Prevalence and incidence of diabetes in patients with non-functional adrenal tumors.

BACKGROUND: The association between non-functional adrenal tumors (NFAT) and diabetes is unclear. METHODS: A nationwide retrospective register study was conducted including patients with NFAT diagnosed 2005-2019 and controls, followed until death or 2019. Individuals with a history of overt adrenal hormonal excess or prior malignancy were excluded. Follow-up started after 3 months of cancer-free survival following the date of the NFAT diagnosis. Sensitivity analyses were performed in subgroups with conditions such as gallbladder, biliary tract, or pancreatic disease or acute appendicitis, and 6-month and 12-month cancer-free survival following the date of the NFAT diagnosis. Study outcomes were prevalence and incidence of diabetes, after adjustment for sex, age and comorbidities. RESULTS: Among 17,726 cases with NFAT, 10,777 (60.8%) were females, and the median (IQR) age was 65 (57-73) years. Previous diabetes was more prevalent in patients diagnosed with NFAT compared to controls (odds ratio (OR) 2.01 (95% CI 1.93-2.10), adjusted OR 1.84 (95% CI 1.76-1.93)). During the follow-up period (5.3 years, IQR 2.5-8.6) new diabetes was more common in patients with NFAT (hazard ratio (HR) 1.81 95%CI 1.70-1.91, adjusted HR 1.71 95%CI 1.61-1.81). Females <65 years with NFATs had the highest relative risk for diabetes and males ≥65 years with NFATs had the lowest. Adrenalectomy non-significantly decreased the incidence of diabetes (HR 1.39 95%CI 1.05-1.83; adjusted HR 1.55 95%CI 1.15-1.99). The association between NFAT and diabetes remained in most sensitivity analyses. CONCLUSIONS: NFAT was associated with diabetes, especially in younger females, suggesting that glucose should be monitored.