A blood marker has been identified that may show who is at risk of developing type 2 diabetes many years before the disease is typically diagnosed.
The test could predict diabetes in advance before the damage to blood vessels, the eyes, and other areas of the body and would enable preventive treatment to be put in place to avert or limit the damage.
A team at the Lund University Diabetes Centre (Malmö, Sweden), compared insulin-producing beta cells from diabetics with those of nondiabetics, and found the diabetic cells had significantly higher levels of the secreted frizzled-related protein 4 (SFRP4), which plays a role in inflammatory processes. They explored the pathophysiology of type 2 diabetes (T2D) by analyzing global gene expression in human pancreatic islets. A group of coexpressed genes, enriched for interleukin-1-related genes, was associated with T2D and reduced insulin secretion.
The scientists measured levels of SFRP4 in the blood of nondiabetics three times every three years. They found that 37% of those with higher concentrations of the protein developed diabetes during the study, compared with only 9% of those who had below average levels. Elevated systemic SFRP4 caused reduced glucose tolerance through decreased islet expression of calcium channels and suppressed insulin exocytosis. The protein SFRP4 thus provides a link between islet inflammation and impaired insulin secretion. Moreover, the protein was increased in serum from T2D patients several years before the diagnosis, suggesting that SFRP4 could be a potential biomarker for islet dysfunction in T2D.
Anders Rosengren, MD, PhD, the senior author , said, “We have shown that individuals who have above-average levels of a protein called SFRP4 in the blood are five times more likely to develop diabetes in the next few years than those with below-average levels. We have also identified the mechanism for how SFRP4 impairs the secretion of insulin. The marker therefore reflects not only an increased risk, but also an ongoing disease process." The study was published on November 7, 2012, in the journal Cell Metabolism.