Reduced lean mass in early Alzheimer disease and its association with brain atrophy.
OBJECTIVE
To examine body composition in individuals with early AD and without dementia and its relation to cognition and brain volume.


METHODS
Cross-sectional case-control study.


METHODS
Individuals without dementia (Clinical Dementia Rating, 0; n = 70) and with early-stage AD (Clinical Dementia Rating, 0.5 or 1; n = 70) in the Alzheimer and Memory Program at the University of Kansas School of Medicine.


METHODS
Participants were evaluated with brain magnetic resonance imaging (MRI), neuropsychological testing, and dual-energy x-ray absorptiometry to determine whole-body fat and lean masses. Body mass index was calculated as weight in kilograms divided by height in meters squared.


RESULTS
Lean mass was reduced in persons with early AD compared with controls without dementia (F = 7.73; P = .006) after controlling for sex. Whole-brain volume (beta = .20; P < .001), white matter volume (beta = .19; P < .001), and global cognitive performance (beta = .12; P = .007) were associated with lean mass (dependent variable) when controlling for age and sex. The total body fat and percentage of body fat values were not different across groups or related to cognition and brain volume.


CONCLUSIONS
Loss of lean mass is accelerated in AD and is associated with brain atrophy and cognitive performance, perhaps as a direct or indirect consequence of AD pathophysiology or through shared mechanisms common to both AD and sarcopenia.
Burns
Jeffrey M
JM
Department of Neurology, University of Kansas School of Medicine, 3599 Rainbow Blvd, Kansas City, KS 66160, USA. jburns2@kumc.edu
Johnson
David K
DK
Watts
Amber
A
Swerdlow
Russell H
RH
Brooks
William M
WM
D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000502:physiology; D000368:Aged; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000473:pathology; D001284:Atrophy / Q000453:epidemiology / Q000473:pathology; D015415:Biomarkers / Q000032:analysis; D015992:Body Mass Index; D001931:Brain Mapping; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000453:epidemiology / Q000473:pathology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology; D009483:Neuropsychological Tests; D055948:Sarcopenia / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology; D013851:Thinness / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology; D015431:Weight Loss / Q000502:physiology
D015415:Biomarkers
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