Homozygosity for the C677-->T mutation of 5,10-methylenetetrahydrofolate reductase and total plasma homocyst(e) ine are not associated with greater than normal risk of a first myocardial infarction in northern Sweden.

摘要

BACKGROUND: Results of several case-control studies have shown elevated total plasma homocyst(e)ine (TPH) and homozygosity for the point mutation C677-->T in the gene for 5,10-methylenetetrahydrofolate reductase (MTHFR) to be associated with a greater than normal risk of atherosclerotic vascular disease. However, there have been few epidemiologic studies and the interpretation of the results is not clear-cut. OBJECTIVE: To elucidate whether homozygosity for the point mutation C677-->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 36000 persons screened, 78 cases satisfied the inclusion criterion of having developed, after sampling, a first myocardial infarction. For each case, two controls matched for sex and age were randomly selected. RESULTS: We found no statistically significant difference among the prevalences of the three possible MTHFR genotypes -/- (no mutation), +/+ (both alleles have the mutation), and +/- among cases and controls in univariate conditional logistic regression analysis. Mean levels of TPH in patients and controls were 12.2+/-4.9 and 12.2+/-3.5 micromol/l (means +/- SD), respectively (NS). CONCLUSIONS: In this study neither homozygosity for the point mutation C677-->T in the gene for MTHFR nor TPH was related to a greater than normal risk of a first myocardial infarction for members of the population of northern Sweden. Further research is needed in order to show whether TPH is an independent risk factor for a first myocardial infarction.