Hyperhomocyst(e)inemia is an important risk factor for vascular disease in subjects with high-molecular weight apo(a) isoforms.
BACKGROUND
Homocyst(e)ine is reported to increase the binding of lipoprotein(a) [Lp(a)] to fibrin, which may increase the thrombogenic effects of Lp(a) in vivo. The aim of this study was to investigate whether there is a relationship between homocyst(e)ine and Lp(a) levels and vascular disease risk, and if the relationship depends on the apo(a) isoforms.


METHODS
A case-control study was performed in 91 Caucasian male subjects with vascular disease due to athersclerosis, and in 100 healthy age- and sex-matched control subjects.


RESULTS
Both hyperhomocyst(e)inemia and elevated Lp(a) were significantly more prevalent in patients. Concordant elevated Lp(a) and hyperhomocyst(e)inemia were not associated with increased vascular disease risk (relative odds 2.96; 95% CI: 0.90-9.80), while hyperhomocyst(e)inemia in the absence of elevated Lp(a) was associated with increased vascular disease risk (relative odds 7.20; 95% CI: 2.37-21.91). Hyperhomocyst(e)inemia in individuals with high-molecular weight apo(a) isoforms [smaller apo(a) isoform > S3] was observed to be associated with increased vascular disease risk (relative odds 11.02; 95% CI: 3.54-34.30), while vascular disease risk in subjects with low-molecular weight apo(a) isoforms [smaller apo(a) isoform < S3] was not significantly increased, the relative odds being 1.92; 95% CI: 0.51-7.24.


CONCLUSIONS
We conclude that hyperhomocyst(e)inemia is an important risk factor in individuals with high-molecular weight apo(a) isoforms.
Department of Chemical Pathology, Institute of Pathology, University of Pretoria, Pretoria, South Africa.
Rhena
R
Delport
Arnulf W
AW
Lingenhel
Johan B
JB
Ubbink
Hans G
HG
Kraft
D017677:Age Distribution; D001054:Apolipoproteins A / Q000097:blood* / Q000378:metabolism; D001774:Blood Chemical Analysis; D016022:Case-Control Studies; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D012016:Reference Values; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D017678:Sex Distribution; D018709:Statistics, Nonparametric
D001054:Apolipoproteins A