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Metabolism: Clinical and Experimental May 2017Vitamin K is a liposoluble vitamin. The predominant dietary form, phylloquinone or vitamin K1, is found in plants and green vegetables; whereas menaquinone, or vitamin... (Review)
Review
Vitamin K is a liposoluble vitamin. The predominant dietary form, phylloquinone or vitamin K1, is found in plants and green vegetables; whereas menaquinone, or vitamin K2, is endogenously synthesized by intestinal bacteria and includes several subtypes that differ in side chain length. Aside from its established role in blood clotting, several studies now support a critical function of vitamin K in improving bone health. Vitamin K is in fact required for osteocalcin carboxylation that in turn regulates bone mineral accretion; it seems to promote the transition of osteoblasts to osteocytes and also limits the process of osteoclastogenesis. Several observational and interventional studies have examined the relationship between vitamin K and bone metabolism, but findings are conflicting and unclear. This systematic review aims to investigate the impact of vitamin K (plasma levels, dietary intake, and oral supplementation) on bone health with a particular interest in bone remodeling, mineral density and fragility fractures.
Topics: Aged; Bone and Bones; Female; Fractures, Bone; Humans; Male; Nutrition Assessment; Osteoporosis; Vitamin K
PubMed: 28403946
DOI: 10.1016/j.metabol.2017.01.032 -
Stroke Oct 2022High level evidence for direct oral anticoagulants (DOACs) in patients with cerebral venous thrombosis is lacking. We performed a systematic review and meta-analysis to... (Meta-Analysis)
Meta-Analysis
BACKGROUND
High level evidence for direct oral anticoagulants (DOACs) in patients with cerebral venous thrombosis is lacking. We performed a systematic review and meta-analysis to assess the efficacy and safety of DOACs versus vitamin K antagonists in patients with cerebral venous thrombosis.
METHODS
This systematic review was registered in PROSPERO (CRD42021228800). We searched MEDLINE (via Ovid), EMBASE, CINAHL, and the Web of Science Core Collection between January 1, 2007 and Feb 22, 2022. Search terms included a combination of keywords and controlled vocabulary terms for cerebral venous thrombosis, vitamin K antagonists/warfarin, and DOACs. We included both randomized and nonrandomized studies that compared vitamin K antagonists and DOACs in 5 or more patients with cerebral venous thrombosis. Where studies were sufficiently similar, we performed meta-analyses for efficacy (recurrent venous thromboembolism and complete recanalization) and safety (major hemorrhage) outcomes, using relative risks (RRs).
RESULTS
Out of 10 665 records identified, we screened 254 as potentially eligible. Nineteen studies (16 observational studies [n=1735] and 3 randomized controlled trials [n=215]) met the inclusion criteria. All 3 randomized controlled trials had some concerns, and all 16 observational studies had at least moderate risk of bias. When compared with vitamin K antagonist treatment, DOAC had comparable risks of recurrent venous thromboembolism (relative risk [RR], 0.85 [95% CI, 0.52-1.37], I=0%), major hemorrhage (RR, 0.70 [95% CI, 0.40-1.21], I=0%), intracranial hemorrhage (RR, 0.58 [95% CI, 0.30-1.12]; I=0%), death (RR, 1.14 [95% CI, 0.54-2.43], I=1%), and complete venous recanalization (RR, 0.98 [95% CI, 0.87-1.11]; I=0%).
CONCLUSIONS
This systematic review and meta-analysis suggest that in patients with cerebral venous thrombosis, DOACs, and warfarin may have comparable efficacy and safety. Given the limitations of the studies included (low number of randomized controlled trials, modest total sample size, rare outcome events), our findings should be interpreted with caution pending confirmation by ongoing randomized controlled trials and large, prospective, observational studies.
