Data on the incidence, mortality, and causes of death in patients with Cushing's syndrome (CS) are scarce, due to the rarity of CS. The aim of the study was to analyze mortality in a large cohort of patients of all etiologies and to determine the cause of death.
This was a retrospective study of patients with CS, treated over a period of 45 years in the main tertiary referral center in Bulgaria.
Three hundred and eighty-six patients with CS of all etiologies were included. The main outcome measures were the standardized mortality ratio (SMR) and the cause of death.
Mean (±s.d.) age at diagnosis was 38±13 years; 84% of patients were women; mean follow-up was 85 months (range: 0–494 months). The SMR in the CS cohort was 4.05 (95% CI 2.50–5.80) (P<0.0001). The following subgroups did not have a significantly increased SMR: patients with Cushing's disease SMR – 1.88 (95% CI 0.69–4.08), adrenal adenomas 1.67 (95% CI 0.20–6.02), and ACTH-independent bilateral adrenal hyperplasia 1.14 (95% CI 0.21–6.34). Patients with adrenal carcinomas, ectopic CS, and those with CS of undetermined etiology had significantly increased SMR: 48.00 (95% CI 30.75–71.42), 13.33 (95% CI 0.00–24.59), and 4.00 (95% CI 0.48–14.45) respectively (P<0.0001). The significant predictors for mortality were active disease at death, age, male sex, etiology of the disease, and the overall duration of active disease. The major causes of death were vascular events (40%) – cardiovascular 29%, and cerebrovascular 11% – followed by infections (12%).
Patients with CS have increased mortality due to vascular events and infections.