Diabetes, peripheral neuropathy, and old age disability

Abstract

The purpose of this study was to determine whether peripheral neuropathy explains the apparent association between diabetes and disability in old age, and to evaluate the utility of lower extremity function tests in older diabetic adults with and without neuropathy. We evaluated 39 adults, aged 70-79 years, for pressure sensation (log(10)g), vibration perception threshold (VPT; microns), and electrophysiologic function of the peroneal nerve. The subjects included patients with established diabetic neuropathy (DN; n = 14), diabetic controls without neuropathy (DC; n = 13), and nondiabetic controls (NDC; n = 12). Nonparametric statistical methods were used to relate neuropathy measures to performance in tests of walking speed, static and dynamic balance, coordination, and ankle strength (kilograms). Significant age-adjusted correlations were observed between measures of sensory neuropathy and a variety of performance measures, and electrophysiologic measures were related to static balance. DN subjects had significantly higher pressure sensation than NDC (5.17 vs 3.38g, P < 0.05), higher VPT (62.5 vs 21.7 microm, P < 0.05), and lower peroneal motor response amplitudes at multiple sites. Pressure sensation and nerve conduction measures did not differ between DC and NDC. Compared with NDC, DN subjects performed significantly worse on tests of walking speed (0.99 vs 1.34 m/s; P < 0.05), static balance (4.9 vs 20.4 s; P < 0.05), dynamic balance (9.23 vs 25.52 s; P < 0.05), and coordination (6.73 vs 4.76 s; P < 0.05). No differences were observed in these measures between DC and NDC. Observed differences in physical abilities between older diabetic and nondiabetic adults may have been due to the subset of diabetic individuals with peripheral neuropathy. Quantitative measures of sensory and motor nerve function have distinct effects on physical performance. Interventions aimed at reducing the impact of diabetes-associated disability in old age may have the greatest impact among people with peripheral neuropathy.

Focal Entrapment Neuropathies in Diabetes

“…Tinel sign may be positive and is elicited by striking the peroneal nerve at the neck of the fibula, which produces pain and tingling in the distribution of the peroneal nerve supply. Diabetes was thought to be a relatively uncommon cause of peroneal nerve palsy (5-12%) (20); however, in the Women's Health and Aging Study (21), weakness of dorsiflexion occurred in two-thirds of women Ͼ65 years of age and more so if diabetes was superimposed on aging. Conduction blocks were found across the fibular head and suggested external compression at the fibular head during sleep with the legs crossed or in bedridden patients.…”

Predictors of depressive symptoms in persons with diabetic peripheral neuropathy: a longitudinal study

“…Diabetic somatic peripheral neuropathy (DPN) is a chronic and potentially disabling complication of diabetes, having a negative impact on physical and psychosocial functioning and on the quality of life of persons affected by this disorder [1][2][3][4]. DPN is not a single entity but encompasses a variety of clinical manifestations that can include unremitting pain, reduced feeling in the feet and postural instability.…”

“…In the context of diabetes, for example, the results of a large community-based study indicate that functional limitations play an important role in the development of depression in people with type 2 diabetes [19]. This finding is of particular relevance to DPN in view of its association with severe physical disability, and in some patient populations it fully accounts for diabetes-related functional limitations [2]. Other researchers argue that the impact of ADL restrictions on depression may depend on the extent to which being unable to perform daily activities has a negative impact on sense of self [20].…”

Identifying Peripheral Neuropathy in Fall Patients with the Heat-Washout Method

“…The symptoms of large fibre neuropathy mainly affect light touch, vibration sense, and proprioception possibly causing impaired balance, gait and muscle weakness, whereas the small fibre dysfunction can result in abnormal pain and temperature sensation causing impaired balance, and autonomic deficit causing postural hypotension [14][15][16][17] .…”