymphocyte count.

RESULTS

Compared with the control group, the MCI group was older and had a higher NLR but a lower education level and Montreal Cognitive Assessment (MoCA) score (p < 0.05). Spearman correlation and multiple linear regression analyses confirmed that the MoCA score was negatively associated with the NLR (p < 0.001). Multivariate logistic regression analysis demonstrated that the NLR was an independent risk factor for MCI in patients with T2D (p < 0.001). After adjusting for confounding factors, the risk of MCI for those in the third tertile of the NLR was 2.907 times higher than that of those in the first tertile of the NLR (OR = 2.907, 95%CI = 1.978-4.272, p < 0.001).

CONCLUSION

An elevated NLR is associated with MCI in patients with T2D.

Lung function and risk of incident dementia: A prospective cohort study of 431,834 individuals

BACKGROUND

Whether lung function prospectively affects cognitive brain health independent of their overlapping factors remains largely unknown. This study aimed to investigate the longitudinal association between decreased lung function and cognitive brain health and to explore underlying biological and brain structural mechanisms.

METHODS

This population-based cohort included 43,1834 non-demented participants with spirometry from the UK Biobank. Cox proportional hazard models were fitted to estimate the risk of incident dementia for individuals with low lung function. Mediation models were regressed to explore the underlying mechanisms driven by inflammatory markers, oxygen-carrying indices, metabolites, and brain structures.

FINDINGS

During a follow-up of 3,736,181 person-years (mean follow-up 8.65 years), 5,622 participants (1.30 %) developed all-cause dementia, which consisted of 2,511 Alzheimer's dementia (AD) and 1,308 Vascular Dementia (VD) cases. Per unit decrease in lung function measure was each associated with increased risk for all-cause dementia (forced expiratory volume in 1 s [liter]: hazard ratio [HR, 95 %CI], 1.24 [1.14-1.34], P = 1.10 × 10^-07; forced vital capacity [liter]: 1.16 [1.08-1.24], P = 2.04 × 10^-05; peak expiratory flow [liter/min]: 1.0013 [1.0010-1.0017], P = 2.73 × 10^-13). Low lung function generated similar hazard estimates for AD and VD risks. As underlying biological mechanisms, systematic inflammatory markers, oxygen-carrying indices, and specific metabolites mediated the effects of lung function on dementia risks. Besides, brain grey and white matter patterns mostly affected in dementia were substantially changed with lung function.

INTERPRETATION

Life-course risk for incident dementia was modulated by individual lung function. Maintaining optimal lung function is useful for healthy aging and dementia prevention.

Peripheral Inflammation Links with the Severity of Clinical Phenotype in Spinocerebellar Ataxia 2

BACKGROUND

The role of peripheral inflammation in spinocerebellar ataxia type 2 (SCA2) is unknown.

OBJECTIVE

The objective of this study was to identify peripheral inflammation biomarkers and their relationship with the clinical and molecular features.

METHODS

Blood cell count-derived inflammatory indices were measured in 39 SCA2 subjects and their matched controls. Clinical scores of ataxia, nonataxia, and cognitive dysfunction were assessed.

RESULTS

The neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), the Systemic Inflammation Index (SII), and the Aggregate Index of Systemic Inflammation (AISI) were significantly increased in SCA2 subjects compared with controls. The increases in PLR, SII, and AISI were even observed in preclinical carriers. NLR, PLR, and SII were correlated with the Scale for the Assessment and Rating of Ataxia speech item score rather than with the total score. The NLR and SII were correlated with the nonataxia and the cognitive scores.

CONCLUSIONS

Peripheral inflammatory indices are biomarkers in SCA2, which may help to design future immunomodulatory trials and advance our understanding of the disease. © 2023 International Parkinson and Movement Disorder Society.