Topics: Administration, Oral; Anticoagulants; Fibrinolytic Agents; Hemorrhage; Humans; Intracranial Thrombosis; Prospective Studies; Venous Thromboembolism; Venous Thrombosis; Vitamin K; Warfarin
PubMed: 35938419
DOI: 10.1161/STROKEAHA.122.039579 -
Chest May 2023The management of patients who are receiving chronic oral anticoagulation therapy and require an elective surgery or an invasive procedure is a common clinical scenario. (Meta-Analysis)
Meta-Analysis
BACKGROUND
The management of patients who are receiving chronic oral anticoagulation therapy and require an elective surgery or an invasive procedure is a common clinical scenario.
RESEARCH QUESTION
What is the best available evidence to support the development of American College of Chest Physicians guidelines on the perioperative management of patients who are receiving long-term vitamin K agonist (VKA) or direct oral anticoagulant (DOAC) and require elective surgery or procedures?
STUDY DESIGN AND METHODS
A literature search including multiple databases from database inception through July 16, 2020, was performed. Meta-analyses were conducted when appropriate.
RESULTS
In patients receiving VKA (warfarin) undergoing elective noncardiac surgery, shorter (< 3 days) VKA interruption is associated with an increased risk of major bleeding. In patients who required VKA interruption, heparin bridging (mostly with low-molecular-weight heparin [LMWH]) was associated with a statistically significant increased risk of major bleed, representing a very low certainty of evidence (COE). Compared with DOAC interruption 1 to 4 days before surgery, continuing DOACs may be associated with higher risk of bleeding demonstrated in some, but not all studies. In patients who needed DOAC interruption, bridging with LMWH may be associated with a statistically significant increased risk of bleeding, representing a low COE.
INTERPRETATION
The certainty in the evidence supporting the perioperative management of anticoagulants remains limited. No high-quality evidence exists to support the practice of heparin bridging during the interruption of VKA or DOAC therapy for an elective surgery or procedure, or for the practice of interrupting VKA therapy for minor procedures, including cardiac device implantation, or continuation of a DOAC vs short-term interruption of a DOAC in the perioperative period.
Topics: Humans; Heparin, Low-Molecular-Weight; Anticoagulants; Heparin; Warfarin; Fibrinolytic Agents; Hemorrhage; Vitamin K; Administration, Oral
PubMed: 36462533
DOI: 10.1016/j.chest.2022.11.032 -
Journal of the American Heart... Jul 2017The original non-vitamin K antagonist oral anticoagulant (NOAC) trials in nonvalvular atrial fibrillation (AF) enrolled patients with native valve pathologies. The... (Meta-Analysis)
Meta-Analysis Review
Effects of Non-Vitamin K Antagonist Oral Anticoagulants Versus Warfarin in Patients With Atrial Fibrillation and Valvular Heart Disease: A Systematic Review and Meta-Analysis.
BACKGROUND
The original non-vitamin K antagonist oral anticoagulant (NOAC) trials in nonvalvular atrial fibrillation (AF) enrolled patients with native valve pathologies. The object of this study was to quantify the benefit-risk profiles of NOACs versus warfarin in AF patients with native valvular heart disease (VHD).
METHODS AND RESULTS
Trials were identified by exhaustive literature search. Trial data were combined using inverse variance weighting to produce a meta-analytic summary hazard ratio (HR) and 95% confidence interval (CI) of efficacy and safety of NOACs versus warfarin. Our final analysis included 4 randomized controlled trials that enrolled 71 526 participants, including 13 574 with VHD. Pooling results from included trials showed that NOACs versus warfarin reduced stroke or systemic embolism (HR: 0.70; 95% CI, 0.60-0.82) and intracranial hemorrhage (HR: 0.47; 95% CI, 0.24-0.92) in AF patients with VHD. However, risk reduction of major bleeding and intracranial hemorrhage was driven by apixaban, edoxaban, and dabigatran (HR for major bleeding: 0.79 [95% CI, 0.69-0.91]; HR for intracranial hemorrhage: 0.33 [95% CI, 0.25-0.45]) but not rivaroxaban (HR for major bleeding: 1.56 [95% CI, 1.20-2.04]; HR for intracranial hemorrhage: 1.27 [95% CI, 0.77-2.10]).
