title: Independent association of liver fat accumulation with insulin resistance.
abstract: BACKGROUND
  To examine the association of intrahepatic fat with homeostasis model assessment-insulin resistance (HOMA-IR), a marker of insulin resistance, in Japanese adults, and whether intrahepatic fat is associated with insulin resistance independent of waist circumference and other measures of obesity.
  
  
  METHODS
  Fifty-three individuals aged 37-69 were studied. Spectrum obtained using a 3-T magnetic resonance imager was analysed with LCModel to quantify intrahepatic fat. Blood levels of insulin, glucose and other biochemical markers were obtained after 8h or more fasting. Percent body fat was estimated by a bioelectrical impedance analyzer. HOMA-IR and intrahepatic fat content were log-transformed in the analysis.
  
  
  RESULTS
  We found a positive correlation between intrahepatic fat and HOMA-IR, which was independent of the anthropometric measures of obesity. In contrast, significant and positive correlations of body mass index, percent body fat, and waist circumference with HOMA-IR were largely explained by their associations with intrahepatic fat. Intrahepatic fat was positively associated with alanine transaminase and triglycerides even after adjustment for HOMA-IR.
  
  
  CONCLUSIONS
  Intrahepatic fat was associated with insulin resistance independent of age, sex, and measures of obesity in Japanese adults. Hypertriglyceridemia and liver injury may directly occur subsequent to intrahepatic fat accumulation.
authors.affiliation: Department of Public Health, Fujita Health University, Toyoake, Japan; Department of Public Health and Health Systems, Nagoya University Graduate School of Medicine, Nagoya, Japan. Electronic address: yatsuya@gmail.com.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yatsuya
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nihashi
authors.affiliation: Department of Public Health and Health Systems, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Yuanying
authors.initials: Y
authors.lastname: Li
authors.affiliation: Geriatric Health Services Facility Mizusato, Nagoya, Japan.
authors.forename: Yo
authors.initials: Y
authors.lastname: Hotta
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA.
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Matsushita
authors.affiliation: Department of Interventional Cardiology, Erasmus Medical Center, Thoraxcenter, Rotterdam, The Netherlands.
authors.forename: Takashi
authors.initials: T
authors.lastname: Muramatsu
authors.affiliation: Department for Development of Preventive Medicine, National Center for Geriatrics and Gerontology, Obu, Japan.
authors.forename: Rei
authors.initials: R
authors.lastname: Otsuka
authors.affiliation: Inazawa City Hospital, Inazawa, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Matsunaga
authors.affiliation: Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yamashita
authors.affiliation: Department of Public Health and Health Systems, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Chaochen
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Public Health and Health Systems, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Mayu
authors.initials: M
authors.lastname: Uemura
authors.affiliation: Institute of Stress Science, Public Health Research Foundation, Tokyo, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Harada
authors.affiliation: Division of Medical Infomatics, Aichi Medical University Hospital, Nagakute, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fukatsu
authors.affiliation: Health Care Center, Anjo Kosei Hospital, Anjo, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Toyoshima
authors.affiliation: Department of Public Health and Health Systems, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Atsuko
authors.initials: A
authors.lastname: Aoyama
authors.affiliation: Department of Nursing, Nagoya University School of Health Sciences, Nagoya, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Tamakoshi
mesh_terms: D050154:Adiposity; D000328:Adult; D000368:Aged; D000410:Alanine Transaminase / Q000097:blood; D044466:Asian People; D001219:Aspartate Aminotransferases / Q000097:blood; D001786:Blood Glucose; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005215:Fasting; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D015228:Hypertriglyceridemia / Q000097:blood; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008019:Life Style; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009765:Obesity / Q000097:blood; D014280:Triglycerides / Q000097:blood; D055105:Waist Circumference
chemical_list: D000410:Alanine Transaminase; D001219:Aspartate Aminotransferases; D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007328:Insulin; D014280:Triglycerides
keywords: Ectopic fat; Insulin resistance; Liver; Magnetic resonance spectroscopy; Obesity