Night eating in Cushing's disease: Disentangling psychological, sleep, and endocrine contributions

Cushing's disease (CD) is characterized by chronic exposure to excess cortisol and disruption of circadian cortisol rhythms. Given cortisol's role in affective regulation and circadian synchronization, eating disturbances-particularly those linked to mood and sleep-may represent an underexplored aspect of CD. We investigated night eating symptoms and chronotype in CD and examined their clinical, psychological, sleep-related, and endocrine correlates.

Ninety-eight participants were included (22 active CD, 33 remission, 43 healthy controls). Night eating symptoms were assessed using the Night Eating Questionnaire (NEQ) and chronotype with the Morningness-Eveningness Questionnaire. Psychological distress and sleep were measured using Hospital Anxiety and Depression Scale, Pittsburgh Sleep Quality Index, and Insomnia Severity Index. Endocrine measures included 24-hour urinary free cortisol, late-night salivary cortisol, and 1-mg dexamethasone suppression test. Hierarchical regression models identified independent predictors of NEQ scores.

Patients with active CD exhibited greater night eating severity than controls (p = .005), with 16.4% meeting criteria for night eating syndrome. Chronotype did not differ across groups (p = .917). Night eating severity was not associated with cortisol biomarkers. The active disease-night eating association diminished after adjusting for psychological distress. Psychological distress and sleep disturbance independently predicted night eating, accounting for ∼59% of variance.

Night eating symptoms are elevated in active CD but appear more closely linked to psychological distress and sleep disruption than to concurrent cortisol levels. Similar chronotype across groups suggests sleep problems may occur without a shift in circadian preference. Screening for night eating may inform multidisciplinary care in CD.