Neuropad® assists in ascertaining presence of peripheral small fibre autonomic dysfunction and to identify preulcerative foot lesions in people with diabetes

Diabetic autonomic neuropathy (DAN), an underdiagnosed diabetes complication, is defined as ‘an autonomic nervous system disorder that results from changes caused by diabetes or prediabetes, after exclusion of other possible causes.’ It is due to damage to the small unmyelinated type C nerve fibers, and the clinical picture may vary from subclinical to symptomatic states, requiring specific tests for diagnosis confirmation. Several risk factors have been shown to contribute to DAN development, including diabetes duration, poor glucose control, obesity, dyslipidemia, high blood pressure, and microvascular complications.

Gold-standard diagnostic tests for DAN, while sensitive and specific, require sophisticated expensive equipment and, in general, quite cumbersome for patients and providers.

Among the manifestations of DAN, sudomotor dysfunction has been shown to be a risk factor for cardiovascular disautonomy, diabetic peripheral neuropathy (DPN), foot complications and preulcerative lesions in people with diabetes. Several screening devices have been developed to assess this complication; they are simple, practical, and low-cost, such as the already validated adhesive with cobalt salt colour indicator Neuropad®, which is easily applied to the plantar skin of the forefoot region bilaterally to verify post ganglionic small fiber C sudomotor dysfunction.

Considering that DAN is an underdiagnosed diabetes complication despite its great impact on the quality and survival of patients with diabetes mellitus (DM), the authors  aimed to assess symptoms of DAN combined with a digital app and an inexpensive and easy-to-use skin test (Neuropad®) for sudomotor dysfunction to evaluate DAN in people with diabetes followed at a large public referral centre in Brazil.