Association between the neutrophil-to-lymphocyte ratio and obstructive sleep apnea: a meta-analysis

The role of neutrophil to lymphocyte ratio in patients with COPD-OSA overlap syndrome

PURPOSE

The aim of this study is to investigate the role of the neutrophil to lymphocyte ratio (NLR) in patients diagnosed with the chronic obstructive pulmonary disease-obstructive sleep apnea (COPD-OSA) overlap syndrome and comorbid pulmonary hypertension (PH).

PATIENTS AND METHODS

We enrolled a consecutive of stable COPD patients and conducted spirometry measurements, nocturnal polysomnography (PSG), and echocardiography for all participants. Clinical laboratory data were collected.

RESULTS

A total of 178 patients with stable COPD were enrolled among whom 33.14% (59/178) were diagnosed with OSA. Of the patients with overlap syndrome, 35.59% (21/59) showed comorbid PH, compared to 34.45% (41/119) in COPD patients without OSA. There was no significant difference in the occurrence of PH between COPD with and without OSA. NLR was significantly higher in patients with overlap syndrome compared to those with either disease alone. The difference in NLR between COPD-OSA patients with and without PH was not significant. Correlation analysis revealed that NLR was associated with age, total sleep time spent with oxygen saturation below 90% (T90), CRP, pulmonary artery systolic pressure (PASP), and minimum peripheral capillary oxygen saturation (SpO2min) in all COPD patients. NLR was identified as an independent factor contributing to OSA in COPD. The median cut-off value for detecting OSA in stable COPD was 2.49. However, NLR was not found to be a predictor for PH in COPD-OSA overlap syndrome.

CONCLUSIONS

NLR can serve as a predictive marker for comorbid OSA in patients with COPD. NLR is expected to increase its clinical application as a convenient and cost-effective biomarker for COPD-OSA overlap syndrome.

The relationship between the systemic immune-inflammation index and obstructive sleep apnea

AIM

To investigate the predictive value of the systemic immune-inflammation index (SII) in patients with obstructive sleep apnea (OSA).

MATERIAL AND METHODS

Patients diagnosed with OSA formed the patient group, and those with a normal polysomnography (PSG) result formed the control group. The neutrophil, thrombocyte, monocyte, and lymphocyte counts obtained from the hemogram were used to calculate the neutrophil-to-lymphocyte ratio (NLR), thrombocyte-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and the SII values. The two groups were compared with respect to the NLR, PLR, MLR, and SII values. Correlations were examined between the PSG parameters and the NLR, PLR, MLR, and SII values in the patient group.

RESULTS

Evaluation included 146 subjects with 85 in the patient group and 61 in the control group. Statistically significantly higher SII and NLR values were found in the patient group (p = 0.037, p < 0.05; p = 0.015, p < 0.05). A statistically significant negative correlation was observed between the SII and the lowest O2 saturation measurements (r =  - 0.246; p = 0.003; p < 0.01). A statistically significant negative correlation was found between the NLR and the lowest O2 saturation measurement (r =  - 0.255; p = 0.002; p < 0.01). The cutoff value for SII was found to be 290, with 84.7% sensitivity and 29.5% specificity. A cutoff value of 1.71 for NLR was determined to have 61.2% sensitivity and 60.7% specificity.

CONCLUSION

SII may be a new, rapid, low-cost, and easy-to-measure biomarker for the prediction of obstructive sleep apnea.

Prognostic Role of Neutrophil to Lymphocyte Ratio in Allergic Rhinitis: A Systematic Review and Meta-analysis

One of the crucial triggers of allergic diseases is an inflammatory reaction and neutrophil to lymphocyte ratio (NLR) is one of the systemic inflammation biomarkers. Our review aimed to evaluate role of NLR in predicting severity and comorbidities of allergic rhinitis (AR). We systematically searched Scopus, Web of Science, and PubMed to find relevant studies. Standardized mean difference (SMD) with a 95% confidence interval (CI) was reported. Due to the high levels of heterogeneity, the random-effects model was used to generate pooled effects. Eleven articles were included in the systematic review, among which ten were included in meta-analysis including 1122 healthy controls and 1423 patients with AR. We found that patients with AR had a significantly higher level of NLR than healthy controls (SMD = 0.19, 95%CI = 0.03-0.36, P = 0.03). In addition, patients with moderate to severe AR had significantly higher levels of NLR compared to those with mild AR (SMD = 0.41, 95%CI = 0.20-0.63, P < 0.001). Interestingly, it was found that NLR could associate with some comorbidities of AR, like asthma. Our results confirmed that NLR could assist clinicians in predicting the severity and comorbidities of AR.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-04148-8.

Diagnostic Value of Neutrophil to Lymphocyte Ratio for Assessing Obstructive Sleep Apnea Risk in Surgical Patients

PURPOSE

Obstructive sleep apnea (OSA) is an important risk factor leading to perioperative complications in surgical patients. Neutrophil-to-lymphocyte ratio (NLR) is an important biomarker of increasing interest in recent years, and is used in the determination of systemic inflammatory response.

