Vitamin D is a pro-hormone characterized by an intricate metabolism and regulation. It is well known for its role in calcium and phosphate metabolism, and in bone health. However, several studies have assessed a huge number of extra-skeletal functions, ranging from cell proliferation in some oncogenic pathways to antioxidant and immunomodulatory functions. Vitamin D exerts its role by binding to VDRs (vitamin D receptors), which are located in many different tissues. Moreover, VDRs are able to bind hundreds of genomic loci, modulating the expression of various primary target genes. Interestingly, plenty of gene polymorphisms regarding VDRs are described, each one carrying a potential influence against gene expression, with relapses in several chronic diseases and metabolic complications. In this review, we provide an overview of the genetic aspects of vitamin D and VDR, emphasizing the gene regulation of vitamin D, and the genetic modulation of VDR target genes. In addition, we briefly summarize the rare genetic disease linked to vitamin D metabolism.

Because other coronaviruses enter the cells by binding to dipeptidyl‐peptidase‐4 (DPP‐4), it has been speculated that DPP‐4 inhibitors (DPP‐4is) may exert an activity against severe acute respiratory syndrome coronavirus 2. In the absence of clinical trial results, we analysed epidemiological data to support or discard such a hypothesis. We retrieved information on exposure to DPP‐4is among patients with type 2 diabetes (T2D) hospitalized for COVID‐19 at an outbreak hospital in Italy. As a reference, we retrieved information on exposure to DPP‐4is among matched patients with T2D in the same region. Of 403 hospitalized COVID‐19 patients, 85 had T2D. The rate of exposure to DPP‐4is was similar between T2D patients with COVID‐19 (10.6%) and 14 857 matched patients in the region (8.8%), or 793 matched patients in the local outpatient clinic (15.4%), 8284 matched patients hospitalized for other reasons (8.5%), and when comparing 71 patients hospitalized for COVID‐19 pneumonia (11.3%) with 351 matched patients with pneumonia of another aetiology (10.3%). T2D patients with COVID‐19 who were on DPP‐4is had a similar disease outcome as those who were not. In summary, we found no evidence that DPP‐4is might affect hospitalization for COVID‐19.

Purpose: The clinical and hormonal overlap between neoplastic (CS) and non-neoplastic (NNH/pCS) hypercortisolism is a challenge. Various dynamic tests have been proposed to allow an early discrimination between these conditions, but to date there is no agreement on which of them should be used. Aim: To provide an overview of the available tests and to obtain a quantitative synthesis of their diagnostic performance in discriminating NNH/pCS from CS. Methods: The included articles, published between 1990 and 2022, applied one or more second line tests to differentiate NNH/pCS from CS patients. For the NNH/pCS group, we admitted the inclusion of patients presenting clinical features and/or biochemical findings suggestive of hypercortisolism despite apparent lack of a pCS-related condition. Results: The electronic search identified 339 articles. After references analysis and study selection, we identified 9 studies on combined dexamethasone-corticotropin releasing hormone (Dex-CRH) test, 4 on Desmopressin test and 3 on CRH test; no study on Dex-Desmopressin met the inclusion criteria. Dex-CRH test provided the highest sensitivity (97%, 95 CI% [88%; 99%]). CRH tests showed excellent specificity (99%, 95% CI [0%; 100%]), with low sensitivity. Although metaregression analysis based on diagnostic odds ratio failed to provide a gold standard, CRH test (64.77, 95% CI [0.15; 27,174.73]) seemed to lack in performance compared to the others (Dex-CRH 138.83, 95% CI [49.38; 390.32] and Desmopressin 110.44, 95% CI [32.13; 379.63]). Discussion: Both Dex-CRH and Desmopressin tests can be valid tools in helping discrimination between NNH/pCS and CS. Further studies are needed on this topic, possibly focusing on mild Cushing’s Disease and well-characterized NNH/pCS patients. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022359774, identifier CRD42022359774.

Pharmacotherapy involving hormones and hormone-derived molecules has various potential treatment targets. This includes addressing (partial) hormonal deficiencies, pursuing osteoanabolic effects, providing contraceptive options, or supporting gender-affirming transitions. In chronotherapy, the timing of the administration of active ingredients and different pharmaceutical forms is leveraged to maximize therapeutic efficacy while minimizing adverse effects, based on the principle that it is optimal for drugs to be administered according to the body's circadian rhythms. Just as a drummer sets the pace and keeps the rhythm steady for the entire band, the physician, through the application of chronotherapy, ensures the treatment regimen is harmonized with the body's internal clock. However, while this is a consolidated aspect for several endocrine treatments, for others, it represents a novelty. The new advancements in the treatment of osteoporosis, with the latest parathyroid hormone–related protein analogue, abaloparatide, or in congenital adrenal hyperplasia with the new long-lasting hydrocortisone formulation, are notable examples. We herein summarized the state of the art regarding the hormonal circadian rhythm to discuss in depth the evidence available regarding the correct timing of commonly administered hormonal therapies in adult patients. By offering clear indications, this manuscript delves into the importance of harmonizing hormonal therapy with circadian rhythms through chronotherapy, exploring its potential to enhance therapeutic outcomes while minimizing adverse effects.

Introduction: An adrenal incidentaloma (AI) is an adrenal neoplasm incidentally discovered during an imaging unrelated to suspected adrenal disease. The aim of the present review is to offer practical guidance on the multidisciplinary approach of AIs. Areas covered: The prevalence of AI is high in the aging population (up to 5–8%); however, hormonally active or malignant conditions are rare. After the discovery of an AI, it is suggested to assess in parallel if the mass is potentially malignant and functionally active. The answer to the former question is mainly based on medical history (extra-adrenal malignancies, new-onset of signs or symptoms) and imaging (conventional radiology and/or nuclear medicine). The answer to the latter question is a complete endocrine evaluation of both cortical (glucocorticoids, mineralocorticoids) and medullary (catecholamines) secretion. Expert opinion: A multidisciplinary discussion is suggested for patients with adrenal disease, after the exclusion of nonfunctioning benign cortical adenoma, in order to plan a close and tailored follow-up for the suspected malignant or functioning forms. Surgery is advised for patients with malignant disease (adrenocortical cancer) or with clinically relevant secreting neoplasm (primary aldosteronism, Cushing’s syndrome, and pheochromocytoma).