Hiroshi Yatsuya1, Takashi Nihashi2, Yuanying Li3, Yo Hotta4, Kunihiro Matsushita5, Takashi Muramatsu6, Rei Otsuka7, Masaaki Matsunaga8, Kentaro Yamashita9, Chaochen Wang3, Mayu Uemura3, Akiko Harada10, Hiroshi Fukatsu11, Hideaki Toyoshima12, Atsuko Aoyama3, Koji Tamakoshi13. 1. 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. 2. Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan. 3. Department of Public Health and Health Systems, Nagoya University Graduate School of Medicine, Nagoya, Japan. 4. Geriatric Health Services Facility Mizusato, Nagoya, Japan. 5. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA. 6. Department of Interventional Cardiology, Erasmus Medical Center, Thoraxcenter, Rotterdam, The Netherlands. 7. Department for Development of Preventive Medicine, National Center for Geriatrics and Gerontology, Obu, Japan. 8. Inazawa City Hospital, Inazawa, Japan. 9. Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan. 10. Institute of Stress Science, Public Health Research Foundation, Tokyo, Japan. 11. Division of Medical Infomatics, Aichi Medical University Hospital, Nagakute, Japan. 12. Health Care Center, Anjo Kosei Hospital, Anjo, Japan. 13. Department of Nursing, Nagoya University School of Health Sciences, Nagoya, Japan.
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. CONCLUSION: 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.
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. CONCLUSION: 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.