Chronic Obstructive Pulmonary Disease is Associated with an Increased Risk of Peripheral Arterial Disease

Chronic obstructive pulmonary disease (COPD), peripheral arterial disease (PAD) and ischemic heart disease are considered to be a smoking-related triad. However, only a few studies investigated the relationship between COPD and PAD using limited study sample. We aimed to examine the risk of PAD among patients with COPD using a nationwide cohort database in Taiwan. We conducted a retrospective cohort study using data from the National Health Insurance system of Taiwan. The COPD cohort included 361,023 patients who were newly diagnosed and recruited between 1998 and 2008. Each patient with COPD was randomly frequency-matched with two participants without COPD on age, sex, and the year of index date. The newly diagnosis of PAD was followed up until the end of 2010. The relative risks of PAD were estimated using Cox proportional hazard models after adjusting for age, sex, index year and comorbidities. The overall incidence rate of PAD was 2.34–fold greater in the COPD cohort than in the non-COPD cohort (3.71 vs. 1.58 per 1000 person-years). Further analyses indicated that the risk of PAD was higher in males, individuals younger than 50 years, and without comorbidity among the subgroups. This nationwide population-based study indicates that the incidence of PAD is significantly higher in patients with COPD than in those without COPD and the hazard ratio was especially high in younger patients. Therefore, regular examination for PAD in patients with COPD may be considered. (J Intern Med Taiwan 2014; 25: 272-280)