Postural visual dependence in asymptomatic type 2 diabetic patients without peripheral neuropathy during a postural challenging task

Increasing evidence indicates that diabetes may negatively affect vestibular function, and postural control more so under postural challenging conditions. Healthy and diabetic subjects were compared on visual control of posture during a postural challenging task. Methods: Forty-eight asymptomatic patients with type 2 diabetes free of peripheral neuropathy and 29 age-matched normal subjects were compared on postural stability on a high-density foam block with computerized posturography. Sway parameters were measured and Romberg ratios calculated and compared between the two groups. Results: For subjects who succeeded in maintaining balance, all sway parameters were larger in the diabetics with vision available. With eye closure, only the sway area was almost significantly larger and of greater variability in diabetics, but with a smaller and less variable Romberg ratio. Among the two groups and visual conditions, the tightest anterioposterior-mediolateral (AP-ML) coupling was found in diabetics during eye closure. Differences in anthropometric factors did not influence postural sway. Conclusions: Despite the smaller Romberg ratios in diabetics than controls, findings still suggest greater but masked postural visual dependence in diabetics faced with postural challenging situations due to subclinical vestibular deficits. They also indicate that diabetics may be vulnerable before any clinical signs of peripheral neuropathy arise to falls on unstable surfaces especially in poorly lit areas, and may require to employ other complex postural tactics such as stiffening to maintain their balance. (C) 2016 Elsevier Inc. All rights reserved.