Vitamin K-Dependent Matrix Gla Protein as Multifaceted Protector of Vascular and Tissue Integrity

Speeding Up Time: New Urinary Peptide Clock Associates Greater Air Pollution Exposures with Faster Biological Aging

A study in Belgium supports earlier findings on associations between higher air pollution exposures and markers of faster biological aging, this time by using urinary peptide levels instead of DNA-based markers.

Role of vitamin K2 in bone-vascular crosstalk

Vitamin K (VK) is a fat-soluble vitamin that is indispensable for the activation of vitamin K-dependent proteins (VKDPs). It has been shown to play an important role in the proper calcium deposit at the bone level, hindering that on the vascular walls. The deficiency of this vitamin in European populations is frequent and unknown. It is related to several factors, poor dietary intake, altered intestinal absorption or altered production by bacteria, indicating possible dysbiosis. For Vitamin K2 (VK2), there is currently no official reference daily intake (RDI). However, the effects of VK2 on the improvement of health in cardiovascular diseases, on bone metabolism, on chronic kidney diseases have been the subject of research in recent decades. The microbiota in the gastrointestinal tract plays an important role: Bacteroides are primarily capable of synthetizing very long chain forms of menaquinones and, in addition to the bacteria present in the intestinal flora, VK2 is also produced by bacteria used in food fermentation processes. This review provides an update on the current literature regarding the origin of VK2 and its implications in what is called the "calcium paradox", namely the lack of calcium in the bone and its storage in the wall of the vessel.

Inter-patient heterogeneity in the hepatic ischemia-reperfusion injury transcriptome: Implications for research and diagnostics

Cellular responses induced by surgical procedure or ischemia-reperfusion injury (IRI) may severely alter transcriptome profiles and complicate molecular diagnostics. To investigate this effect, we characterized such pre-analytical effects in 143 non-malignant liver samples obtained from 30 patients at different time points of ischemia during surgery from two individual cohorts treated either with the Pringle manoeuvre or total vascular exclusion. Transcriptomics profiles were analyzed by Affymetrix microarrays and expression of selected mRNAs was validated by RT-PCR. We found 179 mutually deregulated genes which point to elevated cytokine signaling with NFκB as a dominant pathway in ischemia responses. In contrast to ischemia, reperfusion induced pro-apoptotic and pro-inflammatory cascades involving TNF, NFκB and MAPK pathways. FOS and JUN were down-regulated in steatosis compared to their up-regulation in normal livers. Surprisingly, molecular signatures of underlying primary and secondary cancers were present in non-tumor tissue. The reported inter-patient variability might reflect differences in individual stress responses and impact of underlying disease conditions. Furthermore, we provide a set of 230 pre-analytically highly robust genes identified from histologically normal livers (<2% covariation across both cohorts) that might serve as reference genes and could be particularly suited for future diagnostic applications.

Fat-soluble vitamin deficiency and exocrine pancreatic insufficiency among adults with chronic pancreatitis: Is routine monitoring necessary for all patients?

Chronic pancreatitis (CP) is often associated with exocrine pancreatic insufficiency (EPI), which may increase risk for fat-soluble vitamin depletion. Although vitamin D deficiency is widespread among the general population, vitamins A, E, and K deficiencies may more uniquely present in patients with CP. Yet, it is unclear whether fat-soluble vitamin status should be routinely monitored in all patients with CP or limited to those with EPI. The purpose of this review is to describe the laboratory status of vitamins A, E, and K in adult patients with CP and their association with exocrine pancreatic function. Five primary, observational studies met the inclusion criteria for qualitative synthesis. Biochemical deficiencies in fat-soluble vitamins were observed across trials but results varied with respect to whether EPI increased risk. Challenges related to the diagnosis and treatment of EPI along with potential confounders may contribute to the heterogeneity among study results. Although more studies are needed to determine the influence of pancreatic enzyme replacement therapy on fat-soluble vitamin status as well as effective vitamin repletion strategies, clinicians should consider periodically screening for deficiencies in all patients with CP regardless of EPI to avoid associated health effects of vitamin depletion.

Association of Air Pollution with a Urinary Biomarker of Biological Aging and Effect Modification by Vitamin K in the FLEMENGHO Prospective Population Study

BACKGROUND

A recently developed urinary peptidomics biological aging clock can be used to study accelerated human aging. From 1990 to 2019, exposure to airborne particulate matter (PM) became the leading environmental risk factor worldwide.

OBJECTIVES

This study investigated whether air pollution exposure is associated with accelerated urinary peptidomic aging, independent of calendar age, and whether this association is modified by other risk factors.

METHODS

In a Flemish population, the urinary peptidomic profile (UPP) age (UPP-age) was derived from the urinary peptidomic profile measured by capillary electrophoresis coupled with mass spectrometry. UPP-age-R was calculated as the residual of the regression of UPP-age on chronological age, which reflects accelerated aging predicted by UPP-age, independent of chronological age. A high-resolution spatial-temporal interpolation method was used to assess each individual's exposure to PM 10 , PM 2.5 , black carbon (BC), and nitrogen dioxide (NO 2 ). Associations of UPP-age-R with these pollutants were investigated by mixed models, accounting for clustering by residential address and confounders. Effect modifiers of the associations between UPP-age-R and air pollutants that included 18 factors reflecting vascular function, renal function, insulin resistance, lipid metabolism, or inflammation were evaluated. Direct and indirect (via UPP-age-R) effects of air pollution on mortality were evaluated by multivariable-adjusted Cox models.

