Diet‐induced obesity leads to decreased hepatic iron storage associated with inflammation

Abstract

Increased risk for iron deficiency has been reported in obese subjects. We investigated the effects of high fat diet‐induced obesity on hepatic iron status and serum adipokine and inflammatory marker levels. Four‐ week old C57BL mice were fed diets containing 10 (ND) or 60 (HFD)% energy from fat for 16 wks. Consumption of HFD resulted in higher weight gain (16.3 vs. 30.4g). Serum leptin, total adiponectin, high molecular weight (HMW) adiponectin, and serum amyloid A (SAA) and hepatic non‐heme iron, ferritin, and hepcidin mRNA levels were measured. HFD group had higher leptin (42.6 vs. 104.3 ng/mL), and lower HMW adiponectin (4.80 vs. 3.67 ug/mL) levels. Higher level of SAA in HFD group (57.8 vs. 117.9 ug/mL) suggests inflammation in HFD‐induced obese animals. HFD group had lower hepatic non‐heme iron (3.12 vs 0.869 ug/mg protein) and ferritin levels. HFD group had lower hepcidin expression at 54% level of ND group, however, ratio of hepcidin expression to non‐heme iron was higher (2.5 fold higher in HFD than ND). Hepcidin is a homeostatic regulator of iron metabolism by restricting intestinal iron absorption, but, also known as a mediator of inflammation. Leptin and SAA showed positive correlation with weight gain while HMW adiponectin showed negative correlation. Increased SAA levels and higher hepcidin ratio to iron suggests that lower hepatic iron status in obese animals might be associated with inflammation. Supported by Korea Research Foundation Grant (C00305) and by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2009‐0063409).