Plasma Vitamin B12 Levels, High-Dose Vitamin B12 Treatment, and Risk of Dementia.

BACKGROUND: It is controversial whether B12 deficiency causes dementia or B12 treatment can prevent dementia. OBJECTIVE: To assess associations between low plasma (P-)B12 levels, B12 treatment, and risk of Alzheimer's disease (AD; primary outcome) and all-cause or vascular dementia (secondary outcomes). METHODS: We conducted a population-based cohort study using Danish registry data to assess associations between low P-B12 levels, high-dose injection or oral B12 treatment, and risk of dementia (study period 2000-2013). The primary P-B12 cohort included patients with a first-time P-B12 measurement whose subsequent B12 treatment was recorded. The secondary B12 treatment cohort included patients with a first-time B12 prescription and P-B12 measurement within one year before this prescription. For both cohorts, patients with low P-B12 levels (<200 pmol/L) were propensity score-matched 1:1 with patients with normal levels (200-600 pmol/L). We used multivariable Cox regression to compute 0-15-year hazard ratios for dementia. RESULTS: For low P-B12 and normal P-B12 level groups, we included 53,089 patients in the primary P-B12 cohort and 13,656 patients in the secondary B12 treatment cohort. In the P-B12 cohort, hazard ratios for AD centered around one, regardless of follow-up period or treatment during follow-up. In the B12 treatment cohort, risk of AD was unaffected by low pre-treatment P-B12 levels, follow-up period and type of B12 treatment. Findings were similar for all-cause and vascular dementia. CONCLUSION: We found no associatio1n between low P-B12 levels and dementia. Associations were unaffected by B12 treatment. Results do not support routine screening for B12 deficiency in patients with suspected dementia.

Cancer-associated venous thromboembolism and the non-vitamin K antagonist oral anticoagulants: a review of clinical outcomes and patient perspectives.

INTRODUCTION: Cancer-associated venous thromboembolism remains an important but challenging aspect in the treatment of patients with cancer. Recently, alternatives to injection of low-molecular-weight heparin (LMWH) have been introduced, the non-vitamin K antagonist oral anticoagulants (NOACs), which could potentially alleviate patients from burdensome daily injections. AREAS COVERED: This review discusses the available evidence exploring the role of NOACs in the treatment and secondary prevention of cancer-associated venous thromboembolism, from randomized trials, observational data, contemporary guideline recommendations, and patient perspectives. EXPERT OPINION: Edoxaban, rivaroxaban, and apixaban have proven attractive alternatives to LMWH for the treatment of cancer-associated venous thromboembolism. Contemporary guidelines have promptly endorsed the use of NOACs in patients with most cancer types. Nonetheless, issues remain regarding bleeding risk, interactions with medical cancer treatment, and the effectiveness and safety for extended treatment periods. There are head-to-head comparisons of the NOACs, and therefore no data favoring the use of one NOAC over the others. Patient's preferences are highly diverse and should be part of routine considerations when weighing risks and benefits associated with various available anticoagulant drugs.