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

Prevention of myocardial infarction

Despite the rapid advances that have been made in the treatment of coronary artery disease, myocardial infarction remains the major cause of death in the developed world and a growing problem for developing countries. To address this growing problem, a strategy aimed at prevention of events in high-risk individuals is required. This involves assessment of cardiovascular risk followed by risk reduction. At present there is no perfect technique available for risk prediction, although computed tomography and magnetic resonance imaging scanning, along with serum markers of inflammation, offer the greatest potential. The applicability of these techniques at present is also limited by cost and accessibility. Risk reduction is possible through lifestyle changes and drug therapy, and effective risk assessment is essential in selecting those most likely to benefit from these interventions.

Vitamin nutrition in older adults

Proper vitamin nutrition is essential for all people but especially for elderly persons, because they are at higher risk for deficiency than younger adults. A review of the clinical effects of vitamin deficiency shows how easily deficiency can masquerade as other morbidities, such as skin, neurologic, and gait abnormalities. Given the numerous readily available forms and sources of supplementation, their low cost, and their rather limited potential for harm, the goal of good vitamin nutrition for the elderly is easily attainable. To be successful in this goal, physicians must look for patients at risk and for those with features of frank vitamin deficiency. Laboratory testing is most helpful with respect to vitamin B12 and folate deficiency. Given the great value of clinical assessment, the low cost of vitamins, and the higher cost of laboratory testing, the authors do not recommend testing before instituting multivitamin use or extra supplementation with individual vitamins unless the diagnosis of deficiency is in question or the use of supplementation would put the patient at risk. The authors' general recommendations are * one multivitamin daily * extra vitamin E for patients with cardiovascular risk factors or Alzheimer's dementia * extra vitamin D for patients with known osteoporosis, osteoporosis risk factors, or strong risk factors for vitamin D deficiency * extra folate for patients with cardiovascular risk factors (especially smokers) and alcoholics * extra thiamine for alcoholics.

Dietary folate and the risk of nonfatal myocardial infarction

BACKGROUND

Elevated homocysteine levels have been associated with a higher risk of cardiovascular disease. Because folate intake can reduce homocysteine levels, we investigated the association between dietary folate intake and nonfatal myocardial infarction.

METHODS

We conducted a case-control study in three tertiary hospitals of Pamplona, Spain, between 1999 and 2001. Study physicians enrolled 171 patients less than 80 years of age with a first nonfatal myocardial infarction and 171 control patients matched by age, sex, hospital and calendar month. We excluded patients with any prior major cardiovascular disease. Participants were interviewed about medical factors and life-style and completed a food frequency questionnaire previously validated in Spain. We calculated energy-adjusted intakes of folate and estimated relative risks (RRs) of myocardial infarction and 95% confidence intervals (CIs) using conditional logistic regression. Relative risks were adjusted for conventional risk factors.

RESULTS

Only 6% of participants were taking vitamin supplements. The main sources of folate were green leafy vegetables, green beans, oranges, peppers and lettuces. The estimated matched RR of myocardial infarction for the top three quartiles of folate intake (, above 340 microg/day) was 0.57 (CI = 0.35-0.94), compared with the lowest quartile of intake. The multivariate adjusted RR was 0.51 (CI = 0.24-1.06). There was no apparent dose effect above this threshold.

CONCLUSIONS

Our results in a Mediterranean population with natural plant foods as the main source of folate provide further evidence to support the hypothesis that dietary folate intake may be an independent protective factor for myocardial infarction. The magnitude of the effect, its biological plausibility, and the consistency across studies offer support for a causal association.

Nutrition intervention in ethnic minority groups

Development of effective intervention strategies to meet the needs of people with ethnic minority origins is dependent on two factors: an understanding of the modifiable risk factors which can form the basis of intervention; an understanding of the relevant health behaviours so that appropriate strategies can be designed. The present paper briefly reviews the evidence concerning the part that nutritional and dietary factors play in the aetiology of the observed patterns of disease in these groups and the limitations of the data as a basis for intervention. Consideration is also given to the available information concerning factors influencing health behaviour (particularly eating behaviour) and the applicability of commonly-used models of behaviour change to people of ethnic minority origin. Finally, the results of nutrition intervention programmes will be examined with a view to identifying lessons for the future.

Potential for community programs to prevent depression in older people

Depression is one of the most common mental health disorders in older people. Sequelae include unnecessary suffering, excess physical and social disability, exacerbation of co-existing illness, earlier death, and overuse of services. There are currently no reported public health approaches to prevent late-life depression. Five risk factors appear susceptible to community-level prevention programs: recurrent depression, commonly undertreated precipitants, vascular disease, functional impairments, and metabolite abnormalities. We propose three broad but interacting prevention methods: increasing literacy about late-life depression, exercise, and dietary supplements.

Homocyst(e)ine and coronary heart disease: pharmacoeconomic support for interventions to lower hyperhomocyst(e)inaemia

Homocyst(e)ine, a sulphur-containing amino acid, is an intermediate formed during the metabolism of the essential amino acid methionine. Biological and epidemiological evidence suggest that elevated plasma levels of homocyst(e)ine are a risk factor for atherosclerosis and coronary heart disease (CHD). In the general US population, hyperhomocyst(e)inaemia is common and most often due to mild nutritional deficiencies in the B vitamins (folic acid, vitamin B(12) and vitamin B(6)). While high homocyst(e)ine levels can be effectively lowered using folic acid and other B vitamins, it is unknown whether such vitamin therapy will lead to clinical benefits. Given that strategies for homocyst(e)ine-lowering are safe and inexpensive, however, even small reductions in CHD risk will be highly cost effective. Thus, it may be prudent for patients to ensure an adequate daily intake of dietary folic acid and other B vitamins and for physicians to screen high-risk adults such as those with established CHD as we await definitive results from ongoing clinical trials.