CONCLUSIONS
Among patients with AF and native VHD, NOACs reduce stroke and systemic embolism compared with warfarin. Evidence shows that apixaban, dabigatran, and edoxaban also reduce bleeding in this patient subgroup, whereas major bleeding (but not intracranial hemorrhage or mortality rate) is significantly increased in VHD patients treated with rivaroxaban. NOACs are a reasonable alternative to warfarin in AF patients with VHD.
Topics: Administration, Oral; Aged; Aged, 80 and over; Anticoagulants; Atrial Fibrillation; Blood Coagulation; Chi-Square Distribution; Female; Heart Valve Diseases; Hemorrhage; Humans; Intracranial Hemorrhages; Male; Middle Aged; Odds Ratio; Risk Factors; Stroke; Treatment Outcome; Vitamin K; Warfarin
PubMed: 28720644
DOI: 10.1161/JAHA.117.005835 -
European Heart Journal. Cardiovascular... Apr 2021The aim of the present meta-analysis was to evaluate the efficacy and safety of non-vitamin K oral antagonists (NOACs) vs. vitamin K antagonists (VKAs) in elderly... (Meta-Analysis)
Meta-Analysis
Safety and efficacy of non-vitamin K antagonist oral anticoagulants in elderly patients with atrial fibrillation: systematic review and meta-analysis of 22 studies and 440 281 patients.
AIMS
The aim of the present meta-analysis was to evaluate the efficacy and safety of non-vitamin K oral antagonists (NOACs) vs. vitamin K antagonists (VKAs) in elderly patients with atrial fibrillation (AF) and indirectly compare NOACs in this population.
METHODS AND RESULTS
MEDLINE, Cochrane, ISI Web of Sciences, and SCOPUS were searched for randomized or adjusted observational studies comparing NOACs vs. VKAs for stroke prevention in AF patients ≥75 years. The primary efficacy and safety outcomes of this meta-analysis were the composite of stroke and systemic embolism (SSE) and major bleedings, respectively. Other secondary outcomes were also analysed. The analysis included 22 studies enrolling 440 281 AF patients ≥ 75 years. The risk of SSE was significantly lower with NOACs vs. VKAs [hazard ratio (HR) 0.79; 95% confidence interval (CI) 0.70-0.89], whereas no differences were found for major bleedings (HR 0.94; 95% CI 0.85-1.05). NOACs reduced the risk of intracranial bleeding (HR 0.46; 95% CI 0.38-0.58), haemorrhagic stroke (HR 0.61; 95% CI 0.48-0.79) and fatal bleeding (HR 0.46; 95% CI 0.30-0.72) but increased gastrointestinal (GI) bleedings (HR 1.46; 95% CI 1.30-1.65), compared to VKAs. The adjusted indirect comparison showed no significant differences in term of SSE between NOAC agents. Conversely, the risk of major bleeding was higher for rivaroxaban vs. apixaban (HR 1.69; 95% CI 1.39-2.08) and edoxaban (HR 1.37; 95% CI 1.14-1.67), and for dabigatran vs. apixaban (HR 1.47; 95% CI 1.18-1.85).
CONCLUSION
In elderly patients with AF, NOACs are associated to a lower risk of SSE, intracranial bleeding, haemorrhagic stroke and fatal bleeding than VKAs, but increase GI bleedings. In this analysis, the safety profile of individual NOAC agents was significantly different.
