Investigation of the vitamin b12 deficiency with peripheral neuropathy in the type 2 diabetes mellitus using metformin

Abstract

OBJECTIVE:The relationship between vitamin B12 deficiency and peripheral neuropathy has been shown in a number of previous studies. Metformin is the indispensable first-line treatment for type 2 diabetes mellitus (DM) worldwide. One of the adverse effects of the use of metformin is vitamin B12 deficiency. In the present study, we investigated the relationship between vitamin B12 deficiency and peripheral neuropathy due to the use of metformin.METHODS:Patient’s laboratory and electromyography (EMG) data were retrospectively reviewed. Patients with no EMG report and other necessary information were excluded from the study.RESULTS:Eighty-six patients with type 2 DM using metformin were included in the study. Of these patients, 26 were males and 60 were females. The mean age of the patients was 55.1±7.7 years. The mean body mass index of the patients was 29.1±9.01 kg/m2. The mean HbA1c level of the patients was 8.6%±2.1%. The mean duration of diabetes was 8.02±5.4 years. The incidence of vitamin B12 deficiency was 38.4%. Peripheral neuropathy was detected in 33.7% patients. There was no statistically significant difference in vitamin B12 levels between patients with peripheral neuropathy and those without peripheral neuropathy (p=0.64).CONCLUSION:Therefore, it can be concluded that the lack of vitamin B12 secondary to the use of metformin did not significantly increase the frequency of peripheral neuropathy.

Vitamin B12 deficiency in patients with diabetes at a specialised diabetes clinic, Botswana

“…Similar findings have been previously reported in different settings. 20,[47][48][49] In the current study, NTSS-6 was used to assess neuropathy. The tool is prone to subjectivity as it is symptom dependent, and there is a possibility of misclassification of participants.…”

Metformin Use Is Not Associated With B12 Deficiency or Neuropathy in Patients With Type 2 Diabetes Mellitus in Qatar

“…However, there are conflicting reports on the association between Metformin-induced B 12 deficiency and neuropathy, with some reports showing an association ( 14 , 15 ) while others have refuted this ( 11 , 16 – 18 ). Furthermore, in a recent study from Turkey, while the prevalence of B 12 deficiency was 38.4% there was no difference in B 12 levels in those with and without neuropathy ( 19 ). Despite this there is wide spread administration of vitamin B 12 therapy in patients in the Middle East and Far East, with a recent analysis from five teaching hospitals in Jordan, indicating that cyanocobalamin (B 12 ), was the second most common injectable therapy after insulin ( 20 ).…”

Association of vitamin B12deficiency in people with type 2 diabetes on metformin and without metformin: a multicenter study, Karachi, Pakistan

“…4 It has also been reported that vitamin B 12 deficiency ranges from 9% to 52% in people with T2DM and has been partially attributed to long-term use of metformin. [5][6][7] Vitamin B 12 is essential for remethylation of homocysteine (Hcy) to methionine and B 12 deficiency could lead to hyperhomocysteinemia, which has been associated with macrovascular complications in people with T2DM. 8 B 12 deficiency may also increase the severity of peripheral neuropathy in T2DM.…”