The correlation between skin electrical conductance and the score of qi vacuity

In traditional Chinese medicine, the syndrome of qi vacuity means that the patient's body has a low level of energy to react to stress. Recently, we u sed a score, the QV score, by scaling the severity of symptoms and signs of qi vacuity in patients with tiredness. The aim of this study was to invest igate the relationship between QV score and skin electrical conductance in patients with tiredness. One hundred and forty-three healthy controls and 1 03 patients with tiredness were involved. Each subject received a weak elec trical stimulation with constant voltage (1.75 volt), and conductance was m easured between two different limbs. The mean value of skin conductance amo ng four limbs was calculated and expressed by a special unit, namely Chin. The correlation between the skin conductance and QV score was analyzed by a linear regression analysis. The results showed that skin electrical conduc tance of healthy controls was negatively correlated with age (r-coefficient = -0.51, P = 0.000). The skin conductance of patients with tiredness was s ignificantly lower than that of healthy controls with matching age(P = 0.00 0 by Student's t-test). Moreover, there was a positive correlation between the decrease of skin conductance and the QV score in patients with tirednes s (r-coefficient = + 0.68, P = 0.000). These results suggest that a decreas e in skin electrical conductance may be closely related to the severity of qi vacuity. The skin conductance test is a simple, reliable, and quantitati ve method for detection of syndrome of qi vacuity.