RESULTS

Among 660 participants (50.2% women; mean age: 50.7 y), higher exposure to PM 10 , PM 2.5 , BC, and NO 2 was associated with a higher UPP-age-R. Studying effect modifiers showed that higher plasma levels of desphospho-uncarboxylated matrix Gla protein (dpucMGP), signifying poorer vitamin K status, steepened the slopes of UPP-age-R on the air pollutants. In further analyses among participants with dpucMGP ≥ 4.26 μ g / L (median), an interquartile range (IQR) higher level in PM 10 , PM 2.5 , BC, and NO 2 was associated with a higher UPP-age-R of 2.03 [95% confidence interval (CI): 0.60, 3.46], 2.22 (95% CI: 0.71, 3.74), 2.00 (95% CI: 0.56, 3.43), and 2.09 (95% CI: 0.77, 3.41) y, respectively. UPP-age-R was an indirect mediator of the associations of mortality with the air pollutants [multivariable-adjusted hazard ratios from 1.094 (95% CI: 1.000, 1.196) to 1.110 (95% CI: 1.007, 1.224)] in participants with a high dpucMGP, whereas no direct associations were observed.

DISCUSSION

Ambient air pollution was associated with accelerated urinary peptidomics aging, and high vitamin K status showed a potential protective effect in this population. Current guidelines are insufficient to decrease the adverse health effects of airborne pollutants, including healthy aging trajectories. https://doi.org/10.1289/EHP13414.

How Do Minerals, Vitamins, and Intestinal Microbiota Affect the Development and Progression of Heart Disease in Adult and Pediatric Patients?

Cardiovascular diseases (CVDs) are the leading cause of death worldwide, far ahead of cancer. Epidemiological data emphasize the participation of many risk factors that increase the incidence of CVDs, including genetic factors, age, and sex, but also lifestyle, mainly nutritional irregularities and, connected with them, overweight and obesity, as well as metabolic diseases. Despite the importance of cardiovascular problems in the whole society, the principles of prevention of CVDs are not widely disseminated, especially among the youngest. As a result, nutritional neglect, growing from childhood and adolescence, translates into the occurrence of numerous disease entities, including CVDs, in adult life. This review aimed to draw attention to the role of selected minerals and vitamins in health and the development and progression of CVDs in adults and children. Particular attention was paid to the effects of deficiency and toxicity of the analyzed compounds in the context of the cardiovascular system and to the role of intestinal microorganisms, which by interacting with nutrients, may contribute to the development of cardiovascular disorders. We hope this article will draw the attention of society and the medical community to emphasize promoting healthy eating and proper eating habits in children and adults, translating into increased awareness and a reduced risk of CVD.

The impact of anticoagulation therapy on kidney function in patients with atrial fibrillation and chronic kidney disease

INTRODUCTION

Atrial fibrillation (AF) and chronic kidney disease (CKD) are closely related. These diseases share common risk factors and are associated with increased risk of thromboembolic events. Choosing the appropriate oral anticoagulant therapy (OAC) in patients with AF and CKD is challenging. Deterioration of renal function is common in patients with AF treated with OACs, although not all OACs affect the kidneys equally.

AREAS COVERED

In this review, we aim to summarize the current knowledge of the prevention of thromboembolic events in patients with AF and CKD, focusing on the impact of specific OAC agents on renal function.

EXPERT OPINION

Consideration of OAC use is mandatory in patients with AF and CKD who are at increased risk of stroke or systemic embolism. Available evidence suggests that the use of non-vitamin K antagonist oral anticoagulants (NOACs) is associated with slower deterioration of renal function in comparison to Vitamin K antagonists (VKAs). Hence, a NOAC should be used in preference to VKAs in all NOAC-eligible patients with AF and CKD. Regarding patients with end-stage renal dysfunction and those on dialysis or renal replacement therapy, the use of NOAC should be considered in line with locally relevant formal recommendations.

Vitamin K and the Visual System-A Narrative Review

Vitamin K occupies a unique and often obscured place among its fellow fat-soluble vitamins. Evidence is mounting, however, that vitamin K (VK) may play an important role in the visual system apart from the hepatic carboxylation of hemostatic-related proteins. However, to our knowledge, no review covering the topic has appeared in the medical literature. Recent studies have confirmed that matrix Gla protein (MGP), a vitamin K-dependent protein (VKDP), is essential for the regulation of intraocular pressure in mice. The PREDIMED (Prevención con Dieta Mediterránea) study, a randomized trial involving 5860 adults at risk for cardiovascular disease, demonstrated a 29% reduction in the risk of cataract surgery in participants with the highest tertile of dietary vitamin K1 (PK) intake compared with those with the lowest tertile. However, the specific requirements of the eye and visual system (EVS) for VK, and what might constitute an optimized VK status, is currently unknown and largely unexplored. It is, therefore, the intention of this narrative review to provide an introduction concerning VK and the visual system, review ocular VK biology, and provide some historical context for recent discoveries. Potential opportunities and gaps in current research efforts will be touched upon in the hope of raising awareness and encouraging continued VK-related investigations in this important and highly specialized sensory system.

