Cost-effectiveness of vitamin therapy to lower plasma homocysteine levels for the prevention of coronary heart disease: effect of grain fortification and beyond

Homocysteine concentration in coronary artery disease and severity of coronary lesions

Our previous study reckons that the impact of the rs1801133 variant of 5,10-methylenetetrahydrofolate reductase (MTHFR) on coronary artery disease (CAD) is possibly mediated by cardiometabolic disorder. This study is performed to verify this hypothesis. Four hundred and thirty CAD patients and 216 CAD-free individuals were enrolled in this case-control study. The rs1801133 variant was genotyped by PCR-RFLP. Severity of coronary lesions was evaluated by number of stenotic coronary vessels and extent of coronary stenosis. The rs1801133 T allele significantly increased homocysteine levels in patients with CAD and CAD-free individuals. Individuals with the T allele of rs1801133 had an increased risk of developing CAD. In contrast, individuals with the TT genotype of rs1801133 were at high risk of multiple vessel lesions. The carriers of CT genotype had higher levels of systolic blood pressure (SBP), low-density lipoprotein cholesterol (LDL-C), and high-sensitivity C-reactive protein (hs-CRP), and lower levels of apolipoprotein A1 (APOA1) than those with CC genotype in male patients with CAD. The receiver operating characteristic (ROC) curve and precision-recall (PR) curve indicated that hyperhomocysteinemia was sensitive to predict the severity of CAD. Multivariate logistic regression revealed that homocysteine, rs1801133, age, smoking, weight, body mass index (BMI), lipoprotein(a) [Lp(a)], and hs-CRP were independent risk factors for CAD. The increased risk of CAD and severity of coronary lesions associated with rs1801133 in the Chinese Han population were attributed, at least partly, to high homocysteine levels. Hyperhomocysteinemia had a high predictive value for severe CAD or multiple vessel lesions.

Folic Acid and the Prevention of Birth Defects: 30 Years of Opportunity and Controversies

For three decades, the US Public Health Service has recommended that all persons capable of becoming pregnant consume 400 μg/day of folic acid (FA) to prevent neural tube defects (NTDs). The neural tube forms by 28 days after conception. Fortification can be an effective NTD prevention strategy in populations with limited access to folic acid foods and/or supplements. This review describes the status of mandatory FA fortification among countries that fortify (n = 71) and the research describing the impact of those programs on NTD rates (up to 78% reduction), blood folate concentrations [red blood cell folate concentrations increased ∼1.47-fold (95% CI, 1.27, 1.70) following fortification], and other health outcomes. Across settings, high-quality studies such as those with randomized exposures (e.g., randomized controlled trials, Mendelian randomization studies) are needed to elucidate interactions of FA with vitamin B12 as well as expanded biomarker testing.

Serum folate concentration and health-related quality of life among the elderly in South Korea

Background

The purpose of this study was to investigate the association between serum folate concentration and health-related quality of life (HRQOL) among the elderly in South Korea.

Materials and methods

The data used in this study were drawn from 1,021 participants over 65 years old in the Korea National Health and Nutrition Examination Survey from 2016–2018. HRQOL was measured by the EQ-5D questionnaire. Participants were divided into tertiles of folate concentration (ranges 1.7–5.6, 5.7–9.4, and 9.5–31.9 ng/mL). We performed multivariable linear regression to examine the relationship between folate and HRQOL, and multivariable logistic regression to examine the relationship between folate and the dimensional problem of HRQOL.

Results

Higher folate concentrations were significantly associated with higher HRQOL in the elderly. The average HRQOL score of the elderly in the highest tertile of the folate level was 0.0289 higher than that of the lowest tertile (coefficient: 0.0289; 95% CI 0.0016, 0.0563). The HRQOL score increased by 0.0174 points when the folate concentration increased by 100%. When analyzing specific dimensions, a significant association with folate concentration was found only for the self-care dimension of HRQOL (odds ratio for self-care problems: 0.63; 95% CI 0.41, 0.99).

Conclusions

The elderly with higher serum folate concentration tended to have higher HRQOL. Among HRQOL dimensions, self-care was only significantly associated with folate concentration.

Cysteine/Glutathione Deficiency: A Significant and Treatable Corollary of Disease

Glutathione (GSH) deficiency may play a pivotal role in a variety of apparently unrelated clinical conditions and diseases. Orally administered N-acetylcysteine (NAC), which replenishes the cysteine required for GSH synthesis, has been tested in a large number of randomized placebo-controlled trials involving these diseases and conditions. This chapter focused on developing a base of evidence suggesting that NAC administration improves disease by increasing cysteine and/or GSH in a variety of diseases, thereby implying a significant role for GSH deficiency in the clinical basis of many diseases. To develop this base of evidence, we systematically selected studies which considered the hypothesis that the therapeutic efficacy for NAC is an indication that cysteine and/or GSH deficiency is a pathophysiological part of the diseases studied. In this manner we focus this chapter on explaining the biological mechanisms of NAC therapy in a wide variety of disorders and demonstrate its ubiquitous role in improving disease that involves disrupted GSH and/or cysteine metabolism.

Prevention of influenza in healthy children

Healthy children are high transmitters of influenza and can experience poor influenza outcomes. Many questions remain about the efficacy and impect of preventive measures because most existing studies report imprecise proxies of influenza incidence, do not follow subjects throughout the entire influenza season and across multiple influenza seasons, or do not control for important factors such as timing of implementation and social contact patterns. Modeling and simulation are key methodologies to answer questions regarding influenza prevention. While vaccination may be the most efficacious existing intervention, variations in circulating strains and children's immune systems keep current vaccines from being fully protective, necessitating further clinical and economic studies and technology improvements. Hand hygiene appears to be an important adjunct but improving compliance, standardizing regimens and quantifying its impact remain challenging. Future studies should help better define the specific indications and circumstances for antiviral use and the role of nutritional supplements and nonpharmaceutical interventions.