Topics: Administration, Oral; Aged; Anticoagulants; Atrial Fibrillation; Gastrointestinal Hemorrhage; Humans; Vitamin K
PubMed: 31830264
DOI: 10.1093/ehjcvp/pvz073 -
Medicine Mar 2016Educational advice is often given to patients starting treatment with vitamin K Antagonists (VKAs). A great emphasis is made on nutritional information. Common belief is... (Meta-Analysis)
Meta-Analysis
Educational advice is often given to patients starting treatment with vitamin K Antagonists (VKAs). A great emphasis is made on nutritional information. Common belief is that dietary vitamin K intake could counteract the anticoagulant effect by VKAs and for many years, patients have been discouraged to consume vitamin-K-rich foods, such as green leafy vegetables.The objective of this study is to summarize the current evidence supporting the putative interaction between dietary vitamin K intake and changes in INR with the VKAs.Data sources are MEDLINE via PubMed and Cochrane database.All clinical studies investigating the relationship between dietary vitamin K and measures of anticoagulation were included. We excluded all studies of supplementation of vitamin K alone.We performed a systematic review of the literature up to October 2015, searching for a combination of "food," "diet," "vitamin K," "phylloquinone," "warfarin," "INR," "coagulation," and "anticoagulant."Two dietary interventional trials and 9 observational studies were included. We found conflicting evidence on the effect of dietary intake of vitamin K on coagulation response. Some studies found a negative correlation between vitamin K intake and INR changes, while others suggested that a minimum amount of vitamin K is required to maintain an adequate anticoagulation. Median dietary intake of vitamin K1 ranged from 76 to 217 μg/day among studies, and an effect on coagulation may be detected only for high amount of vitamin intake (>150 μg/day).Most studies included patients with various indications for VKAs therapy, such as atrial fibrillation, prosthetic heart valves, and venous thromboembolism. Thus, INR target was dishomogeneous and no subanalyses for specific populations or different anticoagulants were conducted. Measures used to evaluate anticoagulation stability were variable.The available evidence does not support current advice to modify dietary habits when starting therapy with VKAs. Restriction of dietary vitamin K intake does not seem to be a valid strategy to improve anticoagulation quality with VKAs. It would be, perhaps, more relevant to maintain stable dietary habit, avoiding wide changes in the intake of vitamin K.
Topics: Antifibrinolytic Agents; Blood Coagulation; Dietary Supplements; Humans; International Normalized Ratio; Nutritional Requirements; Thromboembolism; Vitamin K
PubMed: 26962786
DOI: 10.1097/MD.0000000000002895 -
Journal of Perinatology : Official... May 2016We conducted a systematic review to evaluate the burden of late vitamin K deficiency bleeding (VKDB) and the effect of vitamin K prophylaxis on the incidence of VKDB. We... (Review)
Review
We conducted a systematic review to evaluate the burden of late vitamin K deficiency bleeding (VKDB) and the effect of vitamin K prophylaxis on the incidence of VKDB. We searched MEDLINE and other electronic databases, and included all observational studies including population surveys as well as randomized controlled trials (RCT). The median (interquartile range) burden of late VKDB was 35 (10.5 to 80) per 100 000 live births in infants who had not received prophylaxis at birth; the burden was much higher in low- and middle-income countries as compared with high-income countries-80 (72 to 80) vs 8.8 (5.8 to 17.8) per 100 000 live births. Two randomized trials evaluated the effect of intramuscular (IM) prophylaxis on the risk of classical VKDB. Although one trial reported a significant reduction in the incidence of any bleeding (relative risk (RR) 0.73, 95% confidence interval (CI) 0.56 to 0.96) and moderate to severe bleeding (RR 0.19, 0.08 to 0.46; number needed to treat (NNT) 74, 47 to 177), the other trial demonstrated a significant reduction in the risk of secondary bleeding after circumcision in male neonates (RR 0.18, CI 0.08 to 0.42; NNT 9, 6 to 15). No RCTs evaluated the effect of vitamin K prophylaxis on late VKDB. Data from four surveillance studies indicate that the use of IM/subcutaneous vitamin K prophylaxis could significantly reduce the risk of late VKDB when compared with no prophylaxis (pooled RR 0.02; 95% CI 0.00 to 0.10). When compared with IM prophylaxis, a single oral dose of vitamin K increased the risk of VKDB (RR 24.5; 95% CI 7.4 to 81.0) but multiple oral doses did not (RR 3.64; CI 0.82 to 16.3). There is low-quality evidence from observational studies that routine IM administration of 1 mg of vitamin K at birth reduces the incidence of late VKDB during infancy. Given the high risk of mortality and morbidity in infants with late VKDB, it seems appropriate to administer IM vitamin K prophylaxis to all neonates at birth. Future studies should compare the efficacy and safety of multiple oral doses with IM vitamin K and also evaluate the optimal dose of vitamin K in preterm neonates.
