Clinical and Immunological Characteristics of Autoimmune Addison Disease: A Nationwide Swedish Multicenter Study

Context: Studies of the clinical and immunological features of autoimmune Addison disease (AAD) are needed to understand the disease burden and increased mortality. Objective: To provide upgraded data on autoimmune comorbidities, replacement therapy, autoantibody profiles, and cardiovascular risk factors. Design, Setting, and Participants: A cross-sectional, population-based study that included 660 AAD patients from the Swedish Addison Registry (2008–2014). When analyzing the cardiovascular risk factors, 3594 individuals from the population-based survey in Northern Sweden, MONICA (monitoring of trends and determinants of cardiovascular disease), served as controls. Main Outcome Measures: The endpoints were the prevalence of autoimmune comorbidities and cardiovascular risk factors. Autoantibodies against 13 autoantigens were determined. Results: The proportion of 21-hydroxylase autoantibody-positive patients was 83%, and 62% of patients had ≥1 associated autoimmune diseases, more frequently coexisting in females (P < 0.0001). AAD patients had a lower body mass index (P < 0.0001) and prevalence of hypertension (P = 0.027) compared with controls. Conventional hydrocortisone tablets were used by 89% of the patients, with a mean dose of 28.1 ± 8.5 mg/d. The mean hydrocortisone equivalent dose normalized to the body surface was 14.8 ± 4.4 mg/m2/d. A greater hydrocortisone equivalent dose was associated with a greater incidence of hypertension (P = 0.046). Conclusions: Careful monitoring of AAD patients is warranted to detect associated autoimmune diseases. Contemporary Swedish AAD patients did not have an increased prevalence of overweight, hypertension, type 2 diabetes mellitus, or hyperlipidemia. However, high glucocorticoid replacement doses could be a risk factor for hypertension.