Stickle Douglas F, Herman Jay H, Molinaro Ross
Department of Pathology, Kimmel Medical College, Jefferson University, Philadelphia, PA, USA.
Department of Pathology, Kimmel Medical College, Jefferson University, Philadelphia, PA, USA.
Clin Biochem. 2018 Apr;54:73-77. doi: 10.1016/j.clinbiochem.2018.02.015. Epub 2018 Feb 24.
Estimated average glucose (AG) is generally reported along with hemoglobin A1c measurements according to a standard calculation. Given a normal red blood cell lifetime of 120 days, serial A1c measurements at intervals <120 days are not completely independent. For short interval measurements, a change in AG (ΔAG) necessarily underestimates the change in average glucose operative during the interval (ΔG). We use a model for kinetics of HbA1c to evaluate the theoretical relationship between ΔAG and ΔG for HbA1c measurements made at intervals between 0 and 120 days.
From any given starting point for A1c, step changes in G were simulated using model calculations to determine the extent to which A1c could change as a function of the interval of exposure. Values for ΔAG were compared to the operative ΔG as a function of the interval between A1c measurements.
Results of model simulations are a single graph for relationship of ΔAG to ΔG as a function of the interval between A1c measurements. ΔAG for (15, 30, 45, 60, 76, and 90) day intervals underestimated operative ΔG by (73, 51, 34, 21, 11, and 5)%, respectively.
Model calculations predict the relationship between changes in estimated average glucose to changes in operative glucose for serial A1c measurements made at intervals <120 days. Given that serial measurements of A1c made at short intervals are not uncommon in practice, physicians may find this information to be useful.
估计平均血糖（AG）通常根据标准计算与糖化血红蛋白（A1c）测量值一起报告。鉴于正常红细胞寿命为120天，间隔<120天的连续A1c测量并非完全独立。对于短间隔测量，AG的变化（ΔAG）必然低估了该间隔期间实际起作用的平均血糖变化（ΔG）。我们使用一个HbA1c动力学模型来评估在0至120天间隔内进行的HbA1c测量中ΔAG与ΔG之间的理论关系。
从任何给定的A1c起始点开始，使用模型计算模拟G的阶跃变化，以确定A1c随暴露间隔变化的程度。将ΔAG值与作为A1c测量间隔函数的实际ΔG进行比较。
模型模拟结果是一张单一图表，显示了作为A1c测量间隔函数的ΔAG与ΔG之间的关系。间隔为（15、30、45、60、76和90）天的ΔAG分别低估实际ΔG（73、51、34、21、11和5）%。
模型计算预测了间隔<120天进行的连续A1c测量中估计平均血糖变化与实际血糖变化之间的关系。鉴于在实践中短间隔进行A1c的连续测量并不罕见，医生可能会发现这些信息有用。
