The major difference from today’s classification is that type 2 diabetes actually consists of several subgroups, the results indicate.
“This is the first step towards personalised treatment of diabetes”, says Leif Groop, physician and professor of diabetes and endocrinology at Lund University in Sweden.
Today, about 425 million people around the world have diabetes. By 2045, the number is expected to have increased to 629 million*. Secondary diseases in the form of kidney failure, retinopathy (eye damage), amputations and cardiovascular diseases result in huge costs to society and major individual suffering. Thus, the need for new and better treatment options is great.
“Current diagnostics and classification of diabetes are insufficient and unable to predict future complications or choice of treatment”, explains Professor Leif Groop, who initiated the study.
He believes that the results represent a paradigm shift in how to view the disease in the future.
“Today, diagnoses are performed by measuring blood sugar. A more accurate diagnosis can be made by also considering the factors accounted for in ANDIS (All New Diabetics In Skåne).”
Since 2008, the researchers have monitored 13 720 newly diagnosed patients between the ages 18 and 97. By combining measurements of, for example, insulin resistance, insulin secretion, blood sugar levels (BMI, HbA1c, GADA, HOMA-B and HOMA-IR) and age at onset of illness, the researchers were able to distinguish five distinct clusters that differ from today’s classification (see diagram).
In addition to a more refined classification, the researchers also discovered that the different groups are more or less at risk of developing various secondary diseases.
“This will enable earlier treatment to prevent complications in patients who are most at risk of being affected”, says Emma Ahlqvist, associate professor and lead author of the publication.
Diabetes is currently divided into: type 1 diabetes (approx. 10 per cent), type 2 diabetes (85–90 per cent) and a number of less common diseases such as LADA, MODY and secondary diabetes.
However, the researchers suggest a new set of subgroups:
Today’s classification to the left and the new classification to the right
Group 1, SAID (severe autoimmune diabetes): essentially corresponds to type 1 diabetes and LADA (latent autoimmune diabetes in adults), and is characterised by onset at young age, poor metabolic control, impaired insulin production and the presence of GADA antibodies.
Group 2, SIDD (severe insulin-deficient diabetes): includes individuals with high HbA1C, impaired insulin secretion and moderate insulin resistance. Group 2 had the highest incidence of retinopathy.
Group 3, SIRD (severe insulin-resistant diabetes): is characterised by obesity and severe insulin resistance. Group 3 had the highest incidence of kidney damage – the secondary disease producing the highest costs to society.
Group 4, MOD (mild obesity-related diabetes): includes obese patients who fall ill at a relatively young age.
Group 5, MARD (mild age-related diabetes): is the largest group (about 40%) and consists of the most elderly patients.
“The most insulin resistant patients (Group 3) have the most to gain from the new diagnostics as they are the ones who are currently most incorrectly treated”, says Professor Leif Groop.
The researchers subsequently repeated the analysis in a further three studies from Sweden and Finland.
“The outcome exceeded our expectations and highly corresponded with the analysis from ANDIS. The only difference was that Group 5 was larger in Finland than in Skåne. The disease progression was remarkably similar in both groups”, says Leif Groop.
The recruitment of newly diagnosed diabetes patients continues and the researchers have several studies underway based on the data they have already acquired.
“The longer the study is running, the more and better data we’ll get”, says Emma Ahlqvist.
The researchers are also planning to launch similar studies in China and India with people of different ethnic backgrounds.
“This will give us even better opportunities to tailor the treatment to each individual”, she concludes.
Read more about ANDIS
Diabetes, like cancer, is the collective name for several diseases. The most common forms today are type 1, type 2, LADA, MODY and secondary diabetes due to other diseases. There is also pregnancy diabetes and more unusual forms of the disease.
Diabetes is an incurable disease caused by the complete or partial lack of the blood sugar regulating hormone, insulin. Today’s treatments are only life-sustaining and aim at reducing the risk of the many complications that affect the heart, vessels, eyes, kidneys and nerves due to elevated blood sugar levels over a long period of time.
*According to the International Diabetes Federation, www.idf.org
Publication: Clustering of adult-onset diabetes into novel subgroups guides therapy and improves projection of outcome
Emma Ahlqvist, associate professor, Lund University
emma [dot] ahlqvist [at] med [dot] lu [dot] se
+46 70 756 15 71
Leif Groop, professor, Lund University
leif [dot] groop [at] med [dot] lu [dot] se
+46 70 591 25 48
The study was financed by:
The Swedish Research Council (including project grants Dnr.521-2010-3490, 2017-02688 and infrastructure grants Dnr. 2010-5983 and Dnr 2012-5538 to LG), Linnéus grant 349-2006-237, a strategic research grant (Exodiab Dnr 2009-1039), an ERC Advanced Research grant (GA 269045), a Vinnova Swelife grant, and Academy of Finland (grants no. 263401 and 267882) to LG, Novo Nordisk Foundation and ALF. This project has also received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreements No 115974 (BEAt-DKD) and 115881 (RHAPSODY). This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme and EFPIA. Further, this project is financially supported by the Swedish Foundation for Strategic Research (Dnr IRC15-0067). DIREVA was supported by the Vasa Hospital district. LG has received grants from Pfizer, Lilly and Novartis.