Enzyme may increase insulin resistance and type 2 diabetes risk

Higher levels of an enzyme known as PKC-delta may lead to greater insulin resistance and a higher risk of developing type 2 diabetes, according to a new study from the Joslin Diabetes Center. Researchers said that their findings may lead to the development of new medications that improve insulin sensitivity.

Insulin resistance is one of the first steps in the development of type 2 diabetes. It occurs when tissue no longer responds to the hormone, which is responsible for removing glucose from the bloodstream and converting it to energy. Solving this problem could significantly reduce the burden of type 2 diabetes.

For the study, the researchers examined two sets of genetically altered mice, one that was prone to becoming insulin resistant and another was not. They figured that by analyzing the genetic differences between the two groups, they could identify inheritable risk factors for insulin resistance.

Their findings, which were published in the Journal of Clinical Investigation, showed that mice susceptible to insulin resistance had a gene that caused levels of the PKC-delta enzyme to rise. When these mice were fed a high-fat diet, enzyme levels increased at about the same rate as insulin resistance. However, when the researchers eliminated the gene from the mice, they were much less likely to develop insulin resistance.

Additionally, the team noticed that PKC-delta levels were elevated in the livers and other tissues of insulin-resistant mice. They took this as a sign that the enzyme may also play a role in the development of fatty liver disease and obesity.

Given these findings, the researchers said they believe that it may be possible one day to develop medications that suppress PKC-delta levels, and that these could significantly reduce an individual's risk of developing type 2 diabetes, obesity and fatty liver disease.