LONG-TERM ECONOMIC EFFECTIVENESS OF THE MULTIFACTORIAL CARDIOVASCULAR PREVENTION PROGRAMME IN THE CONTEXT OF PRIMARY HEALTH CARE

Economic effects of the multifactorial cardiovascular prevention programme are analysed in the context of prevention-associated preserved work potential. The programme of multifactorial prevention of cardiovascular disease (CVD) is one of the few Russian controlled studies, which was performed in the primary health care settings, in the population-based middle-aged cohort, and included both the active preventive intervention (5 years) and the end-point follow-up (10 years). This study is a post-hoc analysis employing modern parameters of integrated assessment, such as life-years saved (LYS) and estimated cost-effectiveness of the programme. In the active prevention population, the 5-year intervention saved 52,5 life-years per 1000 participants, with the cumulative 10-year LYS number of 147,4. The programme costs per 1 LYS (85512,4 roubles for 5 years and 41679,3 roubles for 10 years) were significantly lower than the gross domestic product per one worker per year (290000 roubles). The payback of the CVD prevention investment (per 1 rouble invested) reached 2,3 roubles for 5 years and 5,8 roubles for 10 years. Multifactorial medical prevention of CVD is economically effective and justifiable when integrated into the routine practice of primary health care. 

Menopause and age-driven changes in blood level of fat- and water-soluble vitamins

OBJECTIVE

The purpose of this cross-sectional study was to assess the association of the menopausal transition with changes in vitamins.

METHODS

The study group comprised women aged 17-85 years from the Third National Health and Nutrition Examination Survey (NHANES), which was conducted between 1988 and 1994, and from the NHANES surveys conducted between 1999 and 2006. Menopausal status was defined using the time since the last period, < 2, 2-12, and > 12 months, for the pre-, peri-, and postmenopause, respectively. The data-cleaning technique employing serum follicle stimulating hormone activity resulted in pre-, peri- and postmenopausal samples encompassing the following age brackets: 17-50, 42-51, and 46-85 years. Statistical inferences were analyzed using non-parametric techniques.

RESULTS

Significant increases in vitamin A and vitamin E concentrations across all phases of the menopausal transition were observed. There was a gradual decrease in the vitamin C concentration across all stages of the menopause but a fairly stable concentration of vitamin B12. There was a statistically significant increase in vitamin D between the pre- and postmenopause. Body mass index correlated negatively with serum vitamin concentration in the pre- and postmenopause.

CONCLUSIONS

Vitamin A should be supplemented in postmenopausal women to decrease the risk of bone fracture. The daily diet should be supplemented with vitamin B12, to avoid possible neurological symptoms due to vitamin B12 deficiency, and with vitamin D to decrease the risk of developing secondary hyperparathyroidism. Due to an adverse influence on serum vitamin concentration, body mass index should be monitored in pre- and postmenopausal women.

Management of hyperhomocysteinemia

Hyperhomocysteinemia is an established risk factor for cardiovascular disease. The modification of traditional cardiovascular risk factors has resulted in better morbidity and mortality outcomes, so the treatment of hyperhomocysteinemia is explored for a similar benefit. Vitamin B(6), vitamin B(12) and folate, as co-factors in the metabolism of homosyteine, are used in the treatment of hyperhomocysteinemia. Betaine, a methyl-donor in a separate homocysteine metabolism pathway, is also used to treat hyperhomocysteinemia. These supplements have been used in various doses and combinations for different periods of time, with favorable outcomes. There is still no concensus whether hyperhomocysteinemia can be treated with folic acid alone, or in combination with vitamin B(6) and vitamin B(12). The dose of the supplements required to normalize fasting homocysteine remains to be determined, especially in diabetic nephropathy, hemodialysis and renal transplant patients. The benefits from lowering homocysteine levels have mainly been demonstrated in surrogate cardiovascular outcomes. The treatment of hyperhomocysteinemia cannot be firmly advocated until there are trials that demonstrate a beneficial clinical endpoint. In patients who have cardiovascular disease in the absence of more established risk factors, investigation and treatment of hyperhomocysteinemia should be considered.

Folate and vitamin B12 deficiency and hyperhomocysteinemia promote oxidative stress in adult type 2 diabetes

OBJECTIVE

The purpose of this study was to examine the status of folate and vitamin B12 (B12) in relation to serum homocysteine (HCY) and oxidative stress indices in patients with type 2 diabetes (T2DM).

METHODS

This case-control study involved 100 Omani adults (50 patients newly diagnosed with T2DM and 50 age- and gender-matched healthy controls). Several parameters were investigated, including dietary intake and biochemical assessments of folate, B12, HCY, oxidative stress markers (glutathione and total antioxidant status), and antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and catalase).

RESULTS

Low serum levels of folate, B12, and hyperhomocysteinemia were prevalent in patients with T2DM compared with controls. Oxidative stress was evident in patients with T2DM as indicated by low serum levels of glutathione, total antioxidant status, and impaired antioxidant enzymatic activities (superoxide dismutase, glutathione peroxidase, and catalase).

CONCLUSION

The low intake of folate and B12 is associated with low serum levels of these two nutrients and hyperhomocysteinemia in Omani adults with T2DM.

Economic analysis of nutrition interventions for chronic disease prevention: methods, research, and policy

Increased interest in the potential societal benefit of incorporating health economics as a part of clinical translational science, particularly nutrition interventions, led the Office of Dietary Supplements at the National Institutes of Health to sponsor a conference to address key questions about the economic analysis of nutrition interventions to enhance communication among health economic methodologists, researchers, reimbursement policy makers, and regulators. Issues discussed included the state of the science, such as what health economic methods are currently used to judge the burden of illness, interventions, or healthcare policies, and what new research methodologies are available or needed to address knowledge and methodological gaps or barriers. Research applications included existing evidence-based health economic research activities in nutrition that are ongoing or planned at federal agencies. International and US regulatory, policy, and clinical practice perspectives included a discussion of how research results can help regulators and policy makers within government make nutrition policy decisions, and how economics affects clinical guideline development.

The impact of the aging population on coronary heart disease in the United States

BACKGROUND

The demographic shift toward an older population in the United States will result in a higher burden of coronary heart disease, but the increase has not been quantified in detail. We sought to estimate the impact of the aging US population on coronary heart disease.

METHODS

We used the Coronary Heart Disease Policy Model, a Markov model of the US population between 35 and 84 years of age, and US Census projections to model the age structure of the population between 2010 and 2040.