DESIGN

The aim of this study was to evaluate the risk of OSA and the relationship between OSA risk and NLR in surgical patients.

METHODS

The study was conducted in a tertiary care hospital between November 2021 and May 2022. The cross-sectional study included 604 patients who underwent surgery. OSA risk was evaluated with the STOP-Bang questionnaire in the preoperative evaluation in all patients. NLR was calculated as the ratio of neutrophil count to lymphocyte count.

FINDINGS

According to the STOP-Bang questionnaire, 62.3% of the patients had a high risk of OSA in the preoperative period. Patients who were male, elderly, obese, had hypertension, diabetes, chronic lung disease, and heart disease and polypharmacy were at greater risk of OSA. Patients at high risk of OSA had significantly higher NLR than patients at low risk of OSA. (2.65 vs 2.92, P.ß=.ß.024). NLR of 2.40 or higher predicted OSA risk with 58.8% sensitivity and 51.0% specificity (AUC.ß=.ß0.561) CONCLUSIONS: Most patients who were to undergo surgery had a high risk of OSA. NLR was higher in patients at high risk of OSA. Although the diagnostic efficacy is not high, NLR can be used to detect high OSA risk because it is a low-cost and easy to obtain biomarker.

Donor white blood cell differential is the single largest determinant of whole blood gene expression patterns

It has become widely accepted that sample cellular composition is a significant determinant of the gene expression patterns observed in any transcriptomic experiment performed with bulk tissue. Despite this, many investigations currently performed with whole blood do not experimentally account for possible inter-specimen differences in cellularity, and often assume that any observed gene expression differences are a result of true differences in nuclear transcription. In order to determine how confounding of an assumption this may be, in this study, we recruited a large cohort of human donors (n = 138) and used a combination of next generation sequencing and flow cytometry to quantify and compare the underlying contributions of variance in leukocyte counts versus variance in other biological factors to overall variance in whole blood transcript levels. Our results suggest that the combination of donor neutrophil and lymphocyte counts alone are the primary determinants of whole blood transcript levels for up to 75% of the protein-coding genes expressed in peripheral circulation, whereas the other factors such as age, sex, race, ethnicity, and common disease states have comparatively minimal influence. Broadly, this infers that a majority of gene expression differences observed in experiments performed with whole blood are driven by latent differences in leukocyte counts, and that cell count heterogeneity must be accounted for to meaningfully biologically interpret the results.

Variability in donor leukocyte counts confound the use of common RNA sequencing data normalization strategies in transcriptomic biomarker studies performed with whole blood

Gene expression data generated from whole blood via next generation sequencing is frequently used in studies aimed at identifying mRNA-based biomarker panels with utility for diagnosis or monitoring of human disease. These investigations often employ data normalization techniques more typically used for analysis of data originating from solid tissues, which largely operate under the general assumption that specimens have similar transcriptome composition. However, this assumption may be violated when working with data generated from whole blood, which is more cellularly dynamic, leading to potential confounds. In this study, we used next generation sequencing in combination with flow cytometry to assess the influence of donor leukocyte counts on the transcriptional composition of whole blood specimens sampled from a cohort of 138 human subjects, and then subsequently examined the effect of four frequently used data normalization approaches on our ability to detect inter-specimen biological variance, using the flow cytometry data to benchmark each specimens true cellular and molecular identity. Whole blood samples originating from donors with differing leukocyte counts exhibited dramatic differences in both genome-wide distributions of transcript abundance and gene-level expression patterns. Consequently, three of the normalization strategies we tested, including median ratio (MRN), trimmed mean of m-values (TMM), and quantile normalization, noticeably masked the true biological structure of the data and impaired our ability to detect true interspecimen differences in mRNA levels. The only strategy that improved our ability to detect true biological variance was simple scaling of read counts by sequencing depth, which unlike the aforementioned approaches, makes no assumptions regarding transcriptome composition.

Inflammatory biomarkers of neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios in 563 severe OSA patients before and after surgery

BACKGROUND

Evidence has proved that high neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were risk factors for cardiovascular comorbidities. The alterations of NLR and PLR following obstructive sleep apnea (OSA) treatment were under studied and thus should be investigated. This study aimed to evaluate the changes of inflammatory biomarkers including NLR and PLR in severe OSA patients after surgical interventions of the upper airway, and their relationships with improvements in polysomnographic (PSG) parameters.

METHODS

This retrospective cohort study included 563 consecutive severe OSA patients at a tertiary academic medical center who received OSA surgery, as well as underwent pre- and post-operative polysomnographic (PSG) examinations and blood tests. The changes of major PSG estimates, NLR, and PLR before and at least 3 months after OSA surgery were analyzed using paired t-tests with subgroup analyses. Pearson's correlations were performed to discover which PSG parameter contributed to the improvement of the values.

