Wednesday, October 05, 2016 4:00pm - 5:00pm
Watson CIT - SWIG Boardroom (CIT241)
Professor of Epidemiology
Director of International Health Institute
The Samoas’ world-leading rate of
obesity is a recent phenomenon, heavily influenced by the globe’s rapid shift
to calorie-rich, processed foods and more sedentary lifestyles.
A new study, however, suggests
nearly half of Samoans have a newly identified and significant genetic variant
that contributes to obesity risk; a variant that had remained undiscovered
until researchers focused on the islands’ populations. In cell models in the
lab, this “thrifty” variant promoted more efficient storage of more fat.
“A previously unknown genetic
variant in an understudied gene is strongly associated with body-mass index
(BMI) levels and other adiposity measures in Samoan men and women we studied in
2010,” said Stephen McGarvey, corresponding author of the paper in Nature
Genetics and professor in the Brown University School of Public Health. While
the variant helps to explain why 80 percent of Samoan men and 91 percent of
Samoan women were overweight or obese in 2010, he said, it is by no means a
“Although we have found a genetic
variant with a reasonable biological mechanism, this genetic variant is just
one part of the many reasons for the high levels of BMI and obesity among
Samoans,” he said.
McGarvey with a team of colleagues
at the University of Pittsburgh, the University of Cincinnati and Yale
University, as well as Samoan government officials, conducted the study. The
team pinpointed a single genetic variant on chromosome 5 that, according to the
researchers’ estimate, is associated with about 35 percent higher odds of being
obese compared to not having the gene variant.