RESULTS

Assuming no substantive changes in risks factors or treatments, incident coronary heart disease is projected to increase by approximately 26%, from 981,000 in 2010 to 1,234,000 in 2040, and prevalent coronary heart disease by 47%, from 11.7 million to 17.3 million. Mortality will be affected strongly by the aging population; annual coronary heart disease deaths are projected to increase by 56% over the next 30 years, from 392,000 to 610,000. Coronary heart disease-related health care costs are projected to rise by 41% from $126.2 billion in 2010 to $177.5 billion in 2040 in the United States. It may be possible to offset the increase in disease burden through achievement of Healthy People 2010/2020 objectives or interventions that substantially reduce obesity, blood pressure, or cholesterol levels in the population.

CONCLUSIONS

Without considerable changes in risk factors or treatments, the aging of the US population will result in a sizeable increase in coronary heart disease incidence, prevalence, mortality, and costs. Health care stakeholders need to plan for the future age-related health care demands of coronary heart disease.

Review of economic methods used in complementary medicine

OBJECTIVE

The purpose of this research is to review the economic methods used in complementary medicine (CM).

METHOD

A comprehensive literature review was undertaken (1995-2007) to identify peer-reviewed articles related to economic methods used in CM.

RESULTS

The literature found 15 full economic evaluations of CM: 3 in the manipulative and body-based practices, 5 in the whole medical systems, and 7 in the biologically based practices. No evaluations were identified for the areas of mind-body medicine, alternative medical systems, or energy medicine. The review failed to locate any articles that used alternate economic methods such as contingent valuation or discrete choice modelling. The overall consensus from the 15 economic evaluations, despite variations in project design and methodological rigor, was that CM, as evaluated in these studies, was cost-effective compared to usual care.

CONCLUSIONS

As health care costs continue to rise, decision makers, both consumers and policymakers, must allocate scarce resources toward those treatments that offer the best value for the money. Considerable scope exists to advance the science behind CM through a more systematic integration of economic methods into CM research.

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

OBJECTIVES

In the Norwegian Vitamin Trial and the Western Norway B Vitamin Intervention Trial, patients were randomly assigned to homocysteine-lowering B-vitamins or no such treatment. We investigated their effects on cardiovascular outcomes in the trial populations combined, during the trials and during an extended follow-up, and performed exploratory analyses to determine the usefulness of homocysteine as a predictor of cardiovascular outcomes.

DESIGN

Pooling of data from two randomized controlled trials (1998-2005) with extended post-trial observational follow-up until 1 January 2008.

SETTING

Thirty-six hospitals in Norway.

SUBJECTS

6837 patients with ischaemic heart disease.

INTERVENTIONS

One capsule per day containing folic acid (0.8 mg) plus vitamin B12 (0.4 mg) and vitamin B6 (40 mg), or folic acid plus vitamin B12, or vitamin B6 alone or placebo.

MAIN OUTCOME MEASURES

Major adverse cardiovascular events (MACEs; cardiovascular death, acute myocardial infarction or stroke) during the trials and cardiovascular mortality during the extended follow-up.

RESULTS

Folic acid plus vitamin B12 treatment lowered homocysteine levels by 25% but did not influence MACE incidence (hazard ratio, 1.07; 95% CI, 0.95-1.21) during 39 months of follow-up, or cardiovascular mortality (hazard ratio, 1.12; 95% CI, 0.95-1.31) during 78 months of follow-up, when compared to no such treatment. Baseline homocysteine level was not independently associated with study outcomes. However, homocysteine concentration measured after 1-2 months of folic acid plus vitamin B12 treatment was a strong predictor of MACEs.

CONCLUSION

We found no short- or long-term benefit of folic acid plus vitamin B12 on cardiovascular outcomes in patients with ischaemic heart disease. Our data suggest that cardiovascular risk prediction by plasma total homocysteine concentration may be confined to the homocysteine fraction that does not respond to B-vitamins.

Economic evaluation of lifestyle interventions for preventing diabetes and cardiovascular diseases

Lifestyle interventions (i.e., diet and/or physical activity) are effective in delaying or preventing the onset of diabetes and cardiovascular disease. However, policymakers must know the cost-effectiveness of such interventions before implementing them at the large-scale population level. This review discusses various issues (e.g., characteristics, modeling, and long-term effectiveness) in the economic evaluation of lifestyle interventions for the primary and secondary prevention of diabetes and cardiovascular disease. The diverse nature of lifestyle interventions, i.e., type of intervention, means of provision, target groups, setting, and methodology, are the main obstacles to comparing evaluation results. However, most lifestyle interventions are among the intervention options usually regarded as cost-effective. Diabetes prevention programs, such as interventions starting with targeted or universal screening, childhood obesity prevention, and community-based interventions, have reported favorable cost-effectiveness ratios.

Tratamento dietético da hiper-homocisteinemia na doença arterial periférica

A homocisteína está envolvida na gênese da aterosclerose e, assim, é considerada um importante e prevalente fator de risco na doença arterial periférica. O estado nutricional vitamínico deficiente, em especial do folato, é a principal causa de hiper-homocisteinemia nesses casos. Embora ainda não haja consenso sobre a dose exata e a forma de utilização do folato em suplementos e sobre adequação alimentar ou fortificação de cereais para o tratamento da hiper-homocisteinemia, diversos estudos realizados em pacientes com doença vascular periférica mostraram que o folato, isoladamente, pode reduzir as concentrações de homocisteína, bem como a concentração de alguns marcadores biológicos do processo de aterosclerose. No entanto, estudos recentes não comprovaram esse benefício sobre o processo inflamatório associado à hiper-homocisteinemia. Desta forma, embora a utilização isolada do folato seja uma terapêutica custo-efetiva no controle da hiper-homocisteinemia, seu impacto na evolução das doenças arteriais ainda persiste inconclusivo. Esta revisão abordará os efeitos obtidos com as diversas formas de utilização do folato no tratamento da hiper-homocisteinemia.

Cost-effectiveness of mandatory folate fortification v. other options for the prevention of neural tube defects: results from Australia and New Zealand

OBJECTIVE

To provide input to Australian and New Zealand government decision making regarding an optimal strategy to reduce the rate of neural tube defects (NTD).

