title: Perimenopausal hormone therapy is associated with regional sparing of the CA1 subfield: a HUNT MRI study.
abstract: Observational studies support a neuroprotective role of hormone therapy (HT) in the perimenopause, with hippocampal size being a widely used biomarker. We investigated the effect of HT started before the onset of menopause and lasting for at least 3 years on hippocampal volume and shape in 80 postmenopausal women and 80 controls matched on age and intracranial volume taken from a large community-based sample (Nord-Trøndelag Health Study-magnetic resonance imaging). The main effect of hormone group showed a statistically significant difference in hippocampal volumes (p = 0.028). Both the right (3.2%) and left (2.8%) hippocampal volumes were larger in the HT group but only significant for the right hippocampus (p = 0.023). Shape analysis revealed significant regional sparing of the medial aspect of the right hippocampal head and lateral aspect of the body extending to the tail, corresponding to the cornu ammonis, including part of the subiculum, in the HT group. A similar nonsignificant pattern was observed in the left hippocampus. The present study provides support for the critical window theory demonstrating that HT initiated in the perimenopause has neuroprotective properties.
authors.affiliation: Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Medical Imaging, St. Olav's Hospital, Trondheim, Norway.
authors.forename: Carl W S
authors.initials: CW
authors.lastname: Pintzka
authors.affiliation: Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Medical Imaging, St. Olav's Hospital, Trondheim, Norway. Electronic address: asta.haberg@ntnu.no.
authors.forename: Asta K
authors.initials: AK
authors.lastname: Håberg
mesh_terms: D000368:Aged; D056547:CA1 Region, Hippocampal / Q000187:drug effects*; D016022:Case-Control Studies; D005260:Female; D020249:Hormone Replacement Therapy / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008569:Memory Disorders / Q000473:pathology* / Q000628:therapy*; D008875:Middle Aged; D047648:Perimenopause
keywords: Aging; Alzheimer's disease; Critical widow theory; Estrogen; Hippocampus; Menopause