Relationship of Red Cell Index with the Severity of Chronic Obstructive Pulmonary Disease

Abstract

Background We aimed to investigate the association between red cell index (RCI) and the severity of Chronic Obstructive Pulmonary Disease (COPD), and compare predictive value of RCI, neutrophil–lymphocyte ratio (NLR) and platelet–lymphocyte ratio (PLR) for the severity of COPD. Methods A total of 207 participants were recruited (100 COPD patients and 107 healthy controls). COPD patients were divided into two groups according to the optimal cut-off value of RCI determined by the receiver operating characteristic (ROC) curve. Pearson’s correlation test, logistic regression analysis and other tests were performed. Results Compared with low RCI group, the forced expiration volume in 1 second (FEV 1 ) and FEV 1 in percent of the predicted value (FEV 1 %) in high RCI group were lower ( p = 0.016, p = 0.001). There was a negative correlation between RCI and FEV 1 % ( r = −0.302, p = 0.004), while no correlation between FEV 1 % and NLR as well as PLR were found. RCI showed higher predictive value than NLR and PLR for predicting Global Initiative for Chronic Obstructive Lung Disease classification (GOLD), with a cut-off value of 1.75 and area under the curve (AUC) of 0.729 ( p = 0.001). Multivariate logistic regression analysis proved that RCI was an independent factor for lung function in COPD patients (odds ratio [OR] = 4.27, 95% CI: 1.57–11.63, p = 0.004). Conclusion RCI is a novel biomarker that can better assess pulmonary function and severity of COPD than NLR and PLR. Higher RCI is related to deterioration of pulmonary function.

The Emerging Clinical Significance of the Red Cell Distribution Width as a Biomarker in Chronic Obstructive Pulmonary Disease: A Systematic Review

“…Following the full-text review of the remaining 38 articles, one was further excluded because it did not fulfil the inclusion criteria (comment letter without providing new data), thus leaving 37 studies for final analysis ( Figure 1 ). Sixteen studies investigated patients with stable COPD [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ], 20 investigated patients with AECOPD [ 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ], and one investigated both groups [ 62 ]. Fourteen studies were conducted in China [ 32 , 33 , 35 , 36 , 38 , 40 , 41 , 48 , 51 , 53 , 56 , 57 , 58 , 61 ]; eleven in Turkey [ 26 , …”

“…Sixteen studies investigated patients with stable COPD [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ], 20 investigated patients with AECOPD [ 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ], and one investigated both groups [ 62 ]. Fourteen studies were conducted in China [ 32 , 33 , 35 , 36 , 38 , 40 , 41 , 48 , 51 , 53 , 56 , 57 , 58 , 61 ]; eleven in Turkey [ 26 , 27 , 28 , 29 , 30 ,…”

“…Fourteen studies were conducted in China [ 32 , 33 , 35 , 36 , 38 , 40 , 41 , 48 , 51 , 53 , 56 , 57 , 58 , 61 ]; eleven in Turkey [ 26 , 27 , 28 , 29 , 30 , 31 , 34 , 44 , 49 , 60 , 62 ]; two in Iran [ 42 , 47 ]; two in Israel [ 43 , 46 ]; and one in Indonesia [ 37 ], Croatia [ 39 ], Greece [ 50 ], India [ 45 ], Spain [ 52 ], Italy [ 54 ], Japan [ 55 ], and Belgium [ 59 ], respectively. Mean or median haemoglobin concentrations were reported as normal in 20 studies [ 26 , 27 , 28 , 30 , 31 , 32 , 34 , 35 , 36 , 40 , 41 , 42 , 44 , 47 , 49 , 54 , 59 , 60 ,…”

Association of Red Cell Index and Adverse Hospitalization Outcomes in Chronic Obstructive Pulmonary Disease Patients with Acute Exacerbation: A Retrospective Cohort Study

“…Thirdly, multivariate logistic regression models were used to examine whether RCI had an independent effect on adverse hospitalization outcomes. We used the following principles to determine whether the potential confounders were adjusted: reported as relevant or used in previous studies 14 , 16 (especially in the study about predictor of AECOPD) and the potential confounders effect estimates individually changed by at least 10%. 17 A total of three models were established: the crude model did not adjust other covariates; model 1 adjusted for age, sex, BMI and smoking status; model 2 further adjusted for comorbidities (including hypertension, diabetes, congestive heart failure, coronary artery disease, chronic kidney disease and arrhythmia), therapy in stable stage, inflammatory parameters (including PCT, CRP, LDH), FEV 1 /FVC, and PaCO 2 .…”

“… 11 RCI is inversely proportional to pulmonary function in theory, and it can be used to measure pulmonary function. 11 , 14 However, its association with poorer outcomes among AECOPD patients is not fully understood.…”