In subclinical Cushing syndrome (SC), it is assumed that glucocorticoid production is insufficient to cause a clinically recognizable syndrome. Differences in hormonal levels or recovery time of the hypothalamic-pituitary-adrenocortical (HPA) axis after adrenalectomy between patients with overt Cushing syndrome (OC) and SC remain unknown.
Thirty-six patients (10 with OC and 26 with SC) with adrenal Cushing syndrome who underwent adrenalectomy from 2004 to 2014 were reviewed retrospectively. Patients were treated with glucocorticoid after adrenalectomy and were reevaluated every 1 to 6 months using a rapid adrenocorticotropic hormone (ACTH) stimulation test.
Levels of basal 24-hour urine free cortisol (UFC), serum cortisol after an overnight dexamethasone suppression test (DST), and serum cortisol and 24-hour UFC after low-dose DST and high-dose DST were all significantly lower in patients with SC compared with OC. Basal ACTH levels showed significantly higher in patients with SC compared with OC. The probability of recovering adrenal function during follow-up differed significantly between patients with OC and SC (
The HPA axis recovery time after adrenalectomy in patients with SC is rapid and is dependent on the degree of cortisol excess. More precise definition of SC is necessary to achieve a better management of patients and to avoid the risk of under- or over-treatment of SC patients.
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The chronic use of glucocorticoids (GC) suppresses function of the hypothalamic-pituitary-adrenal axis and often results in secondary adrenal insufficiency (AI). The present study aimed to determine the recovery rate of adrenal function in patients with secondary AI within 1 to 2 years and to assess the factors predictive of adrenal function recovery.
This was a retrospective observational study that enrolled patients diagnosed with GC-induced secondary AI between 2007 and 2013. AI was defined by peak serum cortisol levels <18 µg/dL during a standard-dose short synacthen test (SST). A follow-up SST was performed after 1 to 2 years, and responders were defined as those with adrenocorticotropic hormone (ACTH)-stimulated peak serum cortisol levels ≥18 µg/dL.
Of the total 34 patients diagnosed with GC-induced secondary AI at first, 20 patients (58.8%) recovered normal adrenal function by the time of the follow-up SST (median follow-up period, 16.5 months). Although the baseline serum ACTH and cortisol levels at the first SST did not differ between responders and non-responders, the incremental cortisol response during the first SST was higher in responders than that of non-responders (7.88 vs. 3.56,
In the present study, adrenal function recovery was achieved frequently in patients with GC-induced secondary AI within 1 to 2 years. Additionally, an incremental cortisol response at the first SST may be an important predictive factor of adrenal function recovery.
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