Evidence of Persistent Mild Hypercortisolism in Patients Medically Treated for Cushing Disease: the Haircush Study

Cortisol-lowering drugs may not restore a normal cortisol secretion in Cushing disease (CD).

This work aimed to assess the long-term cortisol exposure in medically treated CD patients using hair-cortisol (HF) and hair-cortisone (HE) measurement.

This multicenter prospective study included 3 groups of female patients: CushMed = 16 treated with a stable cortisol-lowering drug dosage and normal urinary free cortisol (UFC); CushSurg = 13 cured by pituitary surgery; CushBla = 15 receiving stable recommended doses of hydrocortisone following bilateral adrenalectomy. Patients were evaluated for 3 months with their usual treatments. Two late-night saliva and 24-hour urine samples were collected monthly in CushMed, and at study end in CushSurg and CushBla patients. A 3-cm hair sample was collected at study end from all patients. Main outcome measures included clinical score and centralized measurement of UFC, late-night salivary cortisol (LNSF), late-night salivary cortisone (LNSE), HE, HF.

Despite having almost all UFCs normalized, CushMed patients exhibited increased HE as compared to CushSurg controls (P = .003). CushMed patients also had increased clinical score (P = .001), UFC (P = .03), LNSF, LNSE (P = .0001), and variability in the latter parameters (P = .004). CushBla patients had increased HF and HE, contrasting with LNSEs similar to CushSurg patients. Six of 15 CushMed patients exhibited increased HE concentrations and had increased antihypertensive drug dosage compared to CushMed patients with normal HE (P = .05).

Despite normalized UFCs, a subset of medically treated CD patients displays an altered circadian rhythm of serum cortisol. A single HE measurement identifies chronic mild persistent hypercortisolism and could replace multiple saliva analyzes to monitor medical treatments in CD patients once UFC is normalized.