Association between Serum Copper, Copper/Selenium Ratio and Risk of Chronic Obstructive Pulmonary Disease in Smokers and Non-smokers: A cross-sectional study of NHANES 2011-2016

Abstract

Background Chronic obstructive pulmonary disease (COPD) is a prevalent condition characterized by significant morbidity and mortality. It ranks as the primary cause of adult mortality globally, entailing substantial economic costs. Numerous studies indicate a linkage between serum copper(Cu), copper-selenium ratio(Cu/Se-ratio), and diverse diseases. However, the relationships between serum Cu, Cu/Se-ratio, and COPD among smokers and non-smokers has been understudied, warranting additional investigation. Methods Our study was a cross-sectional analysis based on the 2011–2016 National Health and Nutrition Examination Survey (NHANES)data, including 5154 participants. Utilizing univariable and multivariable logistic regression, alongside restricted cubic spline (RCS) methods, we evaluated the correlation and dose-response relationships of serum Cu and Cu/Se-ratio with COPD risk, focusing on differences between smokers and non-smokers. Results Following adjustment for confounding factors, a positive link was identified in the general population between serum Cu (OR = 1.04; 95%CI, 1.02–1.07), Cu/Se-ratio (OR = 1.06; 95%CI, 1.02–1.09), and COPD risk. Further analysis, stratified by smoking status, showed in smokers, serum Cu (OR = 1.06; 95%CI, 1.03–1.10) and Cu/Se-ratio (OR = 1.07; 95%CI, 1.03–1.12) significantly correlated positively with COPD risk. In the non-smoking group, however, no significant links were detected between serum Cu (OR = 0.99; 95%CI, 0.94–1.04), Cu/Se-ratio (OR = 1.00; 95%CI, 0.94–1.07), and COPD risk. RCS analysis uncovered a linear relationship between serum Cu, Cu/Se-ratio, and COPD risk across both the general populace and smokers. Conclusion Data analysis from the 2011–2016 NHANES indicates a positive correlation between elevated serum Cu levels, Cu/Se-ratios, and COPD risk in smokers.