Nottingham, England: There is a need for regular assessment of vitamin B12 levels in type 2 diabetes (T2D) patients taking metformin, this would help in the prevention of irreversible nerve damage in them, according to a new study.
The study, presented at the Society for Endocrinology annual conference in Glasgow suggest that earlier detection of vitamin B12 deficiency through routine screening of all type-2 diabetes patients treated with metformin can reduce the risk of developing irreversible, painful and potentially disabling nerve damage in them.
Nerve damage in the periphery (e.g. face, limbs, organs) is a common complication of diabetes, with symptoms that range from numbness to pain, and can lead to debilitating loss of balance and coordination.
While metformin is recommended for the first-line treatment of T2D, it is associated with vitamin B12 deficiency, which itself increases the risk of peripheral neuropathy.
Kaenat Mulla, Nottingham University Hospitals, Nottingham, and colleagues conducted an audit of vitamin B12 screening and deficiency among female, metformin-treated, patients with T2D at the GP practice.
The audit findings indicated that 64% of patients had not had their vitamin B12 levels checked at all, and that 9.6% of patients were deficient but only 6.4% were being treated with vitamin B12.
Dr Mulla states, “Current British Society of Haematology guidelines recommend that vitamin B12 levels are checked only when there is clinical suspicion of deficiency. However, peripheral neuropathy is irreversible and it may be too late once symptoms have developed.”
The research team now plan to extend their audit to determine how best to treat patients found to be vitamin B12 deficient, and to provide further evidence that all type-2 patients on metformin should have their levels checked more regularly, for example at their annual check-up.
Dr Mulla comments, “Our findings indicate that patients with diabetes taking metformin should be checked more frequently and that we need to ensure deficiencies are adequately treated to avoid irreversible nerve damage.” However, she also cautions, “Metformin remains the best treatment for type-2 diabetes, these findings should not discourage patients from taking it, but encourage doctors to monitor vitamin B12 levels more routinely, so any deficiency can quickly be treated.”