Hyperhomocysteinemia, deep vein thrombosis and vitamin B12 deficiency in a metformin-treated diabetic patient

Pernicious anaemia: cause of recurrent cerebral venous thrombosis

This case of recurrent cerebral venous thrombosis (CVT) highlights hyperhomocysteinemia in pernicious anemia due to vitamin B₁₂ deficiency. No other risk factors such as trauma, infections, coagulation disorders or autoimmune diseases were present. The patient was cured with vitamin B₁₂ and anticoagulation therapy. So, it is worthwhile and important to investigate levels of vitamin B₁₂ and homocysteine in CVT.

An uncommon presentation of hyperhomocysteinemia and vitamin B12 deficiency: a case report

Introduction

Cerebral venous thrombosis is relatively rare and characterized by a wide spectrum of clinical features. It is more common in young adults with women affected more than men. The diagnosis of cerebral venous thrombosis is easier nowadays due to easy access to advanced neuroimaging techniques. Abnormalities in thrombophilic profile are associated with enhanced risk of cerebral venous thrombosis. It has varied etiologies such as hypercoagulable states, infection, dehydration, pregnancy, and substance abuse. Hyperhomocysteinemia is found to be closely associated with an enhanced risk of cerebral venous thrombosis.

Case presentation

Here we report a case of cerebral venous thrombosis secondary to hyperhomocysteinemia caused by vitamin B₁₂ deficiency in a 32-year-old Indo-Aryan man. A detailed coagulation workup led us to find the etiology of cerebral venous thrombosis in this patient who followed a strict vegetarian diet and had vitamin B₁₂ deficiency leading to hyperhomocysteinemia.

Conclusion

There are conflicting reports in the literature about the association of hyperhomocysteinemia, B₁₂ deficiency, and cerebral venous thrombosis but some reports point to a significant association. We conclude that further studies with a large sample size are required to analyze the effect of hyperhomocysteinemia and low vitamin B₁₂ on the risk of cerebral venous thrombosis.

Correlation between secondary thrombosis in epileptic patients and serum levels of folate and vitamin B12

Epilepsy is a chronic brain dysfunction syndrome and nervous system disease whose pathogenesis remains to be determined. The aim of the present study was to analyze the correlation between secondary thrombosis and the serum levels of folate and vitamin B12 in epileptic patients, as well as to determine whether the supplementation of folate and vitamin B12 was associated with a decreased incidence of thrombosis, and provide the basis for novel clinical treatment. A total of 37 patients, diagnosed as epileptic with secondary thrombosis between April 2012 and April 2014, were included in the treatment group. A total of 37 epileptic patients without secondary thrombosis were included in the control group. The serum levels of homocysteine, folate and vitamin B12 in the two groups and in the epileptic patients with intracranial thrombosis or peripheral thrombosis were compared. According to the Guidance of Epilepsy, the patients in the two groups were administered antiepileptic drugs (AEDs) with the supplementation of folate tablet (0.4 mg/day) and vitamin B12 tablet (100 µg/day). These indicators and the incidence of thrombosis in the two groups were compared after 1 year. The serum levels of homocysteine in the two groups were higher than normal, and the levels in the treatment group were significantly higher than those in the control group. The serum levels of folate and vitamin B12 in the treatment group were significantly higher than those in the control group and the difference was statistically significant (P<0.05). The Pearson correlation analysis revealed that the serum levels of folate and vitamin B12 were not associated with the serum level of homocysteine (P>0.05). The logistic regression analysis revealed that the serum levels of folate and vitamin B12 were independent risk factors for epilepsy with secondary thrombosis [folate: odds ratio (OR)=0.635, P=0.038; vitamin B12: OR=0.418, P=0.042]. The differences in the serum levels of homocysteine, folate and vitamin B12 in the epileptic patients with intracranial thrombosis or peripheral thrombosis were not statistically significant (P>0.05). The serum levels of homocysteine in the two groups, were significantly decreased, while the levels of folate and vitamin B12 were significantly increased. The differences in the serum levels of homocysteine, folate and vitamin B12 in the two groups were not statistically significant (P>0.05). The differences in the incidence of thrombosis in the two groups were not statistically significant (P>0.05). In conclusion, the serum levels of folate and vitamin B12 were independent of serum homocysteine, and were the dependent risk factors for primary epilepsy with secondary thrombosis. The supplementation of folate and vitamin B12 may be beneficial for the prevention of epilepsy with secondary thrombosis, making it valuable in application.