DESIGN

Standard comparative health economic evaluation techniques were employed for a set of intervention options for promoting folate/folic acid consumption in women capable of or planning a pregnancy. Evidence of effectiveness was informed by the international literature and costs were derived for Australia and New Zealand.

RESULTS

Population-wide campaigns to promote supplement use and mandatory fortification were the most effective at reducing NTD, at an estimated 36 and 31 fewer cases per annum respectively for Australia and New Zealand, representing an 8 % reduction in the current annual NTD rate. Population-wide and targeted approaches to increase supplement use were cost-effective, at less than $AU 12,500 per disability-adjusted life year (DALY) averted ($US 9893, pound 5074), as was extending voluntary fortification. Mandatory fortification was not cost-effective for New Zealand at $AU 138,500 per DALY ($US 109 609, pound 56,216), with results uncertain for Australia, given widely varying cost estimates. Promoting a folate-rich diet was least cost-effective, with benefits restricted to impact on NTD.

CONCLUSIONS

Several options for reducing NTD appear to fall well within accepted societal cost-effectiveness norms. All estimates are subject to considerable uncertainty, exacerbated by possible interactions between interventions, including impacts on currently effective strategies. The Australian and New Zealand governments have decided to proceed with mandatory fortification; it is hoped they will support a rigorous evaluation which will contribute to the evidence base.

A cost-effectiveness analysis of folic acid fortification policy in the United States

OBJECTIVE

To quantify the health and economic outcomes associated with changes in folic acid consumption following the fortification of enriched grain products in the USA.

DESIGN

Cost-effectiveness analysis.

SETTING

Annual burden of disease, quality-adjusted life years (QALY) and costs were projected for four steady-state strategies: no fortification, or fortifying with 140, 350 or 700 microg folic acid per 100 g enriched grain. The analysis considered four health outcomes: neural tube defects (NTD), myocardial infarctions (MI), colon cancers and B12 deficiency maskings.

SUBJECTS

The US adult population subgroups defined by age, gender and race/ethnicity, with folate intake distributions from the National Health and Nutrition Examination Surveys (1988-1992 and 1999-2000), and reference sources for disease incidence, utility and economic estimates.

RESULTS

The greatest benefits from fortification were predicted in MI prevention, with 16 862 and 88 172 cases averted per year in steady state for the 140 and 700 microg fortification levels, respectively. These projections were between 6261 and 38 805 for colon cancer and 182 and 1423 for NTD, while 15-820 additional B12 cases were predicted. Compared with no fortification, all post-fortification strategies provided QALY gains and cost savings for all subgroups, with predicted population benefits of 266 649 QALY gained and $3.6 billion saved in the long run by changing the fortification level from 140 microg/100 g enriched grain to 700 microg/100 g.

CONCLUSIONS

The present study indicates that the health and economic gains of folic acid fortification far outweigh the losses for the US population, and that increasing the level of fortification deserves further consideration to maximise net gains.

Measuring the value of public health systems: the disconnect between health economists and public health practitioners

We investigated ways of defining and measuring the value of services provided by governmental public health systems. Our data sources included literature syntheses and qualitative interviews of public health professionals. Our examination of the health economic literature revealed growing attempts to measure value of public health services explicitly, but few studies have addressed systems or infrastructure. Interview responses demonstrated no consensus on metrics and no connection to the academic literature. Key challenges for practitioners include developing rigorous, data-driven methods and skilled staff; being politically willing to base allocation decisions on economic evaluation; and developing metrics to capture "intangibles" (e.g., social justice and reassurance value). Academic researchers evaluating the economics of public health investments should increase focus on the working needs of public health professionals.

A Markov simulation model for analyzing and forecasting the number of coronary artery revascularization procedures in Western Australia

PURPOSE

A Markov chain Monte Carlo simulation model was developed to analyze and forecast the numbers of coronary artery bypass graftings, percutaneous coronary interventions (PCIs) , incident coronary heart disease (CHD) events, and CHD deaths for different age and sex groups in the population of Western Australia (population approximately 1.7 million).

METHODS

The Western Australian health information system contains linked records of all hospital admissions and deaths for individuals from 1980 to the present. This system allows the separation of the population into groups according to CHD/coronary artery revascularization procedure history and also allows the estimation of event probabilities directly from population-level data.

RESULTS AND CONCLUSIONS

The results for the 1990 Western Australian population over the period 1990 to 1994 and the 1995 population over the period 1995 to 1999 indicated that the Markov model fits well and produces good forecasts under "stable" conditions. The model can also be useful in ascertaining the impact of system changes, such as the widespread introduction of stents in PCI operations in 1995.

Cost-effectiveness of a folic acid fortification program in Chile

OBJECTIVE

Periconceptional intake of folic acid reduces the risk of neural tube defects (NTDs), a frequent birth defect that can cause significant infant mortality and disability. In Chile, fortification of wheat flour with folic acid has resulted in significant reduction in the risk of anencephaly and spina bifida. We investigated the cost-effectiveness implications of this policy.

METHODS

We conducted an ex-post economic analysis of this intervention. Estimates of the effect of fortification in decreasing NTDs and deaths were derived from a prospective evaluation. The costs of fortification and provision of medical care to children with spina bifida in Chile were based on primary data collection.

FINDINGS

The intervention costs per NTD case and infant death averted were I$ 1200 and 11,000, respectively. The cost per DALY averted was I$ 89, 0.8% of Chile's GDP per capita. Taking into account averted costs of care, fortification resulted in net cost savings of I$ 2.3 million.

CONCLUSION

Fortification of wheat flour with folic acid is a cost-effective intervention in Chile, a middle income country in the post-epidemiological transition. This result supports the continuation of the Chile fortification program and constitutes valuable information for policy makers in other countries to consider.

Diet, nutrition and the prevention of hypertension and cardiovascular diseases

Cardiovascular diseases (CVD) are growing contributors to global disease burdens, with epidemics of CVD advancing across many regions of the world which are experiencing a rapid health transition. Diet and nutrition have been extensively investigated as risk factors for major cardiovascular diseases like coronary heart disease (CHD) and stroke and are also linked to other cardiovascular risk factors like diabetes, high blood pressure and obesity. The interpretation of evidence needs to involve a critical appraisal of methodological issues related to measurement of exposures, nature of outcome variables, types of research design and careful separation of cause, consequence and confounding as the basis for observed associations.

