New Study Reveals Metabolic Differences Between LADA and Type 1 Diabetes

Type 1 diabetes and LADA (latent autoimmune diabetes in adults) are both autoimmune conditions affecting the pancreas, but they develop and progress differently. Now, new research published in Diabetologia suggests these differences may extend to how the body's metabolism functions in each condition.

In a study of 136 individuals—including people with LADA, Type 1 diabetes, rheumatoid arthritis, and healthy controls—researchers used advanced metabolomic and lipidomic analysis to identify what distinguishes these conditions at a molecular level. Metabolomics examines small molecules involved in metabolism; lipidomics focuses on fats and fat-like substances.

The findings showed that LADA and Type 1 diabetes have distinctly different patterns of fats and metabolites compared to each other. This suggests that the two forms of autoimmune diabetes may involve different biological mechanisms, even though both involve the immune system attacking insulin-producing beta cells.

One metabolic pathway stood out in the analysis: tryptophan metabolism. Tryptophan is an amino acid—a building block of protein—that the body also converts into other important molecules through a process called the kynurenine pathway.

The researchers measured the ratio of kynurenine to tryptophan (Kyn/Trp) in study participants' blood. A higher ratio indicates that the kynurenine pathway is more active—meaning the body is breaking down tryptophan at a faster rate. In people with autoimmune disorders, this ratio was elevated compared to healthy controls. Notably, the ratio differed across conditions: it was highest in rheumatoid arthritis, intermediate in LADA, and lowest in Type 1 diabetes.

When the researchers exposed pancreatic islet cells from healthy donors to inflammatory signals in the lab, tryptophan levels dropped by 80%, suggesting that immune-driven inflammation directly triggers changes in tryptophan metabolism.

The discovery that LADA and Type 1 diabetes have different metabolic signatures provides a new lens for understanding the heterogeneity—the variety and complexity—of autoimmune diabetes. Rather than viewing these as simply variations of the same condition, these findings suggest they may involve distinct biological processes.

The prominent role of tryptophan metabolism points to a potential pathway involved in how the immune system damages beta cells. Future research may explore whether modulating tryptophan metabolism could influence disease development or progression, though much more work is needed before such approaches could be tested in people.

This research is part of ongoing efforts to better characterize the biological differences between Type 1 diabetes and LADA, which could ultimately inform more personalized approaches to understanding and studying these conditions.

Source: Diabetologia. Evidence type: PubMed indexed literature. Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.