Integrating heart rate variability and electrochemical skin conductance as severity screening of cardiovascular autonomic neuropathy in type 2 diabetes

Background: Clinical studies show that either heart rate variability (HRV) or electrochemical skin conductance (ESC) alone can serve as a simple and objective method for screening cardiovascular autonomic neuropathy (CAN). We tested the hypothesis that combining these two quantitative approaches can provide a better estimate of CAN severity in patients with type 2 diabetes (T2DM) who had already suffered from CAN in outpatient clinics.Methods: Each patient received a complete battery of cardiovascular autonomic reflex tests (CARTs), with ESC measured by SUDOSCAN, time domain measured by standard deviation of all normal RR intervals (SDNN) and frequency domain of HRV (low frequency [LF], high frequency [HF], and LF/HF ratio), and peripheral blood studies for vascular risk factors. Severity of CAN was measured by CAN score.Results: The 90 T2DM patients included 50 males and 40 females. Those with more severe CAN had a higher CAN score value (P<0.0001) and lower values in feet ESC (P=0.023) and SDNN (P<0.0001). Stepwise linear regression analysis also showed that feet ESC and SDNN value (P<0.0001 and P<0.0001) were significantly associated with CAN score, respectively.Conclusions: Based on our results, a combination of electrophysiologic biomarkers (SDNN and feet ESC) as a test battery can improve the diagnostic accuracy and reinforce the accuracy in estimating CAN severity and can serve as a time-effective screening service in outpatient clinics.