Researchers in Sweden and China analyzed two decades of health records from more than 4,500 middle-aged adults following the Malmö Diet and Cancer Study. They found that those with the highest levels of prostasin, a protein that circulates in the blood, were almost twice as likely to develop diabetes as those with the lowest levels. Some of those enrolled in the study already had diabetes, so the scientists looked at which of those who did not have the disease went on to be diagnosed later. People in the top trimester for prostasin levels were found to be 76% more likely to develop diabetes than those in the bottom trimester. Dr. Xue Bao, the study’s first author at the Affiliated Hospital of Nanjing University School of Medicine in China, said prostasin is a potential new “risk marker” for diabetes as well as cancer death, particularly in people who have high blood sugar. Prostasin plays several roles in the body, including regulating blood pressure and blood volume, and also suppresses the growth of tumors fueled by high blood sugar. While type 2 diabetes is known to increase the risk of certain cancers, including pancreatic, liver, bowel, and endometrial tumors, the biological mechanisms are far from clear. After investigating the link between prostasin and diabetes, the researchers looked at whether people with high levels of the protein were at greater risk of cancer. Writing in Diabetologia, they describe how those in the first trimester for prostasin levels were 43% more likely to die from cancer than those in the last trimester. Participants with high levels of both prostasin and blood sugar had a significantly higher risk of dying from cancer, the study found. For every doubling of prostasin concentration, the risk of dying from cancer increased by 24% in those without high blood sugar and by 139% in those with high blood sugar. “Special attention should be paid to these individuals,” the authors write. It is unclear whether a high level of prostasin plays a role in the disease or is simply a biological marker that increases as the condition develops. One possibility, the authors suggest, is that prostasin levels rise in an attempt to suppress high blood sugar levels, but are unable to stop or reverse the damage caused. “The relationship between diabetes and cancer is poorly understood and this protein could provide a possible common link between the two diseases,” said Professor Gunnar Engström, senior author of the study at Lund University. “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,” added Engström. “It may also be possible to identify people at increased risk of diabetes and cancer and offer preventive measures.” Because the findings are from people in one city, they may not apply to wider populations. The researchers also point out that prostasin was measured from frozen blood taken at only one point in time, and that the study was unable to distinguish between different types of diabetes. Subscribe to First Edition, our free daily newsletter – every morning at 7am. BST Jessica Brown, from Diabetes UK, said: “We know there is a link between diabetes and some types of cancer and this study suggests that levels of a particular protein, called prostasin, are linked to both conditions. “Better understanding of the changes inside the body that may put people at risk of diabetes and cancer will help scientists find ways to protect people from these serious conditions, but there is still much to discover. “We need further research to learn whether prostasin plays a direct role in the development of type 2 diabetes and worse cancer outcomes in people with high blood sugar.”
