Diabetes 'consists of 5 distinct types'
2nd March 2018 – Diabetes can be separated into 5 different types, rather than just type 1 and type 2, according to a new study.
Scientists in Sweden and Finland say the discovery could be a first step towards individually tailored treatments.
Increasing rates of diabetes
Rates of diabetes are increasing worldwide. A recent analysis found that the number of people with diabetes in the UK had doubled in the past 20 years. It now affects 3.7 million people in the UK.
Type 1 diabetes is an autoimmune disease. It is usually diagnosed in childhood and is caused by the body's immune system wrongly destroying cells in the pancreas that make insulin. Without insulin, the body is unable to regulate blood sugar levels.
Most people with diabetes – between 85% and 90% – have type 2 diabetes, in which the body does not produce enough insulin, or the insulin they have does not work properly. It is generally considered a 'lifestyle' disease, as excessive body fat can disrupt the workings of insulin.
Identifying 5 types of diabetes
The scientists from Lund University Diabetes Centre and Skåne University Hospital in Malmö, Sweden, and the Institute for Molecular Medicine, Helsinki, Finland, analysed 5 studies involving 14,775 adults from Sweden and Finland who had recently been diagnosed with diabetes.
They were able to analyse key measurements of the disease, as well as blood composition and genetic features.
They were able to distinguish 3 severe and 2 mild forms of disease. One corresponded to type 1 diabetes and the other 4 were subtypes of type 2 diabetes.
- Cluster 1: This is a severe autoimmune form of diabetes – close to type 1 diabetes – affecting around 6% to 15% of participants.
- Cluster 2: This group consists of relatively young, insulin-deficient individuals with high blood sugar levels, faulty insulin secretion and moderate insulin resistance. Affecting between 9% and 20% of individuals, they had the highest level of eye damage.
- Cluster 3: Characterised by obesity and severe insulin resistance, individuals in this group accounted for between 11% and 17% of participants and had the highest incidence of kidney damage.
- Cluster 4: Comprises 18 to 23% of cases, who are obese individuals who are not insulin resistant but develop mild diabetes at a relatively young age.
- Cluster 5: Mild diabetes among mostly older patients, accounting for 34 to 47% of cases.
The authors of the study, published in The Lancet Diabetes and Endocrinology journal, say all 5 types of diabetes were found to be genetically distinct, with no mutations associated with all types of the disease.
They say this supports the idea that the 5 types of diabetes are not simply different stages of the same disease.
Future tailored treatments
The researchers also report that many of the people in the studies were not receiving appropriate treatment, suggesting that a more individual approach to the disease could be beneficial.
They say further studies are needed in non-Scandinavian populations to test their findings further.
Dr Emily Burns, head of research communications at Diabetes UK, comments in an emailed statement: "Type 1 and type 2 diabetes are very different conditions, but we don’t yet know enough about the subtypes that could exist within them. Finding those subtypes will help us personalise treatments and potentially reduce the risk of diabetes-related complications in the future.
"This research takes a promising step toward breaking down type 2 diabetes in more detail, but we still need to know more about these subtypes before we can understand what this means for people living with the condition."