Combined analyses and extended follow-up of two randomized controlled homocysteine-lowering B-vitamin trials

Association between dietary macronutrient composition and plasma one-carbon metabolites and B-vitamin cofactors in patients with stable angina pectoris

Elevated plasma concentrations of several one-carbon metabolites are associated with increased CVD risk. Both diet-induced regulation and dietary content of one-carbon metabolites can influence circulating concentrations of these markers. We cross-sectionally analysed 1928 patients with suspected stable angina pectoris (geometric mean age 61), representing elevated CVD risk, to assess associations between dietary macronutrient composition (FFQ) and plasma one-carbon metabolites and related B-vitamin status markers (GC-MS/MS, LC-MS/MS or microbiological assay). Diet-metabolite associations were modelled on the continuous scale, adjusted for age, sex, BMI, smoking, alcohol and total energy intake. Average (geometric mean (95 % prediction interval)) intake was forty-nine (38, 63) energy percent (E%) from carbohydrate, thirty-one (22, 45) E% from fat and seventeen (12, 22) E% from protein. The strongest associations were seen for higher protein intake, i.e. with higher plasma pyridoxal 5'-phosphate (PLP) (% change (95 % CI) 3·1 (2·1, 4·1)), cobalamin (2·9 (2·1, 3·7)), riboflavin (2·4 (1·1, 3·7)) and folate (2·1 (1·2, 3·1)) and lower total homocysteine (tHcy) (-1·4 (-1·9, -0·9)) and methylmalonic acid (MMA) (-1·4 (-2·0, -0·8)). Substitution analyses replacing MUFA or PUFA with SFA demonstrated higher plasma concentrations of riboflavin (5·0 (0·9, 9·3) and 3·3 (1·1, 5·6)), tHcy (2·3 (0·7, 3·8) and 1·3 (0·5, 2·2)) and MMA (2·0 (0·2, 3·9) and 1·7 (0·7, 2·7)) and lower PLP (-2·5 (-5·3, 0·3) and -2·7 (-4·2, -1·2)). In conclusion, a higher protein intake and replacing saturated with MUFA and PUFA were associated with a more favourable metabolic phenotype regarding metabolites associated with CVD risk.

A micronutrient supplement modulates homocysteine levels regardless of vitamin B biostatus in elderly subjects

Elevated homocysteine (Hcy) levels (≥15 μmol/L) in the elderly are frequently associated with a higher risk of cardiovascular disease and cognitive decline. Several studies have already shown an Hcy-lowering effect of B vitamin supplementation in cohorts deficient in these nutrients. The aim of this randomized, double-blinded 12-week intervention study was to investigate whether Hcy levels in healthy elderly subjects (75.4±4.5 years, n=133) could be lowered with a micronutrient supplement (i.e., 400 μg folic acid, 100 μg cobalamin). Difference in mean initial Hcy levels between intervention (17.6±7.1 μmol/L, n=65) and placebo group (18.9±6.1 μmol/L, n=68) was not significant. The prevalence of cobalamin and folate deficiency in the total study population was low: 27% had serum-cobalamin levels ≤150 pmol/L, 12% holo-transcobalamin (Holo-TC) levels ≤50 pmol/L, 13% low cobalamin status using the aggregated cobalamin marker 4cB12 and 10% red blood cell (RBC) folate ≤570 nmol/L. Nevertheless, the treated subjects still showed improved cobalamin and folate biostatus (serum cobalamin Δt12-t0: 63±48 pmol/L; Holo-TC Δt12-t0: 17±19 pmol/L; RBC folate Δt12-t0: 326±253 nmol/L) and Hcy levels (Δt12-t0: -3.6±5.7 μmol/L). The effects were statistically significant compared to the placebo group with p=0.005 (serum cobalamin), p=0.021 (Holo-TC), p=0.014 (RBC-folate) and p<0.001 (Hcy). The Hcy-lowering effect was dependent on the initial Hcy levels (p<0.001). Our findings suggest that elevated Hcy levels in elderly subjects can be lowered regardless of the initial cobalamin and folate biostatus.

Intakes of folate, vitamin B6, and vitamin B12 and cardiovascular disease risk: a national population-based cross-sectional study

Background

Only a few studies that investigated dietary intakes of folate, vitamin B6, and vitamin B12 in relation to cariovascular disease (CVD). This study aimed to assess the association of dietary folate, vitamin B6, and vitamin B12 with CVD in the United States population.

Methods

A cross-sectional analysis of 65,322 adults aged ≥ 20 years who participated in the Third National Health and Nutrition Examination Survey (NHANES III) and NHANES 1999-2018. Before 2003, dietary intake data were assessed using a 24-hour dietary call, and two 24-hour dietary calls were used during 2003 and 2018. Odds ratios and 95% confidence intervals (CIs) for CVD associated with dietary folate, vitamin B6, and vitamin B12 were estimated using multivariate logistic regression models.

Results

Dietary vitamin B6 intake were inversely associated with the odds of CVD. In males, the multivariable OR for the highest vs. lowest quartiles of vitamin B6 was 0.77 (95%CI: 0.61-0.97, Ptrend = 0.013) for the odds of CVD. In females, the adjusted OR for the highest quartile of vitamin B6 compared with the lowest quartile was 0.73 (95%CI: 0.56-0.95, Ptrend = 0.038) for the odds of CVD. No significant association was observed between dietary folate and vitamin B12 intakes and the odds of CVD.

Conclusions

Our findings indicate that higher intake of dietary vitamin B6 may be associated with lower prevalence of CVD, suggesting that dietary vitamin B6 has major public health implications in the prevention of CVD in the United States population.

Levodopa, homocysteine and Parkinson's disease: What's the problem?

Elevated circulating homocysteine levels have been associated with cognitive impairment and cardio-cerebro-vascular events. Levodopa treatment of Parkinson's disease tends to further elevate circulating homocysteine levels due to the metabolism of levodopa via catechol-O-methyltransferase (COMT). COMT co-factors are vitamins B12, B6 and folic acid. Accumulating deficiencies of these vitamins are presumed to be the substrate for the homocysteine elevation. B-vitamin therapy reduces homocysteine levels. This begs the question of whether Parkinson's disease patients on levodopa should be concurrently treated with ongoing B-vitamin therapy (versus long-term monitoring of B-vitamins/homocysteine). There is a substantial literature on this topic that has accumulated over the last quarter-century, and this topic is still debated. This review summarizes the relevant literature with the aim of approximating closure on this issue. Also, noteworthy is that Parkinson's disease patients with renal insufficiency may not tolerate cyanocobalamin, the standard oral B12 supplement due to facilitation of renal decline; alternatives are discussed.

Effect of folic acid, vitamin B12, and B6 supplementation on the risk of cardiovascular and cerebrovascular diseases: An updated meta-analysis of randomized controlled trials

Background

Numerous studies indicated that B vitamin supplementation can reduce cardiovascular risk; nonetheless, available proof reported from individual studies have not been consistent, so we performed an updated meta-analysis of randomized controlled trials (RCTs) to evaluate the relationship between B vitamin supplementation and cardiovascular outcomes.

Materials and method

Relevant studies published before May 2022 were searched from the electronic databases of PubMed, Embase, the Cochrane Library, Chinese Biology Medicine, and the Chinese National Knowledge Infrastructure. Outcomes included major adverse cardiovascular event (MACE), myocardial infarction (MI), stroke, hospitalization for unstable angina, revascularization, total mortality, and cardiovascular death. The strength of the association was examined by risk ratio (RR) with 95% confidence interval (95% CI).