Establishment and Verification of a Predictive Nomogram for New Vertebral Compression Fracture Occurring after Bone Cement Injection in Middle-Aged and Elderly Patients with Vertebral Compression Fracture

OBJECTIVE

New vertebral compression fracture (NVCF) occurring after bone cement injection in middle-aged and elderly patients with vertebral compression fracture is very common. Preoperative baseline characteristics and surgical treatment parameters have been widely studied as a risk factor, but the importance of the patients' laboratory indicators has not been thoroughly explored. We aimed to explore the relationship between laboratory indicators and NVCF, and attempt to construct a clinical prediction model of NVCF together with other risk factors.

METHODS

Retrospective analysis was performed for 200 patients who underwent bone cement injection (percutaneous kyphoplasty or vertebroplasty) for vertebral compression fractures between January 2019 and January 2020. We consulted the relevant literature and collated the factors affecting the occurrence of NVCF. Feature selection of patients with NVCF was optimized using the least absolute shrinkage and selection operator regression model, which was used to conduct multivariable logistic regression analysis, to create a predictive model incorporating the selected features. The discrimination, calibration, and clinical feasibility of the predictive model were assessed using the concordance index (C-index), calibration plots, and decision curve analysis. Internal validation was performed using Bootstrap resampling verification.

RESULTS

Time from injury to surgery exceeding 7 days, low osteocalcin levels, elevated homocysteine levels, osteoporosis, mode of operation (percutaneous vertebroplasty), lack of postoperative anti-osteoporosis treatment, and poor diffusion of bone cement were independent risk factors for NVCF in middle-aged and elderly patients with vertebral compression fracture after bone cement injection. The C-index of the nomogram constructed using these seven factors was 0.895, indicating good discriminatory ability. The calibration plot showed that the model was well calibrated. Bootstrap resampling verification yielded a significant C-index of 0.866. Decision curve analysis demonstrated that the greatest clinical net benefit for predicting NVCF after bone cement injection could be achieved with a threshold of 1%-91%.

CONCLUSION

This nomogram can effectively predict NVCF incidence after bone cement injection in middle-aged and elderly patients with vertebral compression fracture, thus aiding clinical decision-making and postoperative management, promoting effective postoperative rehabilitation, and improving the quality of life.

Alkaline Phosphatase: An Old Friend as Treatment Target for Cardiovascular and Mineral Bone Disorders in Chronic Kidney Disease

Alkaline phosphatase (ALP) is an evolutionary conserved enzyme and widely used biomarker in clinical practice. Tissue-nonspecific alkaline phosphatase (TNALP) is one of four human isozymes that are expressed as distinct TNALP isoforms after posttranslational modifications, mainly in bone, liver, and kidney tissues. Beyond the well-known effects on bone mineralization, the bone ALP (BALP) isoforms (B/I, B1, B1x, and B2) are also involved in the pathogenesis of ectopic calcification. This narrative review summarizes the recent clinical investigations and mechanisms that link ALP and BALP to inflammation, metabolic syndrome, vascular calcification, endothelial dysfunction, fibrosis, cardiovascular disease, and mortality. The association between ALP, vitamin K, bone metabolism, and fracture risk in patients with chronic kidney disease (CKD) is also discussed. Recent advances in different pharmacological strategies are highlighted, with the potential to modulate the expression of ALP directly and indirectly in CKD–mineral and bone disorder (CKD-MBD), e.g., epigenetic modulation, phosphate binders, calcimimetics, vitamin D, and other anti-fracture treatments. We conclude that the significant evidence for ALP as a pathogenic factor and risk marker in CKD-MBD supports the inclusion of concrete treatment targets for ALP in clinical guidelines. While a target value below 120 U/L is associated with improved survival, further experimental and clinical research should explore interventional strategies with optimal risk–benefit profiles. The future holds great promise for novel drug therapies modulating ALP.

Urinary Proteomic Profile of Arterial Stiffness Is Associated With Mortality and Cardiovascular Outcomes

Background

The underlying mechanisms of arterial stiffness remain not fully understood. This study aimed to identify a urinary proteomic profile to illuminate its pathogenesis and to determine the prognostic value of the profile for adverse outcomes.

Methods and Results

We measured aortic stiffness using pulse wave velocity (PWV) and analyzed urinary proteome using capillary electrophoresis coupled with mass spectrometry in 669 randomly recruited Flemish patients (mean age, 50.2 years; 51.1% women). We developed a PWV‐derived urinary proteomic score (PWV‐UP) by modeling PWV with proteomics data at baseline through orthogonal projections to latent structures. PWV‐UP that consisted of 2336 peptides explained the 65% variance of PWV, higher than 36% explained by clinical risk factors. PWV‐UP was significantly associated with PWV (adjusted β=0.73 [95% CI, 0.67–0.79]; P<0.0001). Over 9.2 years (median), 36 participants died, and 75 experienced cardiovascular events. The adjusted hazard ratios (+1 SD) were 1.46 (95% CI, 1.08–1.97) for all‐cause mortality, 2.04 (95% CI, 1.07–3.87) for cardiovascular mortality, and 1.39 (95% CI, 1.11–1.74) for cardiovascular events (P≤0.031). For PWV, the corresponding estimates were 1.25 (95% CI, 0.97–1.60), 1.35 (95% CI, 0.85–2.15), and 1.22 (95% CI, 1.02–1.47), respectively (P≥0.033). Pathway analysis revealed that the peptides in PWV‐UP mostly involved multiple pathways, including collagen turnover, cell adhesion, inflammation, and lipid metabolism.

Conclusions

PWV‐UP was highly associated with PWV and could be used as a biomarker of arterial stiffness. PWV‐UP, but not PWV, was associated with all‐cause mortality and cardiovascular mortality, implying that PWV‐UP–associated peptides may be multifaceted and involved in diverse pathological processes beyond arterial stiffness.

