title: Sympathetic overactivity and plasma leptin levels in Rett syndrome.
abstract: Rett syndrome (RTT) is a severe developmental-neurological disorder, characterized by profound and progressive loss of intellectual functioning, occurring after a period (of at least 6 months) of normal development with classic stereotype hand movements, gait ataxia, jerky truncal ataxia, deceleration of brain and body organ growth and cardiac dysautonomia. Pathogenesis of sympathetic overactivity in RTT is unknown, but a previous study observed increased plasma leptin levels in Rett girls and it is well known the role of leptin in the regulation of sympathetic nervous system activity. Aim of our study is to evaluate a relationship between plasma leptin levels and sympathetic activity in RTT. Thirty-two female patients (12.1+/-6.3 years), affected by RTT were enrolled in the study. In all the subjects, we analyzed heart rate variability, QT corrected interval and plasma leptin levels. A significant correlation was found between plasma leptin levels and LF/HF (expression of sympatho-vagal balance) (Spearman r=0.44, p=0.001). There is also a significant negative correlation between HF component (expression of vagal activity) and plasma leptin levels (Spearman r=-0.037, p=0.03) and a positive correlation between LF component and plasma leptin levels (Spearman r=0.047, p=0.01). These results show that in RTT higher plasma leptin levels appear to be associated with sympathetic overactivity, suggesting a role for leptin in cardiac dysautonomia.
authors.affiliation: Department of Clinical Medicine and Immunological Sciences, Section of Internal Medicine, University of Siena, Siena, Italy. M.Acampa@ao-siena.toscana.it
authors.forename: Maurizio
authors.initials: M
authors.lastname: Acampa
authors.forename: Francesca
authors.initials: F
authors.lastname: Guideri
authors.forename: Jousef
authors.initials: J
authors.lastname: Hayek
authors.forename: Patrizia
authors.initials: P
authors.lastname: Blardi
authors.forename: Arianna
authors.initials: A
authors.lastname: De Lalla
authors.forename: Michele
authors.initials: M
authors.lastname: Zappella
authors.forename: Alberto
authors.initials: A
authors.lastname: Auteri
mesh_terms: D000293:Adolescent; D000328:Adult; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D001342:Autonomic Nervous System Diseases / Q000209:etiology* / Q000378:metabolism* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D020738:Leptin / Q000097:blood*; D015518:Rett Syndrome / Q000150:complications* / Q000378:metabolism* / Q000503:physiopathology; D014630:Vagus Nerve / Q000503:physiopathology
chemical_list: D020738:Leptin