Intensive smoking diminishes the differences in quality of life and exacerbation frequency between the alpha-1-antitrypsin deficiency genotypes PiZZ and PiSZ

Abstract

Background: Alpha-1-antitrypsin deficiency (AATD) is a rare genetic disorder that is associated with low levels of circulating alpha-1-antitrypsin in serum. In comparison to the genotype PiZZ, PiSZ usually leads to lower risk of emphysema, better lung function and better survival. The aim of this study was to analyze the relationship between cigarette smoking (packyears) and the AATD genotypes (PiZZ and PiSZ) concerning quality of life (SGRQ), transfer factor of the lung for carbon monoxide (TLCO), forced expiratory volume in one second (FEV1) and exacerbation rate. Methods: We compared PiZZ and PiSZ individuals from the German registry for individuals with AATD (AATDR) in univariate analysis and multivariate linear regression models. All subjects were stratified into three groups according to their cumulative nicotine consumption (0 py; 0 < py < 30; 30 py). Results: 868 PiZZ individuals (mean age 52.6 ± 12.8 years (43.5% female)) and 114 PiSZ individuals (mean age 50.3 ± 17.4 years (46.5% female)) were compared. In contrast to never- and intensive (ex-) smokers, moderate (ex-) smoking PiSZ individuals had a significantly better SGRQ total score (B ¼ 8.148; p ¼ 0.020) and less exacerbations (B ¼ 0.354; p ¼ 0.037) than individuals with PiZZ in multivariate analysis. Conclusions: The differences in quality of life and exacerbation frequency between PiZZ and PiSZ individuals diminish by intensive (ex-) smoking.