In more than 15% of people with benign adrenal tumors, the growths produce clinically relevant levels of serum cortisol that are significantly linked with an increased prevalence of hypertension and, in 5% of those with Cushing syndrome (CS), an increased prevalence of type 2 diabetes, based on data from more than 1300 people with benign adrenal tumors, the largest reported prospective study of the disorder.