Adequate evidence is available, from studies conducted within and across populations, to link several nutrients, minerals, food groups and dietary patterns with an increased or decreased risk of CVD. Dietary fats associated with an increased risk of CHD include trans–fats and saturated fats, while polyunsaturated fats are known to be protective. Dietary sodium is associated with elevation of blood pressure, while dietary potassium lowers the risk of hypertension and stroke. Regular frequent intake of fruits and vegetables is protective against hypertension, CHD and stroke. Composite diets (such as DASH diets, Mediterranean diet, ‘prudent’ diet) have been demonstrated to reduce the risk of hypertension and CHD. Sufficient knowledge exists to recommend nutritional interventions, at both population and individual levels, to reduce cardiovascular risk. That knowledge should now be translated into policies which promote healthy diets and discourage unhealthy diets. This requires coordinated action at the level of governments, international organizations, civil society and responsible sections of the food industry.

Medical foods: products for the management of chronic diseases

Medical foods are a specific category of therapeutic agents created under the Orphan Drug Act of 1988, which separated medical foods from drugs for regulatory purposes. Products in this category share the requirements that they are intended for the nutritional management of a specific disease, are used under the guidance of a physician, and contain ingredients that are generally recognized as safe (GRAS). An example of medical foods are formulations intended to manage patients with inborn errors in amino acid metabolism. Newer medical foods are designed to manage hyperhomocysteinemia, pancreatic exocrine insufficiency, inflammatory conditions, cancer cachexia, and other diseases.

Dietetic guidelines on food and nutrition in the secondary prevention of cardiovascular disease ? evidence from systematic reviews of randomized controlled trials (second update, January 2006)

AIM

To update dietetic guidelines based on systematic review evidence on dietary advice to prevent further events in people with existing cardiovascular disease (CVD) (secondary prevention).

METHODS

The Cochrane Library, MEDLINE and EMBASE were comprehensively searched to January 2005 for systematic reviews on aspects of diet and heart health. Reviews were included if they searched systematically for randomized controlled trials relating to diet and secondary prevention of CVD. Each review was critically appraised by at least two members of the UK Heart Health and Thoracic Dietitians Group. The quality and results of each review were discussed and summarized at a group meeting.

RESULTS

Evidence-based strategies that reduce cardiovascular events in those with CVD include reduction in saturated fat and substitution with unsaturated fats. Individuals who have suffered a myocardial infarction may also benefit from adopting a Mediterranean type diet and increasing intake of omega 3 fats, but it is not clear whether they are beneficial for all patients with CVD. There is no systematic review evidence to support the use of antioxidant vitamins supplements, low glycaemic index diets, or homocysteine lowering therapies in this group.

CONCLUSION

There remains good evidence that reducing saturated fat reduces morbidity in patients with CVD. This advice is consistent for most manifestations of CVD, with the addition of Mediterranean dietary advice and increased omega 3 fats for those who have had a myocardial infarction.

Population-level changes in folate intake by age, gender, and race/ethnicity after folic acid fortification

OBJECTIVES

We sought to quantify the impact of the 1998 US Food and Drug Administration (FDA) folic acid fortification policy by estimating folate intake at the population level.

METHODS

We analyzed total folate intake levels (from food and supplements) according to gender, age, and race/ethnicity, using data from 2 National Health and Nutrition Examination Surveys. We measured pre- and postfortification folate intake distributions, adjusted for measurement error, and examined proportions of the population who reached certain thresholds of daily total folate intake.

RESULTS

Mean daily food and total folate intake increased by approximately 100 microg/day after fortification. The proportion of women aged 15-44 years who consume more than 400 microg/day of folate has increased since fortification, but has not yet reached the FDA's 50% target and varies by race/ethnicity from 23% to 33%. Among persons aged 65 years and older who may be at risk for masking a vita-microg/day (the min B12 deficiency, the percentage who consume more than 1000 "tolerable upper intake level") has at least doubled among Whites and Black men, but has remained less than 5% for all groups.

CONCLUSIONS

Since fortification, folic acid intake among the US population has increased, and there are substantial variations by age, gender, and race/ethnicity.

Folic acid, inflammation, and atherosclerosis: False hopes or the need for better trials?

An increasing body of evidence supports the existence of a strong link between inflammation, endothelial dysfunction, and the onset and progression of atherosclerosis. However, a cause-effect relationship between these phenomena has not been demonstrated yet. Although some inflammatory markers, such as C-reactive protein, have been recently shown to improve risk stratification and to strongly predict cardiovascular outcome, it is largely unknown whether modifications of these markers might provide salutary effects and reduce cardiovascular morbidity and mortality. The B-vitamin folic acid has recently gained attention because of its potential to provide beneficial effects on surrogate end-points, such as endothelial function, in patients at high cardiovascular risk. However, the role of folic acid in mitigating the pro-inflammatory state associated with atherosclerosis is controversial. Despite the theoretical arguments supporting the potential anti-atherosclerotic and anti-inflammatory effects of folic acid, the current evidence is limited, deriving from small trials on different study populations, using folic acid often in combination with other vitamins and for different treatment periods. This review will consider the current evidence supporting the role of some well-established inflammatory markers in predicting cardiovascular outcomes, the mechanisms by which folic acid might exert anti-inflammatory effects, the epidemiological data relating folic acid concentrations with inflammatory markers, the published interventional studies on the effects of folic acid supplementation on these markers, and the factors that need to be considered in designing future trials.

