title: Association of hearing impairment with brain volume changes in older adults.
abstract: Hearing impairment in older adults is independently associated in longitudinal studies with accelerated cognitive decline and incident dementia, and in cross-sectional studies, with reduced volumes in the auditory cortex. Whether peripheral hearing impairment is associated with accelerated rates of brain atrophy is unclear. We analyzed brain volume measurements from magnetic resonance brain scans of individuals with normal hearing versus hearing impairment (speech-frequency pure tone average>25 dB) followed in the neuroimaging substudy of the Baltimore Longitudinal Study of Aging for a mean of 6.4 years after the baseline scan (n=126, age 56-86 years). Brain volume measurements were performed with semi-automated region-of-interest (ROI) algorithms, and brain volume trajectories were analyzed with mixed-effect regression models adjusted for demographic and cardiovascular factors. We found that individuals with hearing impairment (n=51) compared to those with normal hearing (n=75) had accelerated volume declines in whole brain and regional volumes in the right temporal lobe (superior, middle, and inferior temporal gyri, parahippocampus, p<.05). These results were robust to adjustment for multiple confounders and were consistent with voxel-based analyses, which also implicated right greater than left temporal regions. These findings demonstrate that peripheral hearing impairment is independently associated with accelerated brain atrophy in whole brain and regional volumes concentrated in the right temporal lobe. Further studies investigating the mechanistic basis of the observed associations are needed.
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Johns Hopkins University, Baltimore, MD, USA; Department of Geriatric Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Mental Health, Johns Hopkins University, Baltimore, MD, USA; Department of Epidemiology, Johns Hopkins University, Baltimore, MD, USA; Center on Aging and Health, Johns Hopkins Medical Institutions, Baltimore, MD, USA. Electronic address: flin1@jhmi.edu.
authors.forename: F R
authors.initials: FR
authors.lastname: Lin
authors.affiliation: Longitudinal Studies Section, Clinical Research Branch, National Institute on Aging, Baltimore, MD, USA.
authors.forename: L
authors.initials: L
authors.lastname: Ferrucci
authors.affiliation: Laboratory of Behavioral Neuroscience, Intramural Research Program, National Institute on Aging, Baltimore, MD, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: An
authors.affiliation: Laboratory of Behavioral Neuroscience, Intramural Research Program, National Institute on Aging, Baltimore, MD, USA; Graduate Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: J O
authors.initials: JO
authors.lastname: Goh
authors.affiliation: Section for Biomedical Image Analysis, Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Jimit
authors.initials: J
authors.lastname: Doshi
authors.affiliation: Longitudinal Studies Section, Clinical Research Branch, National Institute on Aging, Baltimore, MD, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Metter
authors.affiliation: Section for Biomedical Image Analysis, Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: C
authors.initials: C
authors.lastname: Davatzikos
authors.affiliation: Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Kraut
authors.affiliation: Laboratory of Behavioral Neuroscience, Intramural Research Program, National Institute on Aging, Baltimore, MD, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Resnick
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D001284:Atrophy / Q000473:pathology; D001299:Audiometry; D001921:Brain / Q000473:pathology*; D005260:Female; D034381:Hearing Loss / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size
keywords: Aging; Brain volume; Hearing impairment; Hearing loss; MRI