Fleischer Jesper, Nielsen Roni, Laugesen Esben, Nygaard Hans, Poulsen Per Logstrup, Ejskjaer Niels
Medical Research Laboratories, Clinical Institute of Medicine, Aarhus University, Aarhus, Denmark.
J Diabetes Sci Technol. 2011 Jan 1;5(1):107-12. doi: 10.1177/193229681100500115.
Cardiovascular autonomic neuropathy (CAN) is associated with diabetes and may be related to the development of hypertension, ischemic stroke, and a number of other late complications. The earliest sign of CAN is a reduction of heart rate variability (HRV). Standard HRV tests for CAN include expiration-to-inspiration ratio, response to active standing (30:15), and the Valsalva maneuver. Because of the technical requirements for these tests, they are limited to the point-of-care office or a clinical laboratory setting. It is unknown if a "white-coat" phenomenon exists in autonomic neuropathy testing and if home testing is feasible. The aims of this study were (1) to evaluate the reproducibility of CAN testing in a clinical setting, (2) to evaluate the feasibility of self-monitoring of cardiovascular autonomic function at home, and (3) report possible differences in measurements taken at the hospital versus those taken at home.
Ten healthy subjects were included. Participants underwent in-hospital testing for CAN before and after home monitoring. For 6 consecutive days, participants measured autonomic function once a day at home. The intra- and interindividual reproducibility was determined by coefficient of variation (CV) and the reproducibility coefficient (RC). Agreement between hospital and home testing was analyzed using Pearson r, mean difference, and Bland-Altman analysis with Pitman's test of difference in variance.
Pitman's test showed no significant difference in variance between hospital and home measurements, indicating suitable agreement between the two measurements. Reproducibility was moderate to high in all measures, with RC ranging from 66-94% and CV ranging from 5-10%.
Home testing of CAN is feasible. The evaluations showed no significant systematic error of in-hospital testing compared with self-monitoring at home. In this study, we were not able to demonstrate the presses of "white coat" effect in standard cardiovascular reflex tests.
心血管自主神经病变（CAN）与糖尿病相关，可能与高血压、缺血性中风及许多其他晚期并发症的发生有关。CAN最早的迹象是心率变异性（HRV）降低。用于CAN的标准HRV测试包括呼气与吸气比率、主动站立反应（30:15）和瓦尔萨尔瓦动作。由于这些测试的技术要求，它们仅限于即时护理办公室或临床实验室环境。尚不清楚自主神经病变测试中是否存在“白大衣”现象以及家庭测试是否可行。本研究的目的是：（1）评估临床环境中CAN测试的可重复性；（2）评估在家自我监测心血管自主功能的可行性；（3）报告在医院与在家进行测量可能存在的差异。
纳入10名健康受试者。参与者在家庭监测前后进行了院内CAN测试。连续6天，参与者每天在家测量一次自主神经功能。通过变异系数（CV）和重复性系数（RC）确定个体内和个体间的可重复性。使用Pearson r、平均差异以及带有皮特曼方差差异检验的布兰德-奥特曼分析来分析医院测试与家庭测试之间的一致性。
皮特曼检验显示医院测量与家庭测量之间的方差无显著差异，表明两次测量之间具有适当的一致性。所有测量的可重复性为中度至高，RC范围为66%-94%，CV范围为5%-10%。
CAN的家庭测试是可行的。评估显示，与在家自我监测相比，院内测试没有显著的系统误差。在本研究中，我们未能在标准心血管反射测试中证明“白大衣”效应的存在。