Results

A total of 17 RCTs involving 31,085 subjects were included in the meta-analysis. The combined supplementation of B vitamins had no significant effect on MACE based on eight RCTs (RR = 0.98, 95% CI = 0.92–1.04), MI based on 13 RCTs (RR = 1.00, 95% CI = 0.92–1.09), and revascularization based on 12 RCTs (RR = 1.02, 95% CI = 0.95–1.10). Ten studies showed that the combined supplementation of B vitamins reduced the risk of stroke by 12% (RR = 0.88, 95% CI = 0.81–0.97). Eleven studies showed that the combined supplementation of B vitamins had no significant effect on the total mortality (RR = 0.99, 95% CI = 0.94–1.05), and nine studies showed that the combined B vitamins had no significant effect on cardiovascular death (RR = 0.96, 95% CI = 0.88–1.05). Besides, with the extension of follow-up duration and those with a history of cardio-cerebrovascular diseases, supplementation of B vitamins could reduce the risk of stroke.

Conclusion

The supplementation of folic acid, Vitamin B6, and B12 is associated with a reduction in stroke, but not in total mortality, cardiovascular death, MACE, and MI.

The Controversial Role of HCY and Vitamin B Deficiency in Cardiovascular Diseases

Plasma homocysteine (HCY) is an established risk factor for cardiovascular disease CVD and stroke. However, more than two decades of intensive research activities has failed to demonstrate that Hcy lowering through B-vitamin supplementation results in a reduction in CVD risk. Therefore, doubts about a causal involvement of hyperhomocysteinemia (HHcy) and B-vitamin deficiencies in atherosclerosis persist. Existing evidence indicates that HHcy increases oxidative stress, causes endoplasmatic reticulum (ER) stress, alters DNA methylation and, thus, modulates the expression of numerous pathogenic and protective genes. Moreover, Hcy can bind directly to proteins, which can change protein function and impact the intracellular redox state. As most mechanistic evidence is derived from experimental studies with rather artificial settings, the relevance of these results in humans remains a matter of debate. Recently, it has also been proposed that HHcy and B-vitamin deficiencies may promote CVD through accelerated telomere shortening and telomere dysfunction. This review provides a critical overview of the existing literature regarding the role of HHcy and B-vitamin deficiencies in CVD. At present, the CVD risk associated with HHcy and B vitamins is not effectively actionable. Therefore, routine screening for HHcy in CVD patients is of limited value. However, B-vitamin depletion is rather common among the elderly, and in such cases existing deficiencies should be corrected. While Hcy-lowering with high doses of B vitamins has no beneficial effects in secondary CVD prevention, the role of Hcy in primary disease prevention is insufficiently studied. Therefore, more intervention and experimental studies are needed to address existing gaps in knowledge.

Metabolic Therapy of Heart Failure: Is There a Future for B Vitamins?

Heart failure (HF) is a plague of the aging population in industrialized countries that continues to cause many deaths despite intensive research into more effective treatments. Although the therapeutic arsenal to face heart failure has been expanding, the relatively short life expectancy of HF patients is pushing towards novel therapeutic strategies. Heart failure is associated with drastic metabolic disorders, including severe myocardial mitochondrial dysfunction and systemic nutrient deprivation secondary to severe cardiac dysfunction. To date, no effective therapy has been developed to restore the cardiac energy metabolism of the failing myocardium, mainly due to the metabolic complexity and intertwining of the involved processes. Recent years have witnessed a growing scientific interest in natural molecules that play a pivotal role in energy metabolism with promising therapeutic effects against heart failure. Among these molecules, B vitamins are a class of water soluble vitamins that are directly involved in energy metabolism and are of particular interest since they are intimately linked to energy metabolism and HF patients are often B vitamin deficient. This review aims at assessing the value of B vitamin supplementation in the treatment of heart failure.

Hyperhomocysteinemia and Ischemic Stroke: A Potential Dose-Response Association-A Systematic Review and Meta-analysis

Background and Purpose  Previous studies suggest an association between increased homocysteine (Hcy) and risk of ischemic stroke. Yet, it remains unknown whether a dose-response association exists between Hcy levels and risk of ischemic stroke. Methods  Systematic literature searches were performed in PubMed, Embase, Scopus, and Web of Science. Inclusion criteria were studies investigating ischemic stroke risk in an adult population with measured Hcy levels. We computed odds ratios (ORs) for a 5 µmol/L increase in Hcy levels using a random effects meta-analysis. Results  In total, 108 studies met the inclusion criteria of which 22 were rated as high-quality studies, and 20 studies included a dose-response analysis. Hcy levels were analyzed either as a continuous or categorical variable. The majority of the studies found an increased risk of ischemic stroke when comparing the highest-to-lowest Hcy strata. A graded association was observed over the Hcy strata, indicating a dose-response association, with the most apparent effect when Hcy levels exceeded approximately 15 µmol/L. No studies explored a potential nonlinear association between Hcy levels and ischemic stroke. Six studies were included in a meta-analysis, showing an OR of 1.43 (95% confidence interval [CI]: 1.28-1.61) per 5 µmol/L increase in Hcy levels. Conclusion  This review and meta-analysis indicate a dose-response association between Hcy levels and ischemic stroke. An evident increase in effect measures was observed when Hcy levels exceeded 15 µmol/L, indicating a nonlinear association between ischemic stroke and Hcy levels. This nonlinear association warrants further study. This study is registered with clinical trial ( https://www.crd.york.ac.uk/prospero/ ; unique identifier: CRD42019130371).

Effect of Vitamin B6, B9, and B12 Supplementation on Homocysteine Level and Cardiovascular Outcomes in Stroke Patients: A Meta-Analysis of Randomized Controlled Trials

Globally, stroke is the fifth-most leading cause of mortality and also the third leading cause of disability. This study aimed to assess the effect of vitamin B₆, B₉, and B₁₂ supplementation on homocysteine level, risk of stroke, cardiovascular disorders, and vascular death among stroke participants. An extensive literature search was done through PubMed, Medline, Embase, and Clinical key database from 1 January 2000 to 1 January 2020. Effect of vitamin B (B₆, B₉, and B₁₂) supplementation on homocysteine was assessed with a mean difference in both vitamin and placebo groups. Risk ratio (RR) was calculated for determining the risk of stroke, major cardiovascular disorder, and vascular death by using a fixed-effect model. A total of eight trials with 8513 participants were included for the final analysis. Vitamin B supplementation intervention was found to have a significant benefit in reducing homocysteine in stroke patients (mean difference -3.84; p<0.00001). The intervention of vitamin B supplementation showed a significant risk reduction of 11% for combined risk of stroke, myocardial infarction, and vascular death among stroke patients, 13% for stroke and 17% for vascular death, whereas no beneficial effect was seen for cardiovascular disorders. This meta-analysis demonstrated up-to-date evidence on the beneficial effect of vitamin B supplementations in reducing homocysteine and preventing the combined risk of stroke, myocardial infarction, and vascular death among stroke patients.

Homocysteine is associated with severity of microvasculopathy in sickle cell disease patients

The pathophysiology of sickle cell disease (SCD) includes vasculopathy as well as anaemia. Elevated plasma homocysteine is a risk factor for vascular disease and may be associated with increased risk of vascular complications in SCD patients. In the present study, microvascular characteristics were assessed in the bulbar conjunctiva of 18 paediatric and 18 adult SCD patients, using the non-invasive technique of computer-assisted intravital microscopy. A vasculopathy severity index (SI) was computed to quantify the degree of microvasculopathy in each patient. Plasma homocysteine and several of its determinants [serum folate and vitamin B12, plasma pyridoxal-5'-phosphate (vitamin B6 status) and creatinine (kidney function)] were measured. Age was strongly correlated with microvasculopathy in the SCD patients, with the SI increasing about 0·1 unit per one-year increase in age (P < 0·001). After adjusting for age, gender, B-vitamin status and creatinine, homocysteine concentration was directly correlated with severity index (P < 0·05). Age and homocysteine concentration were independent predictors of microvasculopathy in SCD patients. It remains to be determined whether lowering homocysteine concentrations using appropriate B-vitamin supplements (folate and vitamins B12 and B6) - particularly if started early in life - could ameliorate microvasculopathy and its associated complications in SCD patients.

Neurology of Nutritional Deficiencies

PURPOSE OF REVIEW

The goal of this chapter is to educate clinicians on the neurologic manifestations of certain nutritional deficiencies in order to promptly identify and appropriately treat these patients.

RECENT FINDINGS

Many vitamin and nutritional deficiencies have been described dating back to the early days of neurology and medicine. Some are very rare and thus, there are no randomized controlled studies to assess supplementation or dosage; however, there are reviews of case reports that can assist clinicians in choosing treatments. While endemic vitamin and nutritional deficiencies may be rarely encountered in many countries, vulnerable populations continue to be at risk for developing neurologic complications. These populations include those with diseases causing malabsorption, the elderly, chronic alcohol users, as well as pregnant mothers with hyperemesis gravidarum to name a few. It is important to recognize syndromes associated with these nutritional deficiencies, as prompt identification and treatment may prevent permanent neurologic damage.

Homocysteine Modification in Protein Structure/Function and Human Disease

Epidemiological studies established that elevated homocysteine, an important intermediate in folate, vitamin B₁₂, and one carbon metabolism, is associated with poor health, including heart and brain diseases. Earlier studies show that patients with severe hyperhomocysteinemia, first identified in the 1960s, exhibit neurological and cardiovascular abnormalities and premature death due to vascular complications. Although homocysteine is considered to be a nonprotein amino acid, studies over the past 2 decades have led to discoveries of protein-related homocysteine metabolism and mechanisms by which homocysteine can become a component of proteins. Homocysteine-containing proteins lose their biological function and acquire cytotoxic, proinflammatory, proatherothrombotic, and proneuropathic properties, which can account for the various disease phenotypes associated with hyperhomocysteinemia. This review describes mechanisms by which hyperhomocysteinemia affects cellular proteostasis, provides a comprehensive account of the biological chemistry of homocysteine-containing proteins, and discusses pathophysiological consequences and clinical implications of their formation.

Mecobalamin and early functional outcomes of ischemic stroke patients with H-type hypertension

OBJECTIVE

To analyze the effect of mecobalamin on the early-functional outcomes of patients with ischemic stroke and H-type hypertension.

METHODS

From October of 2014 to October of 2016, 224 cases of ischemic stroke and H-type hypertension were selected. The patients were randomly divided into treatment control groups, with 112 patients in each group. The control group was treated with the conventional therapy. The observation group was treated with 500 µg of mecobalamin three times a day in addition to the conventional therapy. We compared serum homocysteine (Hcy), hs-CRP levels, carotid plaques, and NIHSS scores between the two groups on the 2nd day and at 4 weeks, 8 weeks, 3 months, and 6 months.

RESULTS

After 4 weeks, 8 weeks, 3 months and 6 months, the difference of serum Hcy level between the two groups was statistically significant (t = 4.049, 3.896, 6.052, 6.159, respectively. All P <0.05). After the treatment, at 4 weeks, 8 weeks, 3 months and 6 months, the levels of hs-CRP in the treatment group were significantly lower than those in the control group (t = 37.249, 28.376, 26.454, 20.522, respectively. All P <0.01). After 3 months and 6 months, the carotid artery plaques were significantly reduced in the treatment group compared to those in the control group (t = 2.309 and 2.434. All P <0.05). After 3 months and 6 months, the NIHSS score was significantly higher in the treatment group compared to those in the control group (t = 2.455 and 2.193. All P <0.05).

CONCLUSION

Mecobalamin can reduce the level of plasma homocysteine, then lead to reductions of levels of plasma inflammatory factors and volume of carotid artery plaques, resulting in more significant functional recovery.

Vitamins for Cardiovascular Diseases: Is the Expense Justified?

Despite the knowledge that a well-balanced diet provides most of the nutritional requirements, the use of supplemental vitamins is widespread among adults in the United States. Evidence from large randomized controlled trials over the last 2 decades does not support vitamin supplementation for the reduction of cardiovascular risk factors or clinical outcomes. Many of the vitamins used in common practice likely are safe when consumed in small doses, but long-term consumption of megadoses is not only expensive but has the potential to cause adverse effects. Therefore, a need exists to revisit this issue, reminding the public and healthcare providers about the data supporting the use of vitamins for cardiovascular disease, and the potential for harm and the expense associated with their unnecessary use. In this review, we highlight the scientific evidence from randomized controlled studies regarding the efficacy and safety of vitamin supplementation for primary and secondary prevention of cardiovascular diseases and outcomes. We also draw attention to issues related to widespread and indiscriminate use of vitamin supplements and the need to educate the public to curtail unnecessary consumption and expense by limiting their use based on strong scientific evidence.

B Vitamins and Hip Fracture: Secondary Analyses and Extended Follow-Up of Two Large Randomized Controlled Trials

Elevated plasma homocysteine levels are associated with increased risk of fractures in observational studies. However, it is unsettled whether homocysteine-lowering treatment affects fracture risk. The aim of this study was to investigate the effect of an intervention with B vitamins on the risk of hip fracture in a secondary analysis of combined data from two large randomized controlled trials originally designed to study cardiovascular diseases. Both trials had identical design, intervention, and primary objective. Based on a two-by-two factorial design, the intervention consisted of a daily capsule with either (1) folic acid (0.8 mg) plus vitamin B₁₂ (0.4 mg) and vitamin B₆ (40 mg); (2) folic acid (0.8 mg) plus vitamin B₁₂ (0.4 mg); (3) vitamin B₆ alone (40 mg); or (4) placebo. The participants were followed with respect to hip fracture during the trial or during an extended follow-up (from the trial start for each patient until the end of 2012). No statistically significant association was found between folic acid plus vitamin B₁₂ treatment and the risk of hip fracture, neither during the trial (median 3.3 years; hazard ratio [HR] 0.87; 95% confidence interval [CI], 0.48 to 1.59) nor during the extended follow-up (median 11.1 years; HR 1.08; 95% CI, 0.84 to 1.40). Nor were there significant differences in the risk of hip fracture between groups receiving versus not receiving vitamin B₆ during the trial (HR 1.42; 95% CI, 0.78 to 2.61). However, during the extended follow-up, those receiving vitamin B₆ showed a significant 42% higher risk of hip fracture (HR 1.42; 95% CI, 1.09 to 1.83) compared to those not receiving vitamin B₆ . In conclusion, treatment with folic acid plus vitamin B₁₂ was not associated with the risk of hip fracture. Treatment with a high dose of vitamin B₆ was associated with a slightly increased risk of hip fracture during the extended follow-up (in-trial plus post-trial follow-up). © 2017 American Society for Bone and Mineral Research.

Homocysteine-lowering interventions for preventing cardiovascular events

BACKGROUND

Cardiovascular disease, which includes coronary artery disease, stroke and peripheral vascular disease, is a leading cause of death worldwide. Homocysteine is an amino acid with biological functions in methionine metabolism. A postulated risk factor for cardiovascular disease is an elevated circulating total homocysteine level. The impact of homocysteine-lowering interventions, given to patients in the form of vitamins B6, B9 or B12 supplements, on cardiovascular events has been investigated. This is an update of a review previously published in 2009, 2013, and 2015.

OBJECTIVES

To determine whether homocysteine-lowering interventions, provided to patients with and without pre-existing cardiovascular disease are effective in preventing cardiovascular events, as well as reducing all-cause mortality, and to evaluate their safety.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 5), MEDLINE (1946 to 1 June 2017), Embase (1980 to 2017 week 22) and LILACS (1986 to 1 June 2017). We also searched Web of Science (1970 to 1 June 2017). We handsearched the reference lists of included papers. We also contacted researchers in the field. There was no language restriction in the search.

SELECTION CRITERIA

We included randomised controlled trials assessing the effects of homocysteine-lowering interventions for preventing cardiovascular events with a follow-up period of one year or longer. We considered myocardial infarction and stroke as the primary outcomes. We excluded studies in patients with end-stage renal disease.