Associations Between Mild Cognitive Impairment and Whole Blood Zinc and Selenium in the Elderly Cohort

Some studies have shown that an imbalance in trace element homeostasis can lead to cognitive dysfunction, but data are lacking. The purpose of this study was to investigate the association between whole blood zinc (Zn), selenium (Se), copper-zinc ratio (Cu/Zn), copper-selenium ratio (Cu/Se), and zinc-selenium ratio (Zn/Se) and mild cognitive impairment (MCI) in elderly Chinese individuals. The study was based on the Elderly Health and Controlled Environmental Factors Cohort in Lu'an, Anhui Province, China, from June to September 2016. The cognitive function of the elderly was determined by the Mini-Mental State Examination (MMSE) and activities of daily living (ADL) scales. The concentrations of Zn, Cu, and Se in the whole blood were measured by inductively coupled plasma-mass spectrometry (ICP-MS). Binary logistic regression was used to analyze the associations between trace elements and MCI. A total of 1006 participants with an average age of 71.70 years old were included in this study. Compared with healthy people, MCI patients had higher whole blood Zn levels and lower Se levels, and Cu/Zn, Cu/Se, and Zn/Se were also significantly different. Binary logistic regression analysis showed that Zn, Cu/Se, and Zn/Se exposure in the third tertile was associated with an increased risk of MCI, while Se exposure in the third tertile was associated with a reduced risk of MCI. After adjustment for sex, age, marital status, BMI, and living status, whole blood Zn, Se, Cu/Zn, Cu/Se, and Zn/Se were significantly associated with MCI risk, especially in elderly women.

Association of dietary inflammatory index and leukocyte telomere length with mild cognitive impairment in Chinese older adults

BACKGROUND

There are minimal data on the relationship between DII and MCI in an elderly Chinese population and no research has assessed the potential effect of LTL.

OBJECTIVE

We investigated the association between DII and MCI while taking into account the potential effect of LTL.

METHODS

This cross-sectional study included 3,386 participants aged ≥ 60 years of age from the Tianjin Elderly Nutrition and Cognition Cohort study. DII score was constructed based on a validated self-administered food frequency questionnaire was calculated based on the method developed by Shivappa et al. LTL was measured by quantitative real-time polymerase chain reaction. Multivariable logistic regression analysis was used to analyze the association between DII, LTL and MCI. Moreover, mediation analysis was employed to test the mediation effect of LTL on the total effect of DII on MCI.

RESULTS

Compared with the participants in the lowest tertiles of LTL and DII score, the odds ratios (ORs) of MCI in the highest tertiles were 0.386(95% CI: 0.281-0.529) and 1.650 (95% CI: 1.232-2.209), respectively. The significant association between DII score and MCI persisted after further adjusting for LTL (OR: 1.595; 95% CI: 1.189-2.140). The link between DII score and MCI was mediated partially by LTL (βindirect effect= -0.008, P<0.05).

CONCLUSION

High DII score was positively associated with MCI prevalence in an elderly Chinese population and the link between DII scores and MCI seemed to be mediated partially by LTL.

Blood cell ratios in mood and cognitive outcomes following electroconvulsive therapy

Systemic inflammation is commonly reported in depression, with dysregulation of both the innate and adaptive arms of the immune system documented. Obtaining ratios of neutrophils, platelets, and monocytes to counts of lymphocytes (NLR, PLR, MLR, respectively) represents a low-cost and easily reproducible measure of an individual's inflammatory burden that can be calculated effortlessly from routine clinical full white blood cell counts. Electroconvulsive therapy (ECT) remains the most effective acute antidepressant treatment for depression but is often limited by its cognitive side-effects. Here, we examined differences in blood cell ratios in subgroups of depressed patients (unipolar/bipolar, psychotic/non-psychotic, early-onset/late-onset) and ECT-related subgroups (responder/non-responder, remitter/non-remitter). We also explored the relationships between blood cell ratios and depression severity and immediate cognitive outcomes post-ECT. Our results show baseline NLR was raised in patients with psychotic depression. In the entire group of patients, significant negative correlations were noted between the PLR and SII and baseline HAM-D24 score, signifying that lower systemic inflammation is associated with more severe depressive symptoms. Significant positive correlations were noted between various blood cell ratios and mean time to recovery of orientation in the entire group of patients and in depression subgroups, indicating that increased peripheral inflammation is linked to worse cognitive outcomes post-ECT. Overall, our results suggest that assessment of blood cell ratios could be useful for predicting mood changes in patients at risk of developing depressive episodes or relapse following successful treatment or for identifying those at risk for cognitive side-effects following ECT.

