title: Dyslipidemia links obesity to early cerebral neurochemical alterations.
abstract: OBJECTIVE
  To examine the role of hypertension, hyperglycemia, and dyslipidemia in potentially accounting for obesity-related brain vulnerability in the form of altered cerebral neurochemistry.
  
  
  METHODS
  Sixty-four adults, ages 40-60 years, underwent a health screen and proton magnetic resonance spectroscopy ((1) H MRS) of occipitoparietal gray matter to measure N-acetyl aspartate (NAA), choline (Cho), myo-inositol (mI), and glutamate (Glu) relative to creatine (Cr). The causal steps approach and nonparametric bootstrapping were utilized to assess if fasting glucose, mean arterial pressure or peripheral lipid/lipoprotein levels mediate the relationship between body mass index (BMI) and cerebral neurochemistry.
  
  
  RESULTS
  Higher BMI was significantly related to higher mI/Cr, independent of age and sex. BMI was also significantly related to two of the proposed mediators, triglyceride, and HDL-cholesterol, which were also independently related to increased mI/Cr. Finally, the relationship between BMI and mI/Cr was significantly attenuated after inclusion of triglyceride and HDL-cholesterol into the model, one at a time, indicating statistical mediation.
  
  
  CONCLUSIONS
  Higher triglyceride and lower HDL levels statistically account for the association between BMI and myo-inositol, pointing toward a potentially critical role for dyslipidemia in the development of cerebral neurochemical alterations in obesity.
authors.affiliation: Department of Psychology, The University of Texas at Austin, Austin, TX, USA; University of Texas Imaging Research Center, Austin, TX, USA.
authors.forename: Andreana P
authors.initials: AP
authors.lastname: Haley
authors.forename: Mitzi M
authors.initials: MM
authors.lastname: Gonzales
authors.forename: Takashi
authors.initials: T
authors.lastname: Tarumi
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001786:Blood Glucose; D001794:Blood Pressure; D015992:Body Mass Index; D001921:Brain / Q000503:physiopathology; D001927:Brain Diseases / Q000209:etiology / Q000503:physiopathology*; D008076:Cholesterol, HDL / Q000097:blood; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D050171:Dyslipidemias / Q000150:complications / Q000503:physiopathology*; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism; D006801:Humans; D007294:Inositol / Q000378:metabolism; D016014:Linear Models; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009448:Neurochemistry; D009765:Obesity / Q000150:complications / Q000503:physiopathology*; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D014280:Triglycerides; D001224:Aspartic Acid; D018698:Glutamic Acid; D007294:Inositol; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline