Ali-Baya Grace, Zenile Emmanuel, Aikins Bridgette Obuor, Amoaning Regina Elorm, Simpong David Larbi, Adu Patrick
Department of Medical Laboratory Science, School of Allied Health Science, University of Cape Coast, Ghana.
Heliyon. 2021 Aug 5;7(8):e07720. doi: 10.1016/j.heliyon.2021.e07720. eCollection 2021 Aug.
This study estimated total body water (TBW), daily water intake (DWI) and haemoglobin-haematocrit relationship in adults in a tropical environment where active lifestyles could precipitate plasma volume contraction.
This cross-sectional study recruited 170 participants, and was carried out between February 2018 and May 2018 at University of Cape Coast. Semi-structured questionnaires were used to obtain demographic data and DWI. Five ml of venous blood sample was drawn for full blood count, haemoglobin variant determination, serum sodium and potassium levels. TBW was estimated using Chumlea's anthropometric equation. Statistical significance was set at p < 0.05 under two-tail assumption.
Whereas 72.3% had low haematocrit, only 22.4% were anaemic per haemoglobin cut-off demonstrating a poor haemoglobin-haematocrit correlation. Also, whereas 30% of participants had low TBW, 22.9% had hypernatraemia, with 97.1% reporting DWI of <3 L. Bland-Altman plot showed that calculated haematocrit (HCT = Hb∗3) underestimated HCT by a factor of 1.788 (p = 0.0314). A scatter-plot showed a trend towards higher haematocrit-haemoglobin deviations as haemoglobin increased. Furthermore, 32.6% of participants with normal haemoglobin levels had low TBW. Moreover, whereas haemoglobin and serum K+ significantly positively correlated to TBW, serum Na+ was inversely related to TBW.
The low DWI is suggestive that measuring plasma volume and/or haemoglobin mass may be required to correctly diagnose anaemia.
本研究估计了热带环境中成年人的总体水（TBW）、每日水摄入量（DWI）以及血红蛋白-血细胞比容关系，在这种环境中，积极的生活方式可能会导致血浆容量收缩。
这项横断面研究招募了170名参与者，于2018年2月至2018年5月在开普海岸大学进行。使用半结构化问卷获取人口统计学数据和DWI。抽取5毫升静脉血样本进行全血细胞计数、血红蛋白变异体测定、血清钠和钾水平检测。使用Chumlea人体测量方程估计TBW。在双侧假设下，统计学显著性设定为p<0.05。
虽然72.3%的人血细胞比容较低，但根据血红蛋白临界值，只有22.4%的人贫血，这表明血红蛋白与血细胞比容的相关性较差。此外，虽然30%的参与者TBW较低，但22.9%的人有高钠血症，97.1%的人报告DWI<3L。布兰德-奥特曼图显示，计算得出的血细胞比容（HCT = Hb∗3）低估了HCT 1.788倍（p = 0.0314）。散点图显示，随着血红蛋白增加，血细胞比容-血红蛋白偏差有增大趋势。此外，32.6%血红蛋白水平正常的参与者TBW较低。而且，虽然血红蛋白和血清K+与TBW显著正相关，但血清Na+与TBW呈负相关。
低DWI提示可能需要测量血浆容量和/或血红蛋白量才能正确诊断贫血。
