Exposing children to secondhand tobacco smoke increases their risk of developing habitual snoring, according to an analysis of existing research. The results, from 24 studies including nearly 88,000 kids, may create a "teachable moment" for parents to consider quitting smoking, the authors write in the Journal of Epidemiology & Community Health.
"Some parents might think that snoring in kids is benign or even cute, but snoring is often the first step towards developing sleep apnea and has been linked to high blood pressure, stroke and heart disease," said Lucy Popova, a researcher at Georgia State University in Atlanta
who wasn't involved in the study.
"Furthermore, parental smoking and secondhand smoke in children causes multiple other problems - respiratory and ear infections, asthma, SIDS (sudden infant death syndrome), and behavioral problems, such as ADHD," Popova said in an email.
The younger the child, the more vulnerable she or he is - and prenatal exposure to tobacco smoke, when the body is just developing in the womb, is particularly harmful, she added.
The authors, led by Ke Sun of the School of Public Health of Qingdao University in China, combined and reanalyzed data from previous studies in a wide range of countries that had compared exposure to tobacco smoke and the risk of habitual snoring in children.
They found that exposure to smoke before and after birth raised a child's odds of habitual snoring compared to unexposed kids. Children exposed to smoke while their mothers were pregnant were almost twice as likely to be habitual snorers.
After birth, children whose mothers smoked were 87 percent more likely to snore than unexposed kids. Other exposures to smoke in the home, including fathers who smoked, raised the risk by 45 percent.
The study team also found that a child's snoring risk increased in proportion to their amount of smoke exposure, and calculated that the risk rose by about 2 percent for every cigarette smoked daily in the home.
The researchers did not respond to a request for comments, but they note in their report that their study doesn't examine how smoke may make a child more vulnerable to snoring. The analysis is also limited by differences among the included studies and difficulty teasing apart the roles of a mother's smoking during pregnancy and afterward.
While prenatal exposure to tobacco smoke is likely to be linked to heavier environmental exposure after the child is born, the study took that into account, and the results for each type of exposure are independent of one another, Popova said.
"Quitting smoking is one of the best things a parent can do for his or her health, and for the health of their children," said Dr. Sophie Balk, a pediatrician at Children's Hospital at Montefiore in New York who wasn't involved in the analysis.
"People who smoke should talk to their own doctors, or their child's doctor, about how to quit," she said in an email. "Medications - such as nicotine replacement therapies - are available to help with the quit-smoking process."
In the US, every state has its own quit-smoking telephone line (1-800-QUIT-NOW or 1-800-784-8669) staffed with counselors trained to help smokers quit, Balk said.
"If your child goes to daycare, make sure that your child care provider does not smoke," she added.
If a smoker can't quit right now, it's important to never to smoke in the home or car, or to allow visitors to the home to smoke.
"If smokers smoke outside, they should change clothes and wash hands before being with children. But quitting tobacco use entirely is the best way to preserve your own health and the health of your children," she said.