Serum Levels of Alpha1-antitrypsin and Their Relationship With COPD in the General Spanish Population

Abstract Background Low plasma level of alpha1-antitrypsin (AAT) is an established risk factor for early-onset chronic obstructive lung disease (COPD). However, less attention is given to the levels of AAT in the general population. Methods This is a part of a multicentre, population-based study conducted at 11 sites throughout Spain. Plasma levels of AAT were available for 837 persons with a mean (SD) age of 58.05 (11.3) years: 328-smokers, 272-ex-smokers and 237 non-smokers. Out of 837, 303 (36.2%) had a diagnosis of COPD, 222 (26.5%) had respiratory symptoms but no COPD, and 312 (37.3%) were healthy controls. Results In the whole cohort, the mean level of plasma AAT was 1.51 (0.47) g/L. Levels were higher in COPD patients [1.55 (0.45) g/L] and individuals with respiratory symptoms [1.57 (0.47) g/L] than in controls [1.43 (0.47) g/L], p Conclusion Increased circulating levels of AAT, similarly to CRP and other markers of systemic inflammation, is an important feature of COPD. Our results highlight a complex interrelationship between levels of AAT and health of respiratory system.