A protein that may predict diabetes and the likelihood of dying from cancer has been discovered by scientists. Researchers found people with high levels of the protein prostasin were 76 per cent more likely to get diabetes and 43 per cent more likely die from cancer, and more likely to die from all other causes.
The study, published in the journal Diabetologia, unveils an important link between the diseases. It suggests people with elevated prostasin – a protein regulating blood pressure, blood volume and sodium balance – and blood sugar levels are significantly more likely to die from cancer.
Co-lead author of the 24-year study that looked at 4,500 people, Professor Gunnar Engström from Lund University, said: "This is the most comprehensive analysis of its kind to date and sheds new light on the biological connection between diabetes and cancer, Prostasin may be just an indicator that disease might occur, or could be causally relevant, which is exciting because it raises the possibility of targeting this protein with future treatments for both diabetes and cancer."
It is already known diabetes, and some of its medications, increases the risk of getting and dying from cancer. Type 2 diabetes sufferers are twice as likely to contract pancreatic, endometrial and liver cancer.
However, the researchers said why this happens is poorly understood, and the study is the first to examine the relationship between prostasin, blood levels and cancer mortality. It analysed blood samples from over 4,658 middle-aged Swedish adults that were taken over a decade ago for the Malmö Diet and Cancer Study, a large ongoing study that in 1993 began searching for links between Western diet and cancer in the 230,000-person population of Malmö, Sweden.
Looking at the town's population, Chinese and Swedish researchers found those with the highest quartile of prostasin were twice as likely to already have diabetes, and if they didn’t have it yet they were 76 percent more likely to get it than those in the lowest quartile. At a 22-year follow-up, 702 of the 4,658 participants had developed diabetes.
The team were interested to find prostasin levels were a better predictor for future diabetes in young people and those with lower blood sugar levels and better kidney functions. This led them to speculate that prostasin was a byproduct of high blood sugar levels, produced to try and stop or reverse hypoglycemia without ever fully succeeding.
Because prostasin is found in the urine, researchers believe the good kidney function may maintain optimal prostasin blood levels. Adding to the diabetes threat, the study found “significant” association between prostasin and cancer mortality, as well as death from all other causes.
By the 24-year follow-up, 651 of the 4,658 had died from cancer.
Those in with highest quartile of prostasin were 43 percent more likely to die from cancer than those with the lowest, and if the person already had diabetes alongside these levels, each time the quantity of prostasin doubled their risk of dying from cancer leapt 139 percent.
First author, Dr Xue Bao from the The Affiliated Hospital of Nanjing University Medical School, said: “Prostasin is a new potential risk marker for the development of diabetes and for cancer mortality, especially in individuals with high blood glucose levels. It is easily accessible, which enhances its potential to serve as a warning marker in the future.”
“Since prostasin has a role in regulating several diabetes-associated biological pathways that are also involved in the onset and promotion of some cancers, it may potentially mediate the process from high blood sugar to cancer, or at least may act as a marker for cancer susceptibility in participants with high blood sugar.
“To look at this in more detail, it will be useful for future studies to trace the exact origins of prostasin in blood, and to determine whether the association between prostasin and diabetes is causal.”
