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

Diabetes Metab Res Rev. 2012 Nov;28(8):692-7. doi: 10.1002/dmrr.2340.

Abstract

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.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Diabetic Neuropathies / diagnosis*
  • Female
  • Health Surveys
  • Humans
  • Male
  • Middle Aged
  • Prediabetic State / complications*
  • Prediabetic State / diagnosis
  • Predictive Value of Tests
  • Reagent Kits, Diagnostic
  • Sensitivity and Specificity

Substances

  • Reagent Kits, Diagnostic