In addition, COPD was more likely to develop in the lower ALT level groups (groups 1–4; < 40 IU/L), than in the highest ALT level group (group 5; ≥ 40 IU/L) (univariable, HR: 1.341, 95% CI: 1.263–1.424; multivariable, HR: 1.097, 95% CI: 1.030–1.168). This evidence concerns the gene GPT and chronic obstructive pulmonary disease.