Bertinato Jesse, Aroche Cristina, Plouffe Louise J, Lee Megan, Murtaza Zehra, Kenney Laura, Lavergne Christopher, Aziz Alfred
Nutrition Research Division, Health Products and Food Branch, Health Canada, Sir Frederick G. Banting Research Centre, 251 Sir Frederick Banting Driveway, PL 2203E, Ottawa, ON, K1A 0K9, Canada,
Eur J Nutr. 2014 Apr;53(3):885-95. doi: 10.1007/s00394-013-0592-9. Epub 2013 Oct 6.
Since obesity is associated with poorer iron status, the effects of diet-induced obesity on iron status and iron-regulatory pathways were examined.
Weanling male diet-induced obese sensitive (n = 12/diet group) and resistant (n = 12/diet group) rats were fed one of four high-fat, high-energy diets supplemented with 5 (5Fe, low), 15 (15Fe, marginal), 35 (35Fe, normal) or 70 (70Fe, high) mg iron/kg diet for 12 weeks. At the end of the study, rats in each diet group were categorised as obese (>19 %) or lean (<17 %) based on percentage body fat.
Obese rats gained more weight, had larger total lean mass, consumed more food and showed greater feed efficiency compared with lean rats. Obese rats fed the 5Fe and 15Fe diets had poorer iron status than lean rats fed the same diet. Obese 5Fe rats had lower serum iron and more severe iron-deficiency anaemia. Obese 15Fe rats had lower mean corpuscular haemoglobin and liver iron concentrations. Hepcidin mRNA expression in liver and adipose tissue was similar for obese and lean rats. Iron concentration and content of the iron transporters divalent metal transporter 1 and ferroportin 1 in duodenal mucosa were also similar.
Obese rats that were larger, regardless of adiposity, had higher iron requirements compared with lean rats that appeared independent of hepcidin, inflammation and intestinal iron absorption. Higher iron requirements may have resulted from larger accretion of body mass and blood volume. Greater food consumption did not compensate for the higher iron needs, indicating increased susceptibility to iron deficiency.
由于肥胖与较差的铁状态相关，因此研究了饮食诱导的肥胖对铁状态和铁调节途径的影响。
将断奶雄性饮食诱导肥胖敏感型（每组12只）和抗性型（每组12只）大鼠喂食四种高脂肪、高能量饮食中的一种，这些饮食分别补充了5（5Fe，低）、15（15Fe，边缘）、35（35Fe，正常）或70（70Fe，高）mg铁/千克饮食，持续12周。在研究结束时，根据体脂百分比将每个饮食组中的大鼠分为肥胖（>19%）或瘦（<17%）。
与瘦大鼠相比，肥胖大鼠体重增加更多，总瘦体重更大，食物消耗量更多，饲料效率更高。喂食5Fe和15Fe饮食的肥胖大鼠的铁状态比喂食相同饮食的瘦大鼠差。肥胖的5Fe大鼠血清铁水平较低，缺铁性贫血更严重。肥胖的15Fe大鼠平均红细胞血红蛋白和肝脏铁浓度较低。肥胖和瘦大鼠肝脏和脂肪组织中的铁调素mRNA表达相似。十二指肠黏膜中铁转运蛋白二价金属转运体1和铁转运蛋白1的铁浓度和含量也相似。
体型较大的肥胖大鼠，无论肥胖程度如何，与瘦大鼠相比铁需求量更高，这似乎与铁调素、炎症和肠道铁吸收无关。更高的铁需求量可能是由于更大的体重和血容量增加所致。更多的食物消耗并不能弥补更高的铁需求，表明对缺铁的易感性增加。
