White cell counts in relation to mortality in a general population of cohort study in the Netherlands: a mediating effect or not?

Systemic immune inflammation index with all-cause and cause-specific mortality: a meta-analysis

IMPORTANCE

Studies have reported an association among systemic immune inflammation index (SII), all-cause and cause-specific mortality, but the results are inconsistent.

OBJECTIVE

To comprehensively explore the association between Systemic Immune Inflammation (SII) and the risk of all-cause mortality, cardiovascular disease (CVD), and cancer mortality.

EVIDENCE REVIEW

A meta-analysis was conducted by reviewing existing literature. The search encompassed prominent databases including PubMed, Embase, Cochrane, and the Web of Science, with the cutoff date set at March 1, 2024. Furthermore, subgroup analyses and dose-response assessments were undertaken to provide a nuanced exploration of mortality risk factors.

FINDINGS

A total of 33 articles were included (427,819 participants). In the study, SII was associated with an increased risk of all-cause mortality (HR = 1.45, 95%CI [1.36,1.54], P < 0.05). SII increased the risk of CVD mortality (HR = 1.44, 95%CI [1.29,1.60], P < 0.05). The Linear independence shows that for every 100 units increase in SII, the risk of all-cause and CVD death increases by 5% and 6%. SII was not associated with a statistically significant risk of cancer death (HR = 1.09, 95%CI [0.96,1.23], P < 0.05).

CONCLUSIONS AND RELEVANCE

Meta-analysis showed that SII was associated with all-cause mortality and CVD mortality. More data and basic research are needed to confirm the association.

Systemic Inflammatory Indicators and Risk of Incident Metabolically Unhealthy Phenotype

Objective

This retrospective cohort study was designed to evaluate the association between eight systemic inflammation indicators at baseline and the metabolically unhealthy (MU) phenotype after two years of follow-up.

Methods

Participants were defined as metabolically healthy (MH) if they met 0-2 of the criteria and metabolically unhealthy (MU) if they met ≥ 3 of the criteria. A many of 4175 subjects aged 20-80 years with a metabolically healthy (MH) phenotype at baseline were enrolled in the study. We compared the clinical characteristics between women and men enrolled at baseline according to the metabolic phenotype at follow-up. The associations between baseline inflammation indicators and MU status at follow-up were evaluated using logistic regression analysis.

Results

922 (22.08%) developed new-onset MU symptoms during follow-up. Logistic regression analysis found that most inflammation indicators were significantly associated with MU phenotype at follow-up, aside from the LMR and SII. After adjusting for potential confounders, only the correlations between CRP level, neutrophil count, and MU phenotype reached significance. In comparison to the control group with a CRP of <0.50 mg/L, the odds ratios (ORs) and 95% confidence intervals (CIs) were 1.61 (1.25-2.09), 1.49 (1.15-1.94), and 1.68 (1.30-2.18) for individuals with CRP levels of 0.50-0.90 mg/L, 0.91-1.72 mg/L, and above 1.72 mg/L, respectively. In the population with a neutrophil count <5.00 ×109 cells/L, the neutrophil count correlated positively and significantly with the MU phenotype. In comparison to the control group with a neutrophil count of <2.75 × 109 cells/L, the ORs and 95% CIs were 1.65 (1.30-2.09) in the population with neutrophil count >4.17 × 109 cells/L.

Conclusion

CRP and neutrophil counts positively correlated with the risk of MU phenotype in Chinese subjects. These composite inflammatory markers (NLR, PLR, LMR, and SII) provide limited advantages for predicting MU risks compared to CRP.

Association between diet quality and all-cause mortality in a large Dutch cohort

Food-based dietary guidelines are helpful for governments and health agencies to encourage healthy eating at the population level. In order to assess adherence to such guidelines, index scores have been developed, the version in the Netherlands being the Dutch Healthy Diet-index (2015) (DHD2015-index), which reflect adherence to the 2015 Dutch dietary guidelines. Because a higher diet quality, i.e. a higher adherence to the dietary guidelines, is associated with better health outcomes, a higher DHD2015-index score would also mean better outcomes on measures of health, such as all-cause mortality. The present study aimed to elucidate this by investigating the association between DHD2015-index score and mortality in the Dutch population using data from 97 999 participants in the Lifelines cohort study. For the analyses, Cox Proportional Hazards regression was used, whilst accounting for age, sex, physiological measurements, exercise, and biochemical and lifestyle variables. There was a strong negative association between DHD2015-index score and mortality. Hazard ratios for DHD2015-index scores below 60 were approximately 1.2x larger than the mean. Every 10 unit increase in DHD2015-index scores between 60 and 90 led to a 0.1 reduction in hazard ratio, and every 10 unit increase between 90 and the highest DHD2015-index scores led to a reduction in hazard ratios of 0.05. The hazard ratio for the lowest quartile of DHD2015-index scores was 1.14 (95% CI = 1.04-1.26), whereas that for the highest quartile was 0.88 (95% CI = 0.84-0.92). Our results show a clear inverse relationship between DHD2015-index score and all-cause mortality.

