In the largest ever genome-wide study helped explain the link between genetics and obesity.
The new research highlights a genetic reason for why some people have a tendency to gain weight, the University of Michigan Health System reported. To make their findings researchers analyzed genetic samples for half a million individuals as part of the GIANT research project. The new findings could help researchers develop new weight-loss therapies
"Our work clearly shows that predisposition to obesity and increased body mass index is not due to a single gene or genetic change," said senior study author Elizabeth Speliotes, M.D., Ph.D., M.P.H, assistant professor of internal medicine and computational medicine and bioinformatics at the University of Michigan Health System. "The large number of genes makes it less likely that one solution to beat obesity will work for everyone and opens the door to possible ways we could use genetic clues to help defeat obesity."
The researchers looked at the genetic basis of body mass index (BMI) in up to 339,224 individuals. They identified 97 sites associated with obesity, which triples the number of previously known regions. These findings could one day help explain why not all obese individuals develop related metabolic diseases, such as type 2 diabetes and high cholesterol. They could also be used to develop effective treatments for obesity and new ways to prevent these types of metabolic diseases.The findings show the central nervous central plays a key role in obesity susceptibility, which includes the pathway that responds to diet changes.
"Presently we have no way of knowing if obese individuals will develop these obesity-related metabolic diseases and if so which ones," Speliotes said. "We envision using these genetic markers to help doctors decide which treatments would work best to keep patients healthy."
A companion GIANT analysis of 224,459 individuals also identified 49 sites in the genome related to waist-to-hip ratio, which can be an indicator of body fat distribution. An accumulation of fat in this area has been linked to both cardiovascular and metabolic diseases.
"We need to know these genetic locations because different fat depots pose different health risks," said Karen Mohlke, Ph.D., professor of genetics at the University of North Carolina School of Medicine and a senior author on the paper. "If we can figure out which genes influence where fat is deposited, it could help us understand the biology that leads to various health conditions, such as insulin resistance/diabetes, metabolic syndrome, and heart disease."
The findings were outlined in two papers published today in the journal Nature.
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