Continuum of glucose and bone metabolism impairment across autonomous cortisol secretion: A cross-sectional study

Autonomous cortisol secretion (ACS) is linked to a higher prevalence of metabolic abnormalities and an increased risk of major adverse cardiovascular events.

To evaluate glucose and bone metabolism in patients with ACS using a continuous glucose monitoring system (CGMS) and dual-energy X-ray absorptiometry (DXA).

Patients diagnosed with ACS, including Cushing syndrome, mild ACS (MACS), and nonfunctional adrenal incidentaloma (NFAI), were recruited for this study. Glucose variability and glycemic status were assessed using CGMS. Regional bone mineral content (BMC), bone mineral density (BMD), and bone area (BA) were evaluated using DXA. CGMS- and DXA-derived parameters were compared across the subgroups of ACS. Correlation analysis was performed to examine relationships between varying degrees of cortisol secretion, measured by cortisol after 1 mg overnight dexamethasone suppression test (DST) or 24-hour urine free cortisol (24h UFC), and CGMS- or DXA-derived parameters.

A total of 64 patients with ACS were included in this study: 19 with Cushing syndrome, 11 with MACS, and 34 with NFAI. Glucose variability, time above range (TAR), and time in range (TIR) along with specific areal BMC, BMD, and BA, differed significantly between groups of Cushing syndrome and NFAI. A significant positive correlation was observed between glucose variability or TAR and cortisol after 1 mg overnight DST or 24h UFC. By contrast, TIR, along with regional BMC, BMD, and BA, were negatively correlated with varying degrees of cortisol secretion.

Glucose and bone metabolism impairments are on a continuum alteration from NFAI to MACS and Cushing syndrome. Prompt attention should be given to these patients with ACS, especially those with mild hormone secretion. Parameters of glucose variability and glycemic status along with bone condition in regions rich in cancellous bone will provide valuable information.