MI risk increased by triglyceride-associated SNP
MedWire News: A single nucleotide polymorphism (SNP) in a gene associated with higher fasting triglyceride levels increases the risk for early-onset myocardial infarction (MI), independently of triglyceride levels, Italian scientists have discovered.
MI results from a complex interaction between genetic and environmental factors. While the role of environmental factors has been clearly established, there are only a few original candidate genes confirmed as potential risk factors for MI.
Raffaele de Caterina, from G d'Annunzio University-Chieti in Pisa, and colleagues therefore examined the association between early-onset MI, lipid levels, and 20 SNPs in candidate genes previously reported as being associated with coronary heart disease (CHD) or CHD risk factors.
Specifically, SNPs in the genes ADIPOQ, APOA5, ALOX5AP, CYBA, IL6, LPL, PECAM1, PLA2G2A and PLA2G7 were studied in 1864 patients aged <45 years who were hospitalized for a first MI and 1864 age-, gender-, and place of origin-matched controls.
The results, published in the journal Atherosclerosis, showed that only the SNP APOA5-1131T>C (rs662799) was significantly associated with the risk for early-onset MI, at a per C allele odds ratio after Bonferroni correction of 1.44.
APOA5-1131T>C was also significantly associated with increased plasma triglyceride levels in carrier versus non-carrier controls, raising levels by 11.4% per C allele increase, or 13.27 mg/dl (0.15 mmol/l). Nevertheless, the association between early-onset MI and APOA5-1131T>C remained significant after taking into account triglyceride levels.
"The major outcome of our study is that, of the 20 SNPs representing variation in nine genes previously associated with CHD risk, only the APOA5-1131T>C variant showed a strong, significant association with early-onset MI," the researchers write.
They add: "Moreover, when the effect on early MI risk was adjusted for hypertriglyceridemia, hypercholesterolemia, hypertension, and smoking, and -separately - for plasma triglycerides, the association remained significant, suggesting triglyceride-independent mechanisms affecting MI risk."
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By Liam Davenport