Does Self-Reported Postural Instability Correspond with Objective Measures of Balance in Patients with Diabetic Neuropathy?

Brown, SJ, Reeves, ND, Boulton, A and Vileikyte, L (2016) Does Self-Reported Postural Instability Correspond with Objective Measures of Balance in Patients with Diabetic Neuropathy? Diabetes, 65 (Supple). A151-A151. ISSN 1939-327X

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Abstract

Postural Instability (PI) is common in patients with diabetic peripheral neuropathy (DPN) and is the strongest predictor of depression and non-adherence to foot ulcer treatment. However, as PI was assessed by self-report in PREVIOUS studies, some have challenged the accuracy of self-report in capturing PI. We therefore compared the quantified PI measures during walking to patients’ perception of their own unsteadiness, as measured with 2 item scale from the NeuroQoL questionnaire (alpha=.87). During walking, PI was quantified by the maxima and range of motion of the centre-of-mass and temporal spatial measures of step length, width and walking speed. Fifteen individuals with diabetes and no DPN (D: 56±2yrs, 78±3kg, 1.70±0.02m, 10:5 [M:F], Vibration Perception Thershold (VPT) <25), 15 with diabetes and severe DPN (N: 62±3yrs, 91±4kg, 1.70±0.03m, 11:4 [M:F], VPT>25) and 19 controls without diabetes (C: 56±2yrs, 79±3kg, 1.72±0.02m, 13:6 [M:F], VPT<25). Group N reported poorer balance than group C on NeuroQoL (D:10, N:6, C:10; [score/10]; p<0.05), and perception of balance correlated with individual vibration perception thresholds (r=0.6, p=<0.001). Group N walked slower (D:1.5, N:1.2, C:1.5; [m/s]; p<0.05) with shorter step lengths (D:73, N:65, C:77; [cm]; p<0.05), both variables also correlated with NeuroQoL perception of balance (r=0.6, p<0.001). Anterior range of motion for the centre of mass was also decreased in group N (D: 92, N:83, C:94; [cm]; p<0.05). Shortening step length is a commonly observed trait of patients with physiological weakness in walking. Shorter step length also explains the slower speed and a smaller range of motion of the centre of mass. As these parameters significantly correlate with individuals’ perception of balance, more research is needed to determine whether self-reported postural instability prompts individuals to walk slower, thereby contributing to balance control.