Inflammation-mediated vitamin K and vitamin D effects on vascular calcifications in people with HIV on active antiretroviral therapy

BACKGROUND

People with HIV (PWH) experience increased systemic inflammation and monocyte activation, leading to increased risk of cardiovascular events (death, stroke, and myocardial infarction) and higher coronary artery calcium scores (CACs). Vitamins D and K2 have significant anti-inflammatory effects; in addition, vitamin K2 is involved in preventing vascular calcifications in the general population. The roles of vitamins D and K in increased coronary calcifications in successfully treated PWH is less understood.

METHODS

We prospectively recruited 237 PWH on antiretroviral treatment (ART) and 67 healthy controls. CACs were derived from noncontrast chest computed tomography (CT) and levels of 25-hydroxyvitamin D (vitamin D) and inactive vitamin K-dependent dephosphorylated-uncarboxylated matrix Gla protein (dp-uc MGP, marker of vitamin K deficiency) were measured in plasma during a fasting state. The relationship between inflammation markers, dp-uc MGP, and vitamin D on CACs were estimated using zero-inflated negative binomial regression. Adjusted models included 25(OH)D, MGP, sex, race, age, and markers of inflammation or monocyte activation.

RESULTS

Overall, controls had lower median age (45.8 vs. 48.8; P = 0.03), a larger proportion of female individuals (55.2 vs. 23.6%; P < 0.0001), and nonwhite (33.8 vs. 70%; P < 0.0001). Among PWH, less than 1% had detectable viral load and the median CD4+ cell count was 682 (IQR: 473.00-899.00). 62.17% of the participants had zero CACs and 51.32% were vitamin D-deficient (<20 ng/ml). There was no difference in detectable CACs (P = 0.19) or dp-uc MGP (P = 0.42) between PWH and controls. In adjusted models, PWH with nonzero CACs have three times greater expected CAC burden compared with controls. Every 1% increase in MGP (worse K status) decreases the probability of having CACs equal to zero by 21.33% (P = 0.01). Evidence suggests that the effects of 25(OH)D and MGP are inflammation-mediated, specifically through sVCAM, TNF-αRI, and TNF-αRII.

CONCLUSION

Vitamin K deficiency is a modifiable preventive factor against coronary calcification in PWH. Further research should determine whether vitamin K supplementation would reduce systemic inflammation, vascular calcification, and risk of cardiovascular events in PWH.

Urinary peptidomic profiles to address age-related disabilities: a prospective population study

BACKGROUND

The Global Burden of Diseases, Injuries, and Risk Factors Study 2019 called for innovation in addressing age-related disabilities. Our study aimed to identify and validate a urinary peptidomic profile (UPP) differentiating healthy from unhealthy ageing in the general population, to test the UPP predictor in independent patient cohorts, and to search for targetable molecular pathways underlying age-related chronic diseases.

METHODS

In this prospective population study, we used data from participants in the Flemish Study on Environment, Genes and Health Outcomes (FLEMENGHO), done in northern Belgium from 1985 to 2019, and invited participants to a follow-up examination in 2005-10. Participants were eligible if their address was within 15 km of the examination centre and if they had not withdrawn consent in any of the previous examination cycles (1985-2004). All participants (2005-10) were also invited to an additional follow-up examination in 2009-13. Participants who took part in both the 2005-10 follow-up examination and in the additional 2009-13 follow-up visit constituted the derivation dataset, which included their 2005-10 data, and the time-shifted internal validation dataset, which included their 2009-13 data. The remaining participants who only had 2005-10 data constituted the synchronous internal validation dataset. Participants were excluded from analyses if they were incapacitated, had not undergone UPP, or had either missing or outlying (three SDs greater than the mean of all consenting participants) values of body-mass index, plasma glucose, or serum creatinine. The UPP was assessed by capillary electrophoresis coupled with mass spectrometry. The multidimensional UPP signature reflecting ageing was generated from the derivation dataset and validated in the time-shifted internal validation dataset and the synchronous validation dataset. It was further validated in patients with diabetes, COVID-19, or chronic kidney disease (CKD). In FLEMENGHO, the mortality endpoints were all-cause, cardiovascular, and non-cardiovascular mortality; other endpoints were fatal or non-fatal cancer and musculoskeletal disorders. Molecular pathway exploration was done using the Reactome and Kyoto Encyclopedia of Genes and Genomes databases.