RESULTS

After OSA surgery, the major PSG estimates, NLR and PLR dropped significantly in the overall population. In those with a higher preoperative NLR (pre-operative NLR≧3) and PLR (pre-operative PLR≧150), the mean (SD) difference of NLR (- 0.8 [1.6], 95% CI - 1.5 to - 0.2) and PLR (- 41.6 [40], 95% CI - 52.8 to - 30.5) were even more substantial. The changes of the "apnea, longest (r = 0.298, P = .037)" and "hypopnea, longest (r = 0.321, P = .026)" were found significantly related to the improvement of PLR.

CONCLUSION

NLR and PLR did significantly drop in severe OSA patients following OSA surgery, and this could be related to the alterations of sleep indices. The findings could possess clinical importance for severe OSA patients after OSA surgeries in reducing possible OSA-associated cardiovascular comorbidities.

Evaluation of Inflammation and Oxidative Stress Markers in Patients with Obstructive Sleep Apnea (OSA)

Background: The identification of circulating markers of oxidative stress and systemic inflammation might enhance risk stratification in obstructive sleep apnea (OSA). We investigated the association between specific haematological parameters, as easily measurable markers of oxidative stress and inflammation, and the degree of hypoxia during polysomnography using the apnea hypopnea index (AHI), oxygen desaturation index (ODI), and oxygen saturation (SpO₂), in OSA patients. Methods: Associations between polysomnographic parameters and demographic, clinical, and laboratory characteristics were assessed in a consecutive series of patients with OSA attending the Respiratory Disease Unit of the University Hospital of Sassari, north Sardinia (Italy), between 2015 and 2019. Results: In 259 OSA patients (195 males and 64 females), the body mass index (BMI) was significantly and positively associated with the AHI and ODI, and negatively associated with the mean SpO₂. No haematological parameter was independently associated with the AHI or ODI. By contrast, albumin, neutrophil, and monocyte counts, and the systemic inflammatory response index (SIRI) were independently associated with a lower SpO₂. Conclusions: Our results suggest that albumin and specific haematological parameters are promising markers of reduced oxygen saturation in OSA.

Comparison of clinical features and surgical outcomes between hypopnea- and apnea-predominant obstructive sleep apnea

OBJECTIVES

This study is aimed to investigate the differences in the clinical features and surgical outcomes between hypopnea- and apnea-predominant obstructive sleep apnea (OSA).

DESIGN

Cohort study.

SETTING

Single tertiary care centre.

PARTICIPANTS

This study included 190 patients with OSA who underwent multilevel upper airway surgery between September 2012 and September 2021. The patients were divided into two groups according to the proportion of each respiratory event: hypopnea-predominant (n = 102) and apnea-predominant (n = 88).

MAIN OUTCOME MEASURES

The primary outcome measure was the percentage improvement in the apnea-hypopnea index (AHI) from baseline AHI after surgery.

RESULTS

The apnea-predominant group included more male patients and had higher AHI, respiratory disturbance index (RDI) and oxygen desaturation index (ODI) than the hypopnea-predominant group. Both groups showed significant improvements in AHI, apnea index, RDI, supine AHI, REM AHI, non-REM AHI, ODI, lowest O₂ saturation and Epworth Sleepiness Scale scores following the surgery. Notably, hypopnea index increased after surgery in the apnea-predominant OSA group. Although the improvement in the absolute value of AHI by surgery was significantly greater in the apnea-predominant group than in the hypopnea-predominant group, the two groups showed no significant difference in the percentage improvement in AHI from baseline AHI.

CONCLUSION

Patients with apnea-predominant OSA had more severe disease than those with hypopnea-predominant OSA; however, surgical outcomes, as evaluated by percentage AHI improvement, were comparable between the two groups. In addition, multilevel upper airway surgery may induce the transition from apnea to hypopnea in patients with apnea-predominant OSA.

Clinical Characteristics and Surgical Outcomes of Obstructive Sleep Apnea Patients With Mixed Apnea Components

OBJECTIVE

This study was aimed to investigate clinical implications of mixed apnea (MA) in patients with obstructive sleep apnea (OSA), particularly whether surgical outcomes differ between OSA patients with and without MA events.

STUDY DESIGN

Retrospective cohort study.

SETTING

Single tertiary medical center.

METHODS

Eighty-eight patients with OSA who underwent multilevel upper airway surgery were included. Patients were divided into 2 groups according to the presence of MA events: "pure group" (n = 30) and "mixed group" (n = 58). The clinical characteristics and surgical outcomes were compared between the 2 groups.

