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.
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.


METHODS
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.
Department of Medicine, Umeå University Hospital, Sweden. amt@dadlnet.dk
A M
AM
Thögersen
T K
TK
Nilsson
G
G
Dahlen
J H
JH
Jansson
K
K
Boman
F
F
Huhtasaari
G
G
Hallmans
D016022:Case-Control Studies; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006720:Homozygote; D006801:Humans; D016015:Logistic Models; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology* / Q000235:genetics*; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics*; D017354:Point Mutation; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology
D006710:Homocysteine; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2)