Prevalence of Vitamin B12 Deficiency in Patients with Type II Diabetes Mellitus on Metformin: A Study from Khyber Pakhtunkhwa

Abstract

BackgroundMetformin is the most common oral hypoglycemic used and associated with certain abnormalities. The objective was to evaluate and define the occurrence and bases of vitamin B12 deficiency amongst patients on Metformin for diabetes mellitus type II.MethodsA cross-sectional study was conducted on 209 patients having diabetes type II between January-December 2016. The patients aged > 45 years and who had taken metformin for at least three months were recruited with regular follow-up at the Endocrinology Unit of Hayatabad Medical Complex and Diabetic Center Hayatabad, Peshawar. The patients were included in a survey after which they had their serum B12 levels measured. Serum B12 levels < 150 pg/ml is defined as the B12 deficiency.ResultsAbout 29.66% of diabetic patients had confirmed the B12 insufficiency through laboratory tests. The patients on metformin had statistically lower values of B12 (P = 0.01). For the patients who smoked, vitamin B12 deficiency was significantly higher than those who did not smoke (p= <0.001). Also in patients using multivitamins, vitamin B12 deficiency was lower compared to nonusers (p=0.05).ConclusionOur study shows that for the patients with type 2 diabetes (T2DM), long-term treatment with metformin and smoking are associated with higher chances of developing vitamin B12 deficiency. Clinicians should, therefore, recognize this significant element and should screen diabetics who are on metformin treatment for any B12 insufficiency, which may be hidden, especially patients coming with neurologic symptoms. Additionally, multi vitamins taken daily may have a protective role.

The association of metformin use with vitamin B12 deficiency and peripheral neuropathy in Saudi individuals with type 2 diabetes mellitus

“…Compliance with metformin treatment was not assessed during the study, and this may have had an impact on the change in serum vitamin B12 in response to metformin. The effect of smoking was not examined in this study but has been addressed in other studies, for example, Kham et al [ 34 ], who found lower B12 levels in smokers than in non-smokers. Also, the patients’ intake of supplemental calcium and vitamin D, which have been shown to play major roles in vitamin B12 synthesis, was not evaluated.…”

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

“…The 2018 ADA Clinical Practice Recommendations endorse screening Metformin users for vitamin B 12 deficiency and the 2017 ADA diabetic neuropathy statement recommends that all patients with diabetic neuropathy should be assessed for B 12 deficiency, to exclude a treatable cause of neuropathy ( 13 ). However, previous studies examining the relationship between Metformin use and B 12 deficiency ( 12 ); and indeed between B 12 deficiency and neuropathy have been conflicting ( 11 , 14 – 18 ). Indeed, a study has shown a lower prevalence of DPN in T2DM patients on Metformin compared to those not on Metformin ( 6 ).…”

“…A number of observational and placebo-controlled studies have confirmed that Metformin may reduce vitamin B 12 levels ( 4 – 10 ). Indeed a recent study from Pakistan found that 29.7% of patients on Metformin had B 12 deficiency ( 11 ) and another study from Brazil showed that B 12 deficiency occurred in 22.4% of patients with T2DM on Metformin, and was further reduced in those on proton pump inhibitors (PPI)/H2-antagonists ( 10 ). However, a recent meta-analysis showed that only 10/17 studies showed that Metformin use led to B 12 deficiency and in four prospective studies B 12 was reduced by approximately 57 pmol/L, within 6 weeks to 3 months of commencing Metformin ( 12 ).…”

“…Indeed, the recent 2017 ADA position statement on diabetic neuropathy has emphasized the importance of excluding B 12 deficiency in patients with diabetic neuropathy ( 13 ). 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 ).…”

Deficiencia de Vitamina B12 relacionada al Uso de Metformina

“…En algunos la población femenina es mayor 8,22,23,25,26 . En otros, la masculina; como por ejemplo el estudio de los veteranos en donde representaban el 95% de la población estudiada 27,28,29,30 . Ningún estudio ha demostrado que esta variable represente un factor de riesgo o protector para el desarrollo de deficiencia de vitamina B12 8,22,23,25,26,27,28,29,39 .…”