FINDINGS

778 individuals (395 [51%] women and 383 [49%] men; aged 16·2-82·1 years; mean age 50·9 years [SD 15·8]) from the FLEMENGHO cohort had a follow-up examination between 2005 and 2010, of whom 559 participants had a further follow-up from Oct 28, 2009, to March 19, 2013, and made up the derivation (2005-10) and time-shifted internal validation (2009-13) datasets. 219 were examined once and constituted the synchronous internal validation dataset (2005-10). With correction for multiple testing and multivariable adjustment, chronological age was associated with 210 sequenced peptides mainly showing downregulation of collagen fragments. The trained model relating chronological age to UPP, derived by elastic net regression, included 54 peptides from 17 proteins. The UPP-age prediction model explained 76·3% (r=0·87) of chronological age in the derivation dataset, 54·4% (r=0·74) in the time-shifted validation dataset, and 65·3% (r=0·81) in the synchronous internal validation dataset. Compared with chronological age, the predicted UPP-age was greater in patients with diabetes (chronological age 50·8 years [SE 0·37] vs UPP-age 56·9 years [0·30]), COVID‑19 (53·2 years [1·80] vs 58·5 years [1·67]), or CKD (54·6 years [0·97] vs 62·3 years [0·85]; all p<0·0001). In the FLEMENGHO cohort, independent of chronological age, UPP-age was significantly associated with various risk markers related to cardiovascular, metabolic, and renal disease, inflammation, and medication use. Over a median of 12·4 years (IQR 10·8-13·2), total mortality, cardiovascular mortality, and osteoporosis in the population was associated with UPP-age independent of chronological age, with hazard ratios per 10 year increase in UPP-age of 1·54 (95% CI 1·22-1·95) for total mortality, 1·72 (1·20-2·47) for cardiovascular mortality, and 1·40 (1·06-1·85) for osteoporosis and fractures. The most relevant molecular pathways informed by the proteins involved deregulation of collagen biology and extracellular matrix maintenance.

INTERPRETATION

The UPP signature indicative of ageing reflects fibrosis and extracellular matrix remodelling and was associated with risk factors and adverse health outcomes in the population and with accelerated ageing in patients. Innovation in addressing disability should shift focus from the ontology of diseases to shared disease mechanisms, in particular ageing-related fibrotic degeneration.

FUNDING

European Research Council, Ministry of the Flemish Community, OMRON Healthcare.

Vitamin K-Dependent Proteins in Skeletal Development and Disease

Vitamin K and Vitamin K-dependent proteins (VKDPs) are best known for their pivotal role in blood coagulation. Of the 14 VKPDs identified in humans to date, 6 play also important roles in skeletal biology and disease. Thus, osteocalcin, also termed bone Gla-protein, is the most abundant non-collagenous protein in bone. Matrix Gla protein and Ucma/GRP on the other hand are highly abundant in cartilage. Furthermore, periostin, protein S, and growth arrest specific 6 protein (GAS 6) are expressed in skeletal tissues. The roles for these VKDPs are diverse but include the control of calcification and turnover of bone and cartilage. Vitamin K plays an important role in osteoporosis and serum osteocalcin levels are recognized as a promising marker for osteoporosis. On the other hand, matrix Gla protein and Ucma/GRP are associated with osteoarthritis. This review focuses on the roles of these three VKDPs, osteocalcin, matrix Gla protein and Ucma/GRP, in skeletal development and disease but will also summarize the roles the other skeletal VKDPs (periostin, protein S and GAS6) in skeletal biology.

Association of Dephosphorylated-Uncarboxylated Matrix Gla Protein and Risk of Major Bleeding in Patients Presenting with Acute Myocardial Infarction

The "Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early implementation of the ACC/AHA guidelines" (CRUSADE) score emerged as a predictor of major bleeding in patients presenting with the acute coronary syndrome. On the other hand, previous studies established the association of dephosphorylated-uncarboxylated Matrix Gla protein (dp-ucMGP) and vitamin K, as well as their subsequent impact on coagulation cascade and bleeding tendency. Therefore, in the present study, we explored if dp-ucMGP plasma levels were associated with CRUSADE bleeding score. In this cross-sectional study, physical examination and clinical data, including plasma dp-ucMGP levels, were obtained from 80 consecutive patients with acute myocardial infarction (AMI). A significant positive correlation was found between CRUSADE bleeding score and both dp-ucMGP plasma levels (r = 0.442, p < 0.001) and risk score of in-hospital mortality (r = 0.520, p < 0.001), respectively. In comparing the three risk groups of risk for in-hospital bleeding, the high/very high-risk group had significantly higher dp-ucMGP levels from both very low/low group (1277 vs. 794 pmol/L, p < 0.001) and the moderate group (1277 vs. 941 pmol/L, p = 0.047). Overall, since higher dp-ucMGP levels were associated with elevated CRUSADE score and prolonged hemostasis parameters, this may suggest that there is a biological link between dp-ucMGP plasma levels and the risk of bleeding in patients who present with AMI.

Vitamin K and cardiovascular complications in CKD patients

Vitamin K, well known for its role in coagulation, encompasses two major subgroups: Vitamin K1 is exclusively synthesized by plants, whereas vitamin K2 mostly originates from bacterial synthesis. Vitamin K serves as a cofactor for the enzyme γ-glutamyl carboxylase, which carboxylates and thereby activates various vitamin K dependent proteins. Several vitamin K-dependent proteins are synthesized in bone but the role of vitamin K for bone health in CKD patients, in particular the prevention of osteoporosis is still not firmly established. Here we focus on another prominent action of vitamin K, in particular vitamin K2, namely the activation of matrix Gla protein (MGP), the most potent inhibitor of cardiovascular calcifications. Multiple observational studies link relative vitamin K deficiency or low intake to cardiovascular calcification progress, morbidity and mortality. Patients with advanced chronic kidney disease (CKD) are particularly vitamin K deficient, in part because of dietary restrictions but possibly also due to impaired endogenous recycling of vitamin K. At the same time this population is characterized by markedly accelerated cardiovascular calcifications and mortality. High dose dietary supplementation with vitamin K2, in particular the most potent form menaquinone-7 (MK7), can potently reduce circulating levels of dephosphorylated uncarboxylated, i.e. inactive MGP in patients with end stage kidney disease. However, despite this compelling data basis, several randomized controlled trials with high dose MK7 supplements in patients with advanced CKD have failed to confirm cardiovascular benefits. Here we discuss potential reasons and solutions for this.

