Should We Reclassify Diabetes Subtypes?

Over recent years, there has been a push to shift the typology and nomenclature of diabetes to define the disease more finely beyond simply type 1, type 2 and gestational diabetes.¹ This new terminology would reflect the change in modern diabetes prevalence and presentation itself—and as one expert explained to HCPLive, could possibly help better treat the individual patient.

In an interview with HCPLive during the American Academy of Physician Associates (AAPA) 2024 Conference & Expo in Houston, TX, this week, Ji Hyun “CJ” Chun, MPAS, PA-C, BC-ADM, an endocrine physician assistant at OC Diabetes Endocrinology and La Verne University, discussed the rationale behind the proposal to redefine type 1 and type 2 diabtes as each of the following:

• Severe insulin deficient diabetes
• Severe insulin resistant diabetes
• Severe autoimmune diabetes
• Moderate obesity-related diabetes
• Age-related diabetes

“In type 2 diabetes especially, it's a very heterogeneous group, and they present very differently,” Chun said. “But we're grouping them as type 2 diabetes, and with that simplification, I think it can cover like 90-95% of the cases. However, there are about 5 to 10% of cases which don't really fit into those classifications, but we tend to just default them into type 2 or type 1—and then we tend to miss that 5 to 10% of patients who may have some other underlying cause.”

Chun explained that only 30 years ago, the current classification of type 1 and type 2 diabetes was more than adequate. When obesity rates reached epidemic proportions of prevalence in children and adults, however, relied-upon factors including age was no longer a consistent differentiator between type 1 and type 2 diabetes. Children were become obese more frequently, and therefore pediatric type 2 diabetes cases became more prevalent.

“And those patients who have underlying endocrinopathies, such as acromegaly or hypercortisolism, who tend to become obese, it was easier to spot them out,” Chun said. “But now, with the general population getting obese, it's harder to sort them out.”

The proposed nomenclature changes have gained momentum in the last 5 years, Chun said. Though he can appreciate that primary care providers especially may be resistant to such a significant change, redefining the disease subtypes based on the trajectory of diabetes-related illness may open the door for more tailored treatment. A patient with severe insulin deficient diabetes may be more predisposed to retinopathy and neuropathy, whereas a patient with severe insulin resistant diabetes may face a greater risk of nephropathy.

“So, you could do the screening or management more intensely in that group, or the severe insulin resistant diabetes group, if they're at higher risk for nephropathy, again, using tighter glycemic control, ACE and ARBs earlier on, an SGLT-2 inhibitor or finerenone—those risk-modifying agents can be used early on to prevent injury or change the trajectory,” Chun explained.

References

1. ^{Herder C, Roden M. A novel diabetes typology: towards precision diabetology from pathogenesis to treatment. Diabetologia. 2022;65(11):1770-1781. doi:10.1007/s00125-021-05625-x}
2. ^{Barnes AS. The epidemic of obesity and diabetes: trends and treatments. Tex Heart Inst J. 2011;38(2):142-144.}