Markers of inflammation, vitamin E and peripheral nervous system function: the InCHIANTI study

BACKGROUND: Aging of the peripheral nervous system is associated with several morphologic and functional changes, including a decrease of the nerve conduction velocity. There is evidence that these changes contribute to age-related-decline in muscle strength, sensory discrimination, and autonomic responses. The aim of this study was to characterize the decline in nerve conduction velocity in the peripheral nervous system over the aging process and to identify factors that, independent of age, affect nerve conduction velocity. METHODS: We measured motor nerve conduction velocity of the right superficial peroneal nerve using a standard neurophysiologic technique in a population-based sample of subjects aged between 20 and 103 years old enrolled in the InCHIANTI study. RESULTS: Average conduction velocities in the peripheral nerve decreased linearly with age in both sexes. We found that diabetes, cognitive impairment, uric acid, sIL-6R and alpha-tocopherol were significant predictors of nerve conduction velocity independently of the potential confounding effect of age, sex, sex x age interaction term, height, lymphocytes, neutrophils number, alpha1 and alpha2-globulin serum protein. CONCLUSIONS: Our findings are consistent with the hypothesis that inflammation and inadequate antioxidant defenses are associated with accelerated decline of nerve conduction velocity over the aging process