Diabetes Unit, King Edward Memorial Hospital Research Centre, Pune, India.
Diabetes Metab. 2013 Apr;39(2):126-31. doi: 10.1016/j.diabet.2012.09.004. Epub 2012 Nov 14.
Cardiovascular autonomic neuropathy (CAN) is a common but often overlooked complication of diabetes. Sympathetic C-fibers innervating sweat glands can be impaired early on in patients with diabetes. In this study, SUDOSCAN, a new non-invasive device that assesses sudomotor function was compared to methods generally used for the investigation of CAN.
A total of 232 patients with diabetes were measured for heart rate variability (HRV) at rest and during moderate activity. Time and frequency domain analysis techniques, including measurement of the low-frequency (LF) domain component, were assessed during HRV testing. Ewing tests, as recommended by the French Health Authority, were also done. Electrochemical sweat conductance (ESC) was measured on the hands and feet, and a risk-score was calculated.
Using two abnormal Ewing tests as a reference for the area under the curve (AUC) of the receiver operating characteristics (ROC) curve for SUDOSCAN, the risk-score was 0.74, with a sensitivity of 92% and specificity of 49% for a risk-score cut-off value of 35%. For the ROC curve analysis using the LF power component during moderate activity at a threshold of 90 ms(2) (first quartile) as reference, the AUC was higher for the SUDOSCAN risk-score (0.77) compared with the standard Ewing tests [E:I ratio (0.62), 30:15 ratio (0.76) and blood pressure change on standing (0.55)]. Using a cut-off value of 35%, risk-score sensitivity and specificity were 88 and 54%, respectively.
SUDOSCAN, which allows quick quantitative assessment of sudomotor function, may be used for early screening of CAN in everyday clinical practice before resorting to the more sophisticated and specific, but ultimately more time-consuming, Ewing tests.
心血管自主神经病变（CAN）是糖尿病常见但常被忽视的并发症。糖尿病患者的交感 C 纤维支配汗腺的功能可能会早期受损。在这项研究中，SUDOSCAN 是一种新的非侵入性设备，用于评估出汗功能，它与通常用于 CAN 研究的方法进行了比较。
共有 232 例糖尿病患者进行了静息和中等强度活动时的心率变异性（HRV）测量。在 HRV 测试中，采用时域和频域分析技术，包括低频（LF）域成分的测量。还进行了法国卫生当局推荐的 Ewing 测试。电化学汗液传导（ESC）在手和脚上进行了测量，并计算了风险评分。
使用两个异常 Ewing 测试作为 SUDOSCAN 受试者工作特征（ROC）曲线下面积（AUC）的参考，风险评分为 0.74，风险评分截断值为 35%时，灵敏度为 92%，特异性为 49%。对于使用中等强度活动时 LF 功率成分作为参考的 ROC 曲线分析（阈值为 90ms²（第一四分位数）），SUDOSCAN 风险评分的 AUC 高于标准 Ewing 测试[E：I 比值（0.62），30：15 比值（0.76）和站立时血压变化（0.55）]。使用 35%的截断值，风险评分的灵敏度和特异性分别为 88%和 54%。
SUDOSCAN 可快速定量评估出汗功能，可在 Ewing 测试等更复杂、更耗时的测试之前，用于日常临床实践中 CAN 的早期筛查。
