Does postural instability in type 2 diabetes relate to vestibular function?

Abstract

Introduction: Diabetes mellitus (DM) can lead to complications including postural instability that may be related to impaired function of the vestibular system. Aims and Objectives: This study aims to measure vestibular and balance function in adults diagnosed with type 2 noninsulin-dependent diabetes mellitus (NIDDM) and to compare their findings with healthy age-matched control group. Materials and Methods: This is an experimental cross-sectional study, using purposive sampling method. Eight NIDDM patients (mean age = 36.8 ± 11.4 years) and eight age-matched healthy controls (mean age = 34.6 ± 11.0 years) were recruited. Vestibular end organs (i.e., saccule, utricle, and semicircular canals) were assessed using cervical and ocular vestibular-evoked myogenic potentials (cVEMPs and oVEMPs) and video head impulse test. Upright stance postural stability was assessed using force plate in four testing conditions, i.e., standing on firm or foam surface with eyes opened or closed. Dynamic stability was measured using Timed Up and Go (TUG) and functional gait assessment (FGA). Results: There was no statistically significant difference for all vestibular tests between groups. However, reduced p13-n23 interamplitudes (for cVEMPs) and n10 amplitudes (for oVEMPs) were observed in NIDDM patients. Upright stance postural stability was not significantly worse in patients. For dynamic postural stability, NIDDM patients demonstrated significantly poor performance in TUG and FGA than the healthy controls. Functionally, NIDDM patients walked significantly slower and less stable, and this is evident from poor performance in both TUG and FGA results. Conclusion: Our findings showed significant reduction in dynamic postural stability in NIDDM patients. However, we did not find any significant abnormal vestibular function in the patients as reported by previous studies. Further research studies are advocated.