Evaluation of the Neuropad sudomotor function test as a screening tool for polyneuropathy in the elderly population with diabetes and pre-diabetes: the KORA F4 survey

• Published in: Diabetes/metabolism research and reviews Vol. 28; no. 8; pp. 692 - 697
• Main Authors: Ziegler, D., Papanas, N., Rathmann, W., Heier, M., Scheer, M., Meisinger, C.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.11.2012; Wiley Subscription Services, Inc
• Subjects: Aged; Aged, 80 and over; Diabetic Neuropathies - diagnosis; diabetic polyneuropathy; Female; Health Surveys; Humans; Male; Middle Aged; pre-diabetes; Prediabetic State - complications; Prediabetic State - diagnosis; Predictive Value of Tests; Reagent Kits, Diagnostic; Sensitivity and Specificity; sudomotor dysfunction
• ISSN: 1520-7552; 1520-7560; 1520-7560
• DOI: 10.1002/dmrr.2340

Background Neuropad is a novel indicator test for sudomotor dysfunction, which has not been validated as a screening tool in a population‐based study. This study aimed to evaluate the utility of Neuropad as a screening tool for distal symmetric polyneuropathy among elderly subjects with diabetes and pre‐diabetes in the general population. Methods Eligible subjects aged 61–82 years (n = 940) from the KORA F4 survey were examined, 201 of whom had diabetes and 231 had pre‐diabetes (WHO 1999 criteria). Polyneuropathy was defined by the Michigan Neuropathy Screening Instrument (MNSI) score >3. Results Polyneuropathy was diagnosed in 60 (29.9%) subjects with diabetes and in 45 (19.5%) subjects with pre‐diabetes, respectively (p = 0.013). The sensitivity and negative predictive value of Neuropad (reading time: 10 min) for the diagnosis of polyneuropathy were moderately high, reaching 76.7% and 78.1% in subjects with diabetes and 57.8% and 76.5% in those with pre‐diabetes, respectively. Conversely, the specificity and positive predictive value for the diagnosis of polyneuropathy were rather low: 35.5% and 33.6% in diabetic individuals and 33.3% and 17.3% in subjects with pre‐diabetes, respectively. Use of the >2 cut‐off and MNSI combined with monofilament examination did not improve the diagnostic performance of Neuropad. Conclusions In the elderly general population with diabetes and pre‐diabetes, Neuropad has reasonable sensitivity but rather low specificity for the diagnosis of polyneuropathy. It is a useful simple and inexpensive tool to screen for and to exclude polyneuropathy as desired, while its low specificity implies that a longer reading time merits consideration. Copyright © 2012 John Wiley & Sons, Ltd.