The use of SUDOSCAN® to screen for diabetic neuropathy in individuals with type 2 diabetes and prediabetes.
Juan J. Cabré, Teresa Mur, Bernardo Costa, Francisco Barrio, Charo López-Moya, Ramon Sagarra, Montserrat García-Barco, Jesús Vizcaíno, Immaculada Bonaventura, Nicolau Ortiz, Gemma Flores-Mateo, Oriol Solà-Morales and the Catalan Diabetes Prevention Research Group.
Article title: Feasibility and Effectiveness of Electrochemical Dermal Conductance Measurement
for the Screening of Diabetic Neuropathy in Primary Care. Decoding Study (Dermal Electrochemical Conductance in Diabetic Neuropathy).
J. Clin. Med. 2019, 8(5), 598.
J. Cabré et al from Catalan Diabetes Prevention Research Group, Barcelona, Spain, analyzed the feasibility and effectiveness of dermal electrochemical conductance (DEC) measured with SUDOSCAN (quantitative expression of sudomotor reflex, generally called Electrochemical Skin Conductance, ESC) as a screening test of diabetic neuropathy (DPN) in primary health care centers.
Diabetic neuropathy (DNP) is a prevalent complication of diabetes that carries significant clinical importance due to the potential pain and risk of ulceration in the lower limbs. Detecting neuropathy early on is crucial in managing this complication. Typically, patients with peripheral neuropathy experience initial thin fiber damage affecting the autonomic system (sweating), as well as their thermal and tactile sensitivity, followed by the involvement of larger fibers which can result in altered vibrating sensations and abnormal electromyography (EMG) patterns. Therefore, dysfunction in the sweat reflex of small distal fibers is one of the earliest detectable changes in these patients.
This blind, prospective study included 197 people with type 2 diabetes (n=100), prediabetes (n=50) and normal tolerance (n=47), who underwent all the protocol tests and electromyography (EMG).
SUDOSCAN results (DEC, i.e., ESC) in the three groups are reported in the Table below:
Comparison between DEC results in the three groups of participants
On comparing Dermal Electrochemical Conductance (DEC) with EMG as the gold standard, using area under the receiver operating characteristic (AUC, ROC curve analysis) the AUC was 0.65 in the diabetes population and 0.72 in prediabetes population. See ROC curve below.
Conclusion: in usual clinical practice, Dermal Electrochemical Conductance (i.e., ESC) in Diabetic Neuropathy is feasible, with moderate sensitivity but high specificity. It is also easy to use and interpret and requires little training, thereby making it a good screening test in populations with diabetes and prediabetes. It may also be useful in screening general populations at risk of neuropathy.