Statins, vascular calcification, and vitamin K-dependent proteins: Is there a relation?

The present cross-sectional clinical study aimed to examine the connection between statin exposure, coronary artery calcification (CAC), and vitamin K-dependent proteins (VKDPs) in patients with cardiovascular (CV) conditions. Two groups of patients were studied: patients with established CV disease (CVD) and healthy patients at moderate risk for CVD (a control group). The groups were also split into statin users and non-users. The following VKDPs were measured in plasma: uncarboxylated Matrix Gla-protein (ucMGP), undercarboxylated (ucOC), and carboxylated osteocalcin (cOC), Gla-rich protein (GRP). CAC score (CACS) was determined by multislice computed tomography. Among all the participants in the study, CACS was more pronounced in statin users compared to non-users; the same was found also among the CVD patients and among the controls. While the levels of ucMGP and GRP did not differ between statin users and non-users, ucOC and ucOC/cOC were significantly elevated in statin users, indicating vitamin K deficiency. There was a positive correlation between the levels of ucOC and CACS in the entire population and in the group of statin users, but not in statin non-users. No association was found between ucMGP or GRP and CACS. Statins had also an impact on the international normalized ratio and interacted with vitamin K antagonists (VKAs). Our results are in agreement with the existing evidence about positive association between statins and vascular calcification. They enlighten to a certain extent the possible mechanisms through which statins may enhance calcium accumulation in arterial wall, namely, by inhibition of vitamin K dependent proteins and functions involved in vascular protection.

The Role of Vitamin K in Humans: Implication in Aging and Age-Associated Diseases

As human life expectancy is rising, the incidence of age-associated diseases will also increase. Scientific evidence has revealed that healthy diets, including good fats, vitamins, minerals, or polyphenolics, could have antioxidant and anti-inflammatory activities, with antiaging effects. Recent studies demonstrated that vitamin K is a vital cofactor in activating several proteins, which act against age-related syndromes. Thus, vitamin K can carboxylate osteocalcin (a protein capable of transporting and fixing calcium in bone), activate matrix Gla protein (an inhibitor of vascular calcification and cardiovascular events) and carboxylate Gas6 protein (involved in brain physiology and a cognitive decline and neurodegenerative disease inhibitor). By improving insulin sensitivity, vitamin K lowers diabetes risk. It also exerts antiproliferative, proapoptotic, autophagic effects and has been associated with a reduced risk of cancer. Recent research shows that protein S, another vitamin K-dependent protein, can prevent the cytokine storm observed in COVID-19 cases. The reduced activation of protein S due to the pneumonia-induced vitamin K depletion was correlated with higher thrombogenicity and possibly fatal outcomes in COVID-19 patients. Our review aimed to present the latest scientific evidence about vitamin K and its role in preventing age-associated diseases and/or improving the effectiveness of medical treatments in mature adults ˃50 years old.

Vitamin K in CKD Bone Disorders

Vitamin K is principally known because it is involved in blood coagulation. Furthermore, epidemiological studies showed that its deficit was associated with increased fragility fractures, vascular calcification and mortality. There are two main types of vitamin K vitamers: Phylloquinone (or PK) and Menaquinones (MKn). Vitamin K acts both as coenzyme of y-glutamyl carboxylase (GGCX) transforming undercarboxylated in carboxylated vitamin K-dependent proteins (e.g., Osteocalcin and Matrix Gla Protein) and as a ligand of the nuclear steroid and xenobiotic receptor (SXR) (in murine species Pregnane X Receptor: PXR), expressed in osteoblasts. It has been highlighted that the uremic state is a condition of greater vitamin K deficiency than the general population with resulting higher prevalence of bone fractures, vascular calcifications and mortality. The purpose of this literature review is to evaluate the protective role of Vitamin K in bone health in CKD patients.

Perspective: Evidence before Enthusiasm-A Critical Review of the Potential Cardiovascular Benefits of Vitamin K

A protective role for vitamin K in cardiovascular disease (CVD), a leading cause of morbidity and mortality, has been proposed because vitamin K-dependent proteins, such as matrix Gla (γ-carboxyglutamic acid) protein (MGP), are present in vascular tissue. MGP functions as a vascular calcification inhibitor-but only when it is carboxylated, which requires vitamin K. There is more than one naturally occurring form of vitamin K. Phylloquinone (vitamin K1) is found in plant-based foods, whereas menaquinones (vitamin K2) are a class of vitamin K compounds found in animal-based and fermented foods. Phylloquinone and menaquinones are capable of carboxylating MGP and other vitamin K-dependent proteins. In rodent models, high intakes of either phylloquinone or menaquinone reduced vascular calcification. Evidence of the relative importance of phylloquinone and menaquinone to CVD in humans is limited and controversial. In some observational studies, higher dietary menaquinone intake, but not phylloquinone intake, was associated with less coronary artery calcification (a subclinical manifestation of CVD) and a lower risk for clinical CVD events. These findings have led to claims that menaquinones have unique cardiovascular health benefits compared with phylloquinone. However, this claim is not supported by the results of the limited number of intervention trials conducted to date. The purpose of this review is to evaluate the strengths and limitations of the available evidence regarding the role of vitamin K in vascular calcification, CVD, and mortality.

