Active disease, fibromyalgia and exposure to glucocorticoids differentially associate with sleep and circadian parameters in Behçet's syndrome.

Objective: Sleep disturbances significantly impact Behçet's syndrome (BS) patients' quality of life. Defining the correlates of BS patients' sleep disturbances is needed to improve their management and, in turn, BS patients' quality of life. In this study, we explored fibromyalgia, disease activity and glucocorticoids exposure as possible predictors of sleep and circadian rhythm parameters in a cohort of BS patients.

Methods: Participants' sociodemographic data were collected through a survey. Sleep and circadian parameters were evaluated objectively via a continuous 7-day accelerometric monitoring and subjectively through the Pittsburgh Sleep Quality Index and the reduced Morningness-Eveningness Questionnaire. A comprehensive clinical evaluation investigated disease activity, fibromyalgia and ongoing pharmacological treatments. Clinical records were systematically reviewed to derive glucocorticoids exposure variables. Possible predictors of sleep and circadian parameters were tested estimating linear regression models.

Results: A total of 45 BS patients were enrolled. Both active and fibromyalgic BS patients showed lower reported sleep quality and lower objectively recorded sleep efficiency compared with non-active and non-fibromyalgic BS patients, respectively. Moreover, fibromyalgia was associated with both shorter total sleep time and a more stable day-to-day rest-activity pattern. In parallel, active disease was associated with reduced sleep regularity whereas glucocorticoids exposure was associated with its increase.

Conclusion: Fibromyalgia and active disease shape partially diverging sleep and circadian rhythm disruption patterns in BS patients, with glucocorticoids potentially improving BS patients' sleep regularity by limiting disease activity-related sleep disruption. A multidimensional approach to sleep characterization is needed to better identify the correlates of BS patients' sleep disturbances and improve their management.