Melbourne: Physicians often remove adenoids and tonsils to treat recurrent tonsillitis or middle ear infections but people who have their tonsils or adenoids removed before age 9 years are at higher risk for respiratory, infectious, and allergic diseases up to the age of 30 years, a population-based study of almost 1.2 million patients suggests.
Sean Byars, PhD, from the University of Melbourne in Victoria, Australia, and colleagues found that tonsillectomy was associated with a nearly tripled risk of upper respiratory tract diseases, and that adenoidectomy was associated with doubled risk of [chronic obstructive pulmonary disease] and upper respiratory tract diseases and nearly double the risk of conjunctivitis.
Data from 1,189,061 individuals analyzed
Byars and colleagues analyzed data from the Danish Birth Registry, which included 1,189,061 individuals for health outcomes through age 30 years. Participants included in the analysis were born between 1979 and 1999 and were followed until 2009. Some 17,460 participants had had their adenoids removed, 11,830 had had their tonsils removed and 31,377 underwent an adenotonsillectomy. The remaining participants in the sample served as controls.
The long-term risk
When the investigators calculated the long-term risks of 28 different diseases among each group, they found that tonsillectomy was associated with nearly a threefold relative risk (RR) of diseases of the upper respiratory tract (RR, 2.72; 95% confidence interval [CI], 1.54 – 4.80) compared with children who had not had their tonsils removed. Adenoidectomy, in turn, was associated with a greater than twofold risk for chronic obstructive pulmonary disease (RR, 2.11; 95% CI, 1.53 – 2.92) and a nearly twofold increase for respiratory tract diseases (RR, 1.99; 95% CI, 1.51 – 2.63) and conjunctivitis (RR, 1.75; 95% CI, 1.35 – 2.26). This translated into an NNT of 9 for upper respiratory tract diseases, 349 for chronic obstructive pulmonary disease, and 624 for conjunctivitis.