Circadian rhythm of restless legs syndrome: relationship with biological markers.
Recently, it was suggested that the intensity of restless legs syndrome (RLS) symptoms may be modulated by a circadian factor. The objective of this study was to evaluate, during a 28-hour modified constant routine, the nycthemeral or circadian variations in subjective leg discomfort and periodic leg movements (PLMs) and to parallel these changes with those of subjective vigilance, core body temperature, and salivary melatonin. Seven patients with primary RLS and seven healthy subjects matched for sex and age entered this study. Although the symptoms were more severe in patients than in controls, a significant circadian variation in leg discomfort and PLM (p < 0.01) was found for both groups. In both groups, the profiles of leg discomfort and PLM were significantly correlated with those of subjective vigilance, core body temperature, and salivary melatonin. However, among these variables, the changes in melatonin secretion were the only ones that preceded the increase in sensory and motor symptoms in RLS patients. This result and those of others studies showing that melatonin exerts an inhibitory effect on central dopamine secretion suggest that melatonin might be implicated in the worsening of RLS symptoms in the evening and during the night.
Sleep Disorders Center, Sacré-Coeur Hospital, 5400 boulevard Gouin Ouest, Montréal, Quebec, Canada.
Martin
M
Michaud
Marie
M
Dumont
Brahim
B
Selmaoui
Jean
J
Paquet
Maria Livia
ML
Fantini
Jacques
J
Montplaisir
D000328:Adult; D001143:Arousal / Q000502:physiology; D015415:Biomarkers / Q000032:analysis; D001831:Body Temperature / Q000502:physiology; D016009:Chi-Square Distribution; D002940:Circadian Rhythm / Q000502:physiology*; D003710:Demography; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D007103:Immobilization / Q000502:physiology; D008297:Male; D008550:Melatonin / Q000032:analysis*; D008875:Middle Aged; D009483:Neuropsychological Tests; D017286:Polysomnography / Q000379:methods; D012148:Restless Legs Syndrome / Q000378:metabolism* / Q000503:physiopathology; D012463:Saliva / Q000378:metabolism; D013997:Time Factors
D015415:Biomarkers; D008550:Melatonin