When to suspect hidden hypercortisolism in type 2 diabetes : a meta-analysis

Objective: Among patients with type 2 diabetes (T2D), the prevalence of hidden hypercortisolism (HidHyCo, formally called subclinical hypercortisolism or mild autonomous cortisol secretion) was estimated to be 2.2-12.1%. The aim of this study was to investigate whether the available literature helps to identify the characteristics of T2D patients more frequently associated with HidHyCo. Methods: A meta-analysis was performed using studies that assessed both the prevalence of HidHyCo in patients with T2D and the characteristics of these patients with and without HidHyCo. The DerSimonian and Laird (DSL) and the Hartung, Knapp, Sidik and Jonkman (HKSJ) methods were utilized. Results: Among the 18 available studies, 6 studies provided the necessary data. The association between HidHyCo and advanced T2D (based on the patients' description given in each study in presence of micro/ microvascular complications, or insulin treatment plus hypertension, or hypertension treated with ≥2 drugs), hypertension, insulin treatment and dyslipidemia was reported in 5 (2184 patients), 6 (2283 patients), 3 (1440 patients), and 3 (987 patients) studies, respectively. HidHyCo was associated with advanced T2D as assessed with both DSL (odds ratio, OR, 3.47, 95% Confidence Interval, 95%CI, 2.12-5.67) and HKSJ method (OR 3.60, 95%CI 2.03-6.41) and with the prevalence of hypertension or of insulin treatment as assessed by the DSL approach (OR 1.92, 95%CI 1.05-3.50 and OR 2.29, 95%CI 1.07-4.91, respectively), but not as assessed with HKSJ method. Conclusions: Patients with advanced T2D have a higher prevalence of HidHyCo. These data inform about the selection of T2D patients for HidHyCo screening.