Diabetes Drug Metformin: Scientists Unlock the Key to Lower Glucose Levels

Statistics show that about 120 million people around that world suffer from Type 2 diabetes, with approximately two million in Canada that take the drug metformin in order to control this health issue.

As doctors know that metformin can interact positively with insulin, it can also lower blood sugar on its own. Yet up until now, scientists haven't been able to figure out why.

"The key is that metformin doesn't work to lower blood glucose by directly working on the glucose. It works on reducing harmful fat molecules in the liver, which then allows insulin to work better and lower blood sugar levels," Greg Steinberg, associate professor in the Department of Medicine of the Michael G. DeGroote School of Medicine said, via a press release. 

Study authors note that most taking metformin have a fatty liver that often is caused from obesity.

"Fat is likely a key trigger for pre-diabetes, causing blood sugar to start going up because insulin can't work as efficiently to stop sugar coming from the liver."

As study authors worked to uncover what causes fatty liver, scientists studied mice that have a "genetic disruption" via a single amino acid that's found in proteins called acetyl-CoA carboxylase (ACC).

Such proteins are often controlled by metabolic sensors from AMP-activated proteins kinase that help to regulate fat production as well as the ability to burn fat.

Mice with such mutated proteins may develop signs of a fatty liver or pre-diabetes symptoms even if they are not obese.

"But what was really surprising was that when obese mutant mice were given metformin, the most common and inexpensive drug prescribed to Type 2 diabetics, the drug failed to lower their blood sugar levels," Steinburg said, via the release. "It indicates the way metformin works isn't by directly reducing sugar metabolism, but instead by acting to reduce fat in the liver, which then allows insulin to work better."

"This discovery offers a huge head start in finding combination therapies (and more personalized approaches) for diabetics for whom metformin isn't enough to restore their blood sugar to normal levels," he concludes.

More information regarding the study can be found via the journal Nature Medicine.