RESULTS

The mixed group included more males (P = .020) and hypertensive patients (P = .009) and had a higher apnea-hypopnea index (AHI; P < .001) than the pure group. The surgical success rate was lower in the mixed group (29.3%) than in the pure group (73.3%; P < .001). Furthermore, the postoperative improvements in total AHI (P < .001), supine AHI (P < .001), and oxygen desaturation index (P = .006) were lower in the mixed group than in the pure group. Logistic regression analysis confirmed that the presence of MA (P = .002) was an independent predictor of poor surgical outcomes in patients with OSA.

CONCLUSION

OSA patients with MA showed different clinical features and poor surgical outcomes compared to those without MA. These results imply that OSA with MA components may have a distinct pathophysiology, and the presence of MA should be considered in the surgical treatment of OSA.

T cell receptor repertoire as a novel indicator for identification and immune surveillance of patients with severe obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is the most prevalent sleep disturbance that affects approximately 936 million people worldwide and leads to extensively increased incidence of cardiovascular disease, metabolic syndrome, neurological disorders, and traffic accidents. Severe OSA patients suffer a significantly higher risk of complications and worse comorbidity outcomes. Notwithstanding, with inadequate access to contact diagnosis based on polysomnography (PSG), numerous patients with severe sleep apnea have not been diagnosed, especially during the pandemic. Moreover, how the T cell immunity is impaired in OSA remains largely unknown.

Methods

We primarily investigated the T cell receptor (TCR) repertoires of 50 patients with severe OSA, 23 patients with mild-to-moderate OSA, 23 patients without OSA, and 157 healthy individuals, from their peripheral blood. Firstly, we compared the clinical characteristics, blood cell counts, the ratio of neutrophil-to-lymphocyte (NLR), platelet-to-lymphocyte (PLR), and CD4+/CD8+T cell count between groups. Then, we compared the diversity, clonotypes, unique VJ alleles in patients with different disease severity. Furthermore, by identifying a series of disease-associated amino acid sequences, we employed a repeated hold-out machine learning strategy to explore the optimal algorithm for calculating the TCR repertoire characteristic Index (OSA-TCI). We further confirmed its relation with clinical features by linear regression analysis. Moreover, in followup of severe OSA patients who accepted adherent non-invasive ventilation, we assessed the changes of TCR repertoires, OSA-TCI, ESS, NLR, PLR, and CD4+/CD8+T after therapy.

Results

We found an unexpected increase in diversity and clonotypes in the TCR repertoire of OSA patients. Furthermore, we successfully developed a novel indicator termed OSA-TCI to summarize the unique repertoire alteration, which provided 90% of sensitivity and 87% of specificity in distinguishing severe OSA. In rationalization, OSA-TCI was found correlated to AHI, BMI, hemoglobin, N1, N2 percentage of sleep, snoring, smoking and lowest oxygen saturation, but only independently related to AHI (R = 0.603) and smoking (R = 0.22). Finally, we observed OSA-TCI in the eight severe patients decreased significantly after home noninvasive ventilation for three months during follow-up, consistently in line with the TCR repertoire improvement. In contrast, NLR, PLR, and the ratio of CD4+/CD8+T cell count were found useless to diagnose and therapeutic surveillance of severe OSA.

Conclusions

Our study is the first to unveil the TCR repertoire alteration in OSA, indicates possible insidious autoimmune mechanisms underlying OSA, and suggests that TCR repertoires serve as a convenient peripheral blood biomarker for OSA assessment without long-time contact and facility/instrument occupation. It may shed light on future diagnostic, immunological, pathophysiological, and prognostic research on OSA.

Role of Neutrophil to Lymphocyte Ratio in Predicting Severity of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) has been linked to and is associated with increased cardiovascular and cerebrovascular morbidity. Ongoing inflammatory responses play an important role in this association. Systemic inflammation is important in pathophysiology of OSA and its comorbidity. In this study, we aimed to evaluate the role of neutrophil-to-lymphocyte ratio (NLR) in OSA patients and comparing with other well-known inflammatory marker, C-reactive protein (CRP) along with thyroid-stimulating hormone(TSH) and body-mass index(BMI). We conducted a retrospective analysis of 162 patients with OSA and divided them into 2 categories based on apnea-hypopnea index (AHI) (< 30 and >  = 30), and recorded their leukocyte profiles, sex, age and body mass index. 80 matched healthy controls were taken. Patients were excluded if they had underlying cancer, chronic inflammatory disease, any systemic infection, uncontrolled hypertension and diabetes mellitus, a known acute coronary syndrome, valvular heart disease, renal or hepatic dysfunction. We found that N/L Ratio in severe OSA patients was significantly higher compared with mild and moderate OSA patients and healthy controls (p < 0.001). CRP levels were not different in all OSA stages (p = 0.595). We noted a significant difference in mean BMI of the two groups. In the wake of increase in prevalence of OSA in a developing country like India coupled with inadequate proportion of sleep labs, NLR is an inexpensive, easy to obtain, widely available marker of inflammation that might in combination with other markers assist in identifying patients with severe OSA.

