Goyal Bela, Datta Sudip Kumar, Mir Altaf A, Ikkurthi Saidaiah, Prasad Rajendra, Pal Arnab
Department of Biochemistry, Post Graduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh, 160012 India.
Indian J Clin Biochem. 2016 Apr;31(2):224-230. doi: 10.1007/s12291-015-0522-0. Epub 2015 Sep 12.
The estimation of electrolytes like sodium (Na(+)), potassium (K(+)) and chloride (Cl(-)) using direct and indirect ion-selective electrodes (ISE) is a routine laboratory practice. Interferents like proteins, triglycerides, drugs etc. are known to affect the results. The present study was designed to look into the effect of increasing glucose concentrations on estimation of Na(+), K(+) and Cl(-) by direct and indirect ISE. Pooled sera was mixed with glucose stock solution (20 g/dL) prepared in normal saline to obtain glucose concentrations ranging from ~100 to ~5000 mg/dL. Na(+), K(+) and Cl(-) levels were estimated by direct and indirect ISE analyzers and results were statistically analysed using ANOVA and Pearson's correlation. Similar experiment was also performed in 24 h urine sample from healthy subjects. Significant difference was observed between Na(+) and Cl(-) measurements by direct and indirect ISE, with indirect ISE values being consistently higher than direct ISE. Besides this, significant difference was observed amongst Na(+) and Cl(-) values from baseline values obtained by indirect ISE at glucose concentrations ≥2486 mg/dL. However, no such difference was observed with direct ISE. Na(+) and Cl(-) estimation by indirect ISE showed significant negative correlation with glucose concentration, more so, above ~2000 mg/dL. K(+), however, showed no significant difference with varying glucose. Similar results were observed in 24 h urine samples with a significant difference observed amongst Na(+) and Cl(-) values at ≥2104 mg/dL glucose. Thus we conclude that high glucose concentrations interfere significantly in estimation of Na(+) and Cl(-) by indirect ISE in serum as well as urine.
使用直接和间接离子选择性电极（ISE）对钠（Na(+)）、钾（K(+)）和氯（Cl(-)）等电解质进行测定是实验室的常规操作。已知蛋白质、甘油三酯、药物等干扰物会影响测定结果。本研究旨在探究葡萄糖浓度升高对直接和间接ISE测定Na(+)、K(+)和Cl(-)的影响。将混合血清与在生理盐水中制备的葡萄糖储备溶液（20 g/dL）混合，以获得葡萄糖浓度范围约为100至5000 mg/dL的样本。通过直接和间接ISE分析仪测定Na(+)、K(+)和Cl(-)水平，并使用方差分析（ANOVA）和皮尔逊相关性对结果进行统计分析。对健康受试者的24小时尿液样本也进行了类似实验。直接和间接ISE测定Na(+)和Cl(-)的结果存在显著差异，间接ISE值始终高于直接ISE。除此之外，在葡萄糖浓度≥2486 mg/dL时，间接ISE测得的Na(+)和Cl(-)值与基线值之间存在显著差异。然而，直接ISE未观察到这种差异。间接ISE测定Na(+)和Cl(-)与葡萄糖浓度呈显著负相关，在约2000 mg/dL以上时更是如此。然而，K(+)在葡萄糖浓度变化时未显示出显著差异。在24小时尿液样本中观察到类似结果，在葡萄糖浓度≥2104 mg/dL时，Na(+)和Cl(-)值存在显著差异。因此，我们得出结论，高葡萄糖浓度会显著干扰血清和尿液中通过间接ISE对Na(+)和Cl(-)的测定。
