The current classification of diabetes, although insufficient by the experts’ own admission, comprises two main forms: type 1 diabetes and type 2 diabetes. But there are actually 5 types of diabetes, at least according to a new Swedish retrospective analysis.
Until then diabetes was classified into two types, type 1 or “lean diabetes” and type 2 or diabetes mellitus. “But diabetes is proving to be a much more heterogeneous disease.
A new, more detailed classification could provide a powerful tool for individualizing risks and, ultimately, the most appropriate treatment regimen, right from diagnosis.
The results of the study published in the Lancet on March 1, 2018 report 5 types of diabetes instead of 2, and the arguments are rather consistent with what diabetologists observe in practice.
Researchers analyzed the fate of 8,980 newly diagnosed diabetics in the Swedish “All New Diabetics in Scania” cohort. They examined six parameters that appeared to be discriminating (anti-glutamate decarboxylase antibody, age at diagnosis, BMI, glycated hemoglobin, insulin resistance and insulin-secreting pancreatic beta cell function).
The results of the study were then validated in three other cohorts of diabetic patients and the results obtained overlap.
3 types of severe diabetes
According to this retrospective analysis, there are now 5 types of diabetes, 3 of which are major causes of major complications.
The first group (“Group 1”) is “severe insulin-dependent diabetes” which concerns patients with a low body mass index, insulin deficiency and antibodies indicating an autoimmune origin of the disease. It develops in young people and is close to type 1 diabetes as it is currently defined.
Diabetes “Group 2”: patients have “severe insulin deficient diabetes”, they are close to group 1 patients, but their immune system is not involved in the disease, this is the main difference. These patients would have a higher risk of severe retinopathy, according to the researchers.
A third category of severe diabetes is “Group 3” with “severe insulin-resistant diabetes”: patients are significantly overweight or obese, and their cells are not very sensitive to insulin. These patients who are most exposed to fatty liver and diabetic nephropathy.
2 types of diabetes mellitus
There are also two milder forms of diabetes. First, “Group 4”, the most common, which corresponds to overweight patients suffering from mild diabetes without real insulin resistance.
The last form is “Group 5” which corresponds to “age-related mild diabetes” and corresponds to “insulin senescence” or aging of the pancreas.
A new classification to better treat diabetes
The researchers explain that this new classification in five types makes it possible to highlight a different progression of the pathology and a risk of diabetic complications. Group 3, the most insulin-resistant diabetics have a significantly higher risk of diabetic kidney disease than group 4 and 5. Group 2, insulin-deficient, has the highest risk of retinopathy.
This classification therefore makes a clear difference in prognosis between the first 3 groups and the last 2 groups. The therapeutic implications are obvious and encourage to treat more intensively the diabetes of the first 3 groups.