Plantar threshold sensitivity assessment using an automated tool—Clinical assessment comparison between a control population without type 2 diabetes mellitus, and populations with type 2 diabetes mellitus, with and without neuropathy symptoms

Abstract

Diabetic peripheral neuropathy is often classified as a loss of sensation in the extremities, particularly in elderly populations. The most common diagnosis technique is with the use of the hand-applied Semmes-Weinstein monofilament. This study’s first aim was to quantify and compare sensation on the plantar surface in healthy and type 2 diabetes mellitus populations with the standard Semmes-Weinstein hand-applied methodology and a tool that automates this approach. The second was to evaluate correlations between sensation and the subjects’ medical characteristics. Sensation was quantified by both tools, at thirteen locations per foot, in three populations: Group 1-control subjects without type 2 diabetes, Group 2-subjects with type 2 diabetes and with neuropathy symptoms, and Group 3-subjects with type 2 diabetes without neuropathy symptoms. The percentage of locations sensitive to the hand-applied monofilament, yet insensitive to the automated tool was calculated. Linear regression analyses between sensation and the subject’s age, body mass index, ankle brachial index, and hyperglycemia metrics were performed per group. ANOVAs determined differences between populations. Approximately 22.5% of locations assessed were sensitive to the hand-applied monofilament, yet insensitive to the automated tool. Age and sensation were only significantly correlated in Group 1 (R2 = 0.3422, P = 0.004). Sensation was not significantly correlated with the other medical characteristics per group. Differences in sensation between the groups were not significant (P = 0.063). Caution is recommended when using hand-applied monofilaments. Group 1’s sensation was correlated to age. The other medical characteristics failed to corelate with sensation, despite group.