By Lisa Rapaport

(Reuters Health) – Young children with mild apnea who have their tonsils removed may sleep a little better than kids who don’t get tonsillectomies, but a new study suggests surgery won’t improve cognitive function.

Some previous research suggests that apnea, a sleep-related breathing disorder, may lead to deficits in things like attention, language skills, reasoning, and executive function in school-age children, the study team notes in Pediatrics. While some prior studies also suggest that tonsillectomies may counter these deficits, results have been mixed and less is known about what happens among younger children.

For the current study, researchers randomly assigned 190 children 3 to 5 years old with mild apnea to either undergo to adenotonsillectomy – surgery to remove both the tonsils and adenoids – or to join a waiting list for these operations and continue with routine nonsurgical care.

One year later, kids had similar improvements on tests of intellectual ability, executive function and memory whether or not they had surgery.

“For young, preschool-aged children with only mild obstructive sleep apnea (OSA), there is a limited benefit from adenotonsillectomy with respect to improving cognitive function,” said Dr. Neil Bhattacharyya, a professor of otolaryngology at Harvard Medical School in Boston.

“Parents do not need to think of doing a tonsillectomy early to protect cognitive development in this age group as long as the sleep apnea is mild,” Bhattacharyya, who wasn’t involved in the study, said by email. “However, there are other potential indications for tonsillectomy depending on the child’s emotional and physical behavior or impact of the OSA, and those factors should also be taken into account.”

Sleep studies did show bigger improvements in several sleep measures for kids who had surgery compared to children who didn’t. Tonsillectomies were associated with bigger gains in total sleep time, and more reductions in nighttime awakenings and apnea events.

Parents reported bigger reductions in snoring and breathing difficulties with surgery, too.

Behavior also improved more with surgery than without it. Operations were associated with larger gains in attention, too, but the difference was too small to rule out the possibility it was due to chance.

It’s not clear how much behavior may have improved because of the surgery versus because kids slept better.

One limitation of the study is that many children dropped out before the end, leaving only 141 kids with complete data for analysis. With so few kids remaining, it’s possible researchers lacked enough data to detect small but meaningful differences in outcomes with and without surgery.

Lead study author Karen Waters of The Children’s Hospital at Westmead, in Australia, didn’t respond to requests for comment.

“I am not sure if there is much benefit is getting tonsils removed at an early age unless it is severe,” said Dr. Paul Hong, a researcher at Dalhousie University in Halifax, Canada, who wasn’t involved in the study.

“We know from previous studies that many children with primary snoring and mild OSA can improve over time without any surgery – they grow out of it,” Hong said by email. “And we know this happens as tonsils and adenoids can shrink over time while the child is growing so there is more room in the nose and throat.”

Unless kids have serious problems related to apnea that aren’t getting better over time, there isn’t much advantage to doing surgery in preschoolers, Hong added. Younger patients can have more surgical complications, and more breathing problems after tonsillectomy, and waiting to see if they still need operations when they’re older can often be the best course of action.

SOURCE: Pediatrics, online January 9, 2019.