Sensorimotor peripheral nerve function and the longitudinal relationship with endurance walking in the health, aging and body composition study

Objectives To determine whether lower extremity sensorimotor peripheral nerve deficits are associated with reduced walking endurance in older adults. Design Prospective cohort study with 6 years of follow-up. Setting Two university research clinics. Participants Community-dwelling older adults enrolled in the Health, Aging and Body Composition Study from the 2000-2001 annual clinical examination (N=2393; mean age ± SD, 76.5±2.9y; 48.2% men; 38.2% black) and a subset with longitudinal data (n=1178). Interventions Not applicable. Main Outcome Measures Participants underwent peripheral nerve function examination in 2000-2001, including peroneal motor nerve conduction amplitude and velocity, vibration perception threshold, and monofilament testing. Symptoms of lower extremity peripheral neuropathy included numbness or tingling and sudden stabbing, burning, pain, or aches in the feet or legs. The Long Distance Corridor Walk (LDCW) (400m) was administered in 2000-2001 and every 2 years afterward for 6 years to assess endurance walking performance over time. Results In separate, fully adjusted linear mixed models, poor vibration threshold (>130μm), 10-g and 1.4-g monofilament insensitivity were each associated with a slower 400-m walk completion time (16.0s, 14.4s, and 6.9s slower, respectively; P<.05 for each). Poor motor amplitude (<1mV), poor vibration perception threshold, and 10-g monofilament insensitivity were related to greater slowing per year (4.7, 4.2, and 3.8 additional seconds per year, respectively; P<.05), although poor motor amplitude was not associated with initial completion time. Conclusions Poorer sensorimotor peripheral nerve function is related to slower endurance walking and greater slowing longitudinally. Interventions to reduce the burden of sensorimotor peripheral nerve function impairments should be considered to help older adults maintain walking endurance - a critical component for remaining independent in the community.