Researchers have now sheds light on the role of blood lipid levels and genes in cardiovascular health.
Newer tools for gene analysis show how variations in DNA are underlying actors affecting heart disease-a major worldwide cause of death and disability.
Geneticist Brendan J. Keating, D. Phil., of The Center for Applied Genomics at The Children's Hospital of Philadelphia and his colleagues, working in large international collaborative groups, are wielding advanced gene-analysis tools to uncover important clues to heart disease.
The study team used a recently developed epidemiology tool called Mendelian randomization (MR).
The researchers analyzed DNA data from 17 studies including over 60,000 individuals, of whom more than 12,000 had experienced coronary heart disease, including heart attacks. Because previous studies had found signals from nearly 200 genes to be associated with blood lipid levels, the study team aggregated data into composite groups, called allele scores, for each of three blood lipids: LDL, HDL and triglycerides, then calculated their relationship to coronary heart disease.
As expected, the current study confirmed that higher levels of LDL, the "bad cholesterol," were more likely to cause heart disease. But there were new results: high levels of triglyceride also caused higher risk of heart disease. At the same time, there was little evidence that higher levels of HDL, the "good cholesterol," had a protective effect.
The study has been published in the European Heart Journal.