For decades we have been told that there are two main kinds of diabetes — Type 1 and Type 2. But a recent study from Sweden indicates that there might be five types of Type 2 diabetes. As the report explains, the present classification system “has not been much updated during the past 20 years, and very few attempts have been made to explore heterogeneity of Type 2 diabetes.”
The authors use the term “clusters” to characterize the five types of Type 2 diabetes. First is what the researchers term Severe Insulin-Resistant Diabetes (SIRD). This cluster involves the highest levels of insulin resistance and the greatest risk of kidney disease. Second is Severe Insulin-Deficient Diabetes (SIDD), a condition mostly confined to relatively young adults whose metabolic control is especially poor; these patients make some insulin, but not enough, and have the highest risk of retinopathy (damage to the blood vessels in the retina). Next comes Severe Autoimmune Diabetes, which overlaps with Type 1. The last two clusters, Mild Age-Related Diabetes, or MARD (the most common form of diabetes), and Mild Obesity-Related Diabetes (MOD), are milder forms of the disease.
In the final stage of their research, the authors studied the care the patients in different clusters were receiving and discovered that many were not getting appropriate treatment. Because of that finding, the researchers said that the importance of their study is that it can lead to more personalized treatment of diabetes, resulting in improved ways of individualizing treatment plans, identifying diabetes patients who have an increased risk of complications, and initiating early treatment. The authors acknowledged that their classifications might not be the final word on the varieties of diabetes. More research is needed on that question, they said, as well as on whether people can move from one cluster to another.