People with the highest levels of prostasin in their blood were twice as likely to have diabetes and 43% more likely to die from cancer, the researchers found.
“We know there is a connection between diabetes and some types of cancer, and this study suggests levels of a particular protein, called prostasin, is linked to both conditions,” Jessica Brown, PhD, a research communications officer for Diabetes UK, told The Guardian.
“Gaining a better understanding of the changes inside the body that may put people at risk from diabetes and cancer will help scientists find ways to protect people from these serious conditions, but there’s still much to discover,” she said.
Researchers in Sweden and China analyzed 2 decades of health records from more than 4,600 middle-aged adults, measuring prostasin in frozen samples from the Malmö Diet and Cancer Study Cardiovascular Cohort. The Swedish study, which enrolled patients in the 1990s, looked into the relationship between diet and later cancer risk.
During the 2-decade follow-up period, 702 people in the study developed diabetes and 651 died from cancer.
The research team found that those with the highest levels of prostasin, a protein that circulates in the blood, were twice as likely to have diabetes than those with the lowest levels.
About 360 people already had diabetes when they joined the study, so the researchers analyzed those without the disease to see who was diagnosed later. People in the top 25% for prostasin levels ended up being 76% more likely to get diabetes than those in the bottom 25%.
In another analysis of all participants, the researchers found that those in the top 25% for prostasin levels were also 43% more likely to die from cancer than those in the bottom 25%.
What’s more, participants with high levels of both prostasin and blood sugar had significantly higher risks of dying from cancer. For every doubling in prostasin concentration, the risk of cancer death rose by 24% in those without high blood sugar and 139% in those with high blood sugar.
“Particular attention should be paid to these individuals,” the study authors wrote.
Prostasin plays several roles in the body, such as regulating blood pressure and blood volume. It also curbs the growth of tumors linked to high blood sugar. Although type 2 diabetes is known to raise the risk of certain cancers – such as pancreatic, liver, bowel, and endometrial tumors – the reasons remain unclear.
Scientists aren’t sure whether a high prostasin level leads to the disease or if prostasin merely increases as the disease develops. One possibility is that the prostasin level rises to suppress high blood sugar but can’t stop or reverse the damage that has already been done, the study authors wrote.
“The relationship between diabetes and cancer is poorly understood, and this protein could provide a possible shared link between the two conditions,” Gunnar Engström, PhD, the senior study author and an epidemiologist at Lund University, told The Guardian.
“We now need to examine to what extent prostasin is causally related to these diseases or whether it is a valuable marker of increased disease risk,” he said. “It might also be possible to identify individuals with increased risk of diabetes and cancer and offer preventive measures.”