title: Women sleep objectively better than men and the sleep of young women is more resilient to external stressors: effects of age and menopause.
abstract: The aims of this study were to: (i) assess gender differences of objective sleep patterns in a general population sample; (ii) evaluate the effects of menopause and hormone treatment (HT) on the sleep of the same cohort; and (iii) examine gender differences in sleep resilience towards external stressors. The participants were (i) 1324 subjects without sleep complaints, recruited from the general population of Central Pennsylvania that spent one night in the sleep laboratory and (ii) 66 young, healthy volunteers whose sleep was disturbed during night four by an external stressor, i.e. 24-h blood drawing (average of nights 2 and 3 versus night 4). Women compared with men in the general population sample had significantly higher percentage of sleep time, lower percentage of stage 1, and higher percentage of slow wave sleep. Also, menopause, in the absence of HT, was associated with prolonged sleep latency and decreased deep sleep. Finally, young, healthy women compared with men experienced less sleep disturbance because of blood draws as indicated by a significantly smaller change in per cent sleep time, and percentage of stage 1 sleep. These findings suggest that women without sleep complaints sleep objectively better across age than men and the sleep of young women is more resistant to external stressors. Also, gonadal hormones exert a beneficial effect on women's sleep. This gender dimorphism in sleep regulation may have been to protect women from the demands of infant and child care, and in part, might contribute to women's lower cardiovascular risks and greater longevity.
authors.affiliation: Sleep Research and Treatment Center, Department of Psychiatry, Penn State College of Medicine, Hershey, PA 17033, USA.
authors.forename: Edward O
authors.initials: EO
authors.lastname: Bixler
authors.forename: Maria N
authors.initials: MN
authors.lastname: Papaliaga
authors.forename: Alexandros N
authors.initials: AN
authors.lastname: Vgontzas
authors.forename: Hung-Mo
authors.initials: HM
authors.lastname: Lin
authors.forename: Slobodanka
authors.initials: S
authors.lastname: Pejovic
authors.forename: Maria
authors.initials: M
authors.lastname: Karataraki
authors.forename: Antonio
authors.initials: A
authors.lastname: Vela-Bueno
authors.forename: George P
authors.initials: GP
authors.lastname: Chrousos
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D001143:Arousal / Q000187:drug effects; D001800:Blood Specimen Collection / Q000523:psychology; D015992:Body Mass Index; D015331:Cohort Studies; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D007600:Judgment; D008297:Male; D008593:Menopause / Q000523:psychology*; D008875:Middle Aged; D017286:Polysomnography; D011930:Reaction Time / Q000187:drug effects; D012016:Reference Values; D012727:Sex Characteristics; D012894:Sleep Stages / Q000187:drug effects; D055815:Young Adult