title: Hepatic iron storage is related to body adiposity and hepatic inflammation.
abstract: BACKGROUND
  Obesity has been reported to be associated with iron deficiency. However, few studies have investigated iron status in low adiposity. To investigate whether body adiposity was associated with altered hepatic iron status, we compared liver iron levels and markers involved in inflammation and iron absorption in obese, control, and mildly calorie restricted mice.
  
  
  METHODS
  Seven week old C57BL/6 mice were fed control (10% kcal fat, Control) or high fat (60% kcal fat, HFD) diets, or reduced amount of control diet to achieve 15% calorie restriction (CR) for 16 weeks. Hepatic non-heme iron content and ferritin protein level, and hematocrit and hemoglobin levels were determined to assess iron status. Hepatic expression ofMcp-1andTnf-αwere measured as hepatic inflammatory markers. Hepatic hepcidin (Hamp) andBmp6, and duodenalDmt1,Dcyt1b, hephaestin (Heph) and ferroportin mRNA levels were measured as factors involved in regulation of iron absorption.
  
  
  RESULTS
  Hepatic non-heme iron and ferritin protein levels were significantly higher in the CR group compared with the Control group, and significantly lower in the HFD group. These two iron status markers showed significantly negative correlations with the amount of white adipose tissue (r= -0.689 for hepatic non-heme iron andr= -0.740 for ferritin). HepaticMcp-1andTnf-αmRNA levels were significantly lower in the CR compared with the HFD (74 and 47% lower) and showed significantly negative correlations with hepatic non-heme iron levels (Mcp-1:r= -0.557,P< 0.05;Tnf-α:r= -0.464,P< 0.05). HepaticHampmRNA levels were lower in the HFD and higher in the CR groups compared with the Control group, which could be a response to maintain iron homeostasis. DuodenalDcyt1bmRNA levels were higher in the CR group compared with the HFD group and duodenalHephmRNA levels were higher in the CR group than the Control group.
  
  
  CONCLUSIONS
  We showed that body adiposity was inversely correlated with liver iron status. Low inflammation levels in hepatic milieu and enhanced expression of duodenal oxidoreductases induced by calorie restriction could have contributed to higher iron status.
authors.affiliation: Department of Food and Nutrition, College of Human Ecology, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, South Korea.
authors.forename: Chan Yoon
authors.initials: CY
authors.lastname: Park
authors.affiliation: Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, South Korea.
authors.forename: Jayong
authors.initials: J
authors.lastname: Chung
authors.affiliation: Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, South Korea.
authors.forename: Kyung-Ok
authors.initials: KO
authors.lastname: Koo
authors.affiliation: Department of Food and Nutrition, College of Human Ecology, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, South Korea.
authors.forename: Min Soo
authors.initials: MS
authors.lastname: Kim
authors.affiliation: Department of Food and Nutrition, College of Human Ecology, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, South Korea.|Research Institute of Human Ecology, Seoul National University, Seoul, South Korea.
authors.forename: Sung Nim
authors.initials: SN
authors.lastname: Han
keywords: Body adiposity; Duodenal iron transporter; Hepatic non-heme iron; Hepcidin; Iron absorption; Mild calorie restriction