Division of Endocrinology, Department of Pediatrics, University of California San Francisco, CA, USA.
J Diabetes Sci Technol. 2021 Nov;15(6):1290-1296. doi: 10.1177/1932296820951855. Epub 2020 Sep 1.
The introduction of insulin pumps with bolus calculators (BCs) has improved glycemic outcomes and quality of life for those with type 1 diabetes. Despite the increased reliance on BCs, the formulas used to derive recommended boluses are not standardized. Our objective was to examine whether recommendations from different pump BCs vary significantly for identical clinical scenarios.
Three commercially available insulin pump BCs were programmed with identical settings and then presented with combinations of blood glucose (BG) and carbohydrates (CHOs) to generate a 4-unit bolus. At one- and two-hour time points, while there was insulin-on-board (IOB) present, we simulated various BG and CHO scenarios in order to compare BC-recommended doses.
Differences in suggested doses were noted between BCs, as well as within the same brand. The greatest variation was apparent when BG was below target. Doses suggested by one BC varied depending on whether the IOB resulted from a previous dose given for BG or CHO, while the other two BCs adjusted for total IOB regardless of the source.
In this simulation study, there were large differences in recommended doses between BCs due to the unique way each manufacturer incorporates IOB into their formulas as well as the pharmacokinetics used to derive the IOB amount. Providers should be aware that identical pump settings will result in a different dose recommendation for each pump brand and advise patients accordingly.
带有推注计算器（BC）的胰岛素泵的引入改善了 1 型糖尿病患者的血糖控制结果和生活质量。尽管对 BC 的依赖增加了，但用于推导推荐推注量的公式并未标准化。我们的目的是检查在相同的临床情况下，不同泵 BC 的推荐值是否存在显著差异。
将三种市售的胰岛素泵 BC 设置为相同的参数，然后为其提供血糖（BG）和碳水化合物（CHO）的组合，以生成 4 个单位的推注量。在有胰岛素在体内（IOB）的情况下，在 1 小时和 2 小时的时间点，我们模拟了各种 BG 和 CHO 情况，以比较 BC 推荐的剂量。
BC 之间以及同一品牌的 BC 之间都存在剂量建议的差异。当 BG 低于目标时，差异最为明显。一个 BC 建议的剂量因 IOB 是由于之前的 BG 剂量还是 CHO 剂量而有所不同，而另外两个 BC 则根据总 IOB 进行调整，而不管来源如何。
在这项模拟研究中，由于每个制造商将 IOB 纳入其公式的独特方式以及用于推导 IOB 量的药代动力学不同，因此 BC 之间的推荐剂量存在很大差异。提供者应注意，相同的泵设置将导致每个泵品牌的剂量推荐不同，并相应地告知患者。