DATA COLLECTION AND ANALYSIS

We performed study selection, 'Risk of bias' assessment and data extraction in duplicate. We estimated risk ratios (RR) for dichotomous outcomes. We calculated the number needed to treat for an additional beneficial outcome (NNTB). We measured statistical heterogeneity using the I2 statistic. We used a random-effects model. We conducted trial sequential analyses, Bayes factor, and fragility indices where appropriate.

MAIN RESULTS

In this third update, we identified three new randomised controlled trials, for a total of 15 randomised controlled trials involving 71,422 participants. Nine trials (60%) had low risk of bias, length of follow-up ranged from one to 7.3 years. Compared with placebo, there were no differences in effects of homocysteine-lowering interventions on myocardial infarction (homocysteine-lowering = 7.1% versus placebo = 6.0%; RR 1.02, 95% confidence interval (CI) 0.95 to 1.10, I2 = 0%, 12 trials; N = 46,699; Bayes factor 1.04, high-quality evidence), death from any cause (homocysteine-lowering = 11.7% versus placebo = 12.3%, RR 1.01, 95% CI 0.96 to 1.06, I2 = 0%, 11 trials, N = 44,817; Bayes factor = 1.05, high-quality evidence), or serious adverse events (homocysteine-lowering = 8.3% versus comparator = 8.5%, RR 1.07, 95% CI 1.00 to 1.14, I2 = 0%, eight trials, N = 35,788; high-quality evidence). Compared with placebo, homocysteine-lowering interventions were associated with reduced stroke outcome (homocysteine-lowering = 4.3% versus comparator = 5.1%, RR 0.90, 95% CI 0.82 to 0.99, I2 = 8%, 10 trials, N = 44,224; high-quality evidence). Compared with low doses, there were uncertain effects of high doses of homocysteine-lowering interventions on stroke (high = 10.8% versus low = 11.2%, RR 0.90, 95% CI 0.66 to 1.22, I2 = 72%, two trials, N = 3929; very low-quality evidence).We found no evidence of publication bias.

AUTHORS' CONCLUSIONS

In this third update of the Cochrane review, there were no differences in effects of homocysteine-lowering interventions in the form of supplements of vitamins B6, B9 or B12 given alone or in combination comparing with placebo on myocardial infarction, death from any cause or adverse events. In terms of stroke, this review found a small difference in effect favouring to homocysteine-lowering interventions in the form of supplements of vitamins B6, B9 or B12 given alone or in combination comparing with placebo.There were uncertain effects of enalapril plus folic acid compared with enalapril on stroke; approximately 143 (95% CI 85 to 428) people would need to be treated for 5.4 years to prevent 1 stroke, this evidence emerged from one mega-trial.Trial sequential analyses showed that additional trials are unlikely to increase the certainty about the findings of this issue regarding homocysteine-lowering interventions versus placebo. There is a need for additional trials comparing homocysteine-lowering interventions combined with antihypertensive medication versus antihypertensive medication, and homocysteine-lowering interventions at high doses versus homocysteine-lowering interventions at low doses. Potential trials should be large and co-operative.

Pleiotropic responses to methionine restriction

Methionine restriction (MR) extends lifespan across different species. The main responses of rodent models to MR are well-documented in adipose tissue (AT) and liver, which have reduced mass and improved insulin sensitivity, respectively. Recently, molecular mechanisms that improve healthspan have been identified in both organs during MR. In fat, MR induced a futile lipid cycle concomitant with beige AT accumulation, producing elevated energy expenditure. In liver, MR upregulated fibroblast growth factor 21 and improved glucose metabolism in aged mice and in response to a high-fat diet. Furthermore, MR also reduces mitochondrial oxidative stress in various organs such as liver, heart, kidneys, and brain. Other effects of MR have also been reported in such areas as cardiac function in response to hyperhomocysteinemia (HHcy), identification of molecular mechanisms in bone development, and enhanced epithelial tight junction. In addition, rodent models of cancer responded positively to MR, as has been reported in colon, prostate, and breast cancer studies. The beneficial effects of MR have also been documented in a number of invertebrate model organisms, including yeast, nematodes, and fruit flies. MR not only promotes extended longevity in these organisms, but in the case of yeast has also been shown to improve stress tolerance. In addition, expression analyses of yeast and Drosophila undergoing MR have identified multiple candidate mediators of the beneficial effects of MR in these models. In this review, we emphasize other in vivo effects of MR such as in cardiovascular function, bone development, epithelial tight junction, and cancer. We also discuss the effects of MR in invertebrates.

Treatable high homocysteine alone or in concert with five other thrombophilias in 1014 patients with thrombotic events

In 1014 patients with thrombotic events, we determined how often treatable high serum homocysteine alone, or in concert with five other thrombophilias, was associated with thrombotic events. We studied 1014 outpatients sequentially referred for evaluation of thrombotic events, all having six measures of thrombophilia--three PCR (methylenetetrahydrofolate reductase C677T-A1298C, factor V Leiden G506A, prothrombin G20210A), and three serologic (factors VIII, XI, homocysteine). Of the 1014 patients, 198 (20%) had atherothrombosis, 199 (20%) ocular vascular thrombosis, 211 (21%) osteonecrosis, 180 (18%) pseudotumor cerebri, and 123 (12%) recurrent miscarriage. In 434 of 1014 (43%) patients, all six thrombophilic measures were normal. High homocysteine, present in 126 of 1014 patients (12.4%), was the sole thrombophilia in 50 (5%), accompanied only by methylenetetrahydrofolate reductase homozygosity-compound heterozygosity in 22 (2.2%), and accompanied by other thrombophilias in 54 (5%). Patients were more likely than 110 healthy controls to have high homocysteine (12 vs. 5%; P = 0.02) and high factor VIII (21 vs. 7%; P = 0.0003). On treatment for a median of 18 months with L-methyl folate (5 mg), vitamin B6 (100 mg), and vitamin B12 (2 mg/day), in 74 homocysteinemic patients, median homocysteine fell from 15.6 to 10.0 μmol/l (P < 0.0001), and in 56 (76%), homocysteine fell to normal on treatment. When homocysteinemia was the sole thrombophilia, normalization of homocysteine was accompanied by freedom from new thrombotic events in 38 of 41 patients (93%). In evaluation of 1014 patients with thrombotic events, 126 (12%) had treatable high serum homocysteine, and in 50 (5%), high homocysteine was the sole treatable thrombophilia.

Folic Acid Supplementation and the Risk of Cardiovascular Diseases: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Results from observational and genetic epidemiological studies suggest that lower serum homocysteine levels are associated with lower incidence of cardiovascular disease (CVD). Numerous randomized controlled trials have investigated the efficacy of lowering homocysteine with folic acid supplementation for CVD risk, but conflicting results have been reported.

METHODS AND RESULTS

Three bibliographic databases (Medline, Embase, and the Cochrane Database of Systematic Reviews) were searched from database inception until December 1, 2015. Of the 1933 references reviewed for eligibility, 30 randomized controlled trials involving 82 334 participants were included in the final analysis. The pooled relative risks of folic acid supplementation compared with controls were 0.90 (95% CI 0.84-0.96; P=0.002) for stroke, 1.04 (95% CI 0.99-1.09; P=0.16) for coronary heart disease, and 0.96 (95% CI 0.92-0.99; P=0.02) for overall CVD. The intervention effects for both stroke and combined CVD were more pronounced among participants with lower plasma folate levels at baseline (both P<0.02 for interaction). In stratified analyses, a greater beneficial effect for overall CVD was seen in trials among participants without preexisting CVD (P=0.006 for interaction) or in trials with larger reduction in homocysteine levels (P=0.009 for interaction).

CONCLUSIONS

Our meta-analysis indicated a 10% lower risk of stroke and a 4% lower risk of overall CVD with folic acid supplementation. A greater benefit for CVD was observed among participants with lower plasma folate levels and without preexisting CVD and in studies with larger decreases in homocysteine levels. Folic acid supplementation had no significant effect on risk of coronary heart disease.

