Dynamic postural stability in patients with diabetic peripheral neuropathy and relationship to presence of autonomic neuropathy

Abstract

Diabetic neuropathy is a common complication that can negatively influence balance and is a major cause of falls. We evaluated the association between postural sway and diabetic autonomic neuropathy (DAN) among patients with diabetic peripheral neuropathy (DPN). Patients with DPN documented by typical symptoms with abnormal results of nerve conduction study were included and postural stability was assessed using dynamic posturography. Composite autonomic scoring scale (CASS) score was calculated by evaluating sudomotor, cardiovagal, and adrenergic functions. CASS score >= 2 indicated DAN and the severity of DAN was indicated by the CASS scores divided into three subscales of 10-point total CASS: none or mild autonomic failure (0-3), moderate failure (4-6), and severe failure (7-10). A total of 34 patients comprised the DAN group (n=19) and non-DAN group (n=15). Patients with DAN had higher prevalence of diabetic retinopathy(p=0.011), higher urine albumin-creatinine ratio (p=0.009), and lower HbA1c levels (p<0.001) than those with non-DAN. With regard to dynamic postural instability, the presence (p=0.025) as well as the severity of DAN (p<0.05) was associated with postural instability in the eyes-opencondition. Interestingly, the poorer dynamic postural instability in moderate/severe DAN compared to mild DAN was observed only in medio-lateral direction and this association remained significant after adjusting for age, sex, and glycemic control state (HbA1c). In patients with DAN accompanied by DPN, the dynamic postural instability was affected by visual feedback and medio-lateral directional instability was closely associated with the severity of DAN.