A large number of the patient-level variables were associated with AAT level determination, such as being male (OR 0.47, p<0.001), age ≤55 years old (OR 3.16, p<0.001), pack-year index (10 pack-years) (OR 0.97, p<0.043),being an active smoker (OR 1.30, p = 0.004), BMI≤21 (OR 2.21, p<0.001), Charlson index ≥3 (OR 0.57, p<0.001), symptoms of asthma (OR 1.55, p<0.001), and a FEV1 <50% (OR 1.33, p<0.001). This evidence concerns the gene SERPINA1 and asthma.