Cellular Immune Dysfunction in Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder. Repetitive pauses in breathing during sleep cause a brief but recurrent decrease in oxygen saturation in organs and tissues (chronic intermittent tissue hypoxia). Many studies have proven a pro-inflammatory status in OSA patients. However, few reports are available on the effects of OSA on the cellular immune system, mostly focusing on single immune cell types and their subtypes. The aim of this Mini-Review is to summarize these reports, as OSA is associated with a high prevalence and comorbidities such as atherosclerosis, which are known to involve the cellular immune system.

P. G, Rahman W. Clinical and diagnostic significance of blood leukocyte ratios in young patients with stage III grade C periodontitis

OBJECTIVES

Blood leukocyte ratios have been recently proposed as simple, rapid, cheap and easily accessible biomarkers of systemic inflammation. However, little is known about the relationship of neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and lymphocyte-monocyte ratio (LMR) with periodontitis, which might not only serve as the potential biomarkers of systemic inflammation but also aid in diagnosis/screening of severe periodontitis. Hence, the purpose of this study was to evaluate the differences in the serum levels of these leukocyte ratios in healthy subjects and patients with generalized stage III Grade C periodontitis, and their applicability in identifying patients with the risk of developing severe periodontitis.

MATERIAL AND METHODS

The subjects were categorized into case and control group. Clinical parameters including Plaque index (PI), modified Gingival Index (mGI), Mean ratio of bleeding sites, Probing Pocket depth (PPD) and the clinical attachment loss (CAL) were assessed in both the groups. Venous blood samples were collected from subjects from both groups for the biochemical analysis and blood leukocyte ratios- NLR, PLR and LMR were calculated. The values were then subjected to statistical analysis.

RESULTS

The results showed significantly higher NLR and lower LMR values in patients with generalized stage III grade C periodontitis. Both the blood leukocyte ratios were moderately associated with increasing clinical parameters of periodontal disease. However, the values of PLR, although found to be higher in the periodontitis group, did not make a significant difference when compared with periodontally healthy subjects. The cut-off value of >2.15 for NLR and <7.16 for LMR fairly predicted the risk of severe periodontitis in young adults.

CONCLUSIONS

NLR and LMR can provide a new insight into the relationship between periodontitis and systemic diseases and can be of potential diagnostic value in identifying patients with severe periodontitis of younger age group.

Weight reduction added to CPAP decreases blood pressure and triglyceride level in OSA: systematic review and meta-analysis

Obstructive sleep apnea (OSA) is associated with treatment‐resistant hypertension and high cardiovascular risk. Continuous positive airway pressure (CPAP) fails to reduce cardiovascular risks consistently. Obesity and OSA show reciprocal association and they synergistically increase hypertension via different pathways. Our meta‐analysis aimed to assess the cardiovascular benefits of combining weight loss (WL) with CPAP (vs. WL or CPAP alone) in OSA. Outcomes included systolic and diastolic blood pressure (BP) and blood lipid parameters. We explored Medline, Embase, Cochrane, and Scopus. Eight randomized controlled studies (2627 patients) were included. The combined therapy decreased systolic BP more than CPAP alone. Weighted mean difference (WMD) for CPAP + WL versus CPAP was −8.89 mmHg, 95% confidence interval (95% CI; −13.67 to −4.10, p < 0.001) for systolic BP. For diastolic BP, this decrease was not significant. In case of blood lipids, the combined treatment decreased triglyceride levels more than CPAP alone (WMD = −0.31, 95% CI −0.58 to −0.04, p = 0.027). On the other hand, addition of CPAP to WL failed to suppress BP further. The certainty of evidence according to GRADE was very low to moderate. In conclusion, our results showed that the addition of WL to CPAP significantly improved BP and blood lipid values in OSA. On the other hand, the addition of CPAP to WL could not significantly improve BP or blood lipid values. Review protocol: PROSPERO CRD42019138998.

Is obstructive sleep apnea associated with erythrocytosis? A systematic review and meta‐analysis

Objective

The aim of this systematic review and meta‐analysis was to investigate the association between obstructive sleep apnea (OSA) and erythrocytosis.

Methods

The PubMed, Web of Science, and Cochrane Library databases were searched for articles examining hematocrit values in patients with OSA and control individuals published till September 1, 2021. The pooled standardized mean difference (SMD) with 95% confidence interval (CI) was calculated, and subgroup analyses were performed.

Results

Eleven eligible studies with a total of 4608 patients with OSA were included in this meta‐analysis. Pooled outcomes revealed that hematocrit values were significantly higher in patients with OSA than in controls (SMD, 0.19; 95% CI, 0.08–0.29; p < .01). When studies were stratified by disease severity, the significant differences in hematocrit values between patients and controls were only observed in the severe OSA group (SMD, 0.34; 95% CI, 0.08–0.59; p < .01), but not in the mild and moderate OSA groups. In subgroup analyses according to sex and publication year, significant differences in hematocrit values between patients and controls remained stable in studies with only female patients (SMD, 0.25; 95% CI, 0.12–0.38; p < .01) and in studies published after 2012 (SMD, 0.17; 95% CI, 0.06–0.28, p < .01).