Fortification of industrialized foods with vitamins

Vitamins are essential to life. Inadequate eating habits, high caloric intake and metabolic defects lead to micronutrient deficiencies, affecting more than two billion people worldwide. The increasing intake of industrialized foods, combined with low vitamin stability has led to the common practice of adding these nutrients to processed foods. This review discusses the terminology, availability, intake and risk of hypervitaminosis, due to the intake and nutritional importance of foods fortified with vitamins. The addition of nutrients should occur in foods that are effectively consumed by the target population and must meet the real needs of a significant segment of the population. In Brazil, a total of 166 products available in supermarkets are vitamin-enriched. A 10-year study involving children and adolescents in Germany showed that 90% of those surveyed used at least one fortified food. During this 10-year period, 472 fortified products were consumed. The enrichment of foods should be based on the needs of each country and, if possible, regional needs. For instance, in order to increase its intake, Vitamin D is added to foods in Denmark during the winter, mainly for the elderly. However, in Brazil, there is no evidence of the need to fortify food with this vitamin. A survey showed that of the 76 enriched dairy products, 37 contained vitamin D. Food-fortification is a very important strategy to solve nutritional deficiency problems, but it can also cause many health problems.

The role of homocysteine in multisystem age-related problems: a systematic review

Homocysteine is a sulfur-containing amino acid that is involved in one-carbon metabolism. Hyperhomocysteinemia is a common phenomenon among elderly people. There is growing evidence of an association between hyperhomocysteinemia and geriatric multisystem problems, including coronary artery disease, stroke, peripheral vascular disease, cognitive impairment, dementia, depression, osteoporotic fractures, and functional decline. The proposed mechanisms of the association include angiotoxicity, neurotoxicity, and inhibition of collagen cross-linking. A homocysteine-lowering strategy may prevent or slow the development of these age-related problems. Vitamin supplementation and folic acid fortification of grain foods have been shown to decrease plasma homocysteine concentrations. More research is needed to investigate whether lifelong homocysteine lowering can prevent the development of late-life morbidity.

Kosteneffektivität der Prävention der koronaren Herzkrankheit in Deutschland

It is generally accepted that the incidence of coronary heart disease can effectively be reduced by strengthening prevention. At the same time, it is still unclear how large the effects of life-style oriented preventive measurements such as diet and exercising are in everyday life. Furthermore, there is an ongoing debate on what measurements are effective. Thus, against the background of dwindling financial resources in health care the input of health economic evaluation is explicated. General issues of health economic evaluation are presented. After that, an overview on the current findings of cost-effectiveness in primary prevention of coronary heart disease is given. Risk factors are separately discussed. It is demonstrated that preventive measurements dealing especially with hypertension and hypercholesterolemia can be cost-effective.

Economic Impact of Hyperhomocysteinemia in Switzerland

Since more than 20 years elevated homocysteine plasma levels have been associated with an elevated cardiovascular risk. It can be assumed that approx. 5-7% of the Swiss population suffers from hyperhomocysteinemia. These people have an odds ratio of 1.7 (95% confidence interval: 1.5-1.9) to develop a myocardial infarction and an odds ratio of 2.5 (95% confidence interval 2-3) of developing a stroke. These significant cardiovascular endpoints have monetary implications and lead to a loss in life years. The cost consequences and total life years lost were determined with an incidence-based epidemiological model utilizing a Swiss third party payer perspective. We could demonstrate that hyperhomocysteinemia-related sequelae (myocardial infarction and stroke) amount to 41.1-110.2 million CHF. In addition it can be estimated that 6'941-18'478 life years may be lost. Comparing these data with the total costs for cardiovascular disease in Switzerland of CHF 987 million, we estimate the share of the economic burden of hyperhomocysteinemia at approximately 10%. Preventive measures could thus yield a positive impact on total health care expenditure in the Swiss healthcare system and warrants further research.

A Cost-Effectiveness Analysis of a Hypothetical Catheter-Based Strategy for the Detection and Treatment of Vulnerable Coronary Plaques with Drug-Eluting Stents

AIM

Extensive efforts are underway to develop methods for the detection and treatment of vulnerable/high-risk coronary artery plaques. We utilized decision analysis to evaluate the hypothetical clinical benefits and cost-effectiveness of a catheter-based strategy.

METHODS AND RESULTS

Currently, stenotic coronary plaques are treated without regard to vulnerability. In a new strategy, vulnerable coronary plaques are detected with a catheter-based test and treated with a drug-eluting stent, regardless of degree of stenosis. A Markov-decision model was developed to compare the new strategy with current practice. Monte Carlo simulations were performed from a societal perspective, costs were converted to year 2003 U.S. dollars, and future costs and outcomes were discounted at 3%. Sensitivity analyses were performed to evaluate the effect of assumptions on variables such as the prevalence of vulnerable plaques and treatment effect. In 60-year-old male patients with coronary stenoses the new strategy would be less expensive and more effective than current practice (37,045 dollars vs 38,257 dollars and 10.23 vs 9.86 quality-adjusted life years (QALYs), respectively). The benefits of the new strategy were robust in sensitivity analyses (e.g., if the prevalence of vulnerable plaques in this patient group was 50% or more and the sensitivity and specificity of the new test were at least 0.80).

CONCLUSION

In selected patients with coronary artery stenosis, the detection of vulnerable plaques with a catheter-based test followed by their treatment with a drug-eluting stent could be a less expensive and more effective strategy than current practice. If applied to 1 million such patients in the United States undergoing catheterization, the new strategy would add 370,000 QALYs and save 1.2 billion dollars per year.

Oral Synthetic Folic Acid and Vitamin B12Supplements Work-If One Consumes Them

Oral supplements of synthetic folic acid and vitamin B12 are very effective in increasing blood levels of the vitamins and are known to prevent birth defects and cardiovascular diseases.

Effects of folic acid fortification and multivitamin therapy on homocysteine and vitamin b12 status in cardiac transplant recipients

BACKGROUND

Hyperhomocysteinemia is a frequent finding after cardiac transplantation, but increased folate intake induces a decrease in total homocysteine concentrations. In 1998, food in Canada was fortified nationwide with folic acid. We assessed the impact of routine folate fortification on homocysteine concentrations in our cardiac transplant population.

METHODS

In 18 subjects, we measured total homocysteine (tHcy), serum folate, and cobalamin concentrations in 1997 (before folate fortification) and in 1998 (after fortification). We repeated the analysis after specific multivitamin supplementation for 10 weeks.

