Impact of body mass index on neuronal fiber bundle lengths among healthy older adults

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.

[1]  HighWire Press.  Philosophical Transactions of the Royal Society of London , 1781, The London Medical Journal.

[2]  M. Albert,et al.  Prevalence of Alzheimer's disease in a community population of older persons. Higher than previously reported. , 1989, JAMA.

[3]  John Kornak,et al.  Body mass index and magnetic resonance markers of brain integrity in adults , 2008, Annals of neurology.

[4]  J. Gerberding,et al.  Actual causes of death in the United States, 2000. , 2004, JAMA.

[5]  W. Jagust.  What can imaging reveal about obesity and the brain? , 2007, Current Alzheimer research.

[6]  R. Considine,et al.  Serum immunoreactive-leptin concentrations in normal-weight and obese humans. , 1996, The New England journal of medicine.

[7]  B T Hyman,et al.  Entorhinal cortex pathology in Alzheimer's disease , 1991, Hippocampus.

[8]  M. Raichle,et al.  Tracking neuronal fiber pathways in the living human brain. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[9]  R. Mrak,et al.  Correlation of Astrocytic S100β Expression with Dystrophic Neurites in Amyloid Plaques of Alzheimer's Disease , 1996, Journal of neuropathology and experimental neurology.

[10]  B. Pakkenberg,et al.  Age-Induced White Matter Changes in the Human Brain: A Stereological Investigation , 1997, Neurobiology of Aging.

[11]  G. Latkovskis,et al.  C-reactive protein levels and common polymorphisms of the interleukin-1 gene cluster and interleukin-6 gene in patients with coronary heart disease. , 2004, European journal of immunogenetics : official journal of the British Society for Histocompatibility and Immunogenetics.

[12]  P. Blackman.  Actual causes of death in the United States. , 1994, JAMA.

[13]  C. Barnes,et al.  Age-related changes in parahippocampal white matter integrity: A diffusion tensor imaging study , 2012, Neuropsychologia.

[14]  Karsten Mueller,et al.  Sex-Dependent Influences of Obesity on Cerebral White Matter Investigated by Diffusion-Tensor Imaging , 2010, PloS one.

[15]  David H. Laidlaw,et al.  Quantitative tractography metrics of white matter integrity in diffusion-tensor MRI , 2008, NeuroImage.

[16]  S. Humphries,et al.  Human CRP Gene Polymorphism Influences CRP Levels: Implications for the Prediction and Pathogenesis of Coronary Heart Disease , 2003, Arteriosclerosis, thrombosis, and vascular biology.

[17]  J Mazziotta,et al.  A probabilistic atlas and reference system for the human brain: International Consortium for Brain Mapping (ICBM). , 2001, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[18]  E. Gordon,et al.  Elevated body mass index is associated with executive dysfunction in otherwise healthy adults. , 2007, Comprehensive psychiatry.

[19]  L. Kappelle,et al.  Type 2 diabetes mellitus, hypertension, dyslipidemia and obesity: A systematic comparison of their impact on cognition. , 2009, Biochimica et biophysica acta.

[20]  Leonid Zhukov,et al.  Oriented tensor reconstruction: tracing neural pathways from diffusion tensor MRI , 2002, IEEE Visualization, 2002. VIS 2002..

[21]  E. Akbudak,et al.  Neuroimaging signatures and cognitive correlates of the montreal cognitive assessment screen in a nonclinical elderly sample. , 2011, Archives of clinical neuropsychology : the official journal of the National Academy of Neuropsychologists.

[22]  P. V. van Zijl,et al.  Three‐dimensional tracking of axonal projections in the brain by magnetic resonance imaging , 1999, Annals of neurology.

[23]  B. Wisse,et al.  The inflammatory syndrome: the role of adipose tissue cytokines in metabolic disorders linked to obesity. , 2004, Journal of the American Society of Nephrology : JASN.

[24]  Michael Brady,et al.  Improved Optimization for the Robust and Accurate Linear Registration and Motion Correction of Brain Images , 2002, NeuroImage.

[25]  Andrew J. Saykin,et al.  Optimization of seed density in DTI tractography for structural networks , 2012, Journal of Neuroscience Methods.

[26]  A. Brickman,et al.  Obesity Is Associated With Reduced White Matter Integrity in Otherwise Healthy Adults * , 2011, Obesity.

[27]  M. Tonetti,et al.  Gene polymorphisms in pro-inflammatory cytokines are associated with systemic inflammation in patients with severe periodontal infections. , 2004, Cytokine.

[28]  G. O. Lignac.  [Actual causes of death]. , 1951, Nederlands tijdschrift voor geneeskunde.

[29]  H. Braak,et al.  Neuropathological stageing of Alzheimer-related changes , 2004, Acta Neuropathologica.

[30]  Haiqun Lin,et al.  Body mass index correlates negatively with white matter integrity in the fornix and corpus callosum: A diffusion tensor imaging study , 2013, Human brain mapping.

[31]  Thomas R. Barrick,et al.  White matter structural decline in normal ageing: A prospective longitudinal study using tract-based spatial statistics , 2010, NeuroImage.

[32]  R. von Bernhardi,et al.  Oligodendrocytes damage in Alzheimer's disease: beta amyloid toxicity and inflammation. , 2005, Biological research.

[33]  W. Griffin,et al.  Inflammation and neurodegenerative diseases. , 2006, The American journal of clinical nutrition.

[34]  P. Greenwood,et al.  The frontal aging hypothesis evaluated , 2000, Journal of the International Neuropsychological Society.

[35]  McGinnis Jm,et al.  Actual causes of death in the United States. , 1993 .

[36]  E. Gordon,et al.  Regional White Matter and Neuropsychological Functioning across the Adult Lifespan , 2006, Biological Psychiatry.

[37]  Deborah Gustafson,et al.  An 18-year follow-up of overweight and risk of Alzheimer disease. , 2003, Archives of internal medicine.

[38]  K. Flegal,et al.  Prevalence and trends in obesity among US adults, 1999-2008. , 2010, JAMA.

[39]  B. Pakkenberg,et al.  Marked loss of myelinated nerve fibers in the human brain with age , 2003, The Journal of comparative neurology.

[40]  D. Harvey,et al.  Measures of brain morphology and infarction in the framingham heart study: establishing what is normal , 2005, Neurobiology of Aging.

[41]  P. Basser,et al.  Microstructural and physiological features of tissues elucidated by quantitative-diffusion-tensor MRI. , 1996, Journal of magnetic resonance. Series B.

[42]  R. Schmidt,et al.  Genetics of subcortical vascular dementia , 2012, Experimental Gerontology.