Conclusion

Our meta‐analysis revealed that the hematocrit value was significantly increased in patients with OSA, particularly in severe patients, compared with that in controls. However, the elevation was modest, and the hematocrit value is expected to be within the normal range in patients with OSA. These data suggest that OSA leads to slight increases in hematocrit but does not cause clinically significant erythrocytosis.

The Neutrophil to Lymphocyte Ratio Is Associated With the Risk of Subsequent Dementia in the Framingham Heart Study

Objective: Active neutrophils are important contributors to Alzheimer’s disease (AD) pathology through the formation of capillary stalls that compromise cerebral blood flow (CBF) and through aberrant neutrophil signaling that advances disease progression. The neutrophil to lymphocyte ratio (NLR) is a proxy of neutrophil-mediated inflammation, and higher NLR is found in persons diagnosed with clinical AD. The objective of this study was to investigate whether increased NLR in older adults is independently associated with the risk of subsequent dementia.

Methods: We examined associations of baseline NLR with incident dementia risk in the community-based Framingham Heart Study (FHS) longitudinal cohorts. The association between NLR and risk of dementia was evaluated using the cumulative incidence function (CIF) and inverse probability-weighted Cox proportional cause-specific hazards regression models, with adjustment for age, sex, body mass index (BMI), systolic and diastolic blood pressure, diabetes, current smoking status, low-density lipoprotein (LDH), high-density lipoprotein (LDL), total cholesterol, triglycerides, and history of cardiovascular disease (CVD). Random forest survival models were used to evaluate the relative predictive value of the model covariates on dementia risk.

Results: The final study sample included 1,648 participants with FHS (average age, 69 years; 56% women). During follow-up (median, 5.9 years), we observed 51 cases of incident dementia, of which 41 were AD cases. Results from weighted models suggested that the NLR was independently associated with incident dementia, and it was preceded in predictive value only by age, history of CVD, and blood pressure at baseline.

Conclusion: Our study shows that individuals with higher NLR are at a greater risk of subsequent dementia during a 5.9-year follow-up period. Further evaluating the role of neutrophil-mediated inflammation in AD progression may be warranted.

Association between neutrophil to lymphocyte ratio and mortality among community acquired pneumonia patients: a meta-analysis

The neutrophil to lymphocyte ratio (NLR)is an emerging biomarker used in the prognosis of many conditions. We aimed to conduct a meta-analysis to assess the prognostic accuracy of the NLR in determining mortality in patients with Community acquired pneumonia (CAP). The Pubmed, EBSCO, and Scopus databases were searched to find all relevant articles. 10 articles with 5220 patients were included. The pooled area under the curve (AUC) of NLR admission levels to predict 30-Day mortality of CAP patients was 0.706; 95% CI (0.631 to 0.781), while the pooled AUC of NLR levels taken at 3-5 days was 0.882; 95% CI (0.818 to 0.945). Meta analysis also showed a significant difference in the NLR between the Survivors and 30-Day non-survivors. This difference was greater when NLR levels were taken at 3-5 days; Standardized mean difference (SMD) = 1.646; 95% CI (0.451 to 2.840) compared to NLR levels at admission SMD = 1.139; 95% CI (0.514 to 1.764). These results show that the NLR has potential to be incorporated in the routine assessment and stratification of CAP patients, especially in the early-stage evolution (3-5 days), keeping in mind the availability and cost effectiveness of this test.

Neutrophil-to-Lymphocyte Ratio Facilitates Identification of Obstructive Sleep Apnea in Patients with Type B Aortic Dissection

Purpose

To determine whether the neutrophil-to-lymphocyte ratio (NLR) aids in the detection of obstructive sleep apnea (OSA) in patients with type B aortic dissection (TBAD).

Methods

324 patients with TBAD or type B aortic intramural hematoma (TB-AIMH) underwent an overnight sleep study. We divided the eligible 256 studied subjects into three groups: group A (n = 109, TBAD patients with OSA), group B (n = 68, TB-AIMH patients with OSA), and group C (n = 79, TBAD patients without OSA). Baseline characteristics, biochemical and sleep parameters, and STOP-Bang questionnaire scores were collected. To assess the predictive efficacy of potential variables, multivariate logistic regression analysis and receiver operating characteristic (ROC) curves were used.