Impacts of systemic inflammation response index on the prognosis of patients with ischemic heart failure after percutaneous coronary intervention

Background

Atherosclerosis and cardiovascular diseases are significantly affected by low-grade chronic inflammation. As a new inflammatory marker, the systemic inflammation response index (SIRI) has been demonstrated to be associated with several cardiovascular disease prognoses. This study aimed to investigate the prognostic impact of SIRI in individuals having ischemic heart failure (IHF) following percutaneous coronary intervention (PCI).

Methods

This observational, retrospective cohort study was conducted at a single site. Finally, the research involved 1,963 individuals with IHF who underwent PCI, with a 36-month follow-up duration. Based on the SIRI quartiles, all patients were classified into four groups. Major adverse cardiovascular events (MACEs) were the primary outcomes. Every element of the main endpoint appeared in the secondary endpoints: all-cause mortality, non-fatal myocardial infarction (MI), and any revascularization. Kaplan-Meier survival analysis was conducted to assess the incidence of endpoints across the four groups. Multivariate Cox proportional hazards analysis confirmed the independent impact of SIRI on both the primary and secondary endpoints. The restricted cubic spline (RCS) was used to assess the nonlinear association between the SIRI and endpoints. Subgroup analysis was performed to confirm the implications of SIRI on MACE in the different subgroups.

Results

The main outcome was much more common in patients with a higher SIRI. The Kaplan-Meier curve was another tool that was used to confirm the favorable connection between SIRI and MACE. SIRI was individually connected to a higher chance of the main outcome according to multivariate analyses, whether or not SIRI was a constant [SIRI, per one-unit increase, hazard ratio (HR) 1.04, 95% confidence interval (95% CI) 1.01-1.07, p = 0.003] or categorical variable [quartile of SIRI, the HR (95% CI) values for quartile 4 were 1.88 (1.47-2.42), p <0.001, with quartile 1 as a reference]. RCS demonstrated that the hazard of the primary and secondary endpoints generally increased as SIRI increased. A non-linear association of SIRI with the risk of MACE and any revascularization (Non-linear P <0.001) was observed. Subgroup analysis confirmed the increased risk of MACE with elevated SIRI in New York Heart Association (NYHA) class III-IV (P for interaction = 0.005).

Conclusion

In patients with IHF undergoing PCI, increased SIRI was a risk factor for MACE independent of other factors. SIRI may represent a novel, promising, and low-grade inflammatory marker for the prognosis of patients with IHF undergoing PCI.

Nutritional State, Immunological and Biochemical Parameters, and Mortality in the ICU: An Analytical Study

Intensive care unit (ICU) hospitalization involves critically ill patients with multiple diseases and possible complications, including malnutrition, which increases hospital stay and mortality. Therefore, identifying the patient's prior nutritional state, following up during hospitalization, and implementing early intervention positively affect patient's vital situations at discharge. The objective of this study is to determine the nutritional state of patients admitted to an ICU in Cali (Colombia) in 2019 and its association with immunological and biochemical parameters and mortality observed during hospitalization. This was an observational, analytical, and retrospective study of patients admitted to an ICU in a clinic in Cali (Colombia) from 1 January to 31 March 2019. The association between their nutritional state and outcome variables such as hospital stay, immunological and biochemical function, and mortality was analyzed. Logistic regression was used to predict patients' vital status at hospital discharge. In terms of the nutritional level, low weight was observed in 17.5% patients, and overweight/obesity was observed in 53.5% of the population. Nutritional state was associated with leukocytosis. The patients with lymphocytosis had longer hospital stays than those with normal lymphocyte ranges. Age, blood leukocytes, and creatinine and potassium levels increased the risk of mortality. Lymphocyte values have been used as predictors of severity and hospitalization time. The scientific literature has also evidenced a higher leukocyte count in people with obesity, and such leukocytosis is associated with the risk of mortality. The results of blood and laboratory tests determining kidney function and blood electrolytes allow for the prediction of mortality risk in critically ill patients.

