Rapid Deterioration in Type 2 Diabetes: Rethink the Diagnosis

Hello. I'm Dr Charles Vega, and I am a clinical professor of family medicine at the University of California at Irvine. Welcome to Medscape Morning Report, our 1-minute news story for primary care.

Onset of type 1 diabetes after age 30 is common. But given that the overwhelming majority of adults with new-onset diabetes will have type 2, perhaps we can be forgiven for often misdiagnosing type 1 patients at presentation. Previous research has found that type 1 diabetes is nearly as likely to occur after the age of 30 as it is in younger people.

Recognizing adult-onset type 1 diabetes at presentation can be like trying to pick out a needle in a haystack. The prevalence of overweight and obesity is as high among people with type 1 diabetes as in the general population, making it even more difficult to identify these patients.

This current study involved 600 adults with diabetes who were diagnosed in a primary care practice. Type 1 diabetes was eventually identified in 20% of this group.

One key sign identified from this study is rapid deterioration in glycemic control despite the use of oral glucose-lowering medications. Rapid insulin requirement was highly predictive of late-onset type 1 diabetes, with 84% requiring insulin within 1 year. Over half developed severe endogenous insulin deficiency consistent with type 1 diabetes, but 47% of patients with severe insulin insufficiency claimed that they had type 2 diabetes.

Compared with the group with younger-onset type 1 diabetes, this older-onset group was similar in terms of body mass index (BMI), autoantibody positivity, and genetic risk scores. In contrast, they differed markedly from those with type 2 diabetes diagnosed after age 30 years, with lower average BMIs, a higher likelihood of positive islet autoantibody tests, and higher type 1 diabetes genetic risk scores.

Adult-onset type 1 diabetes patients shouldn't have to wait for ketoacidosis to be recognized. If a patient with presumptive type 2 diabetes deteriorates despite good adherence to aggressive oral treatment, rethink the diagnosis.

Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.

Cite this: Rapid Deterioration in Type 2 Diabetes: Rethink the Diagnosis - Medscape - Nov 20, 2018.

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