Tonsillectomy and adenoidectomy are not associated with an altered risk of childhood-onset type 1 diabetes.

T ype 1 diabetes results from the autoimmune destruction of the pancreatic -cells. As various studies have shown that tonsillectomy and adenoidectomy, particularly in childhood, impact the function of the immune system (1), it is possible that these procedures could increase a child’s risk of type 1 diabetes. Conversely, the hygiene hypothesis (2) suggests that frequent exposure to infections in early life may protect against type 1 diabetes. Therefore, children undergoing tonsillectomy and adenoidectomy may be expected to have a reduced risk of type 1 diabetes because they are likely to have experienced higher rates of respiratory and ear infections in early childhood than other children. Previously, a Finnish case-control study (3) of type 1 diabetes with adenoidectomy reported a modest though not significant increase in the risk of diabetes, while a possible association with tonsillectomy has been investigated only in a small Canadian case-control study (4). The aim of this study was to investigate, for the first time in a cohort setting, the risk of type 1 diabetes after tonsillectomy and/or adenoidectomy in children identified from hospital records.