RESUMO
CONTEXT: Once hypercortisolemia is confirmed, differential diagnosis between Cushing's syndrome (CS) due to neoplastic endogenous hypercortisolism and non-neoplastic hypercortisolism (NNH, pseudo-Cushing's syndrome) is crucial. Due to worldwide corticotropin-releasing hormone (CRH) unavailability, accuracy of alternative tests to dexamethasone (Dex)-CRH, is clearly needed. OBJECTIVE: Assess the diagnostic accuracy of Dex-CRH test, desmopressin stimulation test, midnight serum cortisol (MSC), and late-night salivary cortisol (LNSC) levels to distinguish CS from NNH. METHODS: Articles through March 2022 were identified from Scopus, Web of Science, MEDLINE, EMBASE, and PubMed. All steps through the systematic review were performed independently and in duplicate and strictly adhered to the updated PRISMA-DTA checklist. DATA SYNTHESIS: A total of 24 articles (1900 patients) were included. Dex-CRH had a pooled sensitivity and specificity of 91% (95%CI 87-94%; I2 0%) and 82% (73-88%; I2 50%), desmopressin test 86% (81-90%; I2 28%) and 90% (84-94%; I2 15%), MSC 91% (85-94%; I2 66%) and 81% (70-89%; I2 71%), and LNSC 80% (67-89%; I2 57%) and 90% (84-93%; I2 21%), respectively. Summary receiver operating characteristics areas under the curve were Dex-CRH 0.949, desmopressin test 0.936, MSC 0.942, and LNSC 0.950 without visual or statistical significance. The overall risk of studies bias was moderate. CONCLUSION: Dex-CRH, the desmopressin stimulation test, and MSC have similar diagnostic accuracy, with Dex-CRH and MSC having slightly higher sensitivity, and the desmopressin test being more specific. LNSC was the least accurate, probably due to high heterogeneity, intrinsic variability, different assays, and lack of consistent reported cutoffs. When facing this challenging differential diagnosis, the results presented here should increase clinicians' confidence when deciding which test to perform.
Assuntos
Síndrome de Cushing , Humanos , Síndrome de Cushing/diagnóstico , Hidrocortisona/sangue , Hidrocortisona/metabolismo , Diagnóstico Diferencial , Hormônio Liberador da Corticotropina/metabolismo , Dexametasona , Desamino Arginina VasopressinaRESUMO
BACKGROUND: Insulin resistance (IR) precedes the diagnosis of many metabolic and non-metabolic illnesses, including type 2 diabetes mellitus (T2DM). Acanthosis nigricans (AN) is a clinical sign associated with IR. However, AN prevalence and diagnostic accuracy in middle-age adults before or at the time of prediabetes/diabetes diagnosis remain uncertain. METHODS: With the aim to define AN prevalence and diagnostic accuracy, adults between 40 and 60 years of age were consecutively invited to participate in the study. Participants were categorised into one of two main groups: individuals with normoglycaemia (group 1) and hyperglycaemia (group 2 [ie, prediabetes/diabetes]). Demographic, clinical, anthropometric characteristics, homeostasis model assessment of IR, homeostatic model assessment of ß-cell function, as well as the presence of AN on the neck, axillae, elbows and knuckles were assessed. RESULTS: A total of 320 consecutive participants with a mean age of 49.3 years (59.4% women) were included. Overall, AN prevalence was 46.3%, while AN in group 1 and group 2 was 36.3% and 49.6%, respectively (P = .04). The most common affected sites in group 1 (n = 80) were the knuckles (21.2%) and the neck (17.5%), while in group 2 (n = 240), the neck (29.6%) followed by the knuckles (26.7%). The specificity and positive predictive value of AN for IR were 0.85 and 0.86 in group 1 and 0.90 and 0.96 in group 2, respectively. CONCLUSIONS: In middle-age adults, within the entire spectrum of carbohydrate tolerance, AN is highly prevalent and specific. This finding supports its assessment as a reliable and convenient clinical sign of IR. The understanding of AN behaviour through different carbohydrate tolerance strata, and its different locations, could lead to early detection of individuals at high metabolic risk or help direct a more pathophysiological treatment approach in patients with T2DM.