Introduction: Survival of patients affected by Addison’s Disease (AD) is controversial, because only few studies have been published so far. We decided to evaluate survival of an Italian group of patients, affected by AD of various causes.
Materials and Methods: We examinated 1315 patients (58.6% females and 41.4% males) affected by AD, followed-by Endocrine Units all over Italy: the sum of follow-up years was 16983. 70.5% of patients has autoimmune AD (AAD), 113 with APS-1 and 814 with con AAD not APS-1 correlated (AAD not APS-1); 29.5% has non autoimmune AD, 98 of which with post-tuberculosis AD (TBC-AD), 50 with AD due to malignancy (Tu-AD), 97 with congenital AD (Ge-AD) and 143 with AD due to other causes (Ac-AD). We analyzed mean age of diagnosis, years of follow-up and mean age at the end of follow-up, survival was evaluated with Kaplan-Meier analysis and Cox regression. Results were correlated with Italian population data, correlated for sex and age (ISTAT register). We also performed a similar analysis considering only those patients who terminated the follow-up (1006 subjects).
Results: In APS-1 patients, mean age of diagnosis is 16.1±13.8 years, with 15 deaths in 113 subjects (13.3%) at a mean age of 32.5±18.4 years and a mean estimated survival (MES) of 40.4±5.8 years; in MAA non APS-1, mean age of diagnosis is 35.7±14.4 years, with 18 deaths in 814 subjects (2.2%) at 77.9±13.3 years of age and a MES of 56.1±3.8 years; in TBC-AD, mean age of diagnosis is 50.1±15.7 years, with 11 deaths in 98 subjects (11.2%) at a mean age of 81.1±7.4 years and MES of 42.5±4.1 years; in Tu-AD, mean age of diagnosis is 57.9±15.5 years, with 12 deaths in 50 subjects (24%) at 65.6±14.4 years of age and a MES of 11.3±5.8 years; in Ge-AD, mean age of diagnosis is 7.3±10 years, with 4 deaths in 97 subjects (4.1%) at a mean age of 16.7±4.3 years and a MES of 41.1±1.8 years; in Ac-AD, mean age of diagnosis is 43±19.5 years, with 5 deaths in 143 subjects (3.5%) at a mean age of 55.2±40 years and a MES of 44.4±1.8 years. Comparing mean estimated survival of each subgroup with Italian matched population, only APS-1 and Tu-AD appear lower. Comparing subgroups head to head, Tu-AD patients’ survival is lower than all other groups (p<0.001), while survival of APS-1 and TBC-AD subgroups is lower than AAD non-APS-1 subgroups (p<0.001 and p=0.01, respectively); all other comparisons are not statistically different. Cox regression analysis, referring to AAD non-APS-1 subgroup, demonstrate an higher risk of mortality in APS-1 (HR 4.38, CI 2.18-8.8; p<0.001), TBC-AD (HR 2.99, CI 1.39-6.44; p=0.005) and Tu-AD (HR 47.88, CI 21.07-108.81; p<0.001). Survival analysis performed only on those patients who completed the follow-up results similar to the previous analysis.
Conclusions: AD patients survival depends on ethiology of AD: in APS-1 and Tu-AD patients survival is lower than other subgroups and to the matched Italian population. In all other groups (AAD non-APS-1, TBC-AD, congenital AD and Ac-AD), survival is not different from matched Italian population