Identifying Common Genetic Risk Factors of Diabetic Neuropathies

Type 2 diabetes mellitus (T2DM) is a global public health problem of epidemic proportions, with 60-70% of affected individuals suffering from associated neurovascular complications that act on multiple organ systems. The most common and clinically significant neuropathies of T2DM include uremic neuropathy, peripheral neuropathy, and cardiac autonomic neuropathy. These conditions seriously impact an individual's quality of life and significantly increase the risk of morbidity and mortality. Although advances in gene sequencing technologies have identified several genetic variants that may regulate the development and progression of T2DM, little is known about whether or not the variants are involved in disease progression and how these genetic variants are associated with diabetic neuropathy specifically. Significant missing heritability data and complex disease etiologies remain to be explained. This article is the first to provide a review of the genetic risk variants implicated in the diabetic neuropathies and to highlight potential commonalities. We thereby aim to contribute to the creation of a genetic-metabolic model that will help to elucidate the cause of diabetic neuropathies, evaluate a patient's risk profile, and ultimately facilitate preventative and targeted treatment for the individual.

Revisiting Metformin: Annual Vitamin B12 Supplementation may become Mandatory with Long-Term Metformin Use

Monitoring of adverse drug reactions of a drug is a continuous process and runs through-out the life of a drug. Many rare adverse effects of a drug are documented after years of use; when a single case (signal generation) is reported leading subsequently to reporting of more cases. Deficiency of Vitamin B12 (vit B₁₂) is a known sequel of prolonged metformin therapy. It was recommended to have annual measurement of serum vit B₁₂ levels in patients on long term metformin therapy way back in 1970 itself. After more than 50 years of use of metformin, we have come to know that metformin induced vit B₁₂ deficiency can cause neuropathy; forcing to change the recommendation from annual screening of vit B₁₂ levels to annual supplementation of vit B₁₂.

Vitamin B12 deficiency, hyperhomocysteinemia and thrombosis: a case and control study

This study aimed at assessing the relationship between thrombosis, hyperhomocysteinemia and vitamin B12 deficiency using a case-control study carried out in 326 patients with thrombosis (case group) and 351 patients from the same hospital (control group). Apart from the classic risk factors, a number of hematological variables were evaluated, including serum vitamin B12 (B12), red cell folate (RCF), and serum homocysteine (Hcy). An evaluation of serum methylmalonic acid (MMA) and a clinical study were carried out to investigate B12 pathology. Results of univariate analysis demonstrated decreased B12 levels in thrombosis (Student's t test, p < 0.0001). Vitamin B12 below 200 pmol/l (LB200) or below 150 pmol/l (LB150), and red cell folate below 600 nmol/l were found in 17.2, 8.6, and 2.2% of cases with thromboembolism, respectively. An increase in Hcy was detected in 86 cases with thrombosis (26.3%). An abnormality in vitamin B12 and/or renal function was found in 80% of cases with hyperHcy and thrombosis. The MMA increase demonstrated that vitamin B12 deficiency was present in these patients with low levels of vitamin B12 in serum, and the MMA levels were in concordance with Hcy levels. The clinical study revealed B12 malabsorption in most cases with LB200. Multivariate analysis showed that serum vitamin B12 (RR 0.998, CI 0.997-0.999) was moderately related to thromboembolism. The results indicated that vitamin B12 deficiency was common among patients with hyperhomocysteinemia and thrombosis. Moreover, HyperHcy was caused by vitamin B12 deficiency and/or chronic renal failure in most patients with thrombosis. As the main cause of vitamin B12 deficiency was vitamin malabsorption, parenteral vitamin B12 with or without folic acid should be administered for the treatment of this condition. However, it remains to be demonstrated whether this treatment approach prevents recurrent thromboses in patients with vitamin B12 deficiency and thrombosis, as suggested by some case reports.