Homozygosity for the C-677 -> T mutation of 5,10-methylenetetrahydrofolatereductase and total plasma homocyst(e)ine are not associated with greater than normal risk of a first myocardial infarction in northern Sweden

Background Results of several case-control studies have shown elevated tota l plasma homocyst(e)ine (TPH) and homozygosity for the point mutation C-677 --> T in the gene for 5,10-methylenetetrahydrofolate reductase (MTHFR) to be associated with a greater than normal risk of atherosclerotic vascular d isease. However, there have been few epidemiologic studies and the interpre tation of the results is not clear-cut. Objective To elucidate whether homozygosity for the point mutation C-677 -- > T in the gene for MTHFR, and TPH are risk factors for a first myocardial infarction, Design A prospective nested case-control study in Northern Sweden, Methods Among more than 36 000 persons screened, 78 cases satisfied the inc lusion criterion of having developed, after sampling, a first myocardial in farction. for each case, two controls matched for sex and age were randomly selected. Results We found no statistically significant difference among the prevalen ces of the three possible MTHFR genotypes -/- (no mutation), +/+ (both alle les have the mutation), and +/- among cases and controls in univariate cond itional logistic regression analysis. Mean levels of TPH in patients and co ntrols were 12.2 +/- 4.9 and 12.2 +/- 3.5 mu mol/l (means +/- SD), respecti vely (NS), Conclusions In this study neither homozygosity for the point mutation C-677 --> T in the gene for MTHFR nor TPH was related to a greater than normal r isk of a first myocardial infarction for members of the population of north ern Sweden. Further research is needed in order to show whether TPH is an i ndependent risk factor for a first myocardial infarction, Coron Artery Dis 12:85-90 (C) 2001 Lippincott Williams & Wilkins.