Comparison of the Early Warning Effects of Novel Inflammatory Markers SIRI, NLR, and LMR in the Inhibition of Carotid Atherosclerosis by Testosterone in Middle-Aged and Elderly Han Chinese Men in the Real World: A Small Sample Clinical Observational Study

The purpose of this study was to explore and compare the relationship among serum testosterone, systemic inflammatory response index (SIRI), lymphocyte-to-monocyte ratio (LMR) neutrophil-lymphocyte ratio (NLR), and carotid atherosclerosis in middle-aged and elderly men of Han nationality in the real world. With reference to the inclusion criteria, 89 middle-aged and elderly Han male patients were finally selected. Local weighted regression (LOESS) and multivariate logistic regression models were used to explore the independent correlation between serum testosterone, new inflammatory markers, and atherosclerosis. The diagnostic value of related indexes was evaluated by the receiver working curve characteristic curve (ROC), and the best critical value of testosterone and related inflammatory indexes was discussed. In the LOESS model, bioavailable testosterone (BT), free testosterone (FT), total testosterone (TT) and SIRI, NLR, LMR, and atherosclerosis were significantly correlated. After adjusting for confounding factors, BT, FT, TT, and LMR were negatively correlated with atherosclerosis (odds ratio [OR] < 1, p < .05), and SIRI and NLR were positively associated with atherosclerosis (OR > 1, p < .05). According to the ROC curve results, the area under the curve (AUG) of BT is 0.870, and the optimal threshold point is 4.875. The AUG of SIRI is 0.864, and the best threshold point is 0.769. Low testosterone and high inflammatory levels are closely related to atherosclerosis. Testosterone (TT, FT, and BT) and new inflammatory markers, SIRI, NLR, and LMR, are associated with carotid atherosclerosis in middle-aged and elderly men.

Predictive value of neutrophil-to-apolipoprotein A1 ratio in all-cause and cardiovascular death in elderly non-valvular atrial fibrillation patients

Neutrophil-to-apolipoprotein AI ratio's (NAR's) predictive value for the elderly non-valvular atrial fibrillation (NVAF) patients' death has not been fully recognized. We consecutively enrolled 1224 elderly patients with NVAF (≥75 years). With an average follow-up of 733.35 ± 271.39 days, 222 all-cause deaths were identified. Among these, 101 were caused by cardiovascular diseases. Cox regression showed that after correcting for potential confounders, patients in the Q4 group had an increased all-cause (hazard ratio [HR] = 1.90, 95% confidence interval [CI]: 1.20-2.99) and cardiovascular death (HR = 2.59, 95% CI: 1.30-5.15) risk compared to those in the lowest NAR quartile. Kaplan-Meier analysis indicated that all-cause and cardiovascular death were higher in the high NAR than those in the lowest NAR category (log rank, all, P < 0.001). A nonlinear association was observed between death and NAR. NAR may be a promising predictive biomarker for identifying elderly NVAF patients with poor clinical prognoses.

The Association between Serum Vitamin D Concentration and New Inflammatory Biomarkers-Systemic Inflammatory Index (SII) and Systemic Inflammatory Response (SIRI)-In Patients with Ischemic Heart Disease

The incidence of ischemic heart disease (IHD) increases every year. This cardiovascular disease has an inflammatory factor in its etiology due to different immune cells that influence atherogenesis. New inflammatory biomarkers—the Systemic Inflammatory Index (SII) and the Systemic Inflammatory Response (SIRI)—attempt to describe the pro- and anti-inflammatory balance and quantify the complex impact of the immune system on atherosclerosis, while vitamin D has a multidirectional impact on the human body, including the cardiovascular and immune systems. Hence, the objective of this research was to analyze the association between SII and SIRI and serum vitamin D concentrations in patients with IHD. A significant correlation was observed between SIRI and 25(OH)D in the whole group and between both biomarkers (SII and SIRI) and 25(OH)D in the group of patients with ACS but not in the group of patients with stable IHD. The role of vitamin D in IHD complications and its association with new inflammatory biomarkers requires further well-designed, large-scale research.

