Rather than just type 1 and type 2 diabetes, there could be at least five broad ways that the insulin disorder manifests. 

The news comes after Swedish and Finnish researchers analysed the medical records of approximately 15,000 patients newly diagnosed with diabetes. The results of which were published in The Lancet Diabetes and Endocrinology. 

The records were collected from five patient registries established in both countries. The team focused on six variables that are often used determine the type and severity of a specific diabetes case, from the age of diagnosis to BMI to the level of insulin resistance. As a result, they discovered that there were five distinct groups of patients that could be seen across every registry they examined. 

Right now, people with type 1 have an immune system that attacks and destroys the cells that make insulin, rendering them permanently insulin-deficient. The condition also usually shows up early in life. However, those with type 2 makeup around three-quarters of all cases, either stop producing as much insulin they once did, or they stop responding to the presence of insulin as easily. 

The first group from the study fit the bill of type 1 cases, they were young, otherwise healthy people whose insulin supply was demolished by their immune system. Whereas the remaining four groups could be best associated with type 2. 

Some of the patients’ cells stopped producing insulin, but not because of their immune system; they were actually often young and in good shape. The third group was made up of patients whose bodies kept making insulin but had stopped responding to it. These patients had the most severe symptoms, a highly dysfunctional metabolism, and were typically overweight or obese. Patients in the fourth group were also often overweight, but their bodies weren’t resistant to insulin, and they had milder symptoms and a healthier metabolism. The fifth group was made up of patients who developed diabetes later on in life, they also had the mildest symptoms. 

Attempting to break away from these subgroups and recognising them as distinct types of diabetes could hopefully lead to a better-tailored treatment. People who suffer from severe insulin-resistant diabetes, for example, could be treated more aggressively since they’d be at greater risk of developing serious complications. 

“Current diagnostics and classification of diabetes are insufficient and unable to predict future complications or choice of treatment,” explained lead author Leif Group, an endocrinologist at the Lund University Diabetes Centre in Sweden as well as the Folkhalsan Research Centre in Finland. “This is the first step towards personalised treatment of diabetes.”

Despite this, other researchers have expressed concern that the team’s results need to be replicated elsewhere, using even more diverse patient samples. There are also still unanswered questions about how relevant these differences are. 

Groop and his colleagues have revealed plans to develop a web tool that would help assign patients to specific clusters using the same variables, which is expected to support both future research efforts and doctors treating patients now. It’s currently estimated that over 420 million people globally have diabetes, reports the World Health Organisation.