People lucky enough to carry a
variant in a single gene get added protection against both type 2 diabetes and
heart disease, a new study finds.
Individuals with the trait aren't
immune from the conditions, researchers say, but a study of nearly 7 900
subjects found that they are as much as 48 percent less likely to suffer from
either illness.
"This gives us insight into how heart disease and
diabetes may develop," said co-author Eric Rimm, an associate professor of
epidemiology and nutrition at the Harvard School of Public Health in Boston.
Genes can play a major role
Scientists don't think diabetes and heart
disease are inherited, but genes can play a major role, they say. "We do know
there are genes that make people more susceptible to becoming diabetic if
they're exposed to the right environmental factors," Rimm said. Specific genes
have also been linked to heart disease.
In mice, a gene variation appears to provide protection against type 2
diabetes and clogged arteries. In the new study, Rimm's team examined the
medical and genetic records of 7 899 people to see if the variation did the same
thing for humans.
The study findings appear in this week's issue of the Proceedings of the
National Academy of Sciences.
A total of 4.3 percent of the people studied had one copy of the variant
gene, Rimm said.
12% lower triglyceride levels
These people appear to have won a kind of
genetic lottery, because levels of triglycerides - a potentially dangerous type
of blood fat - were 12 percent lower in their blood than in the other subjects.
Their risk of heart disease was also 34 percent lower, and if they were obese,
their risk for type 2 diabetes was 48 percent less than that of obese
individuals who did not carry the gene variant.
Rimm suspects that the genetic variation helps control molecular signals that
influence how triglycerides circulate in the blood.
What next? It's possible that a better understanding of the genetics of
diabetes and heart disease could lead to more effective treatments, Rimm said.
"If you could emulate what this form of this gene is doing, maybe you could
lower someone's risk of heart disease or diabetes by copying the same type of
physiological effects," he added.
Genetic tests may spot risk
The research raises another possibility:
genetic tests that could alert people if they have a higher likelihood of
getting diabetes later in life.
Ideally, "if you know in advance that you're at risk, that would make people
think and give them the opportunity to protect themselves," said Dr Larry C.
Deeb, the American Diabetes Association's president-elect of medicine and
science.
After all, he said, diabetes is largely preventable.