Scientists at Weill Cornell Medical College report they have discovered that a genetic variation that is linked to increased levels of triglycerides, which is associated with heart disease, type 2 diabetes, obesity, and stroke, is far more common than previously believed. It also disproportionally affects people of African ancestry.
The scientists say their findings (“Prevalence of the Apolipoprotein E Arg145Cys Dyslipidemia At-Risk Polymorphism in African-Derived Populations”), reported in the American Journal of Cardiology, reinforces the need to screen this population for high levels of triglycerides to stave off disease.
This research offers a clue as to why Africans and people of African descent have an increased risk of cardiovascular disease and type 2 diabetes compared to many other populations, according to the study's senior author, Ronald G. Crystal, M.D., chairman of genetic medicine at Weill Cornell.
“The prevalence of the R145C variant [of the ApoE protein] was assessed worldwide in the ‘1000 Genomes Project’ and in 1,012 whites and 1,226 African-Americans in New York, New York. The 1000 Genomes Project data demonstrated that the R145C polymorphism is rare in non-African-derived populations but present in 5% to 12% of Sub-Saharan African-derived populations,” wrote the investigators. “The R145C polymorphism was also rare in New York whites (1 of 1,012, 0.1%); however, strikingly, 53 of the 1,226 New York African-Americans (4.3%) were R145C heterozygotes. The lipid profiles of the Qatari and New York R145C heterozygotes were compared with those of controls. The Qatari R145C subjects had higher triglyceride levels than the Qatari controls (p <0.007) and the New York African-American R145C subjects had an average of 52% greater fasting triglyceride levels than the New York African-American controls (p <0.002).”
“The prevalence of the ApoE mutation may put large numbers of Africans and African descendants worldwide at risk for a triglyceride-linked disorder,” noted Dr. Crystal. “But we don't yet know the extent of that risk or its health consequences.”
He explained that inheriting this genetic variant does not mean a person is going to get heart disease and other diseases. “It increases their risk, and screening for fats in the blood as well as maintaining a healthy lifestyle is important,” said Dr. Crystal. “There are many factors at work in these diseases. This may be one player.”