Oral anticoagulation in chronic kidney disease with atrial fibrillation

Chronic kidney disease (CKD) and atrial fibrillation (AF) frequently coexist, amplifying the risk of cardiovascular events and mortality. In patients with CKD stage 3 and non-valvular AF, direct oral anticoagulants (DOACs) have shown, compared to vitamin K antagonists (VKA), equal or greater efficacy in the prevention of stroke and systemic embolism, and greater safety. There are no randomizedtrials of the efficacy and safety of DOACs and VKA in advanced CKD. On the other hand, observational studies suggest that DOACs, compared to warfarin, are associated with a lower risk of acute kidney damage and generation/progression of CKD. This paper reviews the epidemiological and pathophysiological aspects of the CKD and AF association, the evidence of the efficacy and safety of warfarin and ACODs in various stages of CKD with AF as well as the comparison between warfarin and ACODs in efficacy and anticoagulant safety, and in its renal effects.

The Association of Vitamin D and Vitamin K Status with Subclinical Measures of Cardiovascular Health and All-Cause Mortality in Older Adults: The Hoorn Study

BACKGROUND

A low vitamin D and K status has been associated with increased cardiovascular disease (CVD) risk but the evidence of their combined effect on cardiovascular health is limited.

OBJECTIVES

Our study aimed to investigate the prospective association of vitamin D and K status with subclinical measures of cardiovascular health and all-cause mortality among a population of Dutch Caucasians.

METHODS

We performed an observational prospective study on 601 participants of the Hoorn Study (mean ± SD age: 70 ± 6 y, 50.4% women, BMI: 27.2 ± 4.0 kg/m2), of whom 321 underwent an echocardiogram in 2000-2001 and 2007-2009. Vitamin D and K status was assessed at baseline by serum 25-hydroxyvitamin D [25(OH)D] and plasma desphospho-uncarboxylated matrix-gla protein (dp-ucMGP)-high concentrations indicate low vitamin K status. Vital status was assessed from baseline until 2018. We studied the association of categories of 25(OH)D (stratified by the clinical cutoff of 50 mmol/L) and dp-ucMGP (stratified by the median value of 568 pmol/L) with echocardiographic measures using linear regression and with all-cause mortality using Cox regression, adjusted for confounders.

RESULTS

Compared with markers of normal vitamin D and K status, markers of low vitamin D and K status were prospectively associated with increased left ventricular mass index (5.9 g/m2.7; 95% CI: 1.8, 10.0 g/m2.7). Participants with low vitamin D and K status were also at increased risk of all-cause mortality with an HR of 1.64 (95% CI: 1.12, 2.39) compared with normal vitamin D and K status.

CONCLUSIONS

A combination of low vitamin D and K status is associated with adverse cardiac remodeling and increased risk of all-cause mortality in men and women. Future studies should investigate whether vitamin D and K supplementation could help to improve cardiovascular health and to decrease CVD risk.

Cheung A. Vitamin K and Osteoporosis

Vitamin K acts as a coenzyme of carboxylase, catalyzing the carboxylation of several vitamin K dependent proteins. Beyond its well-known effects on blood coagulation, it also exerts relevant effects on bone and the vascular system. In this review, we point out the relevance of an adequate vitamin K intake to obtain sufficient levels of carboxylated (active form) vitamin K dependent proteins (such as Osteocalcin and matrix Gla protein) to prevent bone health. Another bone-related action of Vitamin K is being a ligand of the nuclear steroid and xenobiotic receptor (SXR). We also discuss the recommended intake, deficiency, and assessment of vitamin K. Furthermore, we review the few available studies that have as pre-specified outcome bone fractures, indicating that we need more clinical studies to confirm that vitamin K is a potential therapeutic agent for bone fractures.

Generation of a Matrix Gla (Mgp) floxed mouse, followed by conditional knockout, uncovers a new Mgp function in the eye

The ability to ablate a gene in a given tissue by generating a conditional knockout (cKO) is crucial for determining its function in the targeted tissue. Such tissue-specific ablation is even more critical when the gene's conventional knockout (KO) is lethal, which precludes studying the consequences of its deletion in other tissues. Therefore, here we describe a successful strategy that generated a Matrix Gla floxed mouse (Mgp.floxed) by the CRISPR/Cas9 system, that subsequently allowed the generation of cKOs by local viral delivery of the Cre-recombinase enzyme. MGP is a well-established inhibitor of calcification gene, highly expressed in arteries' smooth muscle cells and chondrocytes. MGP is also one of the most abundant genes in the trabecular meshwork, the eye tissue responsible for maintenance of intraocular pressure (IOP) and development of Glaucoma. Our strategy entailed one-step injection of two gRNAs, Cas9 protein and a long-single-stranded-circular DNA donor vector (lsscDNA, 6.7 kb) containing two loxP sites in cis and 900-700 bp 5'/3' homology arms. Ocular intracameral injection of Mgp.floxed mice with a Cre-adenovirus, led to an Mgp.TMcKO mouse which developed elevated IOP. Our study discovered a new role for the Mgp gene as a keeper of physiological IOP in the eye.