Vitamin B-6 catabolism and long-term mortality risk in patients with coronary artery disease

BACKGROUND

Low vitamin B-6 status has been related to increased risk of coronary artery disease (CAD), which is a condition that is associated with inflammation. The most common status marker, plasma pyridoxal 5'-phosphate (PLP), decreases during inflammation; therefore, causal relations are uncertain.

OBJECTIVE

We evaluated the vitamin B-6 biomarkers PLP, pyridoxal, and pyridoxic acid (PA) and the pyridoxic acid:(pyridoxal + PLP) ratio (PAr), a proposed marker of vitamin B-6 catabolism during activated cellular immunity, as predictors of mortality.

DESIGN

Associations with risks of long-term all-cause mortality and cardiovascular mortality were evaluated with the use of Cox regression in patients who were undergoing elective coronary angiography for suspected stable angina pectoris (SAP) (n = 4131) and an independent cohort of patients who were hospitalized for acute myocardial infarction (AMI) (n = 3665).

RESULTS

Plasma PLP (AMI patients only) and PA predicted all-cause mortality in models that were adjusted for established risk predictors, but associations were attenuated or nonsignificant after additional adjustment for inflammatory markers. PAr was correlated with biomarkers of inflammation (Pearson's r ≥ 0.37) and predicted all-cause mortality and cardiovascular mortality after adjustment for established risk predictors. In SAP patients, PAr had greater predictive strength than did current smoking, diabetes, hypertension, apolipoproteins, or C-reactive protein. PAr provided multiadjusted HRs per SD of 1.45 (95% CI: 1.30, 1.63) and 1.31 (95% CI: 1.21, 1.41) in SAP and AMI patients, respectively. In both cohorts, PAr was a particularly strong predictor of all-cause mortality for patients with no previous CAD history (P-interaction ≤ 0.04).

CONCLUSION

PAr may capture unique aspects of inflammatory activation and thus provide new insights into disease mechanisms that may aid in identifying patients at increased risk of future fatal events.

Prognostic Value of Elevated Homocysteine Levels in Korean Patients with Coronary Artery Disease: A Propensity Score Matched Analysis

BACKGROUND AND OBJECTIVES

We sought to determine whether an elevated homocysteine (Hcy) level is associated with a worse prognosis in Korean patients with coronary artery disease (CAD).

SUBJECTS AND METHODS

A total of 5839 patients (60.4% male, mean age 61.3±11.2 years) with CAD were enrolled from 2000 to 2010 at Gangnam Severance Hospital. CAD was diagnosed by invasive coronary angiography. Laboratory values including Hcy level were obtained on the day of coronary angiography and analyses were performed shortly after sampling. Patients were divided into two groups according to their Hcy levels. Baseline risk factors, coronary angiographic findings, length of follow-up, and composite endpoints including cardiac death (CD) and non-fatal myocardial infarction (NFMI) were recorded. 1:1 propensity score matched analysis was also performed.

RESULTS

Over a mean follow-up period of 4.4±2.5 years, there were 132 composite endpoints (75 CD and 57 NFMI) with an event rate of 2.3%. Mean Hcy level was 9.9±4.3 µmol/L (normal Hcy 7.9±1.5 µmol/L and elevated Hcy 13.9±5.1 µmol/L). Kaplan-Meier survival analysis showed an association of elevated Hcy level with worse prognosis (p<0.0001). In addition, a multivariate Cox regression analysis showed an association of elevated Hcy level with worse prognosis for both the entire cohort (hazard ratio [HR] 2.077, 95% confidence interval [CI] 1.467-2.941, p<0.0001) and the propensity score matched cohort (HR 1.982, 95% CI 1.305-3.009, p=0.001).

CONCLUSION

Elevated Hcy level is associated with worse outcomes in Korean patients with CAD.

Homocysteine-lowering therapy and early functional outcomes of ischemic patients with H-type hypertension: a retrospective analysis of CNSR

Recently, elevated levels of homocysteine and early neurological deterioration due to acute ischemic stroke have been reported to be strongly correlated. However, the role of homocysteine-lowering therapy (HLT) in the prognosis of acute ischemic stroke patients has remained unclear. This study evaluated the effects of HLT during hospitalization on the early outcomes of the 792 ischemic stroke patients with H-type hypertension from the China National Stroke Registry. The subjects were divided into HLT and non-HLT groups. Demographic and laboratory information were collected, while the functional outcome at discharge and at 90 days follow-up were assessed by National Institutes of Health Stroke Scale and modified Rankin Scale (mRS) in both groups. We found that in the univariate analysis, the proportions of patients with good functional outcomes (mRS = 0-2) were 31.68 versus 29.36 % (OR 0.90, 95 % CI 0.66-1.22, p = 0.45) at discharge and 27.02 versus 28.30 % (OR 1.06, 95 % CI 0.77-1.45, p = 0.72) at 90 days follow-up for the HLT and non-HLT groups, respectively. After multivariate analysis, there was still no significant difference in the outcomes at discharge (OR 0.85, 95 % CI 0.53-1.36, p = 0.49) or at 90 days follow-up (OR 0.98, 95 % CI 0.60-1.60, p = 0.93) for the two groups. The findings of this study indicated that patients with HLT or not during hospitalization had no significant difference in early prognosis. We concluded that HLT during hospitalization did not improve the early functional outcomes of ischemic stroke patients who also had H-type hypertension.

Periconceptional folic acid fortification for the risk of gestational hypertension and pre-eclampsia: a meta-analysis of prospective studies

Published literatures report controversial results about the association of folic acid-containing multivitamins with gestational hypertension and pre-eclampsia. A comprehensive search was performed to identify related prospective studies to assess the effect of folic acid fortification on gestational hypertension and pre-eclampsia. The Q test and I(2) statistic were used to examine between-study heterogeneity. Fixed or random effects models were selected based on study heterogeneity. A funnel plot and modified Egger linear regression test were used to estimate publication bias. Eleven studies conformed to the criteria. Pooled results indicated that folic acid fortification alone was not associated with the occurrence of gestational hypertension [relative risk (RR) = 1.03, 95% confidence interval (CI): 0.98-1.09, P = 0.267] and pre-eclampsia (RR = 0.99, 95% CI: 0.90-1.08, P = 0.738). However, supplementation of multivitamins containing folic acid could prevent gestational hypertension (RR = 0.57, 95% CI: 0.43-0.76, P < 0.001) and pre-eclampsia (RR = 0.64, 95% CI: 0.48-0.84, P = 0.001). The difference between folic acid fortification alone and multivitamins containing folic acid was significant. This meta-analysis suggests that periconceptional multivitamin supplementation with appropriate dose, not folic acid alone, is an appropriate recommendation for pregnant women. The effect should be further confirmed by conducting large-scale randomised controlled trials.

A review of the effect of diet on cardiovascular calcification

Cardiovascular (CV) calcification is known as sub-clinical atherosclerosis and is recognised as a predictor of CV events and mortality. As yet there is no treatment for CV calcification and conventional CV risk factors are not consistently correlated, leaving clinicians uncertain as to optimum management for these patients. For this reason, a review of studies investigating diet and serum levels of macro- and micronutrients was carried out. Although there were few human studies of macronutrients, nevertheless transfats and simple sugars should be avoided, while long chain ω-3 fats from oily fish may be protective. Among the micronutrients, an intake of 800 μg/day calcium was beneficial in those without renal disease or hyperparathyroidism, while inorganic phosphorus from food preservatives and colas may induce calcification. A high intake of magnesium (≥380 mg/day) and phylloquinone (500 μg/day) proved protective, as did a serum 25(OH)D concentration of ≥75 nmol/L. Although oxidative damage appears to be a cause of CV calcification, the antioxidant vitamins proved to be largely ineffective, while supplementation of α-tocopherol may induce calcification. Nevertheless other antioxidant compounds (epigallocatechin gallate from green tea and resveratrol from red wine) were protective. Finally, a homocysteine concentration >12 µmol/L was predictive of CV calcification, although a plasma folate concentration of >39.4 nmol/L could both lower homocysteine and protect against calcification. In terms of a dietary programme, these recommendations indicate avoiding sugar and the transfats and preservatives found in processed foods and drinks and adopting a diet high in oily fish and vegetables. The micronutrients magnesium and vitamin K may be worthy of further investigation as a treatment option for CV calcification.