Results

The study found that about 58% of TBAD patients and 54% of TB-AIMH patients had OSA, a majority of whom had moderate to severe OSA (95.41% and 89.71%, respectively). In the comparison of sleep parameters between patients with TBAD and TB-AIMH, no other than apnea and hypopnea index (AHI) made a significant difference. The multivariate logistic regression analysis showed that neutrophil-to-lymphocyte ratio (NLR) (odds ratio (OR): 3.614, 95% confidence interval (CI): 2.273–5.748, and P < 0.05) and STOP-Bang scores (OR: 1.97, 95% CI: 1.34–2.90, and P < 0.05) were both independent predictors for OSA in patients with TBAD. ROC curves showed NLR had higher sensitivity (65% versus 59%) and specificity (86% versus 57%) for OSA than the STOP-Bang questionnaire. Furthermore, NLR was positively correlated with AHI through the Spearman test (r = 0.398 and P < 0.05).

Conclusion

NLR was an independent predictor of OSA in TBAD patients with higher sensitivity and specificity than the STOP-Bang questionnaire, and it was positively associated with AHI. NLR may aid in the diagnosis and risk stratification of OSA in TBAD patients.

Oxygen saturation as a predictor of inflammation in obstructive sleep apnea

PURPOSE

Obstructive sleep apnea (OSA) is a chronic sleep disorder, and its prevalence is increasing worldwide. This disorder has been consistently associated with several comorbidities. Although it is clear that obstructive sleep apnea severity is associated with inflammation, the trigger for this phenomenon continues to puzzle scientists. Here, we investigated the relationship between obstructive sleep apnea severity and immune parameters.

METHODS

In this cross-sectional epidemiological research, we analyzed the immune profile of 461 adults according to OSA severity (mild, moderate, and severe) and oxygen saturation.

RESULTS

The hallmark of OSA severity - the apnea-hypopnea index (AHI) - weakly correlated with an inflammatory profile. However, individuals who experienced lower oxygen saturation were more likely to exhibit higher total leukocyte and neutrophil counts, a higher neutrophil-lymphocyte ratio (NLR), and an increased concentration of C-reactive protein.

CONCLUSION

Our findings indicated that oxygen saturation is a predictor of inflammation during OSA and should be considered crucial in disease diagnostic and treatment strategies.

Biochemical and immunological changes in obesity

Obesity is a syndemia that promotes high expenditures for public health, and is defined by the excess of adipose tissue that is classified according to its function and anatomical distribution. In obese people, this tissue generates oxidative stress associated with a chronic inflammatory response, in which there is an imbalance in relation to the release of hormones and adipokines that cause loss of body homeostasis and predisposition to the development of some comorbidities. The purpose of this review is to summarize the main events that occur during the onset and progression of obesity with a special focus on biochemical and immunological changes. Hypertrophied and hyperplasia adipocytes have biomarkers and release adipokines capable of regulating pathways and expressing genes that culminate in the development of metabolic changes, such as changes in energy balance and intestinal microbiota, and the development of some comorbidities, diabetes mellitus, dyslipidemias, arterial hypertension, liver disease, cancer, allergies, osteoporosis, sarcopenia and obstructive sleep apnea. Thus, it is necessary to treat and/or prevent pathology, using traditional methods based on healthy eating, and regular physical and leisure activities.

Whole blood gene expression signature in patients with obstructive sleep apnea and effect of continuous positive airway pressure treatment

The molecular mechanisms of obstructive sleep apnea (OSA), in particular the gene expression patterns in whole blood of patients with OSA, can shed more light on the underlying pathophysiology of OSA and suggest potential biomarkers. In the current study, we have enrolled thirty patients with untreated moderate-severe OSA together with 20 BMI, age, and sex-matched controls and 15 normal-weight controls. RNA-sequencing of whole blood and home sleep apnea testing were performed in the untreated state and after three and twelve months of continuous positive airway pressure (CPAP) treatment. Analysis of the whole blood transcriptome of the patients with OSA revealed a unique pattern of differential expression with a significant number of downregulated immune-related genes including many heavy and light chain immunoglobulins and interferon-inducible genes. This was confirmed by the gene ontology analysis demonstrating enrichment with the biological processes associated with various immune functions. Expression of these genes was recovered after three months of CPAP treatment. After 12 months of CPAP treatment, the overall gene expression profile returns to the initial, untreated level. In addition, we have confirmed the importance of choosing BMI-matched controls as a reference group as opposed to normal-weight healthy individuals based on the significantly different gene expression signatures between these two groups.

Galectin-3 and neutrophil-to-lymphocyte ratio are indicative of heart remodelling and disease severity in patients with obstructive sleep apnoea

BACKGROUND

Galectin-3, considered as a new inflammatory marker; it is increased in cardiovascular disease. We investigated Galectin-3 in relation to heart damage in patients with OSA and its role in inflammation, based on the Neutrophil-to-Lymphocyte Ratio (NLR).