Topics: Antifibrinolytic Agents; Humans; Incidence; Infant; Infant, Newborn; Observational Studies as Topic; Prospective Studies; Randomized Controlled Trials as Topic; Retrospective Studies; Risk; Vitamin K; Vitamin K Deficiency Bleeding
PubMed: 27109090
DOI: 10.1038/jp.2016.30 -
Heart (British Cardiac Society) Jan 2023There has been limited systematic evaluation of outcomes and drivers of inappropriate non-vitamin K antagonist oral anticoagulants (NOACs) dosing among patients with... (Meta-Analysis)
Meta-Analysis
Outcomes and drivers of inappropriate dosing of non-vitamin K antagonist oral anticoagulants (NOACs) in patients with atrial fibrillation: a systematic review and meta-analysis.
OBJECTIVE
There has been limited systematic evaluation of outcomes and drivers of inappropriate non-vitamin K antagonist oral anticoagulants (NOACs) dosing among patients with atrial fibrillation (AF). This review identified and systematically evaluated literature on clinical and economic outcomes of inappropriate NOAC dosing and associated patient characteristics.
METHODS
MEDLINE, Embase, Cochrane Library, International Pharmaceutical Abstracts, Econlit, PubMed and NHS EEDs databases were searched for English language observational studies from all geographies published between 2008 and 2020, examining outcomes of, or factors associated with, inappropriate NOAC dosing in adult patients with AF.
RESULTS
One hundred and six studies were included in the analysis. Meta-analysis showed that compared with recommended NOAC dosing, off-label underdosing was associated with a null effect on stroke outcomes (ischaemic stroke and stroke/transient ischaemic attack (TIA), stroke/systemic embolism (SE) and stroke/SE/TIA). Meta-analysis of 15 studies examining clinical outcomes of inappropriate NOAC dosing found a null effect of underdosing on bleeding outcomes (major bleeding HR=1.04, 95% CI 0.90 to 1.19; p=0.625) but an increased risk of all-cause mortality (HR=1.28, 95% CI 1.10 to 1.49; p=0.006). Overdosing was associated with an increased risk of major bleeding (HR=1.41, 95% CI 1.07 to 1.85; p=0.013). No studies were found examining economic outcomes of inappropriate NOAC dosing. Narrative synthesis of 12 studies examining drivers of inappropriate NOAC dosing found that increased age, history of minor bleeds, hypertension, congestive heart failure and low creatine clearance (CrCl) were associated with an increased risk of underdosing. There was insufficient evidence to assess drivers of overdosing.
CONCLUSIONS
Our analysis suggests that off-label underdosing of NOACs does not reduce bleeding outcomes. Patients prescribed off-label NOAC doses are at an increased risk of all-cause mortality. These data underscore the importance of prescriber adherence to NOAC dosing guidelines to achieve optimal clinical outcomes for patients with AF.
PROSPERO REGISTRATION NUMBER
CRD42020219844.
Topics: Adult; Humans; Anticoagulants; Atrial Fibrillation; Stroke; Administration, Oral; Brain Ischemia; Ischemic Attack, Transient; Hemorrhage; Embolism
PubMed: 36316100
DOI: 10.1136/heartjnl-2022-321114 -
Frontiers in Public Health 2022Vitamin K (VK) as a nutrient, is a cofactor in the carboxylation of osteocalcin (OC), which can bind with hydroxyapatite to promote bone mineralization and increase bone... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Vitamin K (VK) as a nutrient, is a cofactor in the carboxylation of osteocalcin (OC), which can bind with hydroxyapatite to promote bone mineralization and increase bone strength. However, some studies have been inconsistent on whether vitamin K2 (VK2) can maintain or improve bone mineral density (BMD) and reduce the incidence of fractures in postmenopausal women. Therefore, the main objective of this meta-analysis was to determine the effect of VK2 as a nutritional supplement on BMD and fracture incidence in postmenopausal women.
