Likoswe Blessings H, Joy Edward J M, Sandalinas Fanny, Filteau Suzanne, Maleta Kenneth, Phuka John C
Department of Public Health, School of Public Health and Family Medicine, College of Medicine, University of Malawi, Private Bag 360, Chichiri, Blantyre 3, Malawi.
Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
Nutrients. 2021 Mar 5;13(3):849. doi: 10.3390/nu13030849.
Retinol Binding Protein (RBP) is responsible for the transport of serum retinol (SR) to target tissue in the body. Since RBP is relatively easy and cheap to measure, it is widely used in national Micronutrient Surveys (MNS) as a proxy for SR to determine vitamin A status. By regressing RBP concentration against SR concentration measured in a subset of the survey population, one can define a population-specific threshold concentration of RBP that indicates vitamin A deficiency (VAD). However, the relationship between RBP and SR concentrations is affected by various factors including inflammation. This study, therefore, aimed to re-define the population-specific cut-off for VAD by examining the influence of inflammation on RBP and SR, among pre-school children (PSC) from the 2015-16 Malawi MNS. The initial association between RBP and SR concentrations was poor, and this remained the case despite applying various methods to correct for inflammation. The World Health Organization (WHO) recommends the threshold of 0.7 µmol/L to define VAD for SR concentrations. Applying this threshold to the RBP concentrations gave a VAD prevalence of 24%, which reduced to 10% after inflammation adjustments following methods developed by the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA). Further research is required to identify why SR and RBP were poorly associated in this population. Future MNS will need to account for the effect of inflammation on RBP to measure the prevalence of VAD in Malawi.
视黄醇结合蛋白（RBP）负责将血清视黄醇（SR）转运至体内的靶组织。由于RBP的测量相对简便且成本低廉，它在全国微量营养素调查（MNS）中被广泛用作SR的替代指标，以确定维生素A状态。通过对调查人群的一个子集中测得的RBP浓度与SR浓度进行回归分析，可以确定一个特定人群的RBP阈值浓度，该浓度表明维生素A缺乏（VAD）。然而，RBP与SR浓度之间的关系受到包括炎症在内的多种因素影响。因此，本研究旨在通过考察炎症对2015 - 16年马拉维MNS中学龄前儿童（PSC）的RBP和SR的影响，重新确定特定人群的VAD临界值。RBP与SR浓度之间最初的关联较差，尽管应用了各种方法来校正炎症，情况依然如此。世界卫生组织（WHO）建议将0.7 µmol/L的阈值用于定义SR浓度的VAD。将此阈值应用于RBP浓度时，VAD患病率为24%，按照反映炎症和贫血营养决定因素的生物标志物（BRINDA）开发的方法进行炎症调整后，该患病率降至10%。需要进一步研究以确定为何该人群中SR与RBP的关联较差。未来的MNS需要考虑炎症对RBP的影响，以测量马拉维VAD的患病率。
