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

Studies of the clinical and immunological features of autoimmune Addison disease (AAD) are needed to understand the disease burden and increased mortality.

To provide upgraded data on autoimmune comorbidities, replacement therapy, autoantibody profiles, and cardiovascular risk factors.

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.

The endpoints were the prevalence of autoimmune comorbidities and cardiovascular risk factors. Autoantibodies against 13 autoantigens were determined.

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).

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.