title: The effect of menopause on objective sleep parameters: data from an epidemiologic study in São Paulo, Brazil.
abstract: OBJECTIVE
  Our objective was to investigate the influence of menopausal status on sleep patterns in a representative sample of women from São Paulo, Brazil.
  
  
  METHODS
  A population-based survey with a probabilistic three-stage cluster sample of the city of São Paulo was used to represent the local population according to gender, age (20-80 years) and socioeconomic status.
  
  
  METHODS
  The female participants answered a sleep questionnaire, underwent polysomnographic recording and allowed their hormone levels to be measured. They also completed a gynecological questionnaire for classification of the reproductive aging stages: premenopausal or reproductive, perimenopausal or menopausal transition, and postmenopausal, defined as being after 12 months of amenorrhea. Women were allocated into early (the first 5 years after menopause) and late (after the first 5 years) stages.
  
  
  RESULTS
  A total of 535 women were included in this study: 339 were premenopausal, 53 were early postmenopausal, 118 were late postmenopausal and 25 were using hormone therapy or isoflavone compounds. Our main findings were that women in postmenopause spent more time in N3 sleep, had a higher apnea-hypopnea index (AHI) and lower SaO2 compared with premenopausal women after an analysis adjusted for confounding factors. We found no significant differences between early and late postmenopausal women in the adjusted analysis.
  
  
  CONCLUSIONS
  Our results indicate menopause itself exerts a modest, but important influence on objective sleep patterns, independent of age, in particular on AHI and SaO2.
authors.affiliation: Departamento of Psicobiologia, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil; Departamento de Ginecologia, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP Brazil; Departamento de Ginecologia, Casa de Saúde Santa Marcelina, São Paulo, SP, Brazil. Electronic address: helena.hachul@hotmail.com.
authors.forename: Helena
authors.initials: H
authors.lastname: Hachul
authors.affiliation: Departamento of Psicobiologia, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: Cristina
authors.initials: C
authors.lastname: Frange
authors.affiliation: Departamento of Psicobiologia, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: Andréia Gomes
authors.initials: AG
authors.lastname: Bezerra
authors.affiliation: Departamento of Psicobiologia, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: Hirotsu
authors.affiliation: Departamento of Psicobiologia, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: Gabriel Natan
authors.initials: GN
authors.lastname: Pires
authors.affiliation: Departamento of Psicobiologia, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: Monica Levy
authors.initials: ML
authors.lastname: Andersen
authors.affiliation: Departamento of Psicobiologia, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: Lia
authors.initials: L
authors.lastname: Bittencourt
authors.affiliation: Departamento of Psicobiologia, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: Sergio
authors.initials: S
authors.lastname: Tufik
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D008593:Menopause / Q000502:physiology; D008875:Middle Aged; D010092:Oximetry; D017286:Polysomnography; D017698:Postmenopause / Q000502:physiology*; D017697:Premenopause / Q000502:physiology*; D012890:Sleep; D020181:Sleep Apnea, Obstructive / Q000453:epidemiology; D012894:Sleep Stages / Q000502:physiology*; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Polysomnography; Population sample; Postmenopausal; Premenopausal; Sleep; Women