Nomogram to predict postoperative cognitive dysfunction in elderly patients undergoing gastrointestinal tumor resection

OBJECTIVE

To establish a nomogram model for the prediction of postoperative cognitive dysfunction (POCD) in elderly patients undergoing gastrointestinal tumor resection.

METHODS

A total of 369 elderly patients scheduled for elective gastrointestinal tumor resection under general anesthesia were included. The cognitive function of each participant was assessed by the Mini-Mental State Examination (MMSE) 1 day before surgery and 7 days after surgery for the diagnosis of POCD. According to the results, patients were divided into a POCD group and a non-POCD group. The differences in hospitalization data and examination results between the two groups were compared. A logistic regression model was used to explore the risk factors for POCD in elderly patients undergoing gastrointestinal tumor resection, and a nomogram was then constructed based on these factors. The diagnostic performance of the nomogram was evaluated using the area under the receiver operating characteristic curve (AUROC) and a calibration plot. The clinical usefulness of the nomogram was estimated using decision curve analysis (DCA).

RESULTS

Among the 369 patients undergoing gastrointestinal tumor resection, 79 patients had POCD, with a positive rate of 21.4%. The nomogram model comprised the following variables: age, body mass index (BMI), history of cerebrovascular disease, preoperative white blood cell (WBC) count, preoperative hemoglobin (Hb) level, intra-operative blood loss, and operation time. The model showed good discrimination, with an area under the curve (AUC) of 0.710 (95% CI = 0.645-0.775), and good calibration (Hosmer-Lemeshow test, χ2 = 5.133, p = 0.274). Internal validation also maintained ideal discrimination and calibration. Decision curves indicated that when the threshold probability was above 0.1, the nomogram achieved more benefit than both the treat-all and treat-none policies.

CONCLUSION

This scoring system is the first nomogram model developed for the prediction of POCD in elderly patients undergoing gastrointestinal tumor resection. It has good efficacy in the prediction of POCD risk and could provide an important reference for the prevention, management, and treatment of POCD.

Lymphocyte Count and Neutrophil-to-Lymphocyte Ratio Are Associated with Mild Cognitive Impairment in Parkinson’s Disease: A Single-Center Longitudinal Study

Lymphocyte count and neutrophil-to-lymphocyte ratio (NLR) may represent useful biomarkers of Parkinson’s disease (PD), but their role in PD-related mild cognitive impairment (MCI) has not been fully elucidated. The present study aimed to confirm whether these immunological measures can discriminate PD patients from healthy controls (HC) and establish their feasibility as prognostic biomarkers of MCI in PD. Immunological data at baseline were analyzed in 58 drug-naïve PD patients and 58 HC matched 1:1 for age, sex, and cardiovascular comorbidities. We selected a subgroup of 51 patients from this initial cohort who underwent longitudinal neuropsychological assessments through the Addenbrooke’s Cognitive Examination Revised (ACE-R) test. We considered the last examination available to analyze the relationship between ACE-R test scores and immunological measures. We found that lymphocyte count was lower and NLR higher in PD than HC (p = 0.006, p = 0.044), with AUC = 0.649 and 0.608, respectively. Secondly, in PD-MCI there were significantly higher levels of circulating lymphocytes (p = 0.002) and lower NLR (p = 0.020) than PD with normal cognitive status (PD-NC). Correlations between lymphocyte count and ACE-R total score and memory subitem (r = −0.382, p = 0.006; r = −0.362, p = 0.01), as well as between NLR and ACE-R total score and memory subitem (r = 0.325, p = 0.02; r = 0.374, p = 0.007), were also found. ROC curve analysis showed that lymphocyte count and NLR displayed acceptable discrimination power of PD-MCI with AUC = 0.759 and 0.691, respectively. In conclusion, we suggest that an altered peripheral immune phenotype could foster cognitive decline development in PD, thus opening the possibility of immune-targeting strategies to tackle this disabling non-motor feature.

