Immune cells play an important role in the development of diabetes and its long-term complications. In type 1 diabetes, for example, T cells (a subgroup of immune cells) are partly responsible for the disease, as they can destroy the cells of the pancreas in which insulin is produced. In type 2 diabetes, on the other hand, inflammation contributes to the development of insulin resistance through a higher number of leukocytes (white blood cells) in the blood.  In addition to the onset of diabetes itself, the altered number and composition of immune cells also plays an important role in the development of complications such as cardiovascular disease. In a recent study, researchers at the German Diabetes Center, a partner of the German Center for Diabetes Research (DZD), have now identified differences in pro-inflammatory cytokines between the new diabetes subtypes, based on the insight that diabetes is more complex than the classic classification suggests. "Prior to this study, it was unknown whether the new diabetes subtypes also differed in terms of blood count and specific blood cells," said Professor Michael Roden, scientific director and spokesman for the board of the DDZ. "Our ultimate goal was to see if this would make it easier to identify the risk of the diabetes subtypes for diabetes complications."

Therefore, the blood composition of more than 650 participants of the German Diabetes Study (GDS) was investigated. These individuals were diagnosed with diabetes only shortly before participating in the study. "Among other things, our investigations revealed that the number of white blood cells, i.e. the leukocytes, was highest in the diabetes subtype with severe insulin resistance and in the diabetes subtype characterized by morbid obesity," said Dr. Jacqueline Ratter-Rieck, who is responsible for the study in the Inflammation research group at the DDZ.  "We found the lowest number of leukocytes in so-called severe autoimmune diabetes, which essentially corresponds to classic type 1 diabetes." In addition, individuals with the diabetes subtype with severe insulin resistance had a different composition of T cells. T cells are also involved in the development of complications of diabetes, so different cell compositions could lead to differences in the underlying inflammatory processes in the different subtypes.

Thus, this study shows that the number of leukocytes and, moreover, their composition in the blood differ between diabetes subtypes. But what does this mean in concrete terms for people with diabetes? The knowledge gained from the study will contribute to a better characterization of the specific characteristics and courses of the corresponding diabetes subtypes and may pave the way for precision diabetology. "For future studies, it will therefore be important to investigate in which diabetes subtypes inflammatory processes play a particularly important role," said Professor Christian Herder, head of the Inflammation research group. "For these subtypes, anti-inflammatory therapies could perhaps also be of interest in order to slow down the development of diabetes and its secondary diseases.“