Prevalences of hyperhomocysteinemia, unfavorable cholesterol profile and hypertension in European populations.

BACKGROUND: Hyperhomocysteinemia (HHCY) is a risk factor for cardiovascular diseases (CVD). HHCY may interact with hypertension (HTEN) and an unfavorable cholesterol profile (UNFAVCHOL) to alter the risk of CVD. OBJECTIVES: To estimate the prevalences of HHCY (1) isolated and (2) in combination with UNFAVCHOL and/or HTEN in different age categories. To provide information that may improve the screening and treatment of subjects at risk of CVD. DESIGN: Cross-sectional data on 12,541 men and 12,948 women aged 20 + y were used from nine European studies. RESULTS: The prevalence of isolated HHCY was 8.5% in subjects aged 20-40 y, 4.7% in subjects aged 40-60 y and 5.9% in subjects aged over 60 y. When combining all age groups, 5.3% had isolated HHCY and an additional 5.6% had HHCY in combination with HTEN and/or UNFAVCHOL. The combinations of risk factors increased with age and, except for HHCY&UNFAVCHOL, were more prevalent than predicted by chance. Of the young subjects (20-40 y), 24% suffered from one or more of the investigated CVD risk factors. This figure was 75.1% in the old subjects (60+ years). CONCLUSIONS: A substantial number of subjects in selected European populations have HHCY (10.9%). In half of these cases, subjects suffer also from other CVD risk factors like UNFAVCHOL and HTEN. Older people in particular tend to have more than one risk factor. Healthcare professionals should be aware of this when screening and treating older people not only for the conventional CVD risk factors like UNFAVCHOL and HTEN but also HHCY, as this can easily be reduced through increased intake of folic acid via supplement or foods fortified with folic acid.

Evidence for a protective (synergistic?) effect of B-vitamins and omega-3 fatty acids on cardiovascular diseases.

The results of dietary intervention trials favor the hypothesis that higher intakes of B-vitamins (folate, vitamin B(6) and B(12)), and subsequently lower total homocysteine (tHcy) concentrations, are causally associated with a decreased risk of vascular disease in patients with cardiovascular diseases (CVD). The same is true for a higher intake of omega-3 fish fatty acids. Yet, the lack of hard end points and/or appropriate study designs precludes a definitive conclusion about causality. In the future, intervention trials with hard end points and randomized double-blind placebo-controlled designs should be able to elucidate the causality problem. There are several pathways by which B-vitamins and omega-3 fatty acids may exert their protective effect on CVD, a common pathway is a beneficial effect on the endothelial function and hemostasis. With respect to synergy between B-vitamins and omega-3 fatty acids, there is no evidence that fish oils have a tHcy-lowering effect beyond the effect of the B-vitamins. Nevertheless, animal studies clearly illustrate that vitamin B(6)- as well as folate-metabolism are linked with those of long-chain omega-3 fatty acids. Furthermore, a human study indicated synergistic effects of folic acid (synthetic form of folate) and vitamin B(6) together with omega-3 fatty acids on the atherogenic index and the fibrinogen concentration. Although these results are promising, they were produced in very small selective study populations. Thus, confirmation in large well-designed intervention trials is warranted.

The use of computerised 24 h dietary recalls in the French SU.VI.MAX Study: number of recalls required.

OBJECTIVE: The 24 h dietary recall is a widely used method to estimate nutritional intakes in epidemiological studies. The objective of the present study was to estimate the number of recalls necessary for an accurate estimation of nutrient intake in French adults followed for 4 y. SUBJECTS AND METHODS: Participants of the SU.VI.MAX study (intervention study on the effects of antioxidant supplementation on chronic diseases) who completed a 24 h dietary recall every 2 months for at least 1 y. Inter- and intra-individual variance ratios (S(w)/S(b)) were calculated by analysis of variance for two time periods: year 1 and 2 (n=4955) and year 3 and 4 (n=1458). The number of recalls necessary was calculated using an accuracy of 0.9. RESULTS: The highest intra-individual/inter-individual variance ratio in the first period was seen for beta-carotene and the lowest for carbohydrate. The number of recalls necessary was five for carbohydrate and calcium intake and 16 for beta-carotene. For proteins, total and saturated fat, fibre, vitamin C and iron eight recalls were required, while nine, 11 and 10 recalls were necessary for mono- and polyunsaturated fat and vitamin E, respectively. The variance ratios in the second period were all lower and fewer recalls were therefore required. The same difference in number of recalls required between the two time periods was observed when only those subjects were included who completed at least 18 recalls (n=727). CONCLUSION: These results indicate that for an accurate estimation of carbohydrate intake only, already five recalls are necessary. Fewer recalls may be needed during long-time follow-up. SPONSORSHIP: The SU.VI.MAX Study has support from public and private sectors: Fruit d'Or Recherche, Candia, Lipton, Kellogg's, Céréal, CERIN, Estée Lauder, L'Oréal, Peugeot, Jet Service, RP Scherer, Sodexho, France Telecom, Santogen, Becton Dickinson, Fould Springer, Boehringer Diagnostic, Seppic Givaudan Lavirotte, Le grand Canal, Danone and Knorr.