PHOENIX — A recently FDA-approved device is proving to be a promising method for detecting neuropathy in patients with diabetes. The non-invasive Sudoscan test, which measures sweat glands in order to detect levels of neuropathy, can be performed in the clinical setting and completed within just a few minutes with no special patient or equipment preparation, according to data presented here at the AACE Annual Scientific and Clinical Congress.
According to Aaron I. Vinik, MD, PhD, professor of medicine and director of research at the neuroendocrine unit at Eastern Virginia Medical School, there are 96,000 amputations that occur every year as a result of neuropathy. Overall, “there is an 11-fold increase in fall and fracture rate. In patients over the age of 65 with a combination of diabetes and aging, there’s a 15-fold increase in falling and fracture. The problem is the physicians aren’t examining patients [for neuropathy]. Even if they do, they aren’t giving proper advice,” Vinik said during a press conference.
Aaron I. Vinik
According to abstract data, patients with diabetes and neuropathy demonstrated significantly poor electrochemical skin conductance (ESC) compared with patients without neuropathy (56.3 vs. 75.9, P<.005 for feet; 51.9 vs. 67.5, P<.005 for hands).
Those with painful neuropathy displayed significantly worse ESC of their feet compared with patients without painful neuropathy (52.8 vs. 68, P<.05), Vinik said.
Moreover, patients with abnormal ESC levels in their hands and feet displayed significantly poor Neuropathy Impairment Score in the Lower Limbs (NIS-LL) scores (7 vs. 2.8, P<.0001 for feet; 5.7 vs. 2.6, P<.005 for hands), according to data.
Further data indicate ROC curve analysis displayed an area under the curve of 0.8563 for feet and 0.8775 for hands ESC (P<.0001) with sensitivity of 78% and specificity of 92% for feet. The NIS-LL total score also showed an AUC of 0.8429 with sensibility of 76% and specificity of 86%.
Vinik also reported that 112 healthy controls before and after VO2max testing measured excellent test and retest reliability for the feet (P<.0001).
He suggests larger studies, including different age groups and ethnic populations to confirm the findings as well as interventional studies to assess the utility of this tool as an objective measure of small fiber neuropathy and peripheral autonomic dysfunction.
Whether the potential applications are screening for early diagnosis of diabetic neuropathy or assessing response of different therapeutic interventions on diabetes subjects, “Sudoscan may become an invaluable tool for today’s clinicians,” Vinik said. – by Samantha Costa
For more information:
Vinik AI. Abstract #276. Presented at: the AACE Annual Scientific and Clinical Congress; May 1-5, 2013; Phoenix.
Disclosure: Vinik received funding for a study on Sudoscan from Impeto Medical.