Increased Risk of Cholesteatoma in Individuals With Alpha‐1 Antitrypsin Deficiency: A Cohort Study

ABSTRACT Objective To estimate the risk of cholesteatoma in patients with alpha‐1 antitrypsin deficiency (AATD) compared to the general population using time‐to‐event analysis. Methods We conducted a nationwide nested cohort study identifying all patients with AATD in Denmark and subsequently matching each case with up to 10 controls based on age, sex, and municipality. Hazard ratios (HR) of cholesteatoma by AATD were calculated using Cox regression analysis adjusted for age and sex. Results The study identified 2702 individuals with AATD and 26,750 control subjects. Individuals with AATD versus controls had a HR for cholesteatoma surgery of 3.62 (95% CI: 1.93–6.80) and a HR for non‐cholesteatoma surgery of 1.40 (1.04–1.89). Conclusion Individuals with AATD had a 3.6‐fold increased risk of cholesteatoma surgery compared with matched controls without AATD. The data support that AATD contributes to pathophysiological processes underlying the development of cholesteatoma. Level of Evidence 3.