Normative values for electrochemical skin conductance measurements for quantitative assessment of sudomotor function in healthy Indian adults

Context: Electrochemical skin conductance (ESC) test is a widely accepted objective technique for quantitatively assessing sudomotor dysfunction, which is one of the earliest-detected neurophysiologic abnormalities in diabetic patients with distal symmetric polyneuropathy. Aims: This study aimed to provide normative data for ESC values among healthy Indian participants and assess the potential influence of age, sex, and body mass index (BMI) on ESC measurements. Settings and Design: A sample of 217 healthy participants aged 18–75 years were recruited and assessed for parameters including age, gender, BMI, and ESC measurements of the hands and feet. Statistical Analysis Used: The Shapiro–Wilk test was used to assess the normality of the data. Pearson's correlation was used to evaluate the association between age, gender, and BMI, and ESC measurements. Results: The mean age of the participants was 43.3 ± 13.2 years, and mean BMI was 26.0 ± 4.3 kg/m2. Mean ESC for the hands and feet was 68.9 ± 13.1 and 71 ± 12.9 micro-Siemens, respectively, and there was a significant correlation between values from the right and left hands and feet (r = 0.9, P < 0.0001). A significant correlation was also observed between ESC measurements of the hands and feet (r = 0.94, P < 0.0001). ESC values of both hands and feet declined with age. A weak but significant inverse correlation between ESC and age was observed for the hands (r = 0.02, P = 0.01) and for the feet (r = 0.12, P < 0.0001). There was no significant difference in hand or feet ESC measurement between male and female participants. No significant correlation was observed between BMI and ESC of hands or feet. Only age was identified as a significant determinant of ESC on multivariate logistic regression analysis. Conclusions: Normative values for Indians are lower than that reported for Caucasians