NPAR, NLR predict risk of death in COPD patients

Increased neutrophil-percentage-to-albumin ratio (NPAR) and neutrophil-to-lymphocyte ratio (NLR) appear predictive of mortality risks in community-dwelling adults with chronic obstructive pulmonary disease (COPD), suggests a US study.

Of note, NPAR performs better than other haematologic inflammatory biomarkers in predicting 5-year all-cause mortality in this population.

A team of investigators performed this longitudinal study and extracted data of adults aged 40‒79 years who had physician-diagnosed COPD from the US National Health and Nutrition Examination Survey (NHANES) 1999‒2018.

Cox regressions were used to explore the associations between NPAR, NLR, eosinophil-to-lymphocyte ratio (ELR), and their counterparts with all-cause mortality, cardiovascular disease (CVD) mortality, and mortality from chronic lower respiratory disease (CLRD). Receiver operating characteristic curve analysis was conducted to estimate the predictive value of these biomarkers for 5-year all-cause mortality.

A total of 1,158 participants had available data for analysis. After adjustment, higher NPAR significantly correlated with higher all-cause and CVD mortality and mortality from CLRD (adjusted hazard ratio [aHR], 1.14, 1.15, and 1.16, respectively).

Higher NLR also correlated with an increase in all-cause and CVD mortality (aHR, 1.16 and 1.29, respectively), while higher neutrophil correlated with increased all-cause mortality and mortality from CLRD (aHR, 1.13 and 1.34, respectively).

On the other hand, albumin showed an association with lower all-cause and CVD mortality (aHR, 0.91 and 0.86). Furthermore, ELR, eosinophil, or lymphocyte did not display a significant association with mortality outcomes.

In predicting 5-year all-cause mortality, the adjusted area under the curve of NPAR and NLR were 0.808 (95 percent confidence interval [CI], 0.722‒0.845) and 0.799 (95 percent CI, 0.763‒0.835), respectively.