Graduate School of Public Health, St. Luke's International University, Japan; Department of Health Science, Basic Science for Clinical Medicine, Division of Medicine, Graduate School Department of Interdisciplinary Research, University of Yamanashi, Japan.
Graduate School of Public Health, St. Luke's International University, Japan; Department of Internal Medicine, University of Hawaii, United States.
Diabetes Res Clin Pract. 2018 Jan;135:166-171. doi: 10.1016/j.diabres.2017.11.013. Epub 2017 Nov 16.
[Aims] This study aims to suggest an informative interval for HbA1c in DM patients with stable glycemic control, based on test characteristics of the HbA1C assay using the signal-to-noise ratio method. [Methods] This was a retrospective, open cohort study. Data were collected between January 2005 to December 2014 at a tertiary-level community hospital in Japan. All adult patients aged under 75 years, with stable glycemic control on a first pharmaceutical regimen for Type II diabetes, and at least two HbA1c measurements after they achieved glycemic stability, were included in the analysis. We defined stable glycemic control as HbA1c <7.0% (52 mmol/mol) and requiring no change in the medication regimen after three consecutive measurements. We adapted a signal-to-noise method for distinguishing true change from measurement error by constructing a linear random effects model to calculate signal and noise for HbA1c. The screening interval for HbA1c was defined as informative when the signal-to-noise ratio exceeded 1. [Results] Among 1066 adults with diabetes, 639 patients (18.5%) were identified as achieving stable glycemic control (511 male (67.3%)), with a mean HbA1c (SD) of 6.4 (0.4)% (46 mmol/mol). Patients with stable glycemic control increase their HbA1c 0.27% (3 mmol/mol) every year while HbA1c has 0.32% (3.5 mmol/mol) noise, as testing characteristics. Signal exceeds noise after 1.2 years (95%CI: 0.9-1.6). [Conclusion] Once patients achieve stable glycemic control at their HbA1c goal, an informative interval for HbA1c monitoring is once every year. Current guidelines, which suggest testing every six months, may contribute to substantial over-testing.
[目的] 本研究旨在基于使用信噪比方法的 HbA1C 检测的试验特征，为血糖控制稳定的糖尿病患者建议 HbA1c 的信息间隔。[方法] 这是一项回顾性、开放队列研究。数据于 2005 年 1 月至 2014 年 12 月在日本一家三级社区医院收集。所有年龄在 75 岁以下、使用二线药物方案血糖控制稳定的成年 2 型糖尿病患者，以及在血糖稳定后至少两次 HbA1c 测量的患者，均纳入分析。我们将血糖控制稳定定义为 HbA1c<7.0%（52mmol/mol），且在连续三次测量后无需更改药物方案。我们通过构建线性随机效应模型来区分真实变化和测量误差，从而采用信号噪声方法来区分 HbA1c 的真实变化和测量误差，从而确定 HbA1c 的信息间隔。当信噪比超过 1 时，将 HbA1c 的筛查间隔定义为信息间隔。[结果] 在 1066 名糖尿病患者中，有 639 名（18.5%）患者血糖控制稳定（511 名男性（67.3%）），平均 HbA1c（SD）为 6.4（0.4）%（46mmol/mol）。血糖控制稳定的患者每年 HbA1c 增加 0.27%（3mmol/mol），而 HbA1c 的噪声为 0.32%（3.5mmol/mol），这是检测特征。信号在 1.2 年后超过噪声（95%CI：0.9-1.6）。[结论] 一旦患者达到 HbA1c 目标下的血糖控制稳定，HbA1c 监测的信息间隔为每年一次。目前建议每 6 个月检测一次的指南可能导致过度检测。
