Use of inhaled corticosteroids and the risk of developing type 2 diabetes in patients with chronic obstructive pulmonary disease

Aim To determine the risk of type 2 diabetes onset associated with accumulated inhaled corticosteroids (ICS) dose during the previous year in patients with chronic obstructive pulmonary disease (COPD). Materials and methods We conducted a nationwide observational cohort study based on data from patients with COPD between 1 January 2010 and 31 December 2017 extracted from Danish health databases. Patients were followed for 7 years, until death or a type 2 diabetes event. A propensity‐matched Cox model and an adjusted Cox proportional hazards model (stratified on body mass index [BMI]) were used to estimate the hazard ratio (HR) for new‐onset type 2 diabetes. Results A total of 50 148 patients with COPD were included, 3566 (7.1%) of whom had a type 2 diabetes event. During the previous year before study entry, 35 368 patients (70.5%) used ICS. The propensity‐matched Cox model (N = 33 466) showed an increased risk of type 2 diabetes, which progressed with increasing accumulated ICS dose (low‐ICS: HR 1.076, confidence interval [CI] 1.075‐1.077, P  < .0001; medium‐ICS: HR 1.106, CI 1.105‐1.108, P  < .0001; high‐ICS: HR 1.150, CI 1.148‐1.151, P  < .0001), compared with no ICS use. Results were confirmed in the adjusted Cox analysis on the entire study population, but only for patients with BMI <30 kg/m 2 . Conclusions In patients with COPD, ICS use was associated with a moderate dose‐dependent increase in the occurrence of type 2 diabetes.