Nonfunctioning Adrenal Incidentalomas are not Clinically Silent: A Longitudinal Cohort Study

Abstract

The association between nonfunctioning adrenal incidentalomas (NFAIs) and cardiometabolic diseases remains controversial. This retrospective cohort study investigated whether NFAIs are related with prevalent and incident cardiometabolic diseases. This study included 154 patients with biochemically confirmed NFAIs and 1:3 age and sex-matched controls without adrenal incidentalomas (n = 462) among subjects who underwent abdominal computed tomography at a single healthcare center in 2003-2012. Electronic medical records were reviewed for comorbidities at baseline and during a mean follow-up of 7.5 years. The logistic regression analysis for prevalent cardiometabolic diseases and the survival analysis for incident cardiometabolic diseases were performed. The subjects were 55.7±8.8 years of age and predominantly male (73.1%). The NFAI group had a higher body mass index compared to the age and sex-matched control group (25.1±2.8 vs. 24.0±2.8 kg/m2; P<.001). In a cross-sectional design, covariate-adjusted logistic regression showed significantly higher odds ratios (ORs) for diabetes mellitus and hypertension in the NFAI group (adjusted OR [95% confidence interval [CI]], 1.89 [1.17 to 3.06] and 2.26 [1.47 to 3.50], respectively). The NFAI group had a 2-fold higher risk of insulin resistance (adjusted ORs [95% CI], 2.03 [1.06 to 3.90]). Moreover, NFAI subjects with diabetes mellitus had a greater increase in size of adrenal lesions than those without diabetes mellitus (3.4±5.5 vs. 1.4±5.5 mm; P =.048). However, in the survival analysis, the incidence of any cardiometabolic diseases did not differ between the NFAI and control groups. NFAIs are related to prevalent diabetes mellitus or hypertension in our cross-sectional study. However, the presence of NFAIs did not affect the development of cardiometabolic diseases. ACTH = adrenocorticotropic hormone; AI = adrenal incidentaloma; BMI = body mass index; CI = confidence interval; CT = computed tomography; HbA1c = hemoglobin A1c; HOMA-IR = homeostasis model assessment of insulin resistance; HU = Hounsfield units; MACE = mild autonomous cortisol excess; NFAI = nonfunctioning adrenal incidentaloma; OR = odds ratio.