Researchers in Sweden and Finland have classified five distinct types of diabetes that can occur in adulthood, instead of the two currently recognized.
The researchers describe this as a paradigm shift in how to view the disease and say tailoring treatment to the different types could be more beneficial for patients than current treatment methods.
The first results of ANDIS — All New Diabetics In Scania — which was a study covering all newly diagnosed diabetics in southern Sweden — were published Thursday in The Lancet Diabetes & Endocrinology.
“This is the first step towards personalized treatment of diabetes,” Dr. Leif Groop, a physician and professor of diabetes and endocrinology at Lund University in Sweden, said in a press release.
“Current diagnostics and classification of diabetes are insufficient and unable to predict future complications or choice of treatment.”
About 425 million people worldwide have diabetes and the number is projected to increase to 629 million by 2045, according to the International Diabetes Foundation.
The disease can also lead to kidney failure, eye damage, amputations and cardiovascular diseases.
“Today, diagnoses are performed by measuring blood sugar,” Groop said. “A more accurate diagnosis can be made by also considering the factors accounted for in ANDIS.”
Researchers since 2008 have monitored 14,775 newly diagnosed type 1 and type 2 diabetes patients between the ages of 18 and 97. In Finland, they were studied by the Institute for Molecular Medicine Finland.
The researchers measured insulin resistance, insulin secretion, blood sugar levels and age at onset of illness in determining the five classes.
Type 2 diabetes, which accounts for 90 percent to 95 percent of all diagnosed cases of diabetes in adults, according to the CDC, was split into four groups.
The five types, which were found to be genetically distinct with no shared mutations, are:
Severe autoimmune diabetes: This essentially corresponds to type 1 and latent autoimmune diabetes in adults. It has onset at young age, poor metabolic control, impaired insulin production and the presence of GADA antibodies.
Severe insulin-deficient diabetes: It consists of type 2 but specifically individuals with high HbA1C, impaired insulin secretion and moderate insulin resistance. They also had the highest incidence of eye damage. Groop said this group has “the most to gain from the new diagnostics as they are the ones who are currently most incorrectly treated.”
Severe insulin-resistant diabetes: These individuals, who originally also are classified as type 2, are mainly overweight and severely resistant to insulin. This group had the highest number with kidney damage.
Mild obesity-related diabetes: They also are obese but are diagnosed at a relatively young age.
Mild age-related diabetes: They mainly are elderly patients and represent the largest group of the five at 40 percent.
The researchers later repeated the analysis in three studies from Sweden and Finland.
“The outcome exceeded our expectations and highly corresponded with the analysis from ANDIS,” Groop said. “The only difference was that Group 5 was larger in Finland than in Skane. The disease progression was remarkably similar in both groups.”
The researchers also want 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,” said author Emma Ahlqvist, associate professor at Lund.
Dr. Victoria Salem, a consultant and clinical scientist at Imperial College London told the BBC that “there is still a massively unknown quantity — it may well be that worldwide there are 500 subgroups depending on genetic and local environment effects.”
By Allen Cone