Population-based cohort study suggesting a significantly increased risk of developing chronic obstructive pulmonary disease in people with type 2 diabetes mellitus

Aims: To investigate whether type 2 diabetes mellitus (T2DM) increases the risk of developing chronic obstructive pulmonary disease (COPD). Methods: This population-based cohort study used Taiwan's National Health insurance claim data to investigate the association of T2DM with the risk of COPD. A total of 716,623 pairs of people (patients with T2DM and their age-, sex-, and calendar year-matched controls) were identified in 2002–2003 and were followed until the occurrence of newly-diagnosed COPD or the end of 2011. Cox proportional hazard models were used to relate COPD incidence to T2DM. Results: People with T2DM experienced a higher incidence rate of COPD than controls (159.6 vs 122.7 per 10⁴ person-years). After controlling for confounders, T2DM significantly increased the hazard of COPD (hazard ratio [HR] = 1.15, 95% confidence interval = 1.14–1.16). Stratified analysis indicated that the association between T2DM and COPD was slightly greater in women than in men (HR, 1.15 vs. 1.11) and in people aged <65 years than in people aged ≥65 years (HR, 1.17 vs. 1.05 in men; 1.16 vs. 1.13 in women). Conclusions: Our findings demonstrated a modest association of T2DM with the risk of developing COPD, possibly shedding light into the adverse effects of hyperglycemia on pulmonary function.