Over the years, diabetes cases have been divided into type 1 or 2. But a new study suggests that there may actually be five different types of disease-some of which may be more dangerous than others. A new classification system could help doctors identify the most vulnerable groups and pave the way for more individualized and effective treatments, say the authors.
The study, published in the lancet: diabetes and endocrinology, calls attention to the need to update diabetes classification systems. The authors wrote in their paper, the current system “in the past 20 years and didn’t get a lot of update”, and very few people attempt to explore the heterogeneity of type 2 diabetes – although the panel asked to do so for many years.
At the same time, they wrote, diabetes is the fastest growing disease in the world, and existing treatments cannot stop trends or prevent chronic complications in many patients. One explanation, they say, is that diabetes diagnoses are based only on one measure – how the body metabolizes glucose – when the disease is actually more complex and more individualized.
Currently, diabetes is classified according to the age of diagnosis (young people often have type 1) and antibodies that exist or do not exist to release insulin in the form of beta cells. People with type 1 diabetes have these antibodies, so they can’t make insulin on their own, and patients with type 2 can’t. Their bodies make insulin, but don’t use it in the right way.
According to these criteria, the authors wrote in their paper that between 75 and 85 percent of people with diabetes were classified as type 2. Recent studies have also discussed the third diabetes subgroup, the adult latent autoimmune diabetes (LADA).
But the authors, from the university of gothenburg in Sweden and lund university, say other groups are needed. To prove their point of view, they analyzed nearly 15000 Swedish health data type 2 diabetes, analyzed diagnostic measure and record the six variables: age, body mass index, the existence of the beta cell antibodies, metabolic control level and beta cell function and insulin resistance measurement.
From this analysis, they found five clusters of diseases with distinct characteristics. Severe insulin resistance diabetes (SIRD) involves the highest level of insulin resistance and the highest risk of diabetic nephropathy. Severe insulin-deficient diabetes (SIDD) consists of relatively young adults with poor metabolic controls. Severe autoimmune diabetes is largely overlapped with the current type 1 diagnosis. Two other clusters, mild age-related diabetes (MARD) and mild obesity-related diabetes (MOD) seem to be a better form of diabetes.
The results show that the new classification system can help identify people with high risk of complications and better guide doctors to choose treatment options, the authors write. They are currently developing a web-based tool that can assign patients to specific clusters.
Specifically, they write that SIDD and SIRD are two new serious forms of the disease “previously covered by type 2 diabetes”. They found a significant increase in renal complications in SIRD patients, and diabetic retinopathy was the highest in SIDD patients. “It is reasonable to target individuals in these groups for the purpose of intensive treatment,” they wrote.
The researchers say their classification system could help patients with new diagnoses and those who have had type 2 diabetes for years. However, it is unclear whether patients with can move with the passage of time between the cluster, the authors say they are not ready to declare their clustering method is the best classification system for diabetes subtypes. Larger studies, including additional variables and more diverse populations, are still needed.
But overall, the authors say, combining several different measurements to form a more specific diabetes diagnosis appears to be more useful than just using one glucose level – simply diagnosing type 1 or type 2. “This new gene replacement may change our ideas about type 2 diabetes, patients and help for the most beneficial and tailored to early treatment,” they wrote, “it represents the first step in treating diabetes accurate. “