There are six clearly distinguishable subtypes in early-stage diabetes, according to a new classification by German researchers. Pinpointing a patient’s subtype can help identify risk and aid in preventive strategies, they say.

The researchers analyzed the metabolism of almost 900 people with prediabetes who still were considered healthy. Participants were part of two extensive German family and lifestyle studies conducted over 25 years in the town of Tübingen. The analysis was then extended to include almost 7,000 residents of London.

The prediabetes disease types differ in blood glucose levels, insulin action and insulin secretion, body fat distribution, liver fat and genetic risk, said first author Robert Wagner, M.D., from the University of Tübingen. For example, although people in clusters 1, 2 and 4 are healthy or relatively healthy despite some risk factors, study participants in clusters 3, 5 and 6 have specific health issues that are more likely to result in a later diabetes diagnosis, Wagner and colleagues reported.

  • People who belong to subtype 3 produce too little insulin and have a high risk of developing diabetes. 
  • People in cluster 5 have a pronounced fatty liver and a very high risk of diabetes because their bodies are resistant to the blood-glucose-lowering effect of insulin. 
  • In subtype 6, damage to the kidneys occurs even before diabetes is diagnosed. Here, mortality is particularly high.

The new classification can help clinicians develop targeted prevention strategies, the researchers concluded.

Since 1980, the number of people with diabetes has quadrupled in the United States. In the long-term care population, the estimated prevalence of diabetes ranges from 25% to 34%, according to multiple studies.

Full findings were published in the journal Nature Medicine.