Effectiveness of Metanx Prescription Medical Food on Small Nerve Fibers and Monofilament Sensation in Patients with Diabetic Peripheral Polyneuropathy

Purpose: Diabetic peripheral neuropathy (DPN) is prevalent among the population with type 2 diabetes, and treatment approaches are limited. The combination of L-methylfolate-methylcobalamin-pyridoxal-5-phospate (LMF-MC-PP, Metanx?) is a prescription medical food that has demonstrated significant improvements in sensory perception and quality of life as well as reduced neuropathic pain in patients with DPN. The present study examined the effects of LMF-MC-PP on sensory perception and epidermal nerve fiber density (ENFD) among patients with confirmed DPN. Methods: Patients with type 2 diabetes and diagnosed with diabetic peripheral polyneuropathy, based on loss of vibratory perception, warm-cold discrimination or monofilament sensation, underwent bilateral lower extremity ENFD assessments via skin punch biopsy and were started on LMF-MC-PP. ENFD and monofilament testing were repeated at 6 months. Findings: Of 123 patients evaluated, all had monofilament testing at baseline and 6 months and 122 had assessments at both time points. A significant (p < 0.05) improvement in ENFD from baseline to 6 months was observed. A significant (p = 0.0001) improvement in monofilament testing also was observed. Overall, more patients had intact sensation after 6 months, with 60 (48.8%) of 123 patients having positive monofilament test at baseline as compared to 95 (77.2%) positive after 6 months. An analysis of the association between improvements in ENFD and monofilament testing found that the two tended to occur together, and this was significant (p < 0.05) for the right limb. Implications: Clinically important and statistically significant improvements in ENFD and monofilament sensation were associated with LMF-MC-PP in patients with DPN. When compared to the decrease in ENFD expected among DPN patients, the improvements are even more clinically significant. These findings should be validated in a larger, placebo-controlled study.