METHODS
We searched PubMed, EMBASE, and Cochrane Library databases (published before March 17, 2022) and then extracted and pooled data from all randomized controlled trials (RCTs) that met the inclusion criteria.
RESULTS
Sixteen RCTs with a total of 6,425 subjects were included in this meta-analysis. The overall effect test of 10 studies showed a significant improvement in lumbar spine BMD (BMD LS) ( = 0.006) with VK2. The subgroup analysis of VK2 combination therapy showed that BMD LS was significantly maintained and improved with the administration of VK2 ( = 0.03). The overall effect test of the six RCTs showed no significant difference in fracture incidence between the two groups (RR=0.96, P=0.65). However, after excluding one heterogeneous study, the overall effect test showed a significant reduction in fracture incidence with VK2 (RR = 0.43, = 0.01). In addition, this meta-analysis showed that VK2 reduced serum undercarboxylated osteocalcin (uc-OC) levels and the ratio of uc-OC to cOC in both subgroups of VK2 combined intervention and alone. However, for carboxylated osteocalcin (cOC), both subgroup analysis and overall effect test showed no significant effect of VK2 on it. And the pooled analysis of adverse reactions showed no significant difference between the VK2 and control groups (RR = 1.03, 95%CI 0.87 to 1.21, = 0.76).
CONCLUSIONS
The results of this meta-analysis seem to indicate that VK2 supplementation has a positive effect on the maintenance and improvement of BMD LS in postmenopausal women, and it can also reduce the fracture incidence, serum uc-OC levels and the ratio of uc-OC to cOC. In conclusion, VK2 can indirectly promote bone mineralization and increase bone strength.
Topics: Bone Density Conservation Agents; Female; Humans; Osteocalcin; Osteoporosis, Postmenopausal; Randomized Controlled Trials as Topic; Vitamin K 2
PubMed: 36033779
DOI: 10.3389/fpubh.2022.979649 -
Food & Function Oct 2023: Previous studies have shown the potential role of vitamin K supplementation in the prevention and treatment of many diseases. However, the effect of vitamin K... (Meta-Analysis)
Meta-Analysis
: Previous studies have shown the potential role of vitamin K supplementation in the prevention and treatment of many diseases. However, the effect of vitamin K supplementation on blood glucose remains controversial. The purpose of this study was to assess the effects of vitamin K supplementation on glycemia-related indicators, including Fasting Blood Sugar (FBS), Fasting Insulin (FINS) and Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). The potential association between vitamin K and type 2 diabetes mellitus (T2DM) risk was also evaluated. : Up to April 2023, Cochrane, PubMed, Web of Science, Medline and EMBASE databases were searched to assess the effects of vitamin K on blood glucose and the risk of developing T2DM. : A -analysis of seven studies (813 participants) found vitamin K supplementation significantly reduced FBS (SMD = -0.150 mg dl, 95% CI = -0.290, -0.010 mg dl) and HOMA-IR (SMD = -0.200, 95% CI = -0.330, -0.060), but not FINS. Five studies with a total of 105 798 participants were included in the -analysis of the association between vitamin K and T2DM. The results showed that vitamin K was associated with the reduced risk of developing T2DM (HR = 0.79, 95% CI [0.71-0.88], < 0.001). : The -analysis demonstrated that vitamin K supplementation had a significant effect on the regulation of FBS and HOMA-IR in the population. Moreover, vitamin K was associated with the reduced risk of developing T2DM. Considering some limitations found in this study, additional data from large clinical trials are needed.
Topics: Humans; Blood Glucose; Diabetes Mellitus, Type 2; Dietary Supplements; Insulin; Insulin Resistance; Vitamin K
PubMed: 37724446
DOI: 10.1039/d3fo02943c