Sleep disturbances in patients with Cushing syndrome and mild autonomous cortisol secretion: a cross-sectional study.

Context: The impact of active hypercortisolism on sleep is incompletely characterized. Studies report impaired sleep in patients with Cushing syndrome (CS). Patients with mild autonomous cortisol secretion (MACS) demonstrate mild nocturnal hypercortisolism that could impact sleep.

Objectives: To characterize sleep abnormalities in patients with CS and MACS using the Pittsburgh Sleep Quality Index (PSQI), identify factors associated with poor sleep, and compare sleep abnormalities in patients with MACS versus referent subjects.

Methods: We conducted a single-center cross-sectional study of adults with active CS and MACS. Clinical and biochemical severity scores for hypercortisolism were calculated. Parallelly, we enrolled referent subjects. Quality of life was assessed using 1) Short Form-36 in all participants, and 2) Cushing QoL in patients with active hypercortisolism. Sleep quality was assessed using PSQI.

Results: PSQI was assessed in 154 patients with CS (mean 12, SD ±4.5), 194 patients with MACS (mean 11, SD 4.6), and 89 referents (mean 5, SD ±3.4). Patients with MACS exhibited shorter sleep duration, longer sleep latency, more severe daytime dysfunction, lower sleep efficiency, and a higher sleep medication use compared to referent subjects (P = <0.001 for all). Age-, sex, and BMI adjusted analysis demonstrated no differences in PSQI or its subcomponents between patients with CS and MACS (P >0.05 for all). In a multivariable analysis of patients with MACS, younger age, female sex and higher clinical hypercortisolism severity score were associated with impaired sleep. In patients with CS, only younger age was associated with poor sleep.

Conclusions: Patients with MACS demonstrate sleep impairment that is similar to patients with CS. Younger women with higher clinical severity of MACS are more likely to have impaired sleep.