METHODS

Sixty-three consecutive patients (45 males, 18 females, 58.60 ± 12.28 years old) were studied. According to the Apnoea-Hypopnoea Index (AHI) patients were divided into Group 1 - non-severe (AHI <30) (17 males and 10 females, 59.89 ± 10.62 years old) and Group 2 - severe (AHI ≥30) (29 males and 6 females, aged 57.53 ± 13.30 years old) OSA. All patients underwent morning blood gas analysis, laboratory tests, nocturnal polygraphy, and echocardiography.

RESULTS

Galectin-3 was significantly increased in Group 2 (p = 0.027) patients. Moreover, it was directly related to left ventricle (LV) mass, left ventricle hypertrophy and LV posterior wall diameter. Tissue Doppler septal velocity (e'), that measures wall motion, was inversely correlated to Galectin-3. Furthermore, a direct association to diastolic dysfunction, evaluated as E/e' ratio, was observed. In line with these data, a direct correlation between Galectin-3 and left atrium volume was also found. Galectin-3 and percentage of total registration time with nocturnal oxygen saturation <90% (TST90) were directly correlated (p = 0.0003), while Galectin-3 and mean nocturnal SpO₂ were negatively correlated (p = 0.0045). We found a direct correlation between Galectin-3 and NLR (p = 0.011). Finally, Galectin-3 was able to predict 3-yr mortality with a specificity of 83.33% and a sensitivity of 91.84%.

CONCLUSION

Galectin-3 showed a direct association to nocturnal respiratory indices and to cardiac remodelling in patients with OSA. OSA-induced inflammation may play an important role in the pathogenesis of heart damage.

Obstructive Sleep Apnea is Related with the Risk of Retinal Vein Occlusion

BACKGROUND

Retinal vein occlusion (RVO) was a vision-threatening retinal vascular disorder, however, the relationship between obstructive sleep apnea (OSA) and RVO risk remained unclear.

METHODS

A total of 45 RVO cases and 45 controls between April 2018 and April 2020 were included. All the participants underwent full-night polysomnography (PSG) and thus detected the severity of OSA. Besides, the relationship between the apnea-hypopnea index (AHI) and oxidative and inflammatory biomarkers, including 8-hydroxy-2 deoxyguanosine (8-OHdG), C-reactive protein (CRP), interleukin 1 beta (IL1β), interleukin 6 (IL6) and tumor necrosis factor alpha (TNFα) were detected. The incidences of macular edema (ME) and neovascular glaucoma (NVG) were detected in a three-months follow-up.

RESULTS

In this case-control study, it was found that OSA incidence was increased in the RVO cases comparing with the cataract controls. Advanced analyses about the RVO subtypes demonstrated that incidence of OSA was higher in the central RVO (CRVO) cases comparing with branch RVO (BRVO) cases. Plasma samples from OSA cases demonstrated relatively higher concentrations of oxidative stress parameters and inflammatory biomarkers, including 8-OHdG, CRP, IL1β, and IL6, in the RVO cases. Significant linear correlations between AHI and oxidative/inflammatory biomarkers were detected, and advanced analyses on the OSA subtypes demonstrated that these biomarkers were significantly higher in cases with later stages of OSA. In a three months follow-up, an impaired visual activity improvement rate and increased ME incidence in the OSA group among all the RVO cases were detected.

CONCLUSION

OSA was related with an increased incidence of RVO. Besides, OSA would lead to increased oxidative and inflammatory biomarkers concentrations in the RVO cases. OSA could be used as a harmful prognostic factor of visual activity improvement and ME incidences. These findings highlighted the role of OSA in the development of RVO.

Elevated neutrophil-to-lymphocyte ratio but not platelet-to-lymphocyte ratio is associated with generalized aggressive periodontitis in a Chinese population

BACKGROUND

Host inflammatory mediators are associated with tissue destruction in patients suffering from generalized aggressive periodontitis (GAgP). However, the correlations between neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) with GAgP remain unknown.

METHODS

Periodontal clinical parameters, including probing depth (PD), bleeding index (BI) and attachment loss (AL) were collected from patients with GAgP and healthy controls. Complete blood cells analyses were obtained; further, NLR and PLR were calculated using neutrophil, platelet, and lymphocyte counts. Smooth curve fitting and segmented regression models were used to analyze the roles and predictive value of NLR with GAgP.

RESULTS

In total, 505 participants from a Chinese population were recruited, including 133 healthy controls and 372 patients with GAgP. Periodontal clinical parameters, NLR, and neutrophil counts were significantly higher in patients with GAgP than the control group. Moreover, NLR was positively correlated with the risk and clinical parameters of GAgP. When NLR < 3, the risk of GAgP increased by 20.6% for each 0.1 increase in NLR, reaching saturation when NLR > 3. An increase in NLR equivalent to 1 was associated with an increase in PD, BI, and AL by 0.41 mm, 0.26, and 0.57 mm, respectively. Notably, PLR did not show obvious correlations with GAgP.

CONCLUSIONS

NLR but not PLR may be a potential marker to identify GAgP in healthy individuals, particularly in a Chinese population.