In overweight and obese women, dietary iron absorption is reduced and the enhancement of iron absorption by ascorbic acid is one-half that in normal-weight women
In overweight and obese women, dietary iron absorption is reduced and the enhancement of iron absorption by ascorbic acid is one-half that in normal-weight women
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DOI：
10.3945/ajcn.114.099218
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发表时间：
2015-12-01
影响因子：
7.1
通讯作者：
Herter-Aeberli, Isabelle
中科院分区：
文献类型：
--
作者：
Cepeda-Lopez, Ana C.;Melse-Boonstra, Alida;Herter-Aeberli, Isabelle
背景：铁缺乏在超重和肥胖人群中很常见。这种缺乏可能是由于肥胖相关的炎症增加了血清hepcidin，减少了膳食铁的吸收。由于hepcidin减少铁从基底外侧肠细胞外排，因此不确定膳食铁吸收的肠道增强剂如抗坏血酸是否对超重和肥胖个体有效。目的：在这项研究中，我们比较了正常体重组（NW）和超重和肥胖联合组（OW/OB）女性在含抗坏血酸（+AA）和不含抗坏血酸（-AA）膳食中的铁吸收。设计：健康、无贫血的女性[n = 62；BMI（单位：kg/m(2)）： 18.5-39.9)消耗了稳定同位素标记的小麦试验粕-AA和小麦试验粕+AA （31.4 mg抗坏血酸）。我们使用双能x线吸收仪测量铁吸收和身体成分，使用一氧化碳（CO）再呼吸法测量血容量，铁状态，炎症和血清hepcidin。结果：NW组炎症生物标志物（P < 0.05）和hepcidin （P = 0.08）低于OW/OB组。NW和OW/OB的几何平均（95% CI）铁吸收率分别为-AA组19.0%（15.2%,23.5%）和12.9% (9.7%,16.9%)(P = 0.049)， +AA组29.5%（23.3%,38.2%）和16.6% (12.8%,21.7%)（P = 0.004）。-AA至+AA饲粮铁吸收增加的中位数百分比在西北组为56% (P < 0.001)，在OW/OB组为28% （P = 0.006）。血清铁蛋白[R-2 = 0.22；β = -0.17 (95% CI: -0.25, -0.09)]，转铁蛋白受体[R-2 = 0.23；β = 2.79 (95% CI: 1.47, 4.11)]和hepcidin [R-2 = 0.13；b = -0.85 (95% CI: -1.41, -0.28)]是铁吸收的重要预测因子。结论：超重和肥胖妇女的铁吸收是正常体重妇女的三分之二，抗坏血酸对铁吸收的促进作用是正常体重妇女的一半。建议肥胖个体摄入更多的抗坏血酸（或其他促进铁吸收的肠道剂）来改善铁的状态可能效果有限。
Background: Iron deficiency is common in overweight and obese individuals. This deficiency may be due to adiposity-related inflammation that increases serum hepcidin and decreases dietary iron absorption. Because hepcidin reduces iron efflux from the basolateral enterocyte, it is uncertain whether luminal enhancers of dietary iron absorption such as ascorbic acid can be effective in overweight and obese individuals.Objective: In this study, we compared iron absorption from a meal with ascorbic acid (+AA) and a meal without ascorbic acid (-AA) in women in a normal-weight group (NW) with those in overweight and obese groups combined (OW/OB).Design: Healthy, nonanemic women [n = 62; BMI (in kg/m(2)): 18.5-39.9] consumed a stable-isotope-labeled wheat-based test meal -AA and a wheat-based test meal +AA (31.4 mg ascorbic acid). We measured iron absorption and body composition with the use of dual-energy X-ray absorptiometry, blood volume with the use of a carbon monoxide (CO)-rebreathing method, iron status, inflammation, and serum hepcidin.Results: Inflammatory biomarkers (all P < 0.05) and hepcidin (P = 0.08) were lower in the NW than in the OW/OB. Geometric mean (95% CI) iron absorptions in the NW and OW/OB were 19.0% (15.2%, 23.5%) and 12.9% (9.7%, 16.9%) (P = 0.049), respectively, from -AA meals and 29.5% (23.3%, 38.2%) and 16.6% (12.8%, 21.7%) (P = 0.004), respectively, from +AA meals. Median percentage increases in iron absorption for -AA to +AA meals were 56% in the NW (P < 0.001) and 28% in OW/OB (P = 0.006). Serum ferritin [R-2 = 0.22; beta = -0.17 (95% CI: -0.25, -0.09)], transferrin receptor [R-2 = 0.23; beta = 2.79 (95% CI: 1.47, 4.11)], and hepcidin [R-2 = 0.13; b = -0.85 (95% CI: -1.41, -0.28)] were significant predictors of iron absorption.Conclusions: In overweight and obese women, iron absorption is two-thirds that in normal-weight women, and the enhancing effect of ascorbic acid on iron absorption is one-half of that in normal-weight women. Recommending higher intakes of ascorbic acid (or other luminal enhancers of iron absorption) in obese individuals to improve iron status may have a limited effect.