The pace and prognosis of peripheral sensory loss in advanced age: association with gait speed and falls.

BACKGROUND: Peripheral sensory loss is considered one of many risk factors for gait impairments and falls in older adults, yet no prospective studies have examined changes in touch sensation in the foot over time and their relationship to mobility and falls. Therefore, we aimed to determine the prevalence and progression of peripheral sensory deficits in the feet of older adults, and whether sensory changes are associated with the slowing of gait and development of falls over 5 years. METHODS: Using baseline, and 18 and 60 month followup data from the Maintenance Of Balance, Independent Living, Intellect, and Zest in the Elderly (MOBILIZE) Study in Boston, MA, we determined changes in the ability to detect stimulation of the great toe with Semmes Weinstein monofilaments in 351 older adults. We used covariate-adjusted repeated measures analysis of variance to determine relationships between sensory changes and gait speed or fall rates. RESULTS: Subjects whose sensory function was consistently impaired over 5 years had a significantly steeper decline in gait speed (- 0.23 m/s; 95% CI: -0.28 to - 0.18) compared to those with consistently intact sensory function (- 0.12 m/s; 95% CI: -0.15 to - 0.08) and those progressing from intact to impaired sensory function (- 0.13 m/s; - 0.16 to - 0.10). Compared to subjects with consistently intact sensation, those whose sensory function progressed to impairment during followup had the greatest risk of falls (adjusted risk ratio = 1.57 (95% confidence interval = 1.12 to 2.22). CONCLUSIONS: Our longitudinal results indicate that a progressive decline in peripheral touch sensation is a risk factor for mobility impairment and falls in older adults.