Lower preoperative serum uric acid level may be a risk factor for postoperative delirium in older patients undergoing hip fracture surgery: a matched retrospective case-control study

Background

Postoperative delirium (POD) is a common complication after hip fracture surgery that is associated with various short- and long-term outcomes. The mechanism of POD may be associated with the oxidative stress process. Uric acid has been shown to provide a neuroprotective effect in various neurodegenerative diseases through its antioxidant properties. However, it is unclear whether lower preoperative serum uric acid levels are associated with the development of POD after hip fracture surgery. Therefore, this study assessed the association of lower preoperative uric acid levels in patients with POD during hospitalization.

Methods

This is a matched retrospective case-control study that included 96 older patients (≥65 y) who underwent hip fracture surgery. POD was diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Patients diagnosed with POD (cases) were matched 1:1 with patients without POD (controls) on the basis of age, sex, and anesthesia type. The relationship between preoperative uric acid and POD was analyzed by multivariable analysis.

Results

The POD and non-POD groups each had 48 patients. In the univariate analysis, lower log preoperative serum uric acid value, higher neutrophil-to-lymphocyte ratio, and cerebrovascular disease were more likely in patients with POD than in those with no POD. Multivariable conditional logistic regression analysis showed that lower log preoperative serum uric acid (adjusted odds ratio [aOR], 0.028; confidence interval [CI], 0.001–0.844; p = 0.040), higher neutrophil-to-lymphocyte ratio (aOR, 1.314; 95% CI, 1.053–1.638; p = 0.015), and increased surgery duration (aOR, 1.034; 95% CI, 1.004–1.065; p = 0.024) were associated with increased risk of POD.

Conclusions

Lower preoperative serum uric acid levels may be an independent risk factor for POD after adjustment for possible confounding factors. However, large prospective studies are needed to confirm this finding.

High neutrophil percentage and neutrophil-lymphocyte ratio in acute phase of ischemic stroke predict cognitive impairment: A single-center retrospective study in China

Background and aims

Recently, various hemocyte and blood cell ratios have garnered researchers' attention, as a low-cost, widely prevalent, and easy-to-measure index for diagnosing and predicting disease. Therefore, we sought to investigate the effect and predictive value of the peripheral blood neutrophil percentage and neutrophil-lymphocyte ratio (NLR) in the acute phase of ischemic stroke (AIS) in post-stroke cognitive impairment (PSCI).

Methods

We selected 454 patients with mild AIS and acquired general clinical data. The patients were divided into PSCI and post-stroke no cognitive impairment (PSNCI) groups according to their Montreal Cognitive Assessment (MOCA) scores. We assessed whether there were differences in clinical data, peripheral blood neutrophil percentage, and NLR values between the different groups. We also analyzed the independent influences on the occurrence of PSCI using a binary logistic regression. Receiver operating characteristic (ROC) curves were used to analyze the predictive value of the above inflammatory indicators and models containing different inflammatory indicators for PSCI.

Results

In total, 454 patients were included, of whom 253 (55.7%) patients were in the PSCI group, with a mean age of 62.15 ± 7.34 years and median neutrophil percentage and NLR of 0.64 (0.32–0.95) and 2.39 (0.71–54.46), respectively. Both neutrophil percentage (adjusted OR = 1.025; 95% confidence interval: 1.005–1.406) and NLR as a categorical variable (Q5, adjusted OR = 2.167; 95% CI: 1.127–4.166) were independent risk factors for PSCI, and the Q5 group (NLR ≥ 4.05) had significantly worse overall cognition and executive function.

