Urinary 6-hydroxy-melatonin-sulfate excretion and circadian rhythm in patients with restless legs syndrome

• Published in: Journal of pineal research Vol. 35; no. 4; pp. 295 - 296
• Main Authors: Tribl, Gotthard G., Waldhauser, Franz, Sycha, Thomas, Auff, Eduard, Zeitlhofer, Josef
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.11.2003; Blackwell
• Subjects: 6-hydroxy-melatonin-sulfate; Biological and medical sciences; circadian rhythm; Circadian Rhythm - physiology; dopamine; Female; Humans; Male; Medical sciences; Melatonin - analogs & derivatives; Melatonin - urine; Middle Aged; Nervous system involvement in other diseases. Miscellaneous; Neurology; restless legs syndrome; Restless Legs Syndrome - metabolism; sleep disorders; urine; Human; Urine; Sensitivity disorder; Nervous system diseases; Excretion; Melatonin; sleep disorders; Sleep disorder; Biological rhythm; Circadian rhythm; Sulfates; 6-hydroxy-melatonin-sulfate. restless legs syndrome; Restless legs syndrome; Neurological disorder; dopamine; Pineal hormone
• ISSN: 0742-3098; 1600-079X
• DOI: 10.1034/j.1600-079X.2003.00080.x

: The precise etiology of the restless legs syndrome (RLS) is unknown. Sensory and motor symptoms of RLS worsen during evening/night, coincident with the physiological peak of pineal melatonin excretion. Decreased melatonin levels have been reported in insomnia, which is an associated feature of RLS. Melatonin substitution improved insomnia. A potential association between the idiopathic RLS (iRLS) and alterations in melatonin excretion was therefore explored. Daytime (7:00–22:00 hr) and night‐time (22:00–7:00 hr) urinary excretion of 6‐OH‐melatonin‐sulfate (aMLTs) was measured in 15 patients with iRLS and 11 controls by a radioimmunoassay. There was no significant difference between daytime and night‐time urinary aMLTs excretion in iRLS as compared with controls (daytime: 6.14 ± 5.20 ng versus 5.02 ± 5.11 ng, NS; night‐time: 21.07 ± 17.05 ng versus 22.92 ± 16.52 ng, NS). Our data do not provide evidence for a decrease of cumulative melatonin production in iRLS. Insomnia in RLS does not seem to be correlated with a deficit of melatonin.