Why more men than women get Type 2 diabetes, and what it means for treatment

Hamilton researchers have figured out why women are less likely to get Type 2 diabetes than men, and it's a discovery that has led them to a "new target" when it comes to developing treatment options. 

In identifying a pathway and protein that "jams" the signal between insulin and muscles, which leads to Type 2 diabetes, researchers found women are more efficient at processing the protein PTEN, leading to a greater protection from developing diabetes.

That protein, and pathway, finally explains why women are less likely to develop Type 2 diabetes, said Dr. M. Constantine Samaan, the lead author of the study, assistant professor of pediatrics at the Michael G. DeGroote School of Medicine and pediatric endocrinologist at the McMaster Children’s Hospital.

"This protein is a potential target that we can try and manipulate as a treatment and prevention strategy for insulin resistance in Type 2 diabetes," Samaan said of the study, published this week in the journal Scientific Reports.

"When people become overweight, that signal between insulin and the muscle gets jammed, and muscles may not be able to respond to the insulin in a normal way. We call this insulin resistance and this leads to Type 2 diabetes," Samaan explained. 

"We know that women, at a given weight when compared to men, have more fat tissues in their bodies, and yet they are actually protected from diabetes compared to men," he said. "And what we found in the study is that women's muscle was far more efficient in neutralizing this protein. And that might be the reason why they could avoid being resistant to insulin when they become overweight at some point."

The Canadian Diabetes Association (CDA) welcomed the news that researchers have a new target for research, but said the difference in efficiency is "small" and cautioned that there are many other risk factors that people can modify with their own behaviours when considering preventing Type 2 diabetes. 

"Some risk factors can't be modified," said Jan Hux, chief science officer at the CDA, "but there are things that can be changed."

The CDA lists a number of risk factors for Type 2 diabetes, including being overweight, being related to someone with diabetes, and being part of high-risk race groups (Aboriginal, Hispanic, South Asian, Asian, and African), among a list of other factors.

Public Health Agency of Canada numbers from 2008 say there is some 10 per cent more men with Type 2 diabetes in than women in Canada overall. Samaan's research is currently looking into if women with Type 2 diabetes show a similar lack of efficiency processing PTEN (which stands for phosphatase and tensin homolog deleted on chromosome 10) as men.

Until then, Samaan couldn't say if a treatment option could be developed for both sexes.

"Certainly this is not the only pathway. There are perhaps other pathways, but we know that this protein does go up in obesity and certainly there appear to be differences in the sexes," Samaan said. "We are certainly very excited about this finding. We are building now our repertoire of tools that will help us target these proteins."