Conclusions

Neutrophil percentage and NLR in the acute phase of AIS were independently associated with PSCI, and a high NLR was strongly associated with executive function. In addition, neutrophil percentage and NLR have diagnostic values for PSCI.

Correlation between neutrophil/lymphocyte ratio and cognitive impairment in cerebral small vessel disease patients: A retrospective study

Background and objective

The blood neutrophil/lymphocyte ratio (NLR) is an objective and convenient parameter of systemic inflammation. Elevated NLR is associated with an increased risk of mild cognitive impairment (CI) in the elderly. However, few data are available on the impact of the NLR on CI in patients with cerebral small vessel disease (CSVD).

Methods

A total of 66 CSVD subjects with CI and 81 CSVD subjects without CI were evaluated in this study. Clinical, laboratory, radiological, and cognitive parameters were collected. The NLR was obtained with the absolute neutrophil count being divided by the absolute lymphocyte count in fasting blood samples. Logistic regression analysis was performed to evaluate the factors associated with CI. Receiver operating characteristic curves were illustrated to predict factors associated with CI in patients with CSVD.

Results

The NLR of the CI group was significantly higher than that of subjects without CI (2.59 vs. 2.21, P = 0.003). In multivariate analysis, NLR was positively correlated to the CI (OR: 1.43, 95% CI: 1.05–1.96, P = 0.024). It was suggested that the optimum NLR cutoff point for CI was 1.89 with 69.7% sensitivity and 59.3% specificity. Subjects with NLR ≥ 1.89 showed higher possibilities of CI compared to those with NLR < 1.89 (OR: 3.38, 95% CI: 1.62–7.07).

Conclusions

Correlations were found between NLR and CI. Patients with CSVD who have higher NLR might have an increased risk of CI.

Association of life course adiposity with risk of incident dementia: a prospective cohort study of 322,336 participants

Cohort studies report inconsistent associations between body mass index (BMI) and all-cause incident dementia. Furthermore, evidence on fat distribution and body composition measures are scarce and few studies estimated the association between early life adiposity and dementia risk. Here, we included 322,336 participants from UK biobank to investigate the longitudinal association between life course adiposity and risk of all-cause incident dementia and to explore the underlying mechanisms driven by metabolites, inflammatory cells and brain structures. Among the 322,336 individuals (mean (SD) age, 62.24 (5.41) years; 53.9% women) in the study, during a median 8.74 years of follow-up, 5083 all-cause incident dementia events occurred. The risk of dementia was 22% higher with plumper childhood body size (p < 0.001). A strong U-shaped association was observed between adult BMI and dementia. More fat and less fat-free mass distribution on arms were associated with a higher risk of dementia. Interestingly, similar U-shaped associations were found between BMI and four metabolites (i.e., 3-hydroxybutrate, acetone, citrate and polyunsaturated fatty acids), four inflammatory cells (i.e., neutrophil, lymphocyte, monocyte and leukocyte) and abnormalities in brain structure that were also related to dementia. The findings that adiposity is associated with metabolites, inflammatory cells and abnormalities in brain structure that were related to dementia risk might provide clues to underlying biological mechanisms. Interventions to prevent dementia should begin early in life and include not only BMI control but fat distribution and body composition.

Association of Peripheral Blood Cell Profile With Alzheimer's Disease: A Meta-Analysis

Background

Inflammation and immune dysfunction play significant roles in the pathogenesis of Alzheimer's disease (AD)-related dementia. Changes in peripheral blood cell profiles are a common manifestation of inflammation and immune dysfunction and have been reported in patients with AD or mild cognitive impairment (MCI). We systematically evaluated the association of peripheral blood cell counts and indices with AD or MCI through a meta-analysis.

