Clinical Research Unit of Nanoro (URCN/IRSS), Nanoro, Burkina Faso.
Centre for Biostatistics, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre (MAHSC), Oxford Road, University of Manchester, Manchester, M139PL, UK.
Clin Nutr. 2020 Jan;39(1):204-214. doi: 10.1016/j.clnu.2019.01.016. Epub 2019 Jan 26.
BACKGROUND & AIMS: Low iron stores may protect from malaria infection, therefore improving iron stores in early pregnancy in line with current recommendations could increase malaria susceptibility. To test this hypothesis we compared iron biomarkers and red cell indices in nulliparae and primigravidae who participated in a randomized controlled trial of long-term weekly iron supplementation.
Cross-sectional and longitudinal data analysis from a randomized controlled trial of long-term weekly iron supplementation in rural Burkina Faso. Malaria parasitaemia was monitored and biomarkers and red cell indices measured at study end-points: plasma ferritin, transferrin receptor (sTfR), zinc protoporphyrin, hepcidin, sTfR/log ferritin ratio, body iron, haemoglobin, red cell distribution width; mean corpuscular haemoglobin concentration/volume, and C-reactive protein. Correlation coefficients between biomarkers and red cell indices were determined. A regression correction approach based on ferritin was used to estimate iron body stores, allowing for inflammation. Body iron differences were compared between nulliparae and primigravidae, and the association determined of iron biomarkers and body iron stores with malaria.
Iron and haematological indices of 972 nulliparae (mean age 16.5 years) and 314 primigravidae (median gestation 18 weeks) were available. Malaria prevalence was 54.0% in primigravidae and 41.8% in nulliparae (relative risk 1.28, 95% CI 1.13-1.45, P < 0.001), anaemia prevalence 69.7% and 43.4% (P < 0.001), and iron deficient erythropoiesis (low body iron) 8.0% and 11.7% (P = 0.088) respectively. Unlike other biomarkers the sTfR/log ferritin ratio showed no correlation with inflammation as measured by CRP. Most biomarkers indicated reduced iron deficiency in early pregnancy, with the exception of haemoglobin. Body iron increased by 0.6-1.2 mg/kg in early gestation, did not differ by malaria status in nulliparae, but was higher in primigravidae with malaria (6.5 mg/kg versus 5.0 mg/kg; relative risk 1.53, 95% CI 0.67-2.38, P < 0.001).
In primigravidae, early pregnancy haemoglobin was not a good indicator of requirement for iron supplementation, which could be detrimental given the association of better iron status with increased malaria infection.
clinicaltrials.gov:NCT01210040. Until placed in a public repository, data relating to the current study can be requested from the corresponding author and will be made available following an end user data agreement and sponsor approval.
铁储存不足可能有助于预防疟疾感染，因此，按照当前的建议，在妊娠早期增加铁的储存量可能会增加对疟疾的易感性。为了验证这一假设，我们比较了参与布基纳法索农村地区长期每周补铁随机对照试验的初产妇和经产妇的铁生物标志物和红细胞指数。
这是一项长期每周补铁随机对照试验的横断面和纵向数据分析，在布基纳法索农村进行。在研究终点监测疟疾寄生虫血症，并测量血浆铁蛋白、转铁蛋白受体（sTfR）、锌原卟啉、铁调素、sTfR/铁蛋白比值、体内铁、血红蛋白、红细胞分布宽度；平均红细胞血红蛋白浓度/体积和 C 反应蛋白。确定了生物标志物和红细胞指数之间的相关系数。采用基于铁蛋白的回归校正方法估计体内铁储存量，同时考虑炎症因素。比较了初产妇和经产妇之间的体内铁差异，并确定铁生物标志物和体内铁储存量与疟疾的关系。
972 名初产妇（平均年龄 16.5 岁）和 314 名经产妇（中位孕龄 18 周）的铁和血液学指标可用。经产妇的疟疾患病率为 54.0%，初产妇为 41.8%（相对风险 1.28，95%CI 1.13-1.45，P<0.001），贫血患病率为 69.7%和 43.4%（P<0.001），缺铁性红细胞生成（体内铁不足）分别为 8.0%和 11.7%（P=0.088）。与其他生物标志物不同，sTfR/铁蛋白比值与 CRP 测量的炎症无相关性。除血红蛋白外，大多数生物标志物表明早期妊娠铁缺乏减少。在初产妇中，体内铁在妊娠早期增加了 0.6-1.2mg/kg，与疟疾状态无关，但在疟疾孕妇中更高（6.5mg/kg 与 5.0mg/kg；相对风险 1.53，95%CI 0.67-2.38，P<0.001）。
在经产妇中，妊娠早期的血红蛋白并不是铁补充的良好指标，鉴于更好的铁状态与增加的疟疾感染有关，这可能是有害的。
clinicaltrials.gov:NCT01210040。在将数据存入公共存储库之前，可以向通讯作者请求与当前研究相关的数据，并且将在获得最终用户数据协议和赞助商批准后提供。
