Changes in B12, MMA, and homocysteine ​​associated with peripheral neuropathy

According to the results of a systematic review and meta-analysis, patients with peripheral neuropathy (PN) were more likely to have elevated methylmalonic acid (MMA) and homocysteine ​​levels, and decreased vitamin B12 levels, regardless of the disease suspected of causing PN Has. These results were published in the European Journal of Neurology.

Researchers searched publication databases through September 2018 for studies on neuropathy that included a plasma or serum assessment for metabolites. This analysis comprised observational (n = 46) and interventional (n = 7) studies in patients with PN.

In the observational studies, decreased plasma vitamin B12 levels were observed in 2948 patients with PN compared to 9432 participants in the control group. The pooled estimate for decreased vitamin B12 levels was 1.51 (95% CI, 1.23-1.84) with moderate heterogeneity (I2, 43.3%; P = 0.003) and no publication bias (P = 0.065).

The relationship between PN and B12 levels was between European (pooled estimate 1.66; 95% CI 1.20-2.31; I2 13.4%; P = 0.314) and North American studies (pooled estimate 1.55; 95% CI 1.14) significantly -2.10; I2, 44.8%; P = 0.053), but not among Asian studies (pooled estimate, 1.43; 95% CI, 0.87-2.36; I2, 63.5%; P = 0.003).

The MMA concentrations were increased in 827 patients with PN compared to the concentrations in 1492 control group participants (pooled estimate 2.53; 95% CI 1.39-4.60; I2 63.8%; P = 0.005), but with a significant publication bias (P =). 033).

The homocysteine ​​levels were increased in 1047 patients with PN compared to 4763 control group participants (pooled estimate 3.48; 95% CI 2.01-6.04; I2 70.6%; P <0.001) without publication bias (P = 0.276).

Among the interventional studies, the odds ratio (OR) for improvement in NP symptoms after vitamin B12 supplementation was 1.36 (95% CI, 0.66-2.79; I2, 28.9%). A significant improvement in symptoms was observed with vitamin B1 supplementation (OR 5.34; 95% CI 1.87-15.19; I2 64.6%; P = 0.059).

These results may have been skewed by the different definitions of vitamin B12 markers.

These data indicated that patients with PN had altered plasma levels of vitamins, MMA, and homocysteine ​​- all of which are potential therapeutic targets.

Disclosure: One author declared affiliation with the pharmaceutical industry. For a full list of the authors’ claims, see the original article.


Stein J, Geisel J, Obeid R. Relationship Between Neuropathy and B Vitamins; a systematic review and meta-analysis. Eur J Neurol. Published online February 22, 2021. doi: 10.1111 / ene.14786

This article originally appeared on Clinical Pain Advisor

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