Investigation of the Associations of Novel Inflammatory Biomarkers-Systemic Inflammatory Index (SII) and Systemic Inflammatory Response Index (SIRI)-With the Severity of Coronary Artery Disease and Acute Coronary Syndrome Occurrence

Atherosclerosis, the underlying cause of coronary artery disease (CAD), has a significant inflammatory component. White blood cell count is an affordable and accessible way to assess the systemic immune response, as it comprises many subgroups with distinct and complex functions. Considering their multidirectional effect on atherosclerosis, new biomarkers integrating various leukocyte subgroups, the Systemic Inflammatory Index (SII) and the Systemic Inflammatory Response Index (SIRI), were recently devised to describe the balance between inflammation and immune reaction. This research aimed to evaluate the relationship of the intensity of inflammation measured by these biomarkers with the severity of CAD assessed with coronary angiography and with the diagnosis of acute coronary syndrome (ACS) or stable CAD in 699 patients. SIRI, but not SII, was associated with the diagnosis, having the highest values for patients with ACS (STEMI), significantly higher than in patients with stable CAD (p < 0.01). The highest SII and SIRI values were observed in patients with three-vessel CAD. SII and SIRI require further in-depth and well-designed research to evaluate their potential in a clinical setting.

Pre-diagnosis neutrophil-to-lymphocyte ratio and mortality in individuals who develop lung cancer

Purpose

The neutrophil-to-lymphocyte ratio (NLR) is a marker of systemic inflammation that has been reported to be associated with survival after chronic disease diagnoses, including lung cancer. We hypothesized that the inflammatory profile reflected by pre-diagnosis NLR, rather than the well-studied pre-treatment NLR at diagnosis, may be associated with increased mortality after lung cancer is diagnosed in high-risk heavy smokers.

Methods

We examined associations between pre-diagnosis methylation-derived NLR (mdNLR) and lung cancer-specific and all-cause mortality in 279 non-small lung cancer (NSCLC) and 81 small cell lung cancer (SCLC) cases from the β-Carotene and Retinol Efficacy Trial (CARET). Cox proportional hazards models were adjusted for age, sex, smoking status, pack years, and time between blood draw and diagnosis, and stratified by stage of disease. Models were run separately by histotype.

Results

Among SCLC cases, those with pre-diagnosis mdNLR in the highest quartile had 2.5-fold increased mortality compared to those in the lowest quartile. For each unit increase in pre-diagnosis mdNLR, we observed 22–23% increased mortality (SCLC-specific hazard ratio [HR] = 1.23, 95% confidence interval [CI]: 1.02, 1.48; all-cause HR = 1.22, 95% CI 1.01, 1.46). SCLC associations were strongest for current smokers at blood draw (Interaction Ps = 0.03). Increasing mdNLR was not associated with mortality among NSCLC overall, nor within adenocarcinoma (N = 148) or squamous cell carcinoma (N = 115) case groups.

Conclusion

Our findings suggest that increased mdNLR, representing a systemic inflammatory profile on average 4.5 years before a SCLC diagnosis, may be associated with mortality in heavy smokers who go on to develop SCLC but not NSCLC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10552-021-01469-3.

Immune Status and Mortality in Smokers, Ex-smokers, and Never-Smokers: The Ludwigshafen Risk and Cardiovascular Health Study

INTRODUCTION

Elevated leukocyte counts are associated with cardiovascular disease. Smoking induces inflammation and alters levels of leukocyte subtypes.

AIMS AND METHODS

Our aim was to investigate the effect of smoking on circulating immune cells and their association with mortality. Lymphocyte subtypes were identified by flow cytometry of fluorescent-labeled cells. We analyzed the association of leukocytes with mortality using Cox regression and assessed their effect on risk prediction based on principle components (PCs) using area under the receiver operating characteristic curve and net-reclassification in 2173 participants from the Ludwigshafen Risk and Cardiovascular Health Study, a prospective case-control study in patients who underwent coronary angiography.

RESULTS

The numbers of T cells, monocytes, and neutrophils were higher and natural killer cells were lower in smokers compared with never-smokers. In never-smokers, lymphocyte counts were inversely associated with mortality while a positive association was observed for neutrophils. The neutrophil-to-lymphocyte ratio (NLR) had the strongest association in never-smokers with a hazard ratio (95% confidence interval) of 1.43 (1.26-1.61). No associations were found in smokers. Adding the first five PCs or the NLR to a risk prediction model based on conventional risk factors did not improve risk prediction in smokers, but significantly increased the area under the curve from 0.777 to 0.801 and 0.791, respectively, in never-smokers.

CONCLUSIONS

Lymphocyte counts were inversely associated with mortality in never-smokers but not in active smokers. Markers of innate immunity, namely total neutrophils and CD11b+/CD18+ and CD31+/CD40- granulocytes, were directly associated with mortality. Adding markers of immune function like PCs or the NLR to basic risk models improved risk prediction in never-smokers only.

