Endocrine Abstracts

Background: It is not known if non-functional adrenal adenomas (NFAA) are associated with increased mortality.

Objective: To investigate mortality in patients with NFAA and compare with matched controls.

Design: Retrospective register-based national cohort study.

Methods: Patients diagnosed with NFAA in Sweden 2005-2019 were identified and followed until death or 2020. For each case, four age/sex/municipality-matched controls were identified. Individuals with diagnosis indicating adrenal hormonal excess or malignancy were excluded. Though, in some cases malignancy of another origin than adrenal glands was detected in conjunction with index date. Statistical analysis was made both including and excluding these cases. Main study outcomes were all-cause 1 and 5-year mortality as well as causes of death after adjustment for comorbidities and socioeconomic factors.

Results: In total, 20390 patients with NFAA and 125392 matched controls were included. Median age at diagnosis was 65 years (IQR-16) and 59.1% were women. During follow-up, 4427 (21.7%) cases and 20480 (16.3%) controls had deceased. Among all patients with NFAA both 1-year and 5-year overall mortality was higher compared to controls (OR-6.79, aOR-5.38 and OR-2.66, aOR-2.03). After eliminating controls with detected malignancy at index date, both 1-year and 5-year overall mortality was still high (OR 2.64 (2.42-2.88), aOR-1.84 (1.68-2.01) and OR 1.69 (1.61-1.77), aOR 1.18 (1.12-1.25)). While all patients with known malignancy were excluded before and at index date, mortality due to new malignancy during the follow-up period was high: 1-year mortality OR was 8.86 (7.54-10.42), aOR 8.04 (6.81-9.51) and 5-years mortality OR was 2.77 (2.55-3.01), aOR 2.43 (2.23-2.65). Moreover, 1-year mortality due to cardiovascular diseases was also increased (OR 2.02 (1.64-2.47), aOR1.33 (1.06-1.66), however 5-years mortality due to cardiovascular diseases was increased only before adjustment (OR 1.39(1.24-1.57), aOR 0.88 (0.76-1.01), the latter was adjusted for, e.g., cardiovascular disease at index date). In total 1273 (28.8%) of controls diseased due to malignancy and 1023 (23.1%) due to cardiovascular diseases.

Conclusions: Patients with NFAA have significantly higher overall mortality rate, as well as mortality due to new malignancy diagnosed during the follow-up time when compared to controls.