title: Impact of body mass index on neuronal fiber bundle lengths among healthy older adults.
abstract: Increased body mass index (BMI) has been linked to various detrimental health outcomes, including cognitive dysfunction. Recent work investigating associations between obesity and the brain has revealed decreased white matter microstructural integrity in individuals with elevated BMI, independent of age or comorbid health conditions. However, the relationship between high BMI and white matter fiber bundle length (FBL), which represents a novel metric of microstructural brain integrity, remains unknown. The present study utilized quantitative tractography based on diffusion tensor imaging (DTI) to investigate the relationship between BMI and FBL in 72 otherwise healthy older adults (24 males, 48 females). All participants were between 51 and 85 years of age (M = 63.26, SD = 8.76). Results revealed that elevated BMI was associated with shorter FBL in the temporal lobe, independent of age (p < .01). In addition, increased age was associated with shorter frontal, temporal, and whole brain FBL (all p values < .01). These findings indicate that, while increased age is an important factor associated with reduced FBL, high BMI is uniquely associated with reduced FBL in the temporal lobe. These data offer evidence for additive adverse effects of high BMI on the brain, especially in areas already vulnerable to aging processes and age-related neurodegenerative diseases. Further research is necessary to determine the physiological mechanisms associated with the shortening of FBL in individuals with high BMI.
authors.affiliation: University of Missouri-Saint Louis, One University Boulevard, Stadler Hall 443, Saint Louis, MO, 63121, USA, jdbdgf@umsl.edu.
authors.forename: Jacob D
authors.initials: JD
authors.lastname: Bolzenius
authors.forename: David H
authors.initials: DH
authors.lastname: Laidlaw
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Cabeen
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Conturo
authors.forename: Amanda R
authors.initials: AR
authors.lastname: McMichael
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Lane
authors.forename: Jodi M
authors.initials: JM
authors.lastname: Heaps
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Salminen
authors.forename: Laurie M
authors.initials: LM
authors.lastname: Baker
authors.forename: John
authors.initials: J
authors.lastname: Gunstad
authors.forename: Robert H
authors.initials: RH
authors.lastname: Paul
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology* / Q000502:physiology*; D015992:Body Mass Index; D001921:Brain / Q000166:cytology / Q000502:physiology; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology* / Q000502:physiology*; D012016:Reference Values; D013223:Statistics as Topic; D013702:Temporal Lobe / Q000166:cytology* / Q000502:physiology*
references.citation: J Am Soc Nephrol. 2004 Nov;15(11):2792-800
references.pmid: 15504932
references.citation: Acta Neuropathol. 1991;82(4):239-59
references.pmid: 1759558
references.citation: Eur J Immunogenet. 2004 Oct;31(5):207-13
references.pmid: 15379752
references.citation: Neurobiol Aging. 1997 Nov-Dec;18(6):609-15
references.pmid: 9461058
references.citation: J Neuropathol Exp Neurol. 1996 Mar;55(3):273-9
references.pmid: 8786385
references.citation: Proc Natl Acad Sci U S A. 1999 Aug 31;96(18):10422-7
references.pmid: 10468624
references.citation: Arch Intern Med. 2003 Jul 14;163(13):1524-8
references.pmid: 12860573
references.citation: Neuropsychologia. 2012 Jul;50(8):1759-65
references.pmid: 22561887
references.citation: Neuroimage. 2002 Oct;17(2):825-41
references.pmid: 12377157
references.citation: PLoS One. 2011 Apr 11;6(4):e18544
references.pmid: 21494606
references.citation: Biol Psychiatry. 2006 Sep 1;60(5):444-53
references.pmid: 16616725
references.citation: Cytokine. 2004 Oct 7;28(1):29-34
references.pmid: 15341923
references.citation: JAMA. 2010 Jan 20;303(3):235-41
references.pmid: 20071471
references.citation: Biochim Biophys Acta. 2009 May;1792(5):470-81
references.pmid: 18848880
references.citation: J Neurosci Methods. 2012 Jan 15;203(1):264-72
references.pmid: 21978486
references.citation: Hippocampus. 1991 Jan;1(1):1-8
references.pmid: 1669339
references.citation: Neuroimage. 2008 Aug 15;42(2):568-81
references.pmid: 18617421
references.citation: Arch Clin Neuropsychol. 2011 Aug;26(5):454-60
references.pmid: 21642663
references.citation: Neurobiol Aging. 2005 Apr;26(4):491-510
references.pmid: 15653178
references.citation: Curr Alzheimer Res. 2007 Apr;4(2):135-9
references.pmid: 17430236
references.citation: J Magn Reson B. 1996 Jun;111(3):209-19
references.pmid: 8661285
references.citation: J Int Neuropsychol Soc. 2000 Sep;6(6):705-26
references.pmid: 11011517
references.citation: Hum Brain Mapp. 2013 May;34(5):1044-52
references.pmid: 22139809
references.citation: JAMA. 1989 Nov 10;262(18):2551-6
references.pmid: 2810583
references.citation: J Comp Neurol. 2003 Jul 21;462(2):144-52
references.pmid: 12794739
references.citation: Obesity (Silver Spring). 2011 Mar;19(3):500-4
references.pmid: 21183934
references.citation: Neuroimage. 2010 Jun;51(2):565-77
references.pmid: 20178850
references.citation: Philos Trans R Soc Lond B Biol Sci. 2001 Aug 29;356(1412):1293-322
references.pmid: 11545704
references.citation: Ann Neurol. 2008 May;63(5):652-7
references.pmid: 18409192
references.citation: Exp Gerontol. 2012 Nov;47(11):873-7
references.pmid: 22735669
references.citation: Am J Clin Nutr. 2006 Feb;83(2):470S-474S
references.pmid: 16470015
references.citation: Arterioscler Thromb Vasc Biol. 2003 Nov 1;23(11):2063-9
references.pmid: 12842840
references.citation: JAMA. 2004 Mar 10;291(10):1238-45
references.pmid: 15010446
references.citation: Compr Psychiatry. 2007 Jan-Feb;48(1):57-61
references.pmid: 17145283
references.citation: Ann Neurol. 1999 Feb;45(2):265-9
references.pmid: 9989633
references.citation: Biol Res. 2005;38(4):381-7
references.pmid: 16579521
references.citation: N Engl J Med. 1996 Feb 1;334(5):292-5
references.pmid: 8532024