Background Previous studies on acute exacerbation of chronic obstructive pulmonary disease (AECOPD) have found that those who died in hospital had higher blood urea nitrogen levels and a worse nutritional status compared to survivors. However, the association between the blood urea nitrogen to serum albumin ratio (BUN/ALB ratio) and in-hospital and short-term prognosis in patients with AECOPD remains unclear. The aim of this study was to explore the usefulness of BUN/ALB ratio in AECOPD as an objective predictor for in-hospital and 90-day all-cause mortality. Methods We recorded the laboratory and clinical data in patients with AECOPD on admission. By drawing the ROC curve for the patients, we obtained the cut-off point for the BUN/ALB ratio for in-hospital death. Multivariate logistic regression was used for analyses of the factors of in-hospital mortality and multivariate Cox regression was used to analyze the factors of 90-day all-cause mortality. Results A total of 362 patients were recruited and 319 patients were finally analyzed. Twenty-three patients died during hospitalization and the fatality rate was 7.2%. Furthermore, 14 patients died by the 90-day follow-up. Compared with in-hospital survivors, patients who died in hospital were older (80.78 ± 6.58 vs. 75.09 ± 9.73 years old, P = 0.001), had a higher prevalence of congestive heart failure(69.6% vs. 27.4%, P < 0.001), had a higher BUN/ALB ratio [0.329 (0.250–0.399) vs. 0.145 (0.111–0.210), P < 0.001], had higher neutrophil counts [10.27 (7.21–14.04) vs. 6.58 (4.58–9.04), P < 0.001], higher blood urea nitrogen levels [10.86 (7.10–12.25) vs. 5.35 (4.14–7.40), P < 0.001], a lower albumin level (32.58 ± 3.72 vs. 36.26 ± 4.53, P < 0.001) and a lower lymphocyte count [0.85 (0.58–1.21) vs. 1.22 (0.86–1.72), P = 0.001]. The ROC curve showed that the area under the curve (AUC) of BUN/ALB ratio for in-hospital death was 0.87, (95%CI 0.81–0.93, P < 0.001), the best cut-off point value to discriminate survivors from non-survivors in hospital was 0.249, the sensitivity was 78.3%, the specificity was 86.5%, and Youden’s index was 0.648. Having a BUN/ALB ratio ≥ 0.249 was an independent risk factor for both in-hospital and 90-day all-cause mortality after adjustment for relative risk (RR; RR = 15.08, 95% CI 3.80–59.78, P < 0.001 for a multivariate logistic regression analysis) and hazard ratio (HR; HR = 5.34, 95% CI 1.62–17.57, P = 0.006 for a multivariate Cox regression analysis). Conclusion An elevated BUN/ALB ratio was a strong and independent predictor of in-hospital and 90-day all-cause mortality in patients with AECOPD.

Background and ObjectivesAccumulating evidence suggests that oxidative stress is involved in the development of chronic obstructive pulmonary disease (COPD) and its progression. Activity of extracellular superoxide dismutase (ecSOD), the only extracellular enzyme eliminating superoxide radicals, has been reported to decline in acute exacerbations of COPD (AECOPD). However, the association between serum ecSOD activity and 1-year all-cause mortality in AECOPD patients remains unclear. The objective of our study was to explore the usefulness of ecSOD activity on admission in AECOPD as an objective predictor for 1-year all-cause mortality.MethodsWe measured serum ecSOD activity in AECOPD patients on admission in a prospective cohort study. We also recorded their laboratory and clinical data. Multivariate Cox regression was used to analyze the association between ecSOD activity and the risk of 1-year all-cause mortality. Restricted cubic spline curves were used to visualize the relationship between ecSOD activity and the hazard ratio of 1-year all-cause mortality.ResultsA total of 367 patients were followed up for 1 year, and 29 patients died during a 1-year follow-up period. Compared with survivors, the non-survivors were older (79.52 ± 8.39 vs. 74.38 ± 9.34 years old, p = 0.004) and had increased levels of tobacco consumption (47.07 ± 41.67 vs. 33.83 ± 31.79 pack-years, p = 0.037). Having an ecSOD activity ≤ 98.8 U/ml was an independent risk factor of 1-year all-cause mortality after adjustment for baseline differences, clinical variables and comorbidities [hazard ratio = 5.51, 95% confidence interval (CI): 2.35–12.95, p &lt; 0.001].ConclusionLower serum ecSOD activity was a strong and independent predictor of 1-year all-cause mortality in AECOPD patients.

Background: Compared with survivors,previous studies of AECOPD have found that those died in hospital had higher blood urea nitrogen levels and poorer nutritional status.Nevertheless,the association between blood urea nitrogen to serum albumin ratio (BUN/ALB ratio) and in-hospital and short-term prognosis in AECOPD patients remains unclear.The aim of this study was to explore the usefulness of BUN/ALB ratio in AECOPD as an objective predictor for in-hospital and 90-day all-cause mortality.Methods: BUN/ALB ratio levels were measured in AECOPD patients on admission.By drawing the ROC curve of the patients,we obtained the cut-point of the BUN/ALB ratio level for in-hospital death.Multivariate logistic regression was used for analyses of the factors of in-hospital mortality and multivariate Cox regression was used to analyse the factors of 90-day all-cause mortality.Results: A total of 362 patients were recruited and 319 patients were finally analyzed,23 patients died during hospitalization and the fatality rate was 7.2%. Furthermore,14 patients died during 90-day follow-up.Compared with those in-hospital survivors,patients who died in hospital were older(80.78±6.58vs.75.09±9.73 years old, P =0.001),had a higher percentage of congestive heart failure(69.6% vs.27.4%, P<0.001),had higher BUN/ALB ratio levels(0.329(0.250,0.399)vs.0.145(0.111,0.210), P<0.001),had higher neutrophil counts(10.27(7.21，14.04)vs.6.58(4.58，9.04), P<0.001),higher blood urea nitrogen levels(10.86(7.10,12.25) vs.5.35(4.14,7.40), P<0.001),a lower albumin level(32.58±3.72vs.36.26±4.53, P<0.001) and had a lower lymphocyte count(0.85(0.58,1.21) vs.1.22(0.86,1.72), P=0.001).The ROC curve showed that the area under the curve (AUC) of BUN/ALB ratio for in-hospital death was 0.87, (95%CI: 0.81-0.93, P< 0.001), the best cut-point value to discriminate survivors from nonsurvivors in hospital was 0.249, the sensitivity was 78.3%, the specificity was 86.5%, and the youden’s index was 0.648.Having an BUN/ALB ratio ≥0.249 was an independent risk factor for both in-hospital and 90-day all-cause mortality after adjustment for relative risk(RR)(RR=15.08,95% CI:3.80-59.78, P< 0.001 for the multivariate logistic regression analysis) and hazard ratio (HR)(HR=5.34,95% CI:1.62-17.57, P=0.006 for the multivariate cox regression analysis).Conclusion: An elevated BUN/ALB ratio level was a strong and independent predictor of in-hospital and 90-day all-cause mortality in AECOPD patients.