Methods

We electronically searched sources to identify all case–control trials comparing peripheral blood cell counts and/or lymphocyte subsets between patients with AD or MCI and healthy controls (HCs). Meta-analyses were used to estimate the between-group standardized mean difference (SMD) and 95% confidence interval (CI).

Results

A total of 36 studies involving 2,339 AD patients, 608 MCI patients, and 8,352 HCs were included. AD patients had significantly decreased lymphocyte counts (SMD −0.345, 95% CI [−0.545, −0.146], P = 0.001) and significantly increased leukocyte counts (0.140 [0.039, 0.241], P = 0.006), neutrophil counts (0.309 [0.185, 0.434], P = 0.01), and neutrophil–lymphocyte ratio (NLR) (0.644 [0.310, 0.978], P < 0.001) compared to HCs. Similarly, significantly increased leukocyte counts (0.392 [0.206, 0.579], P < 0.001), NLR (0.579 [0.310, 0.847], P < 0.001), and neutrophil counts (0.248 [0.121, 0.376], P < 0.001) were found in MCI patients compared with HCs. A significantly decreased percentage of B lymphocytes (−1.511 [−2.775, −0.248], P = 0.019) and CD8⁺ T cells (−0.760 [−1.460, −0.061], P = 0.033) and a significantly increased CD4/CD8 ratio (0.615 [0.074, 1.156], P = 0.026) were observed in AD patients compared to HCs. Furthermore, significant changes in hemoglobin level and platelet distribution width were found in patients with AD or MCI compared with HCs. However, no significant difference was found between AD or MCI patients and HCs in terms of platelet counts, mean corpuscular volume, red cell distribution width, mean platelet volume, and CD4⁺ T, CD3⁺ T, or natural killer cell counts.

Conclusion

Changes in peripheral blood cell profiles, particularly involving leukocyte, lymphocyte, neutrophil, and CD8⁺ T cell counts, as well as the NLR and the CD4/CD8 ratio, are closely associated with AD. The diagnostic relevance of these profiles should be investigated in future.

Leukoaraiosis Mediates the Association of Total White Blood Cell Count With Post-Stroke Cognitive Impairment

Background and Purpose

The inflammatory response could play a key role in cognitive impairment. However, there has been limited research into the association between total white blood cell (WBC) count and post-stroke cognitive impairment (PSCI), and the significance of leukoaraiosis (LA) in this relationship is unknown. We aimed to examine the total WBC count in relation to PSCI and whether this association was mediated by LA.

Methods

Consecutive patients with first-ever ischemic stroke were prospectively enrolled from October 2020 to June 2021. The total WBC count was measured after admission. Cognitive function evaluations were performed at the 3-month follow-up using Mini-mental State Examination (MMSE). We defined the PSCI as an MMSE score <27.

Results

A total of 276 patients (mean age, 66.5 years; 54.7% male) were included in this analysis. Among them, 137 (49.6%) patients experienced PSCI. After adjustment for potential confounders, higher total WBC count was significantly correlated with an increased risk of LA [per 1-SD increase, odds ratio (OR), 1.39; 95% CI 1.06–1.82; p = 0.017] and PSCI (per 1-SD increase, OR, 1.51; 95% CI 1.12–2.04; p = 0.006). Furthermore, mediation analysis demonstrated that the association between total WBC count and PSCI was partly mediated by LA (the regression coefficient was changed by 9.7% for PSCI, and 12.4% for PSCI severity, respectively).

Conclusion

Increased total WBC count is a risk factor for PSCI. The presence of LA was partially responsible for the PSCI in patients who had a higher total WBC count.

Cross-Sectional Association Between Blood Cell Phenotypes, Cognitive Function, and Brain Imaging Measures in the Community-Based Framingham Heart Study

BACKGROUND

Peripheral inflammation is associated with increased risk for dementia. Neutrophil to lymphocyte ratio (NLR), red cell distribution width (RDW), and mean platelet volume (MPV), are easily measured circulating blood cell phenotypes reflecting chronic peripheral inflammation, but their association with dementia status is unclear.

