How we wish to be cited:
Norberg B. Coronary restenosis. Benefits of B vitamins [editorial]. Rondel 2002; 10. URL: http://www.rondellen.net

Homocysteine is a swift, broad and sensitive marker for cobalamin deficiency and folate deficiency. A one-vitamin deficiency as well as a two-vitamin deficiency may increase the plasma homocysteine from the upper reference limit of about 15 micromoles per liter to the range of 50 –100 or higher (cf. 1). This fact is better known by ordinary clinicians than by expert reviewers. Thus, homocysteine provides a screening test, which excludes cobalamin/folate deficiency with a high degree of probability.

Homocysteine is also associated with thromboembolic vascular disease. The correlation could be interpreted to mean that vascular disease leads to elevated homocysteine levels or, conversely, the increased homocysteine levels lead to thromboembolic vascular disease. Intervention studies have so far provided contradictory results (cf. 2-6). Positive findings have not been confirmed in other studies. Conversely, the null hypothesis is a scoundrel, which at best can be acquitted short of evidence.

Homocysteine may be lowered in most persons by cobalamin and folate; the role of pyridoxine remains obscure (cf 5). Homocysteine lowering by different combinations of the central B vitamins has provided more consistent results in patients with coronary disease than in patients with other sorts of thromboembolic vascular disease (cf 3). A new study has supported the idea that intervention with such vitamins has a beneficial effect on the course coronary disease (6, 7).

The new intervention report was performed on 205 consecutive patients after percutaneous coronary angioplasty (6, 7). The study was prospective, randomized and placebo-controlled. The mean age of the group was 61 years, the mean homocysteine before treatment was normal, 11 micromoles per liter. The B vitamin combination (cobalamin 0.4 mg, folic acid 1 mg, pyridoxine 10 mg) lowered homocysteine by 35% in the treatment group. During the first six months, the parameters of morbidity had a more favorable course in the treatment group than in the placebo group with probability values ranging between 0.01-0.06.

The results of the new study (7) provide a merit for the scientists and the vitamin combination involved. The observations are compatible with the main working hypothesis since 1990 that homocysteine lowering is beneficial in vascular disease. However, there is still a step or two from thought to thesis.