Do some people have special "susceptibility" genes that make them vulnerable to obesity and diabetes, triggered by poor diet and less exercise?
Stephen McGarvey, professor of community health and anthropology at Brown University, will attempt to answer that question as part of a new a five-year, $5.2-million National Institutes of Health grant to conduct detailed genotyping of thousands of adults in the independent nation of Samoa. The project will document genetic variation and see whether it has any association with propensities towward obesity, diabetes and cardiovascular disease.
The results should help advance the overall science of genomics-based medicine, McGarvey said.
"If we are saying that the fruits of the genomics revolution are going to be used and shared to improve clinical care, then we need to get this basic type of information from other human populations," McGarvey said. "It's not just European Americans or Europeans in Europe. Right now, we don't know for a lot of other groups which drug or behavioral interventions will work best for a panoply of conditions that they are now showing as they enter the modern world. Understanding diversity in genetic susceptibility across many ethnic groups is an important scientific and ethical goal." Specifically, McGarvey's effort will involve genotyping 3,000 adult Samoans in a study that will also track diet and physical activity.
Samoans are a Polynesian people in the Pacific region, a very homogeneous population that has been characterized as having very large body size and a high prevalence of obesity, diabetes and cardiac problems. The genotyping will try to determine whether there are any special "susceptibility" genes that increase the risk of obesity and diabetes and whether a genetic susceptibility could be exacerbated by unhealthy diets and insufficient exercise.
"They have a unique population history in terms of how their population was formed over the last 5,000 years," McGarvey said. "They may have some of these genetic susceptibilities at higher or lower frequencies than other groups, and we want to understand how that diversity influences health on a worldwide basis."