OBJECTIVE

We sought to investigate the cross-sectional association of these inflammatory measures with neuropsychological (NP) test performance, and brain magnetic resonance imaging (MRI) measures in the Framingham Heart Study (FHS) Offspring, Third-generation, and Omni cohorts.

METHODS

We identified FHS participants who attended an exam that included a complete blood cell count (CBC) and underwent NP testing (n = 3,396) or brain MRI (n = 2,770) within five years of blood draw. We investigated the association between NLR, RDW, and MPV and NP test performance and structural MRI-derived volumetric measurements using linear mixed effect models accounting for family relationships and adjusting for potential confounders.

RESULTS

Participants were on average 60 years old, 53% female, and about 80% attended some college. Higher NLR was significantly associated with poorer performance on visual memory, and visuospatial abilities, as well as with larger white matter hyperintensity volume. We also observed associations for higher RDW with poorer executive function and smaller total cerebral brain volume.

CONCLUSION

Chronic peripheral inflammation as measured by NLR and RDW was associated with worse cognitive function, reduced brain volume, and greater microvascular disease in FHS participants. If confirmed in other samples, CBC may provide informative and cost-effective biomarkers of abnormal brain aging in the community.

Correlation between neutrophil-to-lymphocyte ratio and postoperative mortality in elderly patients with hip fracture: a meta-analysis

Introduction

The neutrophil-to-lymphocyte ratio (NLR) is a crucial prognosis predictor following several major operations. However, the association between NLR and the outcome after hip fracture surgery is unclear. In this meta-analysis, we investigated the correlation between NLR and postoperative mortality in geriatric patients following hip surgery.

Method

PubMed, Embase, Cochrane library, and Google Scholar were searched for studies up to June 2021 reporting the correlation between NLR and postoperative mortality in elderly patients undergoing surgery for hip fracture. Data from studies reporting the mean of NLR and its 95% confidence interval (CI) were pooled. Both long-term (≥ 1 year) and short-term (≤ 30 days) mortality rates were included for analysis.

Result

Eight retrospective studies comprising a total of 1563 patients were included. Both preoperative and postoperative NLRs (mean difference [MD]: 2.75, 95% CI: 0.23–5.27; P = 0.03 and MD: 2.36, 95% CI: 0.51–4.21; P = 0.01, respectively) were significantly higher in the long-term mortality group than in the long-term survival group. However, no significant differences in NLR were noted between the short-term mortality and survival groups (MD: − 1.02, 95% CI: − 3.98 to 1.93; P = 0.5).

Conclusion

Higher preoperative and postoperative NLRs were correlated with a higher risk of long-term mortality following surgery for hip fracture in the geriatric population, suggesting the prognostic value of NLR for long-term survival. Further studies with well-controlled confounders are warranted to clarify the predictive value of NLR in clinical practice in geriatric patients with hip fracture.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02831-6.

Neutrophil-lymphocyte ratio as a predictor of slow gait speed in older adults: The Rugao Longitudinal Aging Study

BACKGROUND

Few studies have investigated the association of the neutrophil-to-lymphocyte ratio (NLR) with gait speed, but whether the NLR is predictive of slow gait speed in older adults remains unknown. The aim of this study is to examine the association of NLR levels with risk of slow gait speed development in older adults.

METHODS

Overall, 1753 participants (53.11% male, aged 60-92 years, with a mean age of 77.01 ± 4.27 years) from the second wave of the Rugao Longitudinal Aging Study were included. The second wave was recognized as the baseline in this study. Gait speed was measured using a 5-m walk test at baseline and at the 3.5-year follow-up. A slow gait speed was considered a walking speed less than 0.8 m/s. The NLR was calculated based on absolute blood neutrophil and lymphocyte counts. Logistic regression models were used to investigate the association between NLR levels and slow gait speed.

