title: Pineal Gland Volume Assessed by MRI and Its Correlation with 6-Sulfatoxymelatonin Levels among Older Men.
abstract: The pineal gland produces the hormone melatonin, and its volume may influence melatonin levels. We describe an innovative method for estimating pineal volume in humans and present the association of pineal parenchyma volume with levels of the primary melatonin metabolite, 6-sulfatoxymelatonin. We selected a random sample of 122 older Icelandic men nested within the AGES-Reykjavik cohort and measured their total pineal volume, their parenchyma volume, and the extent of calcification and cysts. For volume estimations we used manual segmentation of magnetic resonance images in the axial plane with simultaneous side-by-side view of the sagittal and coronal plane. We used multivariable adjusted linear regression models to estimate the association of pineal parenchyma volume and baseline characteristics, including 6-sulfatoxymelatonin levels. We used logistic regression to test for differences in first morning urinary 6-sulfatoxymelatonin levels among men with or without cystic or calcified glands. The pineal glands varied in volume, shape, and composition. Cysts were present in 59% of the glands and calcifications in 21%. The mean total pineal volume measured 207 mm(3) (range 65-536 mm(3)) and parenchyma volume 178 mm(3) (range 65-503 mm(3)). In multivariable-adjusted models, pineal parenchyma volume was positively correlated with 6-sulfatoxymelatonin levels (β = 0.52, p < 0.001). Levels of 6-sulfatoxymelatonin did not differ significantly by presence of cysts or calcification. By using an innovative method for pineal assessment, we found pineal parenchyma volume to be positively correlated with 6-sulfatoxymelatonin levels, in line with other recent studies.
authors.affiliation: Icelandic Cancer Society, Reykjavik, Iceland Centre of Public Health Sciences, University of Iceland, Reykjavik, Iceland Faculty of Medicine, University of Iceland, Reykjavik, Iceland lara@sessionimpossible.com.
authors.forename: Lara G
authors.initials: LG
authors.lastname: Sigurdardottir
authors.affiliation: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Markt
authors.affiliation: Icelandic Heart Association, Kopavogur, Iceland.
authors.forename: Sigurdur
authors.initials: S
authors.lastname: Sigurdsson
authors.affiliation: Centre of Public Health Sciences, University of Iceland, Reykjavik, Iceland Icelandic Heart Association, Kopavogur, Iceland.
authors.forename: Thor
authors.initials: T
authors.lastname: Aspelund
authors.affiliation: Clinical Epidemiology and Biostatistcs, School of Medical Sciences, Örebro University, Örebro, Sweden.
authors.forename: Katja
authors.initials: K
authors.lastname: Fall
authors.affiliation: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA Department of Epidemiology, Medical University of Vienna, Vienna, Austria.
authors.forename: Eva
authors.initials: E
authors.lastname: Schernhammer
authors.affiliation: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Rider
authors.affiliation: Laboratory of Epidemiology and Population Sciences, Intramural Research Program, National Institute on Aging, Bethesda, Maryland, USA.
authors.forename: Lenore
authors.initials: L
authors.lastname: Launer
authors.affiliation: Laboratory of Epidemiology and Population Sciences, Intramural Research Program, National Institute on Aging, Bethesda, Maryland, USA.
authors.forename: Tamara
authors.initials: T
authors.lastname: Harris
authors.affiliation: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Meir J
authors.initials: MJ
authors.lastname: Stampfer
authors.affiliation: Faculty of Medicine, University of Iceland, Reykjavik, Iceland Icelandic Heart Association, Kopavogur, Iceland.
authors.forename: Vilmundur
authors.initials: V
authors.lastname: Gudnason
authors.affiliation: Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Czeisler
authors.affiliation: Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Lockley
authors.affiliation: Centre of Public Health Sciences, University of Iceland, Reykjavik, Iceland Faculty of Medicine, University of Iceland, Reykjavik, Iceland Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.
authors.forename: Unnur A
authors.initials: UA
authors.lastname: Valdimarsdottir
authors.affiliation: Centre of Public Health Sciences, University of Iceland, Reykjavik, Iceland Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Lorelei A
authors.initials: LA
authors.lastname: Mucci
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging; D002940:Circadian Rhythm; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000652:urine; D009929:Organ Size; D010870:Pineal Gland / Q000033:anatomy & histology*
chemical_list: C054513:6-sulfatoxymelatonin; D008550:Melatonin
keywords: MRI; circadian; melatonin; pineal; sleep