IMPLICATIONS

Total leukocyte counts were higher in active smokers as compared to never-smokers due to elevated counts of neutrophils and monocytes but declined in ex-smokers with increasing time since quitting. In the never-smokers but not in smokers, lymphocyte counts were inversely associated with mortality while there was a direct association with neutrophils, even after adjustment for conventional cardiovascular risk factors. Adding markers of immune function to basic risk models improved risk prediction in never-smokers only. Our data indicate that smoking status has an important impact on the ability of leukocyte counts to predict long-term cardiovascular outcomes.

The Associations of Two Novel Inflammation Indexes, SII and SIRI with the Risks for Cardiovascular Diseases and All-Cause Mortality: A Ten-Year Follow-Up Study in 85,154 Individuals

Background

SII and SIRI are two novel systemic inflammation indexes that were suggested in predicting poor outcomes in cancers. However, no studies have examined their effect on cardiovascular diseases (CVDs) and all-cause mortality. Thus, this study aims to investigate associations between SII, SIRI, and the risks for CVDs and all-cause mortality.

Methods

A total of 85,154 participants from the Kailuan cohort were included and followed up for incidents of CVDs (including MI, stroke) and all-cause death for 10 years. Multiple Cox regression was used to calculate the adjusted hazard ratios (HRs).

Results

During the follow-up period, 4262 stroke events, 1233 MI events, and 7225 all-cause deaths were identified, respectively. Compared with the lowest quantile (Q1) of SII or SIRI, after adjusted for most cardiovascular risk factors, both indexes showed positive associations with the risk for stroke (adjusted HRs in Q4 were 1.264 (95% CI: 1.157,1.382) for SII, 1.194 (95% CI: 1.087,1.313) for SIRI), and all-cause death (adjusted HRs in Q4 were 1.246 (95% CI: 1.165,1.331) for SII, 1.393 (95% CI: 1.296,1.498) for SIRI). Additionally, higher SII and SIRI are also associated with increased risk of hemorrhagic stroke and ischemic stroke. Higher SIRI but not SII exhibited a higher MI risk, the adjusted HR in Q4 was 1.204 (1.013,1.431). The significant association remained after additional adjustment for CRP. Subgroup analysis and sensitivity analysis displayed consistent results except for SIRI with MI, where the association did not arrive at significance in subjects aged ≥60.

Conclusion

Elevated SII and SIRI increased the risk of stroke, two stroke subtypes, and all-cause death. Higher SIRI, but not SII associated with increased MI incidence, and the association of SIRI was only significant in subjects aged <60.

Differential effects of testosterone on circulating neutrophils, monocytes, and platelets in men: Findings from two trials

BACKGROUND

Testosterone treatment increases erythrocytes in men, but its effects on leukocyte and platelet counts are unknown and could affect its safety.

OBJECTIVE

To determine whether testosterone affects circulating leukocytes and platelets in men.

METHODS

Secondary analyses of two randomized testosterone trials were performed: the 5α-reductase (5aR) and OPTIMEN trials. In 5aR trial, 102 healthy men, 21-50 years (mean age 38), received a long-acting GnRH agonist, and 50, 125, 300, or 600 mg/week testosterone enanthate (TE) plus placebo or 2.5 mg/ day dutasteride for 20 weeks. In OPTIMEN, 78 functionally limited men, ≥65 years (mean age 72) with protein intake ≤ 0.83 g kg-1  day-1 , were randomized to controlled diets with 0.8 g kg-1  day-1 protein or 1.3 g kg-1  day-1 protein plus placebo or TE (100 mg/week) for 6 months. Changes from baseline in total and differential leukocyte count, and platelet count were evaluated.

RESULTS

In 5aR, testosterone administration was associated with increases in total leukocyte (estimated change from baseline 40, 490, 1230, and 1280 cells/µL, P < .001), neutrophil (65.1, 436.1, 1177.2, and 1192.2 cells/µL, P < .001), monocyte (-20.2, 24.5, 90.6, and 143.9 cells/µL, P < .001), platelet (-7.3, 8.4, 8.7, and 8.9 × 103 cells/µL, P = .033), and erythrocyte counts. Testosterone did not affect absolute lymphocyte count. Similar increase in total leukocyte count was observed with testosterone treatment in OPTIMEN (change 0.77 × 103 cells/µL, P vs placebo = 0.004).

CONCLUSIONS

Testosterone administration in men differentially increases neutrophil and monocyte counts. These findings, together with its erythropoietic effects, suggest that testosterone promotes the differentiation of hematopoietic progenitors into the myeloid lineage. These findings have potential mechanistic, therapeutic, and safety implications.