RESULTS

In the cross-sectional analysis, 394 individuals were identified as having slow gait speed. We found that increased NLR levels were associated with a higher risk of slow gait speed in older adults with and without comorbidities (P-value <0.05). During the 3.5-year follow-up period, 440 individuals had developed new-onset slowness. After confounding factors were controlled, increased NLR levels were significantly and independently associated with an increased risk of slow gait speed among older adults with (odds ratio [OR] 3.82, 95% confidence interval [CI] 1.87-7.89) and without (OR 3.29, 95% CI: 1.54-7.10) comorbidities.

CONCLUSION

The NLR is an inexpensive and easily obtainable inflammatory biomarker that robustly and independently predicts slow gait speed risk in older adults.

Persistent psychopathology and neurocognitive impairment in COVID-19 survivors: Effect of inflammatory biomarkers at three-month follow-up

COVID-19 outbreak is associated with mental health implications during viral infection and at short-term follow-up. Data on psychiatric and cognitive sequelae at medium-term follow-up are still lacking. During an ongoing prospective cohort study, the psychopathological and cognitive status of 226 COVID-19 pneumonia survivors (149 male, mean age 58) were prospectively evaluated one and three months after hospital discharge. Psychiatric clinical interview, self-report questionnaires, and neuropsychological profiling of verbal memory, working memory, psychomotor coordination, executive functions, attention and information processing, and verbal fluency were performed. Three months after discharge from the hospital, 35.8% still self-rated symptoms in the clinical range in at least one psychopathological dimension. We observed persistent depressive symptomatology, while PTSD, anxiety, and insomnia decreased during follow-up. Sex, previous psychiatric history, and the presence of depression at one month affected the depressive symptomatology at three months. Regardless of clinical physical severity, 78% of the sample showed poor performances in at least one cognitive domain, with executive functions and psychomotor coordination being impaired in 50% and 57% of the sample. Baseline systemic immune-inflammation index (SII), which reflects the immune response and systemic inflammation based on peripheral lymphocyte, neutrophil, and platelet counts, predicted self-rated depressive symptomatology and cognitive impairment at three-months follow-up; and changes of SII predicted changes of depression during follow-up. Neurocognitive impairments associated with severity of depressive psychopathology, and processing speed, verbal memory and fluency, and psychomotor coordination were predicted by baseline SII. We hypothesize that COVID-19 could result in prolonged systemic inflammation that predisposes patients to persistent depression and associated neurocognitive dysfunction. The linkage between inflammation, depression, and neurocognition in patients with COVID-19 should be investigated in long-term longitudinal studies, to better personalize treatment options for COVID-19 survivors.

The neutrophil-to-lymphocyte ratio in Alzheimer's disease: Current understanding and potential applications

Alzheimer's disease (AD) is a chronic neurodegenerative disorder affecting millions of people, and its prevalence is expected to continue to grow in the older age population. It is characterized by cognitive impairment and dementia on the long term leading to a wide spectrum of social and financial burdens. Due to these burdens, there is a need to have a better understanding of the disease pathophysiology as well as to come up with more readily available and cost-effective screening tools to provide an acceptable estimate of the disease risk/diagnosis in the early years of the disease before dementia develops as it is in these early years that lifestyle modifications can be more effective in protecting against and delaying the frank cognitive impairment associated with AD. Recently, there has been a more detailed, yet incomplete, comprehension of the inflammatory component of the AD pathophysiology. The inflammatory response in AD entails hyperactivation of neutrophils with noticeable changes in their subsets and increased migration of lymphocytes into the central nervous system (CNS) across the compromised blood-brain barrier (BBB). These changes in the counts of the different immune cells in AD allowed for pursuing a new cost-effective, and more widely accessible diagnostic tool, which is the neutrophil-to-lymphocyte ratio (NLR). In this review, we aimed to discuss the inflammatory response in AD, and how this response is reflected in the counts of different immune cells, mainly neutrophils and lymphocytes which can be implemented in the utility of NLR as a diagnostic tool in AD patients.