Gene polymorphisms and low dietary intake of micronutrients in coronary artery disease

Coronary artery disease (CAD) is a complex disorder involving genetic and non-genetic factors. Food is an important component of the latter. We examined if DNA polymorphisms in genes encoding enzymes of one-carbon metabolism coupled with low consumption of micronutrients such as folate, vitamins B(6) and B(12) might increase the risk of CAD.

A case-control study consisting of 252 CAD patients and 252 controls were included. Three single nucleotide polymorphisms (SNP), 2 insertion/deletion and 1 repeat polymorphism were typed. The micronutrient intake was estimated from a standard 24-hour dietary recall coupled to a food frequency questionnaire.

The results suggest an association of 'early-onset CAD' with betaine homocysteine S-methyl transferase (BHMT) 742G→A SNP (odds ratio = 1.52; 95% confidence interval, 0.96-2.41; p = 0.04). No association was observed for all age of onset, but more patients than controls whose micronutrient intake was in the lowest quintile also carried the minor allele (50% patients vs. 37% controls; p = 0.042). Furthermore, dietary intake of folate micronutrients below the recommended daily allowance was observed in a larger percent of patients than controls with the minor BHMT allele (51% patients vs. 44% controls; p = 0.021).

In the presence of the minor BHMT allele, a decreased consumption of folate micronutrients might increase the risk of CAD.