Fig. 2From: Metformin use mitigates the adverse prognostic effect of diabetes mellitus in chronic obstructive pulmonary diseaseUnadjusted Kaplan–Meier curves for survival in all chronic obstructive pulmonary disease patients with and without diabetes mellitus (N = 4231). The mean follow-up period of the patients was 21.3 months, with 90,068 person-months at risk. DM, diabetes mellitusBack to article page