背景:目前世卫组织针对儿童(<12μg/L)和女性(<15μg/L)铁缺乏(ID)的血清铁蛋白(SF)阈值是基于几十年前使用的放射性测定的专家意见得出的。使用当代免疫比浊法,更高的门槛(儿童,<20μg/L;女性,<25μg/L)从基于生理的分析中鉴定。
目的:我们研究了使用专家意见时代的免疫放射测定法测量的SF与2个独立测量的ID指标的关系,血红蛋白(Hb)和红细胞锌原卟啉(eZnPP),使用来自第三次全国健康和营养调查(NHANESIII,1988-1994)。循环Hb开始降低和eZnPP开始增加的SF为鉴定缺铁性红细胞生成的开始提供了生理基础。
方法:我们分析了2616名明显健康儿童的NHANESIII横断面数据,年龄12-59个月,和4639名明显健康的未怀孕妇女,年龄在15-49岁之间。我们使用受限三次样条回归模型来确定ID的SF阈值。
结果:Hb和eZnPP确定的SF阈值在儿童中没有显着差异,21.2μg/L(95%置信区间:18.5,26.5)和18.7μg/L(17.9,19.7),and,在女性中,是相似的,尽管有很大的不同,24.8μg/L(23.4,26.9)和22.5μg/L(21.7,23.3)。
结论:这些NHANES结果表明,基于生理的SF阈值高于同一时代建立的专家意见的阈值。使用生理指标发现的SF阈值检测缺铁性红细胞生成的发作,而世界卫生组织的门槛确定的是较晚的,更严重的ID阶段。
Current WHO serum ferritin (SF) thresholds for iron deficiency (ID) in children (<12 μg/L) and women (<15 μg/L) are derived from expert opinion based on radiometric assays in use decades ago. Using a contemporary immunoturbidimetry assay, higher thresholds (children, <20 μg/L; women, <25 μg/L) were identified from physiologically based analyses.
We examined relationships of SF measured using an immunoradiometric assay from the era of expert opinion with 2 independently measured indicators of ID,
hemoglobin (Hb) and erythrocyte zinc protoporphyrin (eZnPP), using data from the Third National Health and Nutrition Examination Survey (NHANES III, 1988-1994). The SF at which circulating Hb begins to decrease and eZnPP begins to increase provides a physiological basis for identifying the onset of iron-deficient erythropoiesis.
We analyzed NHANES III cross-sectional data from 2616 apparently healthy children, aged 12-59 mo, and 4639 apparently healthy nonpregnant women, aged 15-49 y. We used restricted cubic spline regression models to determine SF thresholds for ID.
SF thresholds identified by Hb and eZnPP did not differ significantly in children, 21.2 μg/L (95% confidence interval: 18.5, 26.5) and 18.7 μg/L (17.9, 19.7), and, in women, were similar although significantly different, 24.8 μg/L (23.4, 26.9) and 22.5 μg/L (21.7, 23.3).
These NHANES results suggest that physiologically based SF thresholds are higher than the thresholds from expert opinion established during the same era. SF thresholds found using physiological indicators detect the onset of iron-deficient erythropoiesis, whereas the WHO thresholds identify a later, more severe stage of ID.