Vitamin Status and Diet in Elderly with Low and High Socioeconomic Status: The Lifelines-MINUTHE Study

Socioeconomic health inequalities are an important global public health problem. However, it is not well known to what extent socioeconomic inequalities culminate in impaired vitamin status and whether this is mediated by diet. We, therefore, aimed to assess vitamin status in a population already at increased risk of micronutrient deficiency, i.e., elderly with high and low socioeconomic status (SES), and to investigate whether potential differences therein were mediated by diet quality. Vitamin status in 1605 individuals (60–75 years) from the Lifelines- Micronutrients and Health inequalities in Elderly (MINUTHE) Study was assessed by measuring folic acid and the vitamins B6, B12, D, A, E, and K. Multinomial logistic and linear regression analyses were applied to test the associations between SES and vitamin status. Mediation analysis was used to explore the interrelationship between SES, diet quality, and vitamin status. Low SES was associated with poorer status of vitamin B6, vitamin B12, and, notably, folic acid. Moreover, multivitamin deficiencies were more prevalent in the low SES group. Diet quality was found to mediate the associations of SES with folic acid (for 39.1%), vitamin B6 (for 37.1%), and vitamin B12 (for 37.2%). We conclude that low SES is a risk factor for a spectrum of vitamin deficiencies. Diet quality can partially explain the socioeconomic differences in vitamin status, suggesting that policymakers can mitigate socioeconomic inequality in nutritional status through improving diet quality.

MK-7 and Its Effects on Bone Quality and Strength

Vitamin K acts as a cofactor and is required for post-translational γ-carboxylation of vitamin K-dependent proteins (VKDP). The current recommended daily intake (RDI) of vitamin K in most countries has been established based on normal coagulation requirements. Vitamin K1 and menaquinone (MK)-4 has been shown to decrease osteocalcin (OC) γ-carboxylation at RDI levels. Among the several vitamin K homologs, only MK-7 (vitamin K2) can promote γ-carboxylation of extrahepatic VKDPs, OC, and the matrix Gla protein at a nutritional dose around RDI. MK-7 has higher efficacy due to its higher bioavailability and longer half-life than other vitamin K homologs. As vitamin K1, MK-4, and MK-7 have distinct bioactivities, their RDIs should be established based on their relative activities. MK-7 increases bone mineral density and promotes bone quality and strength. Collagen production, and thus, bone quality may be affected by MK-7 or MK-4 converted from MK-7. In this review, we comprehensively discuss the various properties of MK-7.

The Inhibitory Roles of Vitamin K in Progression of Vascular Calcification

Vitamin K is a fat-soluble vitamin that is indispensable for the activation of vitamin K-dependent proteins (VKDPs) and may be implicated in cardiovascular disease (CVD). Vascular calcification is intimately associated with CV events and mortality and is a chronic inflammatory process in which activated macrophages promote osteoblastic differentiation of vascular smooth muscle cells (VSMCs) through the production of proinflammatory cytokines such as IL-1β, IL-6, TNF-α, and oncostatin M (OSM) in both intimal and medial layers of arterial walls. This process may be mainly mediated through NF-κB signaling pathway. Vitamin K has been demonstrated to exert anti-inflammatory effects through antagonizing NF-κB signaling in both in vitro and in vivo studies, suggesting that vitamin K may prevent vascular calcification via anti-inflammatory mechanisms. Matrix Gla protein (MGP) is a major inhibitor of soft tissue calcification and contributes to preventing both intimal and medial vascular calcification. Vitamin K may also inhibit progression of vascular calcification by enhancing the activity of MGP through facilitating its γ-carboxylation. In support of this hypothesis, the procalcific effects of warfarin, an antagonist of vitamin K, on arterial calcification have been demonstrated in several clinical studies. Among the inactive MGP forms, dephospho-uncarboxylated MGP (dp-ucMGP) may be regarded as the most useful biomarker of not only vitamin K deficiency, but also vascular calcification and CVD. There have been several studies showing the association of circulating levels of dp-ucMGP with vitamin K intake, vascular calcification, mortality, and CVD. However, additional larger prospective studies including randomized controlled trials are necessary to confirm the beneficial effects of vitamin K supplementation on CV health.

Renal Resistive Index Is Associated With Inactive Matrix Gla (γ-Carboxyglutamate) Protein in an Adult Population-Based Study

Background Increased renal resistive index (RRI) has been associated with target organ damage as well as renal and cardiovascular outcomes. Matrix Gla (γ-carboxyglutamate) protein (MGP) is a strong inhibitor of soft tissue calcification. Its inactive form (dephospho-uncarboxylated MGP [dp-ucMGP]) has been associated with vascular stiffness, cardiovascular outcomes, and mortality. In this study, we hypothesized that high levels of dp-ucMGP were associated with increased RRI. Methods and Results We recruited participants via a multicenter family-based cross-sectional study in Switzerland. Levels of dp-ucMGP were measured in plasma by sandwich ELISA. RRI was measured by Doppler ultrasound in 3 segmental arteries in both kidneys. We used mixed regression models to assess the relationship between dp-ucMGP and RRI. We adjusted for common determinants of RRI as well as renal function and cardiovascular risk factors. We included 1006 participants in our analyses: 526 women and 480 men. Mean values were 0.44±0.20 nmol/L for dp-ucMGP and 64±5% for RRI. After multivariable adjustment, dp-ucMGP was positively associated with RRI (P=0.001). In subgroup analysis by age tertiles, this association was not significant in the youngest age group (<38 years; P=0.62), whereas it was significant in older age groups (38-55 and >55 years; P=0.016 and P<0.001, respectively). Conclusions Levels of dp-ucMGP are positively and independently associated with RRI after adjustment for common determinants of RRI, cardiovascular risk factors, and renal function. The stronger association among older adults is probably due, in part, to age-related arterial stiffness. RRI thus seems to reflect the global atherosclerotic burden in a general adult population.