Dietary methionine restriction in mice elicits an adaptive cardiovascular response to hyperhomocysteinemia

Dietary methionine restriction (MR) in rodents increased lifespan despite higher heart-to-body weight ratio (w/w) and hyperhomocysteinemia, which are symptoms associated with increased risk for cardiovascular disease. We investigated this paradoxical effect of MR on cardiac function using young, old, and apolipoprotein E-deficient (ApoE-KO) mice. Indeed, MR animals exhibited higher heart-to-body weight ratio (w/w) and hyperhomocysteinemia with a molecular pattern consistent with cardiac stress while maintaining the integrity of cardiac structure. Baseline cardiac function, which was measured by non-invasive electrocardiography (ECG), showed that young MR mice had prolonged QRS intervals compared with control-fed (CF) mice, whereas old and ApoE-KO mice showed similar results for both groups. Following β-adrenergic challenge, responses of MR mice were either similar or attenuated compared with CF mice. Cardiac contractility, which was measured by isolated heart retrograde perfusion, was similar in both groups of old mice. Finally, the MR diet induced secretion of cardioprotective hormones, adiponectin and fibroblast growth factor 21 (FGF21), in MR mice with concomitant alterations in cardiac metabolic molecular signatures. Our findings demonstrate that MR diet does not alter cardiac function in mice despite the presence of hyperhomocysteinemia because of the adaptive responses of increased adiponectin and FGF21 levels.

Homocysteine-lowering interventions for preventing cardiovascular events

BACKGROUND

Cardiovascular disease, which includes coronary artery disease, stroke and congestive heart failure, is a leading cause of death worldwide. Homocysteine is an amino acid with biological functions in methionine metabolism. A postulated risk factor is an elevated circulating total homocysteine level, which is associated with cardiovascular events. The impact of homocysteine-lowering interventions, given to patients in the form of vitamins B6, B9 or B12 supplements, on cardiovascular events. This is an update of a review previously published in 2009 and 2013.

OBJECTIVES

To determine whether homocysteine-lowering interventions, provided in patients with and without pre-existing cardiovascular disease are effective in preventing cardiovascular events, as well as all-cause mortality and evaluate their safety.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2014, Issue 1), MEDLINE (1950 to January week 5 2014), EMBASE (1980 to 2014 week 6) and LILACS (1986 to February 2014). We also searched Web of Science (1970 to 7 February 2014). We handsearched the reference lists of included papers. We also contacted researchers in the field. There was no language restriction in the search.

SELECTION CRITERIA

We included randomised controlled trials assessing the effects of homocysteine-lowering interventions for preventing cardiovascular events with a follow-up period of one year or longer. We considered myocardial infarction and stroke as the primary outcomes. We excluded studies in patients with end-stage renal disease.

DATA COLLECTION AND ANALYSIS

We performed study selection, 'Risk of bias' assessment and data extraction in duplicate. We estimated risk ratios (RR) for dichotomous outcomes. We measured statistical heterogeneity using the I(2) statistic. We used a random-effects model.

MAIN RESULTS

In this second updated Cochrane Review, we identified no new randomised controlled trials. Therefore, this new version includes 12 randomised controlled trials involving 47,429 participants. In general terms, 75% (9/12) trials had a low risk of bias. Homocysteine-lowering interventions compared with placebo did not significantly affect non-fatal or fatal myocardial infarction (1743/23,590 (7.38%) versus 1247/20,190 (6.17%); RR 1.02, 95% confidence interval (CI) 0.95 to 1.10, I(2) = 0%, high quality evidence), stroke (968/22,348 (4.33%) versus 974/18,957 (5.13%); RR 0.91, 95% CI 0.82 to 1.0, I(2) = 11%, high quality evidence) or death from any cause (2784/22,648 (12.29%) versus 2502/19,250 (10.64%); RR 1.01, 95% CI 0.96 to 1.07, I(2) = 6%, high quality evidence). Homocysteine-lowering interventions compared with placebo did not significantly affect serious adverse events (cancer) (1558/18,130 (8.59%) versus 1334/14,739 (9.05%); RR 1.06, 95% CI 0.98 to 1.13; I(2) = 0%, high quality evidence).

AUTHORS' CONCLUSIONS

This second update of this Cochrane Review found no evidence to suggest that homocysteine-lowering interventions in the form of supplements of vitamins B6, B9 or B12 given alone or in combination should be used for preventing cardiovascular events. Furthermore, there is no evidence to suggest that homocysteine-lowering interventions are associated with an increased risk of cancer.

Redox signalling and cardioprotection: translatability and mechanism

The morbidity and mortality from coronary artery disease (CAD) remain significant worldwide. The treatment for acute myocardial infarction has improved over the past decades, including early reperfusion of culprit coronary arteries. Although it is mandatory to reperfuse the ischaemic territory as soon as possible, paradoxically this leads to additional myocardial injury, namely ischaemia/reperfusion (I/R) injury, in which redox stress plays a pivotal role and for which no effective therapy is currently available. In this review, we report evidence that the redox environment plays a pivotal role not only in I/R injury but also in cardioprotection. In fact, cardioprotective strategies, such as pre- and post-conditioning, result in a robust reduction in infarct size in animals and the role of redox signalling is of paramount importance in these conditioning strategies. Nitrosative signalling and cysteine redox modifications, such as S-nitrosation/S-nitrosylation, are also emerging as very important mechanisms in conditioning cardioprotection. The reasons for the switch from protective oxidative/nitrosative signalling to deleterious oxidative/nitrosative/nitrative stress are not fully understood. The complex regulation of this switch is, at least in part, responsible for the diminished or lack of cardioprotection induced by conditioning protocols observed in ageing animals and with co-morbidities as well as in humans. Therefore, it is important to understand at a mechanistic level the reasons for these differences before proposing a safe and useful transition of ischaemic or pharmacological conditioning. Indeed, more mechanistic novel therapeutic strategies are required to protect the heart from I/R injury and to improve clinical outcomes in patients with CAD.

A phthalimide-based fluorescent probe for thiol detection with a large Stokes shift

A phthalimide-based fluorescent probe for thiols with a large Stokes shift (161 nm) was developed via PET and ESIPT mechanisms. This probe displayed good selectivity and high sensitivity toward thiols. Imaging intracellular thiols was successfully achieved in living cells.

Efficacy of Supplementation with B Vitamins for Stroke Prevention: A Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Supplementation with B vitamins for stroke prevention has been evaluated over the years, but which combination of B vitamins is optimal for stroke prevention is unclear. We performed a network meta-analysis to assess the impact of different combinations of B vitamins on risk of stroke.

METHODS

A total of 17 trials (86 393 patients) comparing 7 treatment strategies and placebo were included. A network meta-analysis combined all available direct and indirect treatment comparisons to evaluate the efficacy of B vitamin supplementation for all interventions.

RESULTS

B vitamin supplementation was associated with reduced risk of stroke and cerebral hemorrhage. The risk of stroke was lower with folic acid plus vitamin B6 as compared with folic acid plus vitamin B12 and was lower with folic acid plus vitamin B6 plus vitamin B12 as compared with placebo or folic acid plus vitamin B12. The treatments ranked in order of efficacy for stroke, from higher to lower, were folic acid plus vitamin B6 > folic acid > folic acid plus vitamin B6 plus vitamin B12 > vitamin B6 plus vitamin B12 > niacin > vitamin B6 > placebo > folic acid plus vitamin B12.

