Diabetes type 1 risk not increased by tonsillectomy

The removal of the tonsils and adenoids, common surgical procedures in childhood, does not alter the risk of childhood-onset type 1 diabetes, according to findings published in the medical journal Diabetes Care.

The two procedures - tonsillectomy and adenoidectomy - affect the function of the immune system in a way that could increase a child's risk of type 1 diabetes. Specifically, an autoimmune reaction, in which the body's immune system attacks itself, may be activated to destroy pancreatic beta-cells, which would interfere with insulin production, explain Dr. Chris R. Cardwell, of the Queen's University of Belfast, UK, and colleagues.

On the other hand, they point out, the "hygiene hypothesis" suggests that frequent early exposure to infections may protect against type 1 diabetes. Therefore, children who undergo tonsillectomy or adenoidectomy may have a reduced risk of type 1 diabetes, because they are likely to experience more respiratory and ear infections in early childhood.

In their study, the researchers examined the risk of type 1 diabetes after tonsillectomy and/or adenoidectomy in 25,488 children younger than 15 years who underwent one or both procedures between 1990 and 2003. The children were also linked to a type 1 diabetes register.

There was little evidence of any difference in the incidence of type 1 diabetes in children after tonsillectomy, adenoidectomy, or either procedure.

The findings do not support the hygiene hypothesis because there was no evidence of a lower risk of type 1 diabetes in these children, who most likely have recurrent episodes of respiratory or ear infections, Cardwell's team concludes.

SOURCE: Diabetes Care, October 2007.