Removal of tonsils and appendix heightens risk of heart attack: Study
Published on June 2, 2011 at 6:52 PM
By Dr Ananya Mandal, MD
According to a new study surgical removal of tonsils and the appendix before the age of 20 is likely to elevate the risk of a premature heart attack. The researchers found that tonsillectomy (removal of tonsils) increased the risk by 44 per cent and removal of the appendix by 33 per cent. The risk increases were even higher when both the tonsils and appendix were removed.
The risk association was not evident when the operations were performed on people over the age of 20. Studies suggest that between 10 and 20 per cent of all young people have their tonsils or appendix removed.
The authors of the study published in the European Heart Journal write that the appendix and tonsils are components of the body's immune system, although of modest importance. Investigator Imre Janszky from Sweden's Karolinska Institute said, “One might anticipate that surgical removal of the tonsils and appendix, with their consequent effects on immunity, might also have a long-term effect on coronary heart disease (CHD, narrowing of the small vessels that supply blood and oxygen to the heart)…However, we were aware of no studies evaluating the potential effects of appendectomy or tonsillectomy on atherosclerosis or CHD risk.”
For this study the team examined the national health records of every Swedish resident born between 1955 and 1970 and identified each one who had had their tonsils and/or appendix removed. The researchers identified 54,449 appendectomies and 27,284 tonsillectomies performed on Swedish residents under the age of 20 years. The patients were followed for an average of 23.5 years to determine how many would suffer fatal or non-fatal heart attacks. Within the follow-up period, a total of 89 of the participants who had had appendectomies and 47 of those who had had tonsillectomies experienced a heart attack, the investigators found.
Janszky noted, however, that the absolute numbers of heart attack cases in the study were small, with slightly more than 400 and 200 total cases of heart attack in more than 7.5 million and nearly 4 million person-years of follow-up, respectively. “As expected from the young age of the population,” he said, “the observed moderate increases in relative risk actually corresponded to very small risk increases in absolute terms.” And because the study was limited to childhood procedures and participants were still relatively young during the follow-up period, the findings may not apply to older people at greater risk for heart disease, the researchers added.
“In the light of our current knowledge on the complex relationship between atherosclerosis and the immune system, the findings are biologically plausible” said Dr Janszky. “There is already some evidence that removal of the spleen, another secondary lymphoid organ, is also associated with accelerated atherosclerosis and increased cardiovascular risk.”