Basic Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Mar 15, 2018; 9(3): 59-65
Published online Mar 15, 2018. doi: 10.4239/wjd.v9.i3.59
Patients with type 2 diabetes demonstrate proprioceptive deficit in the knee
Lucas Richard Ettinger, Ami Boucher, Elisabeth Simonovich
Lucas Richard Ettinger, Ami Boucher, Elisabeth Simonovich, Department of Exercise Science, Willamette University, Salem, OR 97302, United States
Author contributions: Boucher A and Simonovich E performed the majority of experiments and were also involved in editing the manuscript; all authors were involved with data analysis and interpretation; Ettinger LR designed the study and wrote the manuscript.
Supported by The Willamette University Mary Stuart Rogers Science Collaborative Research Program Endowment.
Institutional review board statement: This study was reviewed and approved by the Willamette University Institutional Review Board.
Informed consent statement: Written and verbal consent to enrollment in the study was obtained by all study participants prior to all other aspects of this study.
Conflict-of-interest statement: No potential conflicts of interest relevant to this article were reported.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Lucas Richard Ettinger, PhD, Professor, Department of Exercise Science, Willamette University, 900 State Street, Salem, OR 97302, United States. lettinge@willamette.edu
Telephone: +1-503-3706240 Fax: +1-503-3706773
Received: January 25, 2018
Peer-review started: January 26, 2018
First decision: February 27, 2018
Revised: March 5, 2018
Accepted: March 14, 2018
Article in press: March 14, 2018
Published online: March 15, 2018
Processing time: 63 Days and 10.2 Hours
ARTICLE HIGHLIGHTS
Research background

Type 2 diabetics are at greater risk for falls and balance disruption than the general population. This phenomenon may be explained by the interruption of afferent nerves associated with peripheral neuropathy, which is common within this population. The link between afferent nerve disturbance and falls may involve diminished proprioceptive awareness in the distal limb.

Research motivation

The main objective of this study was to investigate limb localization and proprioceptive acuity in the distal limb of persons with type 2 diabetes.

Research objectives

Identification of proprioceptive disturbance in the diabetic population informs clinicians towards alternative forms of diabetic instrumentation for disease progression, identification and efficacy of treatment.

Research methods

We collected knee proprioceptive acuity using a joint position sense (JPS) task. We collected data on 23 diabetics and 23 age and gender matched controls. Instrumentation of JPS was conducted using an Apple iPod touch and a custom JPS application. We used a target position matching task which required the participant to locate specified targets in space with their knee joint.

Research results

Results of the present study support our hypothesis and indicate that type-2 diabetics have proprioceptive errors of 46% greater magnitude than controls. Our findings suggest that fall and balance risk data on type-2 diabetics could be related to proprioceptive imbalances in the distal limb.

Research conclusions

Our novel findings indicate that proprioceptive acuity in the distal limb is disrupted in patients with type-2 diabetes. These disturbances to proprioceptive acuity may be due to degeneration of the afferent nerves commonly reported in this population. Our findings are the first to suggest that larger diameter afferent nerves are likely also influenced by the degeneration of the afferent nerve, which was previously reported as affecting only smaller diameter afferent nerves. We present data that may serve as explanation or partial explanation for the high degree of falls and loss of balance in the type-2 diabetic population as proprioception has been overwhelmingly associated with balance and stability. Furthermore, our study has provided new insights as to measurement and instrumentation of diabetic neuropathy with respect to joint position sense (JPS) testing. Future studies can incorporate JPS into measurement of disease progression, treatment and diagnosis. The application of JPS testing in a clinical setting is also warranted.

Research perspectives

We have demonstrated that proprioceptive disruption can be measured in type-2 diabetics. However, the extent of disruption could be dependent on the degree of peripheral neuropathy, number of years of exposure to the disease and or other physiologic factors. Future studies should investigate diabetic neuropathy as a spectrum with respect to JPS testing in order to establish a causal relationship. Furthermore, future studies could start to examine therapeutic effect of exercise, diet, whole body vibration and pharmacological intervention on proprioceptive acuity in type-2 diabetics.