Relationship Between Vitamin B12 and Sensory and Motor Peripheral Nerve Function in Older Adults

Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Journal of the American Geriatrics Society (Impact Factor: 4.57). 06/2012; 60(6):1057-63. DOI: 10.1111/j.1532-5415.2012.03998.x
Source: PubMed


To examine whether deficient B12 status or low serum B12 levels are associated with worse sensory and motor peripheral nerve function in older adults.
Health, Aging and Body Composition Study.
Two thousand two hundred and eighty-seven adults aged 72 to 83 (mean 76.5 ± 2.9; 51.4% female; 38.3% black).
Low serum B12 was defined as serum B12 less than 260 pmol/L, and deficient B12 status was defined as B12 less than 260 pmol/L, methylmalonic acid (MMA) greater than 271 nmol/L, and MMA greater than 2-methylcitrate. Peripheral nerve function was assessed according to peroneal nerve conduction amplitude and velocity (NCV) (motor), 1.4 g/10 g monofilament detection, average vibration threshold detection, and peripheral neuropathy symptoms (numbness, aching or burning pain, or both) (sensory).
B12-deficient status was found in 7.0% of participants, and an additional 10.1% had low serum B12 levels. B12 deficient status was associated with greater insensitivity to light (1.4 g) touch (odds ratio = 1.50, 95% confidence interval = 1.06-2.13) and worse NCV (42.3 vs 43.5 m/s) (β = -1.16, P = .01) after multivariable adjustment for demographics, lifestyle factors, and health conditions. Associations were consistent for the alternative definition using low serum B12 only. No significant associations were found for deficient B12 status or the alternative low serum B12 definition and vibration detection, nerve conduction amplitude, or peripheral neuropathy symptoms.
Poor B12 (deficient B12 status and low serum B12) is associated with worse sensory and motor peripheral nerve function. Nerve function impairments may lead to physical function declines and disability in older adults, suggesting that prevention and treatment of low B12 levels may be important to evaluate.

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Available from: Eef Hogervorst, May 13, 2014
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    • "Neurologic damage, a possible consequence of metformin-induced vitamin B12 deficiency, can present as peripheral neuropathy and may be mistaken for diabetic neuropathy in patients on metformin treatment (10). Low vitamin B12 levels have been reported to be associated with worse nerve conduction velocities and poorer responses to light touch by monofilament detection (27). This may lead to the unnecessary use of anticonvulsants or tricyclic antidepressants (10, 28, 29). "
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    • "This finding is consistent with classic clinical descriptions of SCD, in which damage to the corticospinal tract (lateral columns) is characterized by a pyramidal syndrome and weakness in the lower extremities in the later stages of the disease (Di Lazzaro et al. 1992; Hemmer et al. 1998). A recent study in older adults reported that B12 deficiency was associated with hypoesthesia to light touch and impairment of sensory and motor peripheral nerve conduction velocity (Leishear et al. 2012). These findings are consistent with those described by Tredici et al. (1998), who reported damage to both thick and thin myelin peripheral fibers. "
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