Even a single episode of diabetic ketoacidosis (DKA) in school-aged children may have an enduring effect on cognitive function, a study suggests. DKA is the most common acute cause of morbidity and mortality in children with type 1 diabetes, Dr. Tandy Aye of Stanford University School of Medicine, in California, and colleagues note Diabetes Care, online December 20.

It has acute structural effects on the brain and has been associated with long-term adverse cognitive effects. To investigate further, the researchers examined data on 144 children aged 4 to 9 years taking part in an observational study. All had unsedated MRI scans and cognitive testing at baseline and 18 months later.

Diabetes diagnosis

The children were initially divided into groups, with 98 having had no or minor DKA events, and 30 have had moderate to severe events. No participant experienced more than one DKA episode, and all but four experienced their DKA episode at diabetes diagnosis. These four were excluded from the analysis

Overall, the moderate/severe DKA group gained more volume of total and regional white and gray matter over the observed 18 months compared with the none/mild group.

To examine the specific effect of DKA severity, the team compared a subgroup of 30 participants matched by age at enrollment and glycemic exposure who experienced an episode of mild DKA, or no DKA, with the 30 participants who experienced a moderate/severe episode of DKA.

The performance differences in cognitive scores at follow-up "became more prominent relative to the overall sample, despite the smaller sample size," the team says. This was also true of gray and white matter.

Compared with those who had no or mild DKA, the moderate/severe group showed significantly lower scores on a variety of instruments involving intelligence quotients, continuous performance, and memory.

As Dr. Aye said, "A history of moderate or severe DKA in children may have a lasting impact on neurocognitive function after the episode." "Future studies that look at the severity of DKA are needed," she added.

The researchers also note that more research is needed "to assess whether an earlier diagnosis of type 1 diabetes and prevention of DKA may reduce the long-term effect of ketoacidosis on the developing brain."