Melatonin dysregulation, sleep disturbances and fatigue in multiple sclerosis

Background: Sleep disruption and fatigue are common in Multiple Sclerosis (MS). Melatonin is one of the major regulators of sleep wake cycle. The role of melatonin in MS-related sleep disturbances and fatigue as well as the interaction between melatonin and Interferon beta (IFN-beta) treatment were the subject of this study. Objective: To assess the influence of IFN-beta treatment on melatonin secretion, fatigue and sleep characteristics in patients with MS. Methods: 13 MS patients and 12 healthy controls participated. Fatigue was evaluated using the Fatigue Impact Scale (FIS), sleep was assessed by actigraphy and day/night levels of 6-sulphatoxy-melatonin (6-SMT) in urine were determined using a highly specific ELISA assay. Results: Naive MS patients demonstrated significantly decreased levels of 6-SMT and disrupted circadian regulation of its secretion, which were increased with IFN-beta treatment, in association with improved fatigue. Sleep Efficiency was significantly lower in the MS group compared to controls. Conclusion: Our findings suggest dysregulation of Melatonin secretion in MS, which may be influenced by IFN-beta treatment. The results call for further characterization of the role of neuro-hormones such as melatonin in MS, and their cross-regulation with immune-mediators. (C) 2011 Elsevier B.V. All rights reserved.