Rate of progression of lung function impairment in α1-antitrypsin deficiency

The aim of the present study was to identify α 1 -antitrypsin (α 1 -AT)-deficient patients who had rapidly progressive disease. PiZ patients (n = 101) underwent annual lung function measurements over a 3-yr period, and the results were related to factors that may influence decline. The mean annual decline in forced expiratory volume in 1 s (FEV 1 ) was 49.9 mL. The greatest FEV 1 decline occurred in the moderate severity group (FEV 1 50–80% of the predicted value), with a mean annual decline of 90.1 mL, compared with 8.1 mL in the very severe group (FEV 1 K CO ) was greatest in the severe and very severe groups. When the whole group was divided into tertiles of FEV 1 decline, the fast tertile compared with the slow tertile had more patients with bronchodilator reversibility (BDR) (73 versus 41%; p = 0.010), more males (79 versus 56%; p = 0.048) and lower body mass index (BMI) (24.0 versus 26.1; p = 0.042). Logistic regression analyses confirmed that FEV 1 decline was independently associated with BMI, BDR, exacerbation rate and high physical component 36-item short-form health survey scores. In PiZ α 1 -AT-deficient patients, FEV 1 decline was greatest in moderate disease, unlike K CO decline, which was greatest in severe disease. The FEV 1 decline showed associations with BDR, BMI, sex and exacerbation rate.