title: Amerindian (but not African or European) ancestry is significantly associated with diurnal preference within an admixed Brazilian population.
abstract: Significant questions remain unanswered regarding the genetic versus environmental contributions to racial/ethnic differences in sleep and circadian rhythms. We addressed this question by investigating the association between diurnal preference, using the morningness-eveningness questionnaire (MEQ), and genetic ancestry within the Baependi Heart Study cohort, a highly admixed Brazilian population based in a rural town. Analysis was performed using measures of ancestry, using the Admixture program, and MEQ from 1,453 individuals. We found an association between the degree of Amerindian (but not European of African) ancestry and morningness, equating to 0.16 units for each additional percent of Amerindian ancestry, after adjustment for age, sex, education, and residential zone. To our knowledge, this is the first published report identifying an association between genetic ancestry and MEQ, and above all, the first one based on ancestral contributions within individuals living in the same community. This previously unknown ancestral dimension of diurnal preference suggests a stratification between racial/ethnic groups in an as yet unknown number of genetic polymorphisms.
authors.affiliation: a Faculty of Health and Medical Sciences , University of Surrey , Guildford , Surrey , UK.
authors.forename: Kieren J
authors.initials: KJ
authors.lastname: Egan
authors.affiliation: b Laboratory of Genetics and Molecular Cardiology , Heart Institute (Incor), University of São Paulo Medical School , São Paulo , SP , Brazil.
authors.forename: Hadassa
authors.initials: H
authors.lastname: Campos Santos
authors.affiliation: c Institute of Psychiatry , University of São Paulo Medical School , São Paulo , SP , Brazil.
authors.forename: Felipe
authors.initials: F
authors.lastname: Beijamini
authors.affiliation: b Laboratory of Genetics and Molecular Cardiology , Heart Institute (Incor), University of São Paulo Medical School , São Paulo , SP , Brazil.
authors.forename: Núbia E
authors.initials: NE
authors.lastname: Duarte
authors.affiliation: b Laboratory of Genetics and Molecular Cardiology , Heart Institute (Incor), University of São Paulo Medical School , São Paulo , SP , Brazil.
authors.forename: Andréa R V R
authors.initials: AR
authors.lastname: Horimoto
authors.affiliation: c Institute of Psychiatry , University of São Paulo Medical School , São Paulo , SP , Brazil.
authors.forename: Tâmara P
authors.initials: TP
authors.lastname: Taporoski
authors.affiliation: c Institute of Psychiatry , University of São Paulo Medical School , São Paulo , SP , Brazil.
authors.forename: Homero
authors.initials: H
authors.lastname: Vallada
authors.affiliation: b Laboratory of Genetics and Molecular Cardiology , Heart Institute (Incor), University of São Paulo Medical School , São Paulo , SP , Brazil.
authors.forename: André B
authors.initials: AB
authors.lastname: Negrão
authors.affiliation: b Laboratory of Genetics and Molecular Cardiology , Heart Institute (Incor), University of São Paulo Medical School , São Paulo , SP , Brazil.
authors.forename: José E
authors.initials: JE
authors.lastname: Krieger
authors.affiliation: d School of Arts, Sciences, and Humanities , University of São Paulo , São Paulo , SP , Brazil.
authors.forename: Mário
authors.initials: M
authors.lastname: Pedrazzoli
authors.affiliation: e Department of Medicine , University of Chicago , Chicago , IL , USA.
authors.forename: Kristen L
authors.initials: KL
authors.lastname: Knutson
authors.affiliation: b Laboratory of Genetics and Molecular Cardiology , Heart Institute (Incor), University of São Paulo Medical School , São Paulo , SP , Brazil.
authors.forename: Alexandre C
authors.initials: AC
authors.lastname: Pereira
authors.affiliation: a Faculty of Health and Medical Sciences , University of Surrey , Guildford , Surrey , UK.|b Laboratory of Genetics and Molecular Cardiology , Heart Institute (Incor), University of São Paulo Medical School , São Paulo , SP , Brazil.|c Institute of Psychiatry , University of São Paulo Medical School , São Paulo , SP , Brazil.
authors.forename: Malcolm
authors.initials: M
authors.lastname: von Schantz
mesh_terms: D000328:Adult; D044383:Black People / Q000235:genetics; D001938:Brazil; D002940:Circadian Rhythm; D015331:Cohort Studies; D005006:Ethnicity; D005260:Female; D005787:Gene Frequency; D006706:Homeostasis; D006801:Humans; D007198:Indians, North American / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012424:Rural Population; D012890:Sleep; D011795:Surveys and Questionnaires; D014505:Urban Population; D044465:White People / Q000235:genetics
keywords: Admixture; American Native Continental Ancestry Group; Brazil; chronotype; circadian rhythm; diurnal preference; sleep homeostasis