RESULTS

We found a significant decrease in baseline tHcy concentrations and in folate concentrations between 1997 and 1998. However, we also found a decrease in serum cobalamin concentrations. We found a correlation between decreased cobalamin concentrations and the methionine synthase A2756G genotype, but not with other common polymorphisms associated with homocysteine metabolism. After multivitamin supplementation, we observed a trend toward further decrease in tHcy concentrations and a significant increase in serum folate and cobalamin concentrations. Finally, we measured serum methylmalonic acid concentrations, an index of tissue cobalamin status. We did not find a correlation between increased methylmalonic acid concentrations and decreased serum cobalamin, perhaps related to the confounding effect of altered renal status on methylmalonic acid excretion.

CONCLUSIONS

National folate fortification was associated with decreased tHcy and increased folate concentrations in our cardiac transplant population. Additional administration of vitamin supplements induced a further decrease in tHcy and an increase in folate. Finally, folate fortification unveiled cobalamin deficiency in some patients, associated with the methionine synthase A2756G mutation.

DACH-LIGA homocystein (german, austrian and swiss homocysteine society): consensus paper on the rational clinical use of homocysteine, folic acid and B-vitamins in cardiovascular and thrombotic diseases: guidelines and recommendations

About half of all deaths are due to cardiovascular disease and its complications. The economic burden on society and the healthcare system from cardiovascular disability, complications, and treatments is huge and getting larger in the rapidly aging populations of developed countries. As conventional risk factors fail to account for part of the cases, homocysteine, a "new" risk factor, is being viewed with mounting interest. Homocysteine is a sulfur-containing intermediate product in the normal metabolism of methionine, an essential amino acid. Folic acid, vitamin B12, and vitamin B6 deficiencies and reduced enzyme activities inhibit the breakdown of homocysteine, thus increasing the intracellular homocysteine concentration. Numerous retrospective and prospective studies have consistently found an independent relationship between mild hyperhomocysteinemia and cardiovascular disease or all-cause mortality. Starting at a plasma homocysteine concentration of approximately 10 micromol/l, the risk increase follows a linear dose-response relationship with no specific threshold level. Hyperhomocysteinemia as an independent risk factor for cardiovascular disease is thought to be responsible for about 10% of total risk. Elevated plasma homocysteine levels (>12 micromol/l; moderate hyperhomocysteinemia) are considered cytotoxic and are found in 5 to 10% of the general population and in up to 40% of patients with vascular disease. Additional risk factors (smoking, arterial hypertension, diabetes, and hyperlipidemia) may additively or, by interacting with homocysteine, synergistically (and hence over-proportionally) increase overall risk. Hyperhomocysteinemia is associated with alterations in vascular morphology, loss of endothelial anti-thrombotic function, and induction of a procoagulant environment. Most known forms of damage or injury are due to homocysteine-mediated oxidative stress. Especially when acting as direct or indirect antagonists of cofactors and enzyme activities, numerous agents, drugs, diseases, and lifestyle factors have an impact on homocysteine metabolism. Folic acid deficiency is considered the most common cause of hyperhomocysteinemia. An adequate intake of at least 400 microg of folate per day is difficult to maintain even with a balanced diet, and high-risk groups often find it impossible to meet these folate requirements. Based on the available evidence, there is an increasing call for the diagnosis and treatment of elevated homocysteine levels in high-risk individuals in general and patients with manifest vascular disease in particular. Subjects of both populations should first have a baseline homocysteine assay. Except where manifestations are already present, intervention, if any, should be guided by the severity of hyperhomocysteinemia. Consistent with other working parties and consensus groups, we recommend a target plasma homocysteine level of <10 micromol/l. Based on various calculation models, reduction of elevated plasma homocysteine concentrations may theoretically prevent up to 25% of cardiovascular events. Supplementation is inexpensive, potentially effective, and devoid of adverse effects and, therefore, has an exceptionally favorable benefit/risk ratio. The results of ongoing randomized controlled intervention trials must be available before screening for, and treatment of, hyperhomocysteinemia can be recommended for the apparently healthy general population.

Nontraditional risk factors for cardiovascular disease in diabetes

People with type 2 diabetes are disproportionately affected by cardiovascular disease (CVD), compared with those without diabetes. Traditional risk factors do not fully explain this excess risk, and other "nontraditional" risk factors may be important. This review will highlight the importance of nontraditional risk factors for CVD in the setting of type 2 diabetes and discuss their role in the pathogenesis of the excess CVD morbidity and mortality in these patients. We will also discuss the impact of various therapies used in patients with diabetes on nontraditional risk factors.

Scientific evidence supporting folic acid fortification of flour in Australia and New Zealand

BACKGROUND

Fortification of flour with folic acid is a safe, sustainable, and cost-effective approach for preventing spina bifida and anencephaly, and it is likely to confer multiple health benefits to the adult population. Scientists and advocates are bringing this intervention to the attention of policymakers in countries around the world, and consequently the demand for sound, science-backed policy rationale is increasing.

METHODS

We recently prepared this scientific review for scientists, physicians, and advocates who were promoting mandatory folic acid fortification of flour in Australia and New Zealand. This short document references the most relevant published scientific data and national and international recommendations from other countries and presents an argument for fortification based on demonstrated need, proven effectiveness, safety, and multiple health benefits.

CONCLUSIONS

With some modifications, this document could be utilized in other countries considering fortification of flour or other staple products with folic acid.

Screening for homocysteine levels in Israel in primary care clinics: a need for guidelines

BACKGROUND

Elevated total homocysteine (tHcy) levels (>/= 15 micromol/L), resulting from enzyme or vitamin deficiency, increase risk for cardiac, cerebral, and peripheral vascular disease. This study examines tHcy levels in an Israeli population and the relationship to vitamin status and disease. The need for screening guidelines is discussed.

METHODS

Fasting blood was tested for tHcy levels in 262 patients (141 male, 121 female) presenting to two primary care clinics. Levels of folic acid and vitamin B12 were examined as well.

RESULTS

Elevated tHcy levels (>/= 15 micromol/L) were found in 43 of the males (30.5%) and four of the female patients (3.3%, P < 0.005), while females had higher levels of both vitamin B12 and folic acid. Those with elevated tHcy levels tended to be older and with lower vitamin levels, with a higher frequency of coronary artery disease.

CONCLUSIONS

Screening for tHcy and fortification of grain products with folic acid is a cost-effective means for preventing disease. Serum tHcy levels are inversely related to vitamin status, and higher levels among males is thought to be due to metabolic differences between the genders. Guidelines for screening for tHcy in Israel should be established, and fortification of grain products implemented.

