Self-monitoring of blood glucose: usefulness and problems

　近年，自己血糖測定器(SMBG器：self-monitoring blood glucose)は急速に技術開発が進み，迅速，簡便に血糖値を測定できるようになった。糖尿病の患者が在宅で使用し，多くの病院や施設において血糖値の指標として利用頻度が高まっている。この研究の目的は，グルコースデヒドロゲナ ー ゼ（glucose dehydrogenase: GDH）酵素電極法である SMBG 器（グ ル テ ス ト ミ ン ト：glutestmint）を用いて基礎的検討を行い，また新しい２機種のSMBG器（グルテストミント，.free style libre）を用いて，温度変化による血糖値への影響を検討することである。基礎的検討において，グルテストミントによる3種類グルコース検体の血糖値の 変動係数（Coefficient of variation：CV）は1.4～1.8％となり同時再現性は良好であった。キシロース添加検体では，10 mg/dl以上において血糖値の増加傾向が見られた。さらに，SMBG器本体保存温度を変えて血糖値への影響を検討した。室温（25℃）より，低温（15℃）保存によって血糖値の変化は，２機種ともに各血糖値濃度（低，中，高）でそれぞれ有意な増加を示した。一方，血糖値は室温（25℃）より，高温（37℃）ではグルコース添加検体において有意な減少を示した。使用時には，SMBG器の特徴をよく理解して血糖検査することが重要である。季節や保管場所による温度変化がある場合の血糖検査は，十分注意が必要であると考えられる。　Recently, the technology for self-monitoring of blood glucose (SMBG) has advanced rapidly, and it is now possible to measure blood glucose levels easily. Diabetes patients use these devices at home, and their frequency of use has also been increasing in many hospitals and institutions. This study aimed to investigate a basic examination of SMBG using Glutestmint (a glucose dehydrogenase: GDH enzyme electrode method), and to examine the effects of temperature changes on measured blood glucose levels by two SMBG devices (Glutestmint and Free style libre). In a basic examination with interference product, the coefficient of variation (% CV) of values in testing of blood glucose specimens at 3 concentrations by using SMBG: Glutestmint was 1.4% to 1.8%, and good results were obtained about the repeatability. In the case of samples to which xylose had been added, there was tendency toward an increase of 10 mg/dL or more in blood glucose levels. We also examined the effects of SMBG device storage temperature on recorded blood glucose levels for the two SMBG meters (glutestmint and free style libre). When the two devices were kept at a lower temperature (15℃) than room temperature (25℃), they both gave significant increases in each blood glucose level (low, intermediate, high). In contrast, when the devices were kept at a higher temperature (37 ℃) than room temperature (25℃), there was a significant decrease in blood glucose levels in each of the glucose addition samples. It is important to have a good understanding of the characteristics of SMBG and to perform blood glucose testing regularly. In such testing, the influences of seasonal temperature changes and changes in temperature with different storage conditions need to be taken into account