The relationship between adrenal incidentalomas and mortality risk

Objective To determine all-cause mortality risk in patients with and without adrenal incidentaloma. Methods Retrospective cohort study of patients with CT abdomen performed within 24 h of emergency room presentation at an academic medical center from January 1, 2005, to December 31, 2009, without history of adrenal disease, adrenal lab testing, or cancer. Incidentaloma cohort identified by database query of imaging reports followed by manual review and matched to no-nodule controls at 3:1 on age +/- 1 year and exam date +/- 3 months. Mortality ascertained by in-hospital deaths and National Death Index query. Survival analysis performed with Kaplan-Meier curves and Cox proportional hazards models. Results Among 42,575 adults with abdominal CT exams, 969 adrenal incidentaloma patients and 2907 no-nodule controls were identified. All 3876 individuals entered survival analysis with 31,182 person-years at risk (median follow-up 8.9 years [IQR, 6.9-10.7]). All-cause mortality was significantly higher among those with adrenal incidentalomas (353/969, 36.4%) compared with those without (919/2907, 31.6%; mortality difference 7.6 per 1000 person-years; multivariable-adjusted hazard ratio [aHR] 1.14; 95% CI, 1.003-1.29). Exploratory analyses, limited by missing covariates, found that adrenal incidentalomas were associated with significantly increased incidence of malignancy (aHR 1.61; 95% CI, 1.22-2.12), diabetes (aHR 1.43; 95% CI, 1.18-1.71), heart failure (aHR 1.32; 95% CI, 1.07-1.63), peripheral vascular disease (aHR 1.28; 95% CI, 1.95-1.56), renal disease (aHR 1.21; 95% CI, 1.01-1.44), and chronic pulmonary disease (aHR 1.22; 95% CI, 1.01-1.46) compared with controls. Conclusions Adrenal incidentalomas are associated with increased mortality and may represent a clinically valuable biomarker.