Use of nutritional supplements for the prevention and treatment of hypercholesterolemia

OBJECTIVE

Hypercholesterolemia is a major risk factor for the development of coronary artery disease. Studies have shown that several vitamins and nutritional supplements may contribute to a reduction in total and low-density lipoprotein cholesterol. This goal of this study was to document the use of vitamins and nutritional supplements that may treat or prevent hypercholesterolemia.

METHODS

Secondary analysis of the National Health and Nutrition Examination Survey III responses from 13,990 patients were available to use for making population estimates.

RESULTS

Of those individuals with a known diagnosis of hypercholesterolemia, 3.6% were taking at least one vitamin or nutritional supplement to decrease cholesterol levels. For individuals trying to prevent hypercholesterolemia, 1.2% were using one of these vitamin or nutritional supplements. Only 0.7% of individuals without or trying to prevent hypercholesterolemia used one of these specific supplements. We used multivariate analysis to control for several factors, and individuals with a diagnosis of hypercholesterolemia had an adjusted odds ratio of 2.10 (95% confidence interval, 1.38-3.21) for vitamin use compared with those without or trying to prevent high cholesterol. Those trying to prevent hypercholesterolemia had an adjusted odds ratio of 0.69 (95% confidence interval, 0.48-1.00) for vitamin use compared with those without or trying to prevent high cholesterol.

CONCLUSIONS

The use of vitamins and nutritional supplements that may reduce total and low-density lipoprotein cholesterol levels is low in the United States. Future research is needed to confirm the effectiveness of these products, examine the quality and purity of currently available products, and explore whether using these supplements are an adequate low-cost alternative to pharmaceuticals now available.

News and views on folate and elderly persons

Elderly persons are especially exposed to folate deficiency, where normal/subnormal folate levels do not exclude tissue deficiency. Accompanying diseases, medication, and lifestyle factors may contribute to/cause deficiency. Symptoms of deficiency can be hematological, neurological, or neuropsychiatric, but it is likely that there are also cardiovascular manifestations as well as associations with malignancies. The physician should make an individualized investigation to establish the probable cause. Among the available determinants of the folate/cobalamin state, plasma homocysteine (Hcy) is a swift and sensitive marker and has the strongest connection to cognitive function. The association is generally stronger between Hcy levels and symptoms than between vitamin-related levels and symptoms. The duration as well as the severity of symptoms are of importance in terms of the improvement of neurological and neuropsychiatric symptoms when substitution is performed. The issue of general folate fortification of flour is complex, and there are as many pros and cons as there are countries in which it is considered to be launched. It is important to bear in mind that in our modern society, deficiency of folate/cobalamin--overt or latent--mainly is a problem of the elderly and a challenge to the doctor.

Metabolic and nutritional support in acute cardiac failure

PURPOSE OF REVIEW

Cardiovascular disease is one of the most important causes of morbidity and mortality in western countries, generating an increasing number of admissions to intensive care units. Cardiac failure has long been associated with nutritional disorders, malnutrition and cachexia being frequent during the late phases of congestive heart failure: undernutrition is also a determinant of outcome, even after cardiac transplantation.

RECENT FINDINGS

It has been shown that early metabolic support can improve the recovery of the ischaemic heart. This paper reviews recent findings on substrates that can support the failing myocardium, which are mainly glucose-insulin, glutamine, taurine, selenium, thiamine, folic acid, and omega-3 fatty acids. Ischaemia-reperfusion generates tissue lesions that can be partly prevented through substrate manipulation.

SUMMARY

Shifting the substrate metabolism from lipids to carbohydrates and reinforcing the antioxidant status reduces the deleterious biological and clinical consequences of acute ischaemic events. The use of the glucose-insulin-potassium infusion has become widespread with the re-discovery of its value in modulating cellular metabolism and accelerating recovery of the ischaemic myocardium. Antioxidants have gained acceptance in the perioperative phase, as well as in chronic heart failure. This constitutes another piece of evidence in favour of early metabolic and nutritional intervention. There also appears to be room for the prevention of acute deterioration of cardiac function after surgery with the preoperative administration of oral supplements containing omega-3 fatty acids.

Hyperhomocysteinemia and vitamin B-12 deficiency in elderly using Title IIIc nutrition services

BACKGROUND

The effect of the folate food fortification program on the prevalence of hyperhomocysteinemia in the older population with coexisting vitamin B-12 deficiency is not known.

OBJECTIVE

The objective was to determine the prevalence of hyperhomocysteinemia and vitamin B-12 deficiency in elderly who were using Title IIIc nutrition services, after folate food fortification in the United States.

DESIGN

Demographic, nutritional, cognitive, routine diagnostic, and serum methylmalonic acid (MMA) and total homocysteine (tHcy) tests were performed in a convenience sample of 103 elderly enrolled in nutrition service programs in rural northeast Georgia. A subgroup (n = 27) was treated with vitamin B-12, 2.5 mg, and a multivitamin with 400 micro g folic acid, 2 mg vitamin B-6, and 27 mg ferrous fumarate.

RESULTS

The total cohort included 103 participants (+/- SD age: 76.4 +/- 8.1; 80% female; 68% white, 32% African American). Vitamin B-12 deficiency (serum vitamin B-12 < 258 pmol/L and MMA > 271 nmol/L) was present in 23%. Mean serum folate was high, 39.3 nmol/L, and no subject had serum folate < 6.8 nmol/L. Mean tHcy was 17.6 +/- 7.2 micro mol/L in vitamin B-12-deficient subjects and 10.8 +/- 3.6 micro mol/L in those who were nondeficient. Determinants of high tHcy were vitamin B-12 deficiency, high serum creatinine, and low red blood cell folate. Those with vitamin B-12 deficiency were more likely to have poor cognition (58% compared with 20%, P < 0.001) and anemia (38% compared with 18%, P = 0.042). High-dose oral B-12 therapy lowered mean MMA and tHcy by 49% and 32%, respectively.

CONCLUSION

Vitamin B-12 deficiency was prevalent and was associated with poor cognition, anemia, and hyperhomocysteinemia.