title: Phase advance of circadian rhythms in Smith-Magenis syndrome: a case study in an adult man.
abstract: Melatonin secretion is usually increased during the daytime and decreased at night in Smith-Magenis syndrome (SMS) and consequently is not a pertinent marker of the circadian phase of the clock in these cases. No data on temperature rhythm is available in SMS, another reliable marker of circadian clock activity. For this reason, we assessed the 24h profiles of core temperature, sleep-wake cycle, hormones (plasma cortisol and melatonin) and plasma and urine 6sulfatoxy-melatonin, the main hepatic melatonin metabolism in a 31-year-old man diagnosed with a SMS. All circadian rhythms, especially temperature rhythm showed a phase-advance, associated with reverse melatonin secretion. Plasma and urine 6sulfatoxy-melatonin profiles showed normal melatonin catabolism and confirmed the reversed melatonin secretion. Taking in consideration the reverse melatonin secretion and the phase-advanced temperature rhythm, which is driven by the suprachiasmatic nucleus, we hypothesize that the central clock is more sensitive to afternoon than to morning melatonin. This different responsiveness to melatonin according to the time of the day (i.e. chronaesthesia) corroborates the phase response curve of melatonin secretion to exogenous melatonin.
authors.affiliation: Service d'Explorations Fonctionnelles Neurologiques, Centre Hospitalier Lyon Sud, Hospices Civils de Lyon, 69310 Pierre-Bénite, France; INSERM U628, Physiologie intégrée du Système d'éveil, Domaine Rockefeller, 69008 Lyon, France. Electronic address: laurence.kocher@chu-lyon.fr.
authors.forename: Laurence
authors.initials: L
authors.lastname: Kocher
authors.affiliation: Service d'Hormonologie, Centre Hospitalier Est, Hospices Civils de Lyon, France.
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Brun
authors.affiliation: Département de Génétique et Procréation, Centre Hospitalier Universitaire, Grenoble, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Devillard
authors.affiliation: Service d'Explorations Fonctionnelles Neurologiques, Centre Hospitalier Lyon Sud, Hospices Civils de Lyon, 69310 Pierre-Bénite, France; Département de Physiologie-Explorations Fonctionnelles, Hôpital Raymond-Poincaré, AP-HP, Université de Versailles Saint Quentin-En-Yvelines, 92380 Garches, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Azabou
authors.affiliation: Service d'Hormonologie, Centre Hospitalier Est, Hospices Civils de Lyon, France; INSERM U846, Institut Cellule Souche et Cerveau, Neurobiologie des Rythmes Circadiens et du Sommeil, 18 avenue du Doyen Lépine 69500 Bron, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Claustrat
mesh_terms: D056044:Actigraphy; D000328:Adult; D001831:Body Temperature; D002940:Circadian Rhythm; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008550:Melatonin / Q000097:blood; D012890:Sleep; D058496:Smith-Magenis Syndrome / Q000097:blood / Q000503:physiopathology*
chemical_list: D008550:Melatonin; D006854:Hydrocortisone
keywords: Circadian rhythms; Cortisol; Melatonin; Smith–Magenis syndrome; Temperature