Doctors have identified a protein in the blood that they believe could serve as an early warning signal for patients who are at risk of diabetes and death from cancer.
Researchers in Sweden and China analyzed two decades of health records from more than 4,500 middle-aged adults in the Malmö Diet and Cancer Study. They found that those with the highest levels of prostatin, a protein that circulates in the blood, were almost twice as likely to have diabetes as those with the lowest levels.
Some of those enrolled in the study already had diabetes, so the scientists looked to see which of those without the disease were later diagnosed. People in the top quartile of prostatin levels were found to be 76% more likely to develop diabetes than those in the bottom quartile.
Dr. Xue Bao, the study’s first author at Nanjing University Medical School Affiliated Hospital in China, said prostasin was a new potential “risk marker” for diabetes, but also for death from cancer, particularly in people who have high blood sugar levels.
Prostatin performs various functions in the body, such as regulating blood pressure and blood volume, and also suppresses the growth of tumors that are fueled by high blood sugar levels. While type 2 diabetes is known to increase the risk of certain types of cancer, including tumors of the pancreas, liver, intestine, and endometrium, the biological mechanisms are far from clear.
After investigating the link between prostatin and diabetes, the researchers looked at whether people with high levels of the protein had an increased risk of cancer.
Writing in Diabetologia, they describe how those in the top quarter of prostatin levels were 43% more likely to die of cancer than those in the bottom quarter.
Participants with high levels of both prostatin and blood sugar had a significantly higher risk of dying from cancer, according to the study. For every doubling of prostatin concentration, the risk of death from cancer increased by 24% in people without high blood sugar and 139% in those with high blood sugar. “Special attention should be paid to these people,” the authors write.
It is not clear whether a high level of prostatin 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 prostatin 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 shared link between the two conditions,” said Professor Gunnar Engström, lead author of the study at Lund University.
“We now need to examine to what extent prostatin is causally related to these diseases or whether it is a valuable marker of increased disease risk,” Engström added.
“It might also be possible to identify people at higher risk of diabetes and cancer, and offer preventive measures.”
Because the findings come from people in one city, they may not apply to broader populations. The researchers also note that prostatin was measured from frozen blood taken at a single time point, and that the study was unable to distinguish between different types of diabetes.
Jessica Brown, from Diabetes UK, said: “We know there is a connection between diabetes and some cancers, and this study suggests that levels of a particular protein, called prostatin, are linked to both conditions.
“Getting a better understanding of the changes within the body that can put people at risk for diabetes and cancer will help scientists find ways to protect people from these serious conditions, but much remains to be discovered.
“We need more research to find out if prostasin is playing a direct role in the development of type 2 diabetes and worse cancer outcomes in people with high blood sugar.”