A simple surgery to prevent heart damage in children
Researchers at Cincinnati Children`s Hospital Medical Center found that adenotonsillectomy, or the surgery to remove tonsils and adenoids, can result in significantly lower blood pressure within 24 months of the procedure in some children with OSA — a sleep disorder characterised by abnormal pauses in breathing.
According to the researchers, who presented their study at the ATS 2011 International Conference in Denver, children with enlarged tonsils and adenoids are particularly prone to developing OSA.
OSA has been linked with elevations in both daytime and nighttime blood pressure and it can also interfere with the normal "dip" in blood pressure levels that occur during sleep.
Persistent elevations in blood pressure can result in organ damage, including heart damage, said Dr Lisa Burns, who led the study.
She said: "Our study emphasises the importance of treating severe sleep apnea in order to prevent persistent elevation in blood pressure and end-organ damage.
"We also show that during sleep, diastolic blood pressure, the measurement of your blood pressure when the heart is relaxing, is more sensitive to the effects of sleep apnea than other measures of blood pressure."
For their research, Dr Burns and colleagues evaluated 115 children, aged between 7 and 13 years — 28 of them had mild OSA, while 27 had severe OSA and 60 were healthy.
The subjects were evaluated for level of OSA using polysomnography, a diagnostic test used to measure breathing during periods of sleep.
All OSA subjects who had enlarged adenoids and tonsils underwent adenotonsillectomy. Their blood pressure, rest and activity levels, and heart size were measured at the beginning of the study and during follow-up at 12 to 24 months.
At follow-up, the researchers found blood pressure levels during sleep decreased following adenotonsillectomy when compared with measurements at baseline.
The procedure also restored the normal nighttime "dip" in blood pressure relative to daytime pressure, Dr Burns said.
In addition, in a subset of children with moderate to severe sleep apnea, there was a decrease in heart size after adenotonsillectomy.
Dr Burns said: "We know that children with sleep apnea tend to have higher blood pressures than children without sleep apnea, even if these elevations still fall within a normal range.
"However this is the first study to evaluate how treatment of sleep apnea impacts blood pressure and heart size in a pediatric population who are free from other diseases, which may also contribute to elevations in blood pressure.
"By identifying and treating elevations in blood pressure at an earlier age through treatment of OSA, we hope to prevent development of cardiovascular disease in childhood and later in life."
However, she said more studies are needed to investigate the mechanisms leading to blood pressure changes with sleep apnea.