CONCLUSIONS

B vitamin supplementation was associated with reduced risk of stroke; different B vitamins and their combined treatments had different efficacy on stroke prevention. Folic acid plus vitamin B6 might be the optimal therapy for stroke prevention. Folic acid and vitamin B6 were both valuable for stroke prevention. The efficacy of vitamin B12 remains to be studied.

Recent advances in thiol and sulfide reactive probes

Because of the biological relevance of thiols and sulfides such as cysteine, homocysteine, glutathione and hydrogen sulfide, their detection has attracted a great deal of research interest. Fluorescent probes are emerging as a new strategy for thiol and hydrogen sulfide analysis due to their high sensitivity, low cost, and ability to detect and image thiols in biological samples. In this short review, we have summarized recent advances in the development of thiol and hydrogen sulfide reactive fluorescent probes. These probes are compared and contrasted with regard to their designing strategies, mechanisms, photophysical properties, and/or reaction kinetics. Biological applications of these probes are also discussed.

The effect of homocysteine-lowering therapy with folic acid on flow-mediated vasodilation in patients with coronary artery disease: a meta-analysis of randomized controlled trials

OBJECTIVE

High level of homocysteine induces injury of endothelial cells and predicts adverse cardiovascular events. The objective was to assess the effect of homocysteine-lowering therapy with folic acid on flow-mediated vasodilation in patients with coronary artery disease.

METHODS AND RESULTS

We conducted a meta-analysis of randomized controlled trials identified from PubMed, Embase, the Cochrane Library. Eight studies were included. Homocysteine-lowering therapy with folic acid in patients with coronary artery disease significantly improve FMD as compared with placebo using random-effect model (SMD = 1.65 with 95% CI 1.12-2.17, p < 0.001). Subgroup analysis of subjects revealed that lipid-lowering therapy, study duration, and Delphi criteria had no effects on FMD.

CONCLUSION

Our meta-analysis demonstrated that folic acid supplementation can significantly improve endothelial dysfunction as assessed by FMD in the brachial artery in patients with coronary heart disease.

Combination of high-sensitivity C-reactive protein and homocysteine predicts the short-term outcomes of Chinese patients with acute ischemic stroke

BACKGROUND

Ischemic stroke is one of the most common causes of death worldwide. Early and accurate prediction of outcome in acute ischemic stroke (AIS) is important and influences risk-optimized therapeutic strategies. We investigated the changes in high-sensitivity C-reactive protein (Hs-CRP) and homocysteine (HCY) levels, two of the risk factors, during the acute period of AIS and evaluated the relationship between these levels and short-term prognosis.

METHODS

We prospectively studied 189 patients with AIS who were admitted within 24 hours after the onset of symptoms. Serum Hs-CRP, HCY levels, and National Institutes of Health Stroke Scale (NIHSS) were measured at the time of admission. Short-term functional outcome was measured by the modified Rankin scale (mRS), 90 days after admission.

RESULTS

The median serum Hs-CRP and HCY levels were significantly higher in AIS patients as compared to normal controls (P < 0.0001, respectively). High-sensitivity C-reactive protein and HCY were independent prognostic markers of functional outcome and death (adjusted for age and the NIHSS) in patients with AIS. In receiver operating characteristic curve analysis, the prognostic accuracy of the combined model (HCY and Hs-CRP) was higher compared to all measured biomarkers individually and the NIHSS score.

CONCLUSION

High-sensitivity C-reactive protein and HCY are independent predictors of short-term outcome and mortality after AIS. The combined model may provide additional general prognostic information.

The association between plasma homocysteine and coronary heart disease is modified by the MTHFR 677C>T polymorphism

OBJECTIVE

An elevated level of total plasma homocysteine (tHcy) has been associated with risk of coronary heart disease (CHD). The level of tHcy is affected by lifestyle, in addition to genetic predisposition. The methylene tetrahydrofolate reductase (MTHFR) 677C>T polymorphism (rs1801133) is among the strongest genetic predictors of tHcy. We examined whether the association between tHcy and CHD is modified by the MTHFR 677C>T polymorphism.

DESIGN AND SETTING

Data from two case-control studies of first-time myocardial infarction (MI), Stockholm Heart Epidemiology Programme (SHEEP), and for MI and unstable angina, INTERGENE, were analysed in parallel.

PATIENTS

THcy was determined in a total of 1150 cases and 1753 controls.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

The outcome comprised first-time MI and unstable angina, subsumed as CHD. Logistic regression was used to investigate the association between tHcy and CHD, and its modification by genotype.

RESULTS

High tHcy was confirmed to be a risk factor for CHD in both studies. In SHEEP, the association between tHcy and MI was observed in MTHFR 677 C-homozygotes (OR=1.4, 95% CI 1.2 to 1.6, for a difference by 1 SD of log tHcy) and in heterozygotes (OR=1.3, 95% CI 1.1 to 1.6) but not in T-homozygotes, independent of smoking, physical activity and obesity. An effect modification of similar magnitude was observed but not statistically significant in the smaller INTERGENE study, and confirmed in a meta-analysis of both studies.

CONCLUSIONS

Two Swedish case-control studies showed that the association between elevated tHcy and CHD was confined to carriers of the MTHFR 677 C-allele, which could have implications for the efficiency of tHcy-lowering treatment.

Methoxistasis: integrating the roles of homocysteine and folic acid in cardiovascular pathobiology

Over the last four decades, abnormalities in the methionine-homocysteine cycle and associated folate metabolism have garnered great interest due to the reported link between hyperhomocysteinemia and human pathology, especially atherothrombotic cardiovascular disease. However, clinical trials of B-vitamin supplementation including high doses of folic acid have not demonstrated any benefit in preventing or treating cardiovascular disease. In addition to the fact that these clinical trials may have been shorter in duration than appropriate for modulating chronic disease states, it is likely that reduction of the blood homocysteine level may be an oversimplified approach to a complex biologic perturbation. The methionine-homocysteine cycle and folate metabolism regulate redox and methylation reactions and are, in turn, regulated by redox and methylation status. Under normal conditions, a normal redox-methylation balance, or “methoxistasis”, exists, coordinated by the methionine-homocysteine cycle. An abnormal homocysteine level seen in pathologic states may reflect a disturbance of methoxistasis. We propose that future research should be targeted at estimating the deviation from methoxistasis and how best to restore it. This approach could lead to significant advances in preventing and treating cardiovascular diseases, including heart failure.

Effect of folic acid supplementation on levels of circulating Monocyte Chemoattractant Protein-1 and the presence of intravascular ultrasound derived virtual histology thin-cap fibroatheromas in patients with stable angina pectoris

BACKGROUND

Virtual Histology Intravascular Ultrasound (VH-IVUS) may be used to detect early signs of unstable coronary artery disease. Monocyte Chemoattractant Protein-1 (MCP-1) is linked with coronary atherosclerosis and plaque instability and could potentially be modified by folic acid treatment.

METHODS

In a randomized, prospective study, 102 patients with stable angina pectoris (SAP) received percutaneous coronary intervention and established medical treatment as well as either homocysteine-lowering folic acid/vitamin B12 (± B6) or placebo (± B6) for 1 year before VH-IVUS was performed. The presence of VH-Thin-Cap Fibroatheroma (VH-TCFA) in non-intervened coronary vessels was registered and serum levels of MCP-1 were measured. The patients were subsequently followed for incident myocardial infarction (MI).

RESULTS

Patients treated with folic acid/vitamin B12 had a geometric mean (SD) MCP-1 level of 79.95 (1.49) versus 86.00 (1.43) pg/mL for patients receiving placebo (p-value 0.34). VH-TCFA lesions were present in 7.8% of patients and did not differ between intervention arms (p-value 0.47). Serum levels of MCP-1 were 1.46 (95% CI 1.12 to 1.92) times higher in patients with VH-TCFA lesions than in those without (p-value 0.005). Afterwards, patients were followed for median 2.1 years and 3.8% experienced a myocardial infarction (MI), which in post-hoc Cox regression analyses was independently predicted by both MCP-1 (P-value 0.006) and VH-TCFA (p-value 0.01).

CONCLUSIONS

In patients with SAP receiving established medical treatment, folic acid supplementation is not associated with either presence of VH-TCFA or levels of MCP-1. MCP-1 is however associated with VH-TCFA, a finding corroborated by increased risk for future MI. ClinicalTrials.gov Identifier: NCT00354081.

The association between progression of atherosclerosis and the methylated amino acids asymmetric dimethylarginine and trimethyllysine

Objective

We previously showed that treatment with folic acid (FA)/B₁₂ was associated with more rapid progression of coronary artery disease (CAD). High doses of FA may induce methylation by increasing the availability of S-adenosyl-methionine (SAM). Asymmetric dimethylarginine (ADMA) and trimethyllysine (TML) are both produced through proteolytic release following post-translational SAM–dependent methylation of precursor amino acid. ADMA has previously been associated with CAD. We investigated if plasma levels of ADMA and TML were associated with progression of CAD as measured by quantitative coronary angiography (QCA).

Methods

183 patients from the Western Norway B Vitamin Intervention Trial (WENBIT) undergoing percutaneous coronary intervention (PCI) were randomized to daily treatment with 0.8 mg FA/0.4 mg B₁₂ with and without 40 mg B₆, B₆ alone or placebo. Coronary angiograms and plasma samples of ADMA and TML were obtained at both baseline and follow-up (median 10.5 months). The primary end-point was progression of CAD as measured by diameter stenosis (DS) evaluated by linear quantile mixed models.

Results

A total of 309 coronary lesions not treated with PCI were identified. At follow-up median (95% CI) DS increased by 18.35 (5.22–31.49) percentage points per µmol/L ADMA increase (p-value 0.006) and 2.47 (0.37–4.58) percentage points per µmol/L TML increase (p-value 0.021) in multivariate modeling. Treatment with FA/B₁₂ (±B₆) was not associated with ADMA or TML levels.

Conclusion

In patients with established CAD, baseline ADMA and TML was associated with angiographic progression of CAD. However, neither ADMA nor TML levels were altered by treatment with FA/B₁₂ (±B₆).

Trial Registration

Controlled-Trials.com NCT00354081

Food synergy: the key to a healthy diet

Food synergy is the concept that the non-random mixture of food constituents operates in concert for the life of the organism eaten and presumably for the life of the eater. Isolated nutrients have been extensively studied in well-designed, long-term, large randomised clinical trials, typically with null and sometimes with harmful effects. Therefore, although nutrient deficiency is a known phenomenon, serious for the sufferer, and curable by taking the isolated nutrient, the effect of isolated nutrients or other chemicals derived from food on chronic disease, when that chemical is not deficient, may not have the same beneficial effect. It appears that the focus on nutrients rather than foods is in many ways counterproductive. This observation is the basis for the argument that nutrition research should focus more strongly on foods and on dietary patterns. Unlike many dietary phenomena in nutritional epidemiology, diet pattern appears to be highly correlated over time within person. A consistent and robust conclusion is that certain types of beneficial diet patterns, notably described with words such as 'Mediterranean' and 'prudent', or adverse patterns, often described by the word 'Western', predict chronic disease. Food is much more complex than drugs, but essentially uninvestigated as food or pattern. The concept of food synergy leads to new thinking in nutrition science and can help to forge rational nutrition policy-making and to determine future nutrition research strategies.

Eating patterns are associated with biomarkers in a selected population of university students and employees

The association between diet and CVD cannot be assigned to a single nutrient, but rather to a set of nutrients and non-nutrients, and eating pattern analyses have become an important tool in investigation of this relationship. Our objective was to investigate eating patterns in relation to nutrient intake and serum concentration of folate, vitamin B12 and TAG in ninety-five healthy adult participants. Dietary information was collected by an FFQ, and eating patterns were obtained by principal components analyses of thirty-three food groups. Three eating patterns were extracted, a sweet eating pattern identified by intakes of cakes, snacks, sugar-sweetened drinks and chocolates; a prudent eating pattern identified by vegetables, fruits and olive oil; and a traditional food pattern identified by red meat, lean fish and cheese. Blood samples were collected in the morning after an overnight fast. Linear regression analyses adjusted for age, BMI and smoking showed a negative association between the sweet eating pattern scores and the serum concentration of folate (β = -2·31 (95 % CI -4·14, -0·45)) and a positive association with serum concentration of TAG (β = 0·35 (95 % CI 0·12, 0·57)). The prudent eating pattern scores were positively associated with the serum concentration of folate (β = 1·69 (95 % CI 0·44, 2·92)). In conclusion, a sweet eating pattern was associated with risk factors for CVD, whereas a prudent eating pattern was associated with protective factors.

Nɛ-homocysteinyl-lysine isopeptide is associated with progression of peripheral artery disease in patients treated with folic acid

OBJECTIVE

Folic acid (FA) administration can reduce plasma total homocysteine (tHcy); however, it fails to decrease cardiovascular events and progression of peripheral artery disease (PAD). Nɛ-homocysteinyl-lysine isopeptide (Nɛ-Hcy-Lys) is formed during catabolism of homocysteinylated proteins. We sought to investigate factors that determine the presence of Nɛ-Hcy-Lys in PAD patients with hyperhomocysteinemia receiving FA.

PATIENTS AND METHODS

We studied 131 consecutive PAD patients with tHcy > 15 μmol l(-1) taking FA 0.4 mg d(-1) for 12 months. Serum Nɛ-Hcy-Lys was determined by high-performance liquid chromatography (HPLC). We also measured interleukin-6 (IL-6), plasminogen activator inhibitor-1 (PAI-1), asymmetric dimethylarginine (ADMA) and 8-iso-prostaglandin F(2α) (8-iso-PGF(2α)).

RESULTS

FA administration resulted in a 70.5% decrease in tHcy (p < 0.0001). However, serum Nɛ-Hcy-Lys was detectable in 28 (21.4%) patients on FA who were more frequently current smokers and survivors of ischaemic stroke (p < 0.001). They had higher tHcy by 46.0%, PAI-1 by 51.7%, 8-iso-PGF(2α) by 59.1% and ADMA by 26.4% (all, p < 0.0001). The presence of Nɛ-Hcy-Lys was associated with lower ankle-brachial index (ABI) values (p < 0.001) and higher prevalence of cardiovascular events (p < 0.001) following therapy.

CONCLUSION

The presence of Nɛ-Hcy-Lys in one-fifth of hyperhomocysteinemic individuals with PAD despite FA treatment is associated with progression of PAD and with increased ADMA formation, oxidative stress and hypofibrinolysis.

Fibrin clot structure and function: a role in the pathophysiology of arterial and venous thromboembolic diseases

The formation of fibrin clots that are relatively resistant to lysis represents the final step in blood coagulation. We discuss the genetic and environmental regulators of fibrin structure in relation to thrombotic disease. In addition, we discuss the implications of fibrin structure for treatment of thrombosis. Fibrin clots composed of compact, highly branched networks with thin fibers are resistant to lysis. Altered fibrin structure has consistently been reported in patients with several diseases complicated by thromboembolic events, including patients with acute or prior myocardial infarction, ischemic stroke, and venous thromboembolism. Relatives of patients with myocardial infarction or venous thromboembolism display similar fibrin abnormalities. Low-dose aspirin, statins, lowering of homocysteine, better diabetes control, smoking cessation, and suppression of inflammatory response increase clot permeability and susceptibility to lysis. Growing evidence indicates that abnormal fibrin properties represent a novel risk factor for arterial and venous thrombotic events, particularly of unknown etiology in young and middle-aged patients.