Gene linked to age-related obesity and diabetes found

Two different mutations in a gene that make some people more vulnerable to weight gain and diabetes as they age have been identified, shows research.

Mutations in this gene cause cells to suck up glucose faster than normal, fattening them up and eventually triggering the type of diabetes linked to obesity, the findings showed.

The findings, which were generated in mice, could help identify at-risk individuals who might be able to tip the scales back in their favour by eating better and exercising more.

"This is one of the first examples of a susceptibility gene that would only be manifested through a modern lifestyle," said senior author of the study Vann Bennett, professor at Duke University School of Medicine.

"The obesity epidemic really took off in the 1980's, when sugary sodas and French fries became popular. It's not like we suddenly changed genetically in 1980, but rather we have carried susceptibility genes that were exacerbated by this new diet," Bennett said.

"We think our findings are just the beginning, and that there are going to be many genes like this," Bennett said in the study that appeared in the Journal of Clinical Investigation.

The researchers found that mutations in the gene ankyrin-B might play a role in insulin secretion and metabolism.

They found that animals with two copies of a particular mutation made less insulin than normal mice.

Despite this shortcoming, their blood glucose levels were normal. So the researchers performed the rodent equivalent of a glucose tolerance test -- commonly used to screen for Type 2 diabetes in people -- to determine how quickly glucose was cleared from the bloodstream in the mutant mice.

To their surprise, the mutant mice metabolised glucose more quickly than normal mice.

"We thought that the main problem in these mice would be with the beta cells that produced and secreted insulin," co-author of the study Jane Healy from Duke University School of Medicine said.

"Instead, our most significant finding lay with the target cells, which took up much more glucose than expected," Healy said.

Next, the researchers would explore whether the effects they observed in mice hold true in humans.