SUDOSCAN in cardiovascular autonomic neuropathy screening

Yun-Ru Lai, Chih-Cheng Huang, Ben-Chung Cheng, Nai-Wen Tsai, Wen-Chan Chiu, Hsueh-Wen Chang,
Jung-Fu Chen, Cheng-Hsien Lu. 
Article title: Feasibility of combining heart rate variability and electrochemical skin conductance as screening and severity evaluation of cardiovascular autonomic neuropathy in type 2 diabetes.
Muscle Nerve. 2021 Apr 1

YR Lai et al from Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine & National Sun Yat-Sen University, Taiwan, tested the hypothesis that combining heart rate variability (HRV) and electrochemical skin conductance (ESC) measured with SUDOSCAN can not only reinforce accuracy in cardiovascular autonomic neuropathy (CAN) screening but also provide a better estimate of CAN severity in patients with type 2 diabetes (T2DM) who had already had CAN in outpatient clinics.

This clinical study included 90 T2DM patients who visited the outpatient diabetic clinic at Kaohsiung Chang Gung Memorial Hospital in Taiwan. Those with more severe CAN had a higher CAN score value (P<0.0001) and lower values in feet ESC (P=0.023) and HRV (SDNN*) (P<0.0001). Multiple linear regression analysis also showed that feet ESC and SDNN value (P=0.003 and P<0.0001) were significantly associated with CAN score.
(*) SDNN: standard deviation of normal RR interval, measure of time domain of HRV

Combining HRV and feet ESC also can increase the diagnostic accuracy of CAN with respective to sensitivity and specificity by using receiver operating characteristic analysis (see the table below).

Combining the results of HRV measurement and feet ESC can not only assess, but also quantitatively reflect the progress or improvement of autonomic nerve function (including sympathetic and parasympathetic activity) in patients with type 2 diabetes.

Sensitivity, specificity, and area under the curve using receiver operating characteristic curve analysis for SDNN, feet electrochemical skin conductance, as well as their combinations in predicting cardiovascular autonomic neuropathy

*=p<0.05; **p<0;01;  Abbreviation: ROC, receiver operating characteristic; ESC, electrochemical
skin conductance; SDNN standard deviation of normal RR interval
Φ=The positive or negative test results of feet ESC, SDDN, and its combination were according to cut-off value of each test in ROC analysis.
The false negative rate of the diagnosis of CAN by feet ESC, SDNN, and its combination were 40.7% (22/54), 27.8% (15/54) and 18.5% (10/54), respectively.

 Keywords: cardiovascular autonomic neuropathy, electrochemical skin conductance, ESC, SUDOSCAN, heart rate variability, HRV.
 Article available here.