Aguree Sixtus, Gernand Alison D
Department of Food Science and Human Nutrition, Iowa State University, Ames, IA, United States of America.
Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA, United States of America.
PeerJ. 2020 Dec 21;8:e10535. doi: 10.7717/peerj.10535. eCollection 2020.
Accurate estimation and interpretation of nutritional biomarker concentrations are important in nutritional research, clinical care, and public health surveillance. Plasma volume (PV) may affect the interpretation of plasma biomarkers but is rarely measured. We aimed to examine the association between plasma volume (PV) and micronutrient biomarker concentrations and mass as part of pilot work to develop methods.
Nine healthy women with regular menstrual cycles provided fasting blood samples to measure micronutrient biomarkers. Indocyanine green was injected, and five timed blood draws were taken from 2 to 5 min to measure PV. Visits were scheduled around menstrual cycle day 2. Retinol, 25-hydroxyvitamin D, riboflavin, alpha-tocopherol, zinc, copper, magnesium, manganese, cobalt, iron, and ferritin concentrations were measured in serum. Total circulating micronutrient biomarker mass was calculated from PV and concentration.
The mean PV was 2067 ± 470 mL. PV correlated positively with concentration of iron ( = 0.87, = 0.005); other correlations were weaker with > 0.05. PV and total mass of retinol ( = 0.90), 25(OH)D ( = 0.75), zinc ( = 0.88), copper ( = 0.83), magnesium ( = 0.93), manganese ( = 0.72), and iron ( = 0.92) were strongly correlated (all < 0.05). PV was positively correlated with circulating micronutrient mass for most biomarkers, implying that concentrations are maintained at different volumes of plasma. Larger studies are needed to further examine these relationships.
Though there appear to be some association between micronutrient biomarker mass and plasma volume, we are unable to draw a firm conclusion about any relationship from these results because of the small sample size. We consider these findings as a preliminary analysis to establish methods for future studies.
在营养研究、临床护理和公共卫生监测中，准确估计和解释营养生物标志物浓度非常重要。血浆容量（PV）可能会影响血浆生物标志物的解释，但很少被测量。作为开发方法的前期工作的一部分，我们旨在研究血浆容量（PV）与微量营养素生物标志物浓度及质量之间的关联。
9名月经周期规律的健康女性提供空腹血样以测量微量营养素生物标志物。注射吲哚菁绿，并在2至5分钟内进行5次定时采血以测量PV。访视安排在月经周期第2天左右。测定血清中视黄醇、25-羟基维生素D、核黄素、α-生育酚、锌、铜、镁、锰、钴、铁和铁蛋白的浓度。根据PV和浓度计算总循环微量营养素生物标志物质量。
平均PV为2067±470 mL。PV与铁浓度呈正相关（r = 0.87，P = 0.005）；其他相关性较弱，P>0.05。PV与视黄醇（r = 0.90）、25(OH)D（r = 0.75）、锌（r = 0.88）、铜（r = 0.83）、镁（r = 0.93）、锰（r = 0.72）和铁（r = 0.92）的总质量密切相关（均P<0.05）。对于大多数生物标志物，PV与循环微量营养素质量呈正相关，这意味着在不同血浆容量下浓度保持稳定。需要更大规模的研究来进一步检验这些关系。
尽管微量营养素生物标志物质量与血浆容量之间似乎存在一些关联，但由于样本量小，我们无法从这些结果中就任何关系得出确凿结论。我们将这些发现视为建立未来研究方法的初步分析。
