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The objective of this study is to systematically review the relationship between lower-extremity peripheral nerve function and mobility in older adults. The National Library of Medicine (PubMed) was searched on March 23, 2015 with no limits on publication dates. One reviewer selected original research studies of older adults (=65 years) that assessed the relationship between lower-extremity peripheral nerve function and mobility-related outcomes. Participants, study design and methods of assessing peripheral nerve impairment were evaluated and results were reported and synthesized. Eight articles were identified, including 6 cross-sectional and 2 longitudinal studies. These articles investigated 6 elderly cohorts (4 from the U.S. and 2 from Italy): 3 community-dwelling (including 1 with only disabled women and 1 without mobility limitations at baseline), 1 with both community-dwelling and institutionalized residents, 1 from a range of residential locations, and 1 of patients with peripheral arterial disease. Mean ages ranged from 71-82 years. Nerve function was assessed by vibration threshold (n=2); sensory measures and clinical signs and symptoms of neuropathy (n=2); motor nerve conduction (n=1); and a combination of both sensory measures and motor nerve conduction (n=3). Each study found that worse peripheral nerve function was related to poor mobility, although relationships varied based on the nerve function measure and mobility domain assessed. Six studies found that the association between nerve function and mobility persisted despite adjustment for diabetes. Evidence suggests that peripheral nerve function impairment at various levels of severity is related to poor mobility independent of diabetes. Relationships varied depending on peripheral nerve measure, which may be particularly important when investigating specific biological mechanisms. Future research needs to identify risk factors for peripheral nerve decline beyond diabetes, especially those common in late-life and modifiable. Interventions to preserve nerve function should be investigated with regard to their effect on postponing or preventing disability in older adults. [ABSTRACT FROM AUTHOR]

Objectives To assess the relationship between sensorimotor nerve function and incident mobility disability over 10 years. Design Prospective cohort study with longitudinal analysis. Setting Two U. S. clinical sites. Participants Population-based sample of community-dwelling older adults with no mobility disability at 2000/01 examination (N = 1,680; mean age ± SD 76.5 ± 2.9, body mass index 27.1 ± 4.6; 50.2% female, 36.6% black, 10.7% with diabetes mellitus). Measurements Motor nerve conduction amplitude (poor <1 mV) and velocity (poor <40 m/s) were measured on the deep peroneal nerve. Sensory nerve function was measured using 10- and 1.4-g monofilaments and vibration detection threshold at the toe. Lower extremity symptoms included numbness or tingling and aching or burning pain. Incident mobility disability assessed semiannually over 8.5 years (interquartile range 4.5-9.6 years) was defined as two consecutive self-reports of a lot of difficulty or inability to walk one-quarter of a mile or climb 10 steps. Results Nerve impairments were detected in 55% of participants, and 30% developed mobility disability. Worse motor amplitude ( HR = 1.29 per SD, 95% CI = 1.16-1.44), vibration detection threshold ( HR = 1.13 per SD, 95% CI = 1.04-1.23), symptoms ( HR = 1.65, 95% CI = 1.26-2.17), two motor impairments ( HR = 2.10, 95% CI = 1.43-3.09), two sensory impairments ( HR = 1.91, 95% CI = 1.37-2.68), and three or more nerve impairments ( HR = 2.33, 95% CI = 1.54-3.53) predicted incident mobility disability after adjustment. Quadriceps strength mediated relationships between certain nerve impairments and mobility disability, although most remained significant. Conclusion Poor sensorimotor nerve function independently predicted mobility disability. Future work should investigate modifiable risk factors and interventions such as strength training for preventing disability and improving function in older adults with poor nerve function. [ABSTRACT FROM AUTHOR]