J Appl Biomed 16:186-191, 2018 | DOI: 10.1016/j.jab.2018.01.005

Oral melatonin administration improves the objective and subjective sleep quality, increases 6-sulfatoxymelatonin levels and total antioxidant capacity in patients with fibromyalgia

M. Yolanda Castaño^a, Maria Garrido^a, Jonathan Delgado-Adámez^b, Sara Martillanes^b, M. Ángeles Gómez^a, Ana Beatriz Rodríguez^a,*

^a University of Extremadura, Faculty of Science, Department of Physiology (Neuroimmunophysiology and Chrononutrition Research Group), Badajoz, Spain

^b Technological Institute of Food and Agriculture (INTAEX), Gobierno de Extremadura, Av. Adolfo Suárez s/n, 06071 Badajoz, Spain

Background/objective
Chronic pain, sleep disturbances and oxidative stress are implicated in the pathogenesis of fibromyalgia. The aim of this study was to assess the effect of melatonin supplementations on sleep quality, 6-sulfatoxymelatonin (aMT6-s) levels, as well as urinary and serum total antioxidant capacity (TAC) in patients with fibromyalgia.
Methods
Thirty three patients carried out the full study. A baseline period (10 days) was included in the experimental design to collect information about patients' initial status. Then, patients took different doses of melatonin, during 10 consecutive days each. Placebo was given during 10 days either before or between melatonin doses. Objective sleep quality was recorded by actigraphy whereas subjective sleep quality was measured by The Pittsburgh Sleep Quality Index. Quantification of aMT6-s and TAC was achieved by ELISA and colorimetric assay kits, respectively.
Results
Six out of seven sleep parameters evaluated by actigraphy were improved after the intake of melatonin as well as the subjective sleep quality. All the biochemical parameters measured were also elevated after the melatonin administration.
Conclusion
The daily intake of melatonin improved the sleep quality, increased the aMT6-s levels and the total antioxidant capacity in patients with fibromyalgia.

Keywords: Fibromyalgia; Melatonin; Sleep quality; 6-Sulfatoxymelatonin; Antioxidant capacity

Received: December 8, 2016; Revised: November 28, 2017; Accepted: January 17, 2018; Published: August 1, 2018  Show citation