A study carried out by Swedish and Finnish researchers could mean diabetes is more complex than we think.
According to a research paper published in The Lancet – Diabetes and Endocrinology, diabetes that begins in adulthood actually falls into five separate categories as opposed to the traditional type 1 and type 2 models.
A personalised approach
The researchers believe their findings could help bring about a new age of personalised medicine for diabetes patients.
Type 1 is a disease of the immune system, where the body cannot manufacture the hormone insulin. Although it is most commonly diagnosed in child patients, it can develop at any age.
Type 2 is also a lifelong condition, which generally develops later in life. With type 2, little insulin is produced, or does not trigger glucose uptake in the cells of the body and can be linked to obesity.
Researchers from Lund University Diabetes Centre in Sweden and the Institute for Molecular Medicine in Finland gathered data on almost 15,000 patients from across five cohorts in both countries.
They then used six standard measurements to identify what they say are the five clusters of patients. One of the types is the existing type 1, while the other four represent subtypes of type 2.
The metrics used in the study include: age at diagnosis, BMI, the presence of certain antibodies linked to autoimmune diabetes, insulin sensitivity measures and blood glucose control measures.
Genetic analysis of the five subgroups revealed that all of them are genetically distinct from one another, but it is not clear from the study if there are different causes or if patients can change type over time.
The five clusters
Cluster 1
Severe autoimmune diabetes, broadly similar to type 1 in that it affected patients at a younger age, leaving them seemingly unable to produce insulin.
Cluster 2
Initially looked very similar to cluster 1, but the immune system in these patients was not at fault. This cluster had the highest incidence of diabetic retinopathy.
Cluster 3
Severe insulin-resistant diabetes patients, generally overweight and producing insulin, which their body was no longer responsive to.
Cluster 4
Mild diabetes related to obesity mainly observed in people who were very overweight, but closer to the norm than those in cluster 3 in terms of their metabolic system.
Cluster 5
This final cluster sees patients who developed diabetes at significantly older ages than other groups, with the condition taking a milder form in this case.
Professor of diabetes and endocrinology at Lund University and study leader, Leif Groop, said: “Diabetes is not the grey mass we have been calling type 2 – there are really subsets of the disease that require different treatment.”
More examination needed
Dr Emily Burns, head of research communications at Diabetes UK, told The Guardian that while the research was promising, there was still more digging to be done.
“We still need to know more about these subtypes before we can understand what this means for people living with the condition,” she said.
“For example, whether we’d find the same subtypes in people of different ethnicity or nationality.”