Incident dysglycemia strongly predicted diabetes in islet cell autoantibody-positive individuals

The high incidence of dysglycemia among islet cell autoantibody-positive individuals with normal glucose tolerance was highly predictive of type 1 diabetes in a new study.

The Diabetes Prevention Trial–Type 1 Study Group examined the incidence of dysglycemia among 515 islet cell autoantibody-positive relatives of patients with type 1 diabetes. Participants had normal glucose tolerance at baseline and underwent periodic oral glucose tolerance tests. At the six-month visit, incident dysglycemia was assessed for type 1 diabetes prediction.

During seven years of follow-up, 60% of participants with a normal baseline OGTT had at least one dysglycemic episode.

Incident dysglycemia was strongly predictive of type 1 diabetes in all age groups, and was especially high among children, according to the researchers. At the six-month visit, dysglycemia was highly predictive of the development to type 1 diabetes in participants younger than 13 years (P<.001) and 13 years or older (P<.01). Children aged younger than 13 years with dysglycemia had a high cumulative incidence (94% by 5 years).

“Fluctuations in and out of the dysglycemic state are not uncommon before the onset of type 1 diabetes,” the researchers wrote.

Fifty-two percent of participants who developed type 1 diabetes after a dysglycemic OGTT and who had at least two OGTTs after the dysglycemic OGTT reverted back to a normal OGTT. However, 79% of those participants then had another dysglycemic OGTT before diagnosis.

“From both clinical and research perspectives, it may be advantageous to identify individuals as early as possible in this process,” the researchers wrote. “The very high likelihood that autoantibody-positive children will develop type 1 diabetes within five years after the occurrence of dysglycemia suggests that the earlier identification of the disease is a distinct possibility.”

